Nutrition Tag

Ketogenic Diet Cut Liver Fat by 67% in a Randomised Trial

Key Takeaways:

• People with obesity who followed a ketogenic diet reduced their liver fat by an average of 67%, compared with an average reduction of 45% in both the Mediterranean and low-fat plant-forward groups – even though all three groups lost a comparable amount of weight.
  
• Around half of the participants following the ketogenic diet no longer met the criteria for prediabetes by the end of the study, compared with 29% in the Mediterranean group and 7% in the plant-forward group.
  
• Despite obtaining 73% of their calories from fat, participants in the ketogenic group showed no increase in blood fat or cholesterol levels, alongside the largest rise in glucagon and the steepest fall in blood insulin of the three groups.
  
  
  

Carbohydrate restriction appeared to add benefits beyond weight loss

A very low-carbohydrate, high-fat diet may deliver stronger metabolic benefits for people with obesity than either a Mediterranean diet or a low-fat diet, according to a clinical trial published on 27 August in the Cell Press journal Cell Metabolism. After four to five months on a ketogenic (or “keto”) diet, about half of the participants with obesity and prediabetes no longer met the criteria for prediabetes.

“We know weight loss can improve metabolic health in people who are obese,” says Samuel Klein, the study’s corresponding author at Washington University School of Medicine in St. Louis, Missouri. “Our data suggest that if you have high liver fat content and prediabetes, reducing carbohydrate intake can have important therapeutic effects on metabolism beyond just weight loss alone.”

The distinction matters clinically. Weight loss itself is known to improve metabolic markers, so the open question has been whether the composition of a diet contributes anything further once the amount of weight lost is held constant. This trial was designed to test exactly that.

Comparing three widely used weight loss diets

An estimated 40% of adults in the United States have obesity. Doctors often recommend low-fat, low-carbohydrate or Mediterranean diets for weight loss, but researchers have not known whether one approach provides extra metabolic advantages beyond the effects of losing weight.

The three diets differ sharply in how much carbohydrate and fat they provide:

• A low-carbohydrate diet, also known as the Atkins or ketogenic diet, greatly restricts carbohydrates. A ketogenic diet can include foods rich in saturated fat, including animal products.
  
• A low-fat diet, by contrast, can obtain as much as 70% of its energy from carbohydrates.
  
• A Mediterranean diet emphasises plant-based foods such as vegetables, olive oil and nuts, along with moderate amounts of fish and dairy.
  
  
  

To compare their effects, Klein and his colleagues enrolled 42 people with obesity, prediabetes and fatty liver disease in a clinical trial. Participants were randomly assigned to follow a ketogenic diet, a Mediterranean diet, or a low-fat, plant-forward diet. The research team supplied all of their food, and participants met with a dietitian every week to help them stay on their assigned eating plan.

That level of support is worth noting. Providing every meal and offering weekly dietetic contact removes much of the adherence variability that undermines free-living diet studies, which strengthens confidence that the differences observed between groups reflect the diets themselves rather than differences in how closely people managed to follow them.

Matching weight loss across the three groups

The ketogenic diet supplied just 4% of calories from carbohydrates and 73% from fat. In the Mediterranean group, 50% of calories came from carbohydrates and 35% from fat. The plant-forward diet provided 70% of calories from carbohydrates and 15% from fat.

Researchers adjusted calorie intake for each person so that participants in all three groups would lose about 10% of their body weight. Reaching that target took roughly four to five months.

By the end of the study, participants in every diet group had significantly reduced their body fat. Insulin sensitivity also improved across all three groups, helping the body control blood sugar more effectively. In other words, all three approaches worked – the question was whether any of them worked better than the others once weight loss was equalised.

The ketogenic diet produced the largest fall in liver fat

Despite similar weight loss, the ketogenic diet produced the strongest changes across several measures of liver and metabolic health. Liver fat fell by an average of 67% among people following keto, compared with an average reduction of 45% in both the Mediterranean and plant-forward groups.

The researchers also tracked participants’ metabolism over a 24-hour period by repeatedly analysing their blood. People in the ketogenic group showed the largest rise in glucagon, a hormone that helps reduce fat stored in the liver. They also had the greatest decline in blood insulin levels, another change that can help lower liver fat, compared with participants following the other two diets.

Together, the hormonal findings offer a plausible mechanism for the liver fat result: lower circulating insulin and higher glucagon both shift the liver away from storing fat, and both are the expected consequence of sharply restricting carbohydrate intake.

Blood fats did not rise on the highest-fat diet

One of the more counter-intuitive results concerned the lipid profile of the ketogenic group, whose diet contained by far the most fat and could include saturated fat from animal products.

“The most surprising finding was that participants in the ketogenic diet group didn’t experience an increase in blood fat or cholesterol levels despite consuming the most fat,” says Max Petersen, the study’s first author at Washington University School of Medicine.

Prediabetes improved most in the ketogenic group

After the weight loss intervention, about 50% of participants following the ketogenic diet no longer met the criteria for prediabetes. That compared with 29% of those on the Mediterranean diet and 7% of those following the plant-forward diet.

The researchers were careful to position dietary composition alongside, rather than against, current pharmacological options for people living with obesity.

“GLP-1-based medications have revolutionized the therapy of obesity. We now have a very effective pharmacotherapy for achieving significant weight loss,” Petersen says. “But in addition, our study shows that the specific composition of the diet can give you added benefits.”

What the findings mean for everyday practice

For healthcare professionals supporting people with obesity, prediabetes or fatty liver disease, the practical implication is that the content of a weight loss plan may deserve as much consultation time as the calorie target attached to it. Two people can lose the same 10% of their body weight and still arrive at meaningfully different liver fat and glycaemic outcomes.

This is the kind of nuance that clinicians increasingly need to be able to explain confidently in a short appointment, and it is a core focus of continuing professional development in nutrition. The College of Contemporary Health’s Nutrition & Weight Management Essentials CPD short course is designed for practitioners who want to strengthen their grounding in evidence-based nutrition and weight management before applying it in conversations with patients.

It is also worth keeping the study’s limits in view. This was a small trial of 42 people, conducted under closely controlled feeding conditions with weekly dietetic support and all food provided. Whether the ketogenic advantage persists in free-living conditions, over longer periods, and across broader populations remains to be established.

The research was supported by the National Institutes of Health and the Foundation for Barnes-Jewish Hospital.

CCH insight

Findings like these are only useful at the point where a clinician can translate them into a realistic, personalised plan with a patient. Nutrition & Weight Management Essentials is a CPD-accredited short course from The College of Contemporary Health, developed for healthcare professionals who want a practical, evidence-informed foundation in nutrition and weight management.

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Higher Coffee Intake Linked to Lower Visceral Fat and Greater Muscle Mass

Key Takeaways: 

• Higher habitual coffee intake was associated with lower total and visceral fat and greater skeletal muscle mass, despite a similar BMI.
  
• Coffee intake was linked to lower branched-chain amino acids in both sexes, and to sex-specific differences in testosterone and SHBG.
  
• The study was observational, so it cannot show that drinking coffee caused any of the differences identified. 
  
  
  

A familiar drink with poorly understood biology

Coffee is consumed around the world every day, and earlier research has associated coffee drinking with a reduced risk of conditions including type 2 diabetes and cardiovascular disease. What has remained unclear is why. Scientists still do not fully understand the biological processes that might explain those connections, which has made it difficult to interpret the epidemiological signal.

New research from Finland now suggests that regular coffee consumption is associated with healthier body composition, favourable metabolic markers, and distinct patterns involving sex hormones in men and women.

What the researchers examined

Researchers at the University of Oulu analysed information from 2,264 people who were 46 years old and taking part in the Northern Finland Birth Cohort 1966. The team investigated how participants’ usual coffee intake related to circulating metabolites, indicators of cardiometabolic risk, and sex hormone levels.

Studying a single birth cohort at a single age has a particular advantage: it removes age itself as a source of variation, allowing differences between people with higher and lower coffee intake to stand out more clearly.

Lower body fat and greater muscle mass

People who consumed more coffee tended to have lower levels of both total body fat and visceral fat, along with greater skeletal muscle mass.

Notably, these differences appeared even though participants with higher and lower coffee intake had a similar body mass index (BMI). That detail matters clinically. BMI cannot distinguish fat mass from lean mass, or subcutaneous fat from the visceral fat that sits around the abdominal organs and carries the stronger association with cardiometabolic risk. Two people with an identical BMI may therefore have meaningfully different metabolic profiles, and in this cohort coffee intake tracked with that hidden difference rather than with weight itself.

A metabolic marker associated with diabetes risk

Higher coffee consumption was also associated with lower circulating concentrations of branched-chain amino acids in both men and women. When chronically elevated, these biomarkers have previously been associated with insulin resistance and a greater risk of developing type 2 diabetes.

This finding sits alongside the body composition results rather than separately from them, since visceral fat and insulin resistance are themselves closely linked.

Different hormonal patterns in men and women

Some of the clearest differences appeared among men. Greater coffee consumption was associated with a more favourable glucose-insulin profile, higher levels of total and bioavailable testosterone, and greater concentrations of sex hormone-binding globulin (SHBG). However, free testosterone and the free androgen index were modestly lower.

The hormonal associations were less extensive in women. Higher coffee consumption was mainly associated with increased SHBG and lower measures of free androgens.

The common thread across both groups was SHBG, the carrier protein that binds circulating sex hormones and influences how much is biologically available to tissues. Higher SHBG has itself been studied in relation to metabolic health, which makes it a plausible point of connection between the hormonal and cardiometabolic findings.

“Coffee is consumed by millions of people every day, yet we still know surprisingly little about how it relates to our metabolism and hormones. What stood out in our findings was a distinct hormonal signature that didn’t disappear even after we took into account BMI and lifestyle factors, with several of these associations differing between men and women,” says Luca Verroest, lead author of the study and Doctoral Researcher at the University of Oulu.

Why the hormonal findings could matter

The findings raise the possibility that hormonal pathways could help explain some of the previously observed relationship between coffee consumption and metabolic health.

Because the research was observational, however, it cannot establish that drinking coffee directly caused any of the biological differences identified in the study. People who drink more coffee may differ from those who drink less in ways the analysis could not fully capture, and the direction of any relationship cannot be determined from data collected at a single point in time.

For clinicians, the more immediately useful message concerns interpretation rather than advice. Findings of this kind reinforce how much a single anthropometric measure can conceal, and how dietary patterns, body composition, and endocrine markers interact when assessing cardiometabolic risk. Practitioners who want to strengthen that interpretive skill set often look to structured CPD such as the College of Contemporary Health’s Nutrition & Weight Management Essentials short course, which examines how dietary intake relates to body composition and metabolic health in everyday practice.

Finland as a study setting

The setting also makes the research especially relevant. Finland ranks among the world’s highest coffee-consuming countries, with average annual consumption of approximately 11.8 kilograms (26 pounds) per person. A population with high and widely varying intake offers greater statistical range than one in which most people drink little coffee at all.

What happens next

Researchers say the results offer a starting point for studies designed to determine whether coffee itself produces these biological changes and, if so, which compounds may be responsible. Scientists are currently investigating these questions using animal models, with the longer-term aim of moving towards human intervention studies.

Additional research will be necessary before the findings can be used to shape dietary recommendations. For now, the study contributes a mechanistic hypothesis rather than a change in practice.

The study, “Associations of habitual coffee intake with testosterone and cardiometabolic markers: the Northern Finland Birth Cohort 1966 study,” was published in the European Journal of Nutrition.

CCH insight

Body composition, dietary patterns, and metabolic markers rarely tell a complete story in isolation, and BMI alone can mask clinically important differences. The College of Contemporary Health’s Nutrition & Weight Management Essentials short course helps healthcare professionals interpret these measures together and apply nutritional evidence confidently in patient-facing practice.

Explore Nutrition & Weight Management Essentials → 

Source: University of Oulu, Finland

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AI Calorie Tracking Apps: Convenient, Popular and Consistently Inaccurate

Key Takeaways: 

• Four popular photo-based calorie apps underestimated meal energy by 250 to 345 calories and fat by around 30 grams – roughly a third in both cases.
  
• Accuracy varied: higher-calorie meals fared better than lower-calorie ones, and carbohydrates were estimated more consistently than other macronutrients.
  
• Ketogenic meals proved hardest to assess, because their high fat content is consistently underestimated.
  
  
  

Convenience that comes with a margin of error

Advances in artificial intelligence have changed how many people record what they eat. Rather than weighing ingredients or searching a database entry by entry, a person can now photograph a plate of food and let an app estimate its nutritional content in seconds. The convenience is obvious. The accuracy, according to new research, is rather less reliable.

A study conducted at the National Institutes of Health (NIH) Clinical Center compared four popular photo-based apps against meals prepared under tightly controlled laboratory conditions. All four underestimated both calories and fat by approximately a third.

How photo-based calorie tracking works

Photo-based calorie tracking uses AI image recognition to identify the foods present in a photograph of a meal and to estimate the portion sizes on the plate. Those identifications and estimates are then matched against nutrition databases, which the app uses to calculate the energy and macronutrient content of the meal.

The appeal for people managing their weight or monitoring their intake for other health reasons is that the process removes several steps of manual data entry. The trade-off is that the app is making two judgements at once – what the food is, and how much of it there is – before any nutritional calculation begins.

“Photo-based calorie tracking apps are very popular, especially for people trying to manage their health or lose weight,” said Aaron Hengist, a postdoctoral visiting fellow with the Intramural Program of the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), part of the National Institutes of Health. “However, the accuracy of many of these apps has not been thoroughly evaluated. Our study helps address this question by looking at whether these apps can reliably estimate calories.”

A metabolic kitchen as the reference standard

The research forms part of a larger diet study at the NIH Clinical Center examining how the body processes nutrients when a person follows either a low-carbohydrate (ketogenic) diet or a standard diet.

Meals for that clinical trial are prepared in a controlled metabolic kitchen – a research kitchen in which every ingredient is weighed to the nearest 0.1 gram. That level of precision gave the investigators something unusual: a set of real, plated meals whose exact nutritional composition was already known.

The researchers took standardised photographs of 102 meals prepared for the diet study and ran the images through four apps: MyFitnessPal, LoseIt!, CalAI and Appediet.

“By using meals prepared in a tightly controlled metabolic kitchen, we were able to compare the apps’ estimates against a precise reference,” said Hengist. “This kind of direct, high-quality comparison hasn’t been available before.”

What the analysis found

Across the 102 meals, all four apps underestimated energy content by approximately 250 to 345 calories on average. Fat was underestimated by around 30 grams. In percentage terms, both calories and fat came in roughly a third below the true values recorded in the metabolic kitchen.

For a person using an app to guide daily intake, an error of this size is not trivial. A consistent shortfall of 250 to 345 calories per meal, repeated across a day, would produce a substantially inaccurate picture of overall energy intake – and would do so in the direction least helpful to someone trying to reduce it.

Where the apps performed better

The findings were not uniformly negative. The analysis showed that MyFitnessPal and LoseIt! estimated the energy content of higher-calorie meals more accurately than lower-calorie meals. All four apps also estimated carbohydrates more consistently than the other macronutrients, suggesting that carbohydrate-containing foods may be easier for image recognition systems to identify and quantify than fats in particular.

Hengist was direct about the practical implication for people using these tools without adjusting the app’s output.

“People using a photo-based tracking app without adjusting the portions or entering the amounts of food should take the results with a grain of salt,” said Hengist. “These apps tend to underestimate calories, especially from fats, so what they actually ate is likely higher than what the app shows.”

Ketogenic meals pose a particular challenge

After completing the initial analysis, the researchers extended the work to more than 200 additional meals in order to understand what factors influence app accuracy.

Their early results suggest that the apps struggle more with meals forming part of a low-carbohydrate ketogenic diet. The likely explanation is straightforward: these meals derive a large proportion of their energy from fat, and fat is precisely the macronutrient the apps most consistently underestimate.

This has implications for anyone supporting people who follow ketogenic or other high-fat dietary patterns, whether for weight management, metabolic health or the management of specific conditions. The tracking tool a person is relying on may be least accurate in exactly the dietary context where fat intake matters most.

For healthcare professionals who regularly review food diaries or app exports during weight management consultations, findings of this kind reinforce the value of structured training in dietary assessment. The College of Contemporary Health’s CPD-accredited Nutrition and Weight Management Essentials short course covers how dietary intake is assessed in practice, the limitations of self-reported data, and how to have constructive conversations with people about what and how much they are eating.

Improving accuracy in the real world

The investigators do not conclude that photo-based tracking should be abandoned. Their view is that combining photo-based features with more traditional methods of measuring diet quality could improve the real-world accuracy of calorie-tracking apps. In practical terms, that means treating the photograph as a starting point rather than a finished record – confirming what the app has identified, adjusting portion sizes, and entering quantities where they are known.

Olivia Charles, a postbaccalaureate intramural research training fellow at NIDDK, will present the findings at NUTRITION 2026, the flagship annual meeting of the American Society for Nutrition, held 25–28 July in National Harbor, Maryland, just outside Washington, D.C. As with research presented at scientific meetings generally, the results should be regarded as preliminary until they appear in a peer-reviewed publication.

For people using these apps day to day, the practical message is a modest one. A photograph is a useful prompt and a low-friction way to build a habit of recording intake. It is not, on the current evidence, a measurement.

CCH insight

Digital tools are increasingly part of how people monitor their diet, but their outputs need to be interpreted rather than accepted at face value – particularly where fat intake or high-fat dietary patterns are involved.

The College of Contemporary Health’s Nutrition and Weight Management Essentials CPD short course equips healthcare professionals with a working understanding of dietary assessment, macronutrient composition and evidence-based weight management, including how to interpret self-reported and app-generated intake data in clinical conversations.

Explore Nutrition and Weight Management Essentials 

Source: EurekAlert!

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Daily Tomato Intake May Lower Liver Fat in People With MASLD, New Study Suggests

Key Takeaways: 

• In a six-week randomised study of 79 adults with metabolic dysfunction-associated liver disease (MASLD), people who ate 200 grams of raw tomatoes and 50 grams of tomato sauce each day showed a greater reduction in hepatic steatosis than people following a tomato-free control diet.
  
• Liver fat fell in both groups, and researchers found no meaningful differences between the groups in liver stiffness, liver enzymes, lipids or body mass index after the intervention period.
  
• Independent specialists described the findings as exploratory rather than practice-changing, noting the short duration, the narrow participant profile and the absence of improvement in clinically relevant markers.
  
  
  

What the research set out to examine

Metabolic dysfunction-associated liver disease (MASLD) covers a spectrum of liver problems, but its defining feature is hepatic steatosis – the accumulation of fat within the liver. A diagnosis also requires the presence of at least one cardiometabolic risk factor, such as obesity or high blood pressure.

Diet and lifestyle changes are a mainstay of support for people living with MASLD, and researchers are increasingly interested in whether particular foods offer measurable advantages over others. A study published in Nutrients set out to test one such food: the tomato, a staple of the Mediterranean diet.

The research team wanted to establish whether regular tomato consumption would influence liver steatosis in people who already had a MASLD diagnosis.

How the study was designed

The study enrolled 79 adults with MASLD. Researchers applied a number of exclusion criteria, ruling out people who consumed above a set threshold of alcohol and those with a body mass index above 30, the point at which obesity is classified.

Participants were divided into two groups. One group followed a tomato-free control diet. The other consumed 200 grams of raw tomatoes and 50 grams of tomato sauce daily. All tomato products were supplied by the same producer to keep the intervention consistent, and participants were asked to carry on with their usual lifestyle in every other respect.

The intervention ran for six weeks. Across that period, researchers tracked a range of health indicators, including body composition, hepatic steatosis, liver stiffness and cholesterol levels.

What the researchers found

Hepatic steatosis declined in both groups over the six weeks. The decrease was greater, however, among people in the tomato group.

Further analysis showed that hepatic steatosis had been broadly similar between the two groups at baseline, which strengthens the comparison. Other measures told a quieter story. Researchers identified no major changes in liver stiffness, and no significant differences between the groups in lipids, liver enzymes or body mass index at the end of the six-week period.

Summarising the result, the authors suggested that “tomato consumption may reduce hepatic fat accumulation independently of major changes in body weight, total and abdominal adiposity.”

Because liver fat shifted while weight and body composition did not, the study raises a familiar practical question for clinicians: how far can dietary composition alone move metabolic outcomes when overall energy intake stays broadly the same? It is the kind of question CCH explores in its CPD short course Nutrition & Weight Management Essentials, which examines the relationship between modern nutrition and weight, and how evidence-based dietary advice translates into everyday clinical conversations.

Study limitations and continued research

The six-week window is short, so the study cannot speak to whether any benefit persists over the longer term. The research also recruited only adults aged 65 and under, leaving it unclear how the findings might apply to older adults.

Most participants were men, so more balanced recruitment would strengthen future work. The decision to exclude people with a body mass index above 30 also narrows how widely the results can be applied.

Endocrinologist and obesity specialist Randa Abdelmasih MD, DipABOM, from the University of Texas Medical Branch (UTMB), who was not involved in this study, told Medical News Today:

“The study demonstrates a modest reduction in hepatic steatosis over only six weeks in a highly selected population of adults with MASLD and BMI [body mass index] of 30 kg/m² [kilograms per square meter] or more. Most patients we see in clinical practice have obesity (BMI over 30 kg/m²), type 2 diabetes, or more advanced metabolic disease, so the generalizability of these findings is limited.”

Jonathan Jennings, MS, MD, a board-certified internist with Medical Offices of Manhattan, who was likewise not involved in the research, raised a related concern about how participants were selected.

“The inclusion criteria required only one cardiometabolic risk factor, and it could be any risk factor. I am concerned that not all risks are equal, and people with multiple factors are at higher risk than those with a single risk factor,” Jennings said.

“Type 2 diabetes is more likely to lead to MASLD than high blood pressure but the study evaluates them as equal risk factors,” he pointed out.

The researchers themselves note that the reduction in liver fat may have been influenced by other factors, including the effect that taking part in a dietary intervention study can have on participants’ behaviour. The team was also reliant on dietary counselling and on participants’ own reports of how closely they followed the intervention.

Abdelmasih added that because the intervention combined raw tomatoes with tomato sauce, it is “difficult to determine which component or combination was responsible for the observed effect.”

A further gap is that researchers did not measure circulating levels of lycopene and carotenoids, the compounds most often proposed as the mechanism behind any effect tomatoes might have on liver health.

Limited clinical application at this stage

The authors describe their study as exploratory, intended primarily to inform future research. They call for confirmation through larger and longer studies, and encourage readers to treat the findings as hypothesis-generating rather than conclusive.

The clinical value is also uncertain because so much else stayed the same. As Abdelmasih put it:

“The study showed improvement in liver fat but no significant improvements in liver stiffness, fibrosis scores, liver enzymes, insulin resistance, inflammatory markers, lipid profile, or body composition. Therefore, while the imaging findings are interesting, we cannot conclude that tomato consumption meaningfully alters disease progression or improves clinically relevant outcomes.”

What this means for people living with MASLD

Within its limits, the study does point to a possible benefit of tomato consumption for people with MASLD, and to a low-cost dietary strategy that may help with fat accumulation in the liver.

Tomatoes may carry other advantages too, with existing research pointing towards cardiovascular benefits and potential anti-cancer properties.

Even so, the sensible route is for people to work with their doctor and wider healthcare team on a dietary plan that addresses their overall health, rather than concentrating on any single food.

Jennings underlined that point, and flagged two practical cautions:

“The study’s conclusions are hopeful but careful discussion with a healthcare provider is still needed before engaging in any radical dietary adjustments. Tomatoes and tomato-based products may be problematic for individuals with gastroesophageal reflux disease (GERD). Many tomato-based foods are also calorically dense and may worsen insulin resistance in certain individuals.”

The broader treatment context matters as well. According to Abdelmasih: “Dietary interventions should be viewed within the broader context of treating the underlying metabolic disease. For patients with obesity, sustained weight loss of approximately 10% or more remains the intervention with the strongest evidence for improving steatohepatitis and fibrosis.”

“While tomatoes can certainly be part of a healthy Mediterranean diet, they should not distract from therapies that have demonstrated meaningful improvements in liver and cardiometabolic outcomes,” she concluded.

CCH insight

Conversations about diet sit at the centre of metabolic and liver care, and single-food headlines can make those conversations harder rather than easier. CCH’s CPD short course Nutrition & Weight Management Essentials gives healthcare professionals a grounding in the fundamentals of nutrition, the factors driving weight gain, and what effective weight management looks like in practice – so you can place findings like these in proportion for the people you support.

Explore Nutrition & Weight Management Essentials →

Expert commentary in this article was provided to Medical News Today. Read the original report here.

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Abdominal Obesity and Vitamin D Deficiency Together More Than Double the Risk of Death After 50

Key Takeaways:

• In people aged 50 and over, having both abdominal obesity and vitamin D deficiency was linked to a 123% higher risk of death.
• Alone, abdominal obesity raised that risk by 47% and vitamin D deficiency by up to 91% – together, the two amplify one another.
• Abdominal fat sequesters circulating vitamin D, and the resulting deficiency worsens the chronic inflammation driven by excess fat.
  
  
  

A six-year study of ageing in England

New research has put a figure on something clinicians have long suspected: that two common and often overlooked problems in later life are considerably more dangerous when they occur together than either is alone.

The study, in the journal Diabetes, Obesity and Metabolism, followed 5,520 people aged 50 and older over a six-year period. It found that people with both abdominal obesity and vitamin D deficiency had a 123% higher risk of death than people without these conditions.

The work was coordinated by Tiago Silva Alexandre, a professor in the Department of Gerontology at the Federal University of São Carlos (UFSCar) in Brazil, and carried out in collaboration with University College London (UCL) in the United Kingdom. Participants were drawn from the English Longitudinal Study of Ageing (ELSA), one of the world’s largest studies on ageing.

The central message is not that either condition is newly dangerous, but that their combination multiplies risk.

“Abdominal obesity is a well-known risk factor because it’s associated with inflammation and metabolic problems. Vitamin D, on the other hand, is a hormone that acts on various organs, and its deficiency impairs several bodily functions. When these two conditions occur together, one amplifies the effects of the other, further increasing the risk of death,” explains Alexandre. “For that reason, monitoring vitamin D levels and treating excess abdominal fat are essential measures to prevent premature death, especially after age 50,” he adds.

How the two conditions were defined

The researchers used established thresholds for both measures, which makes the findings straightforward to translate into everyday practice.

Vitamin D deficiency was defined as a level below 30 nmol/L. Abdominal obesity was defined by waist circumference – greater than 102 centimetres (40 inches) for men and greater than 88 centimetres (35 inches) for women.

Both are measures that can be captured in a routine consultation, one through a standard blood test and the other with a tape measure, without recourse to specialist equipment or imaging.

Each condition carries risk on its own

When the two conditions were examined separately, the data produced a result that may surprise some practitioners: vitamin D deficiency alone posed a greater risk than abdominal obesity alone.

Abdominal obesity on its own was associated with a 47% increase in the risk of death. Vitamin D deficiency on its own raised that risk by up to 91%. When both were present, the risk of death more than doubled.

That pattern is what makes the combination clinically significant. The elevated risk seen in people with both conditions is greater than would be expected from simply adding the two individual risks together, which points towards a biological interaction rather than two independent problems sitting side by side in the same person.

Why the two conditions amplify one another

According to Alexandre, abdominal obesity and vitamin D deficiency feed into each other, creating what he describes as a vicious cycle.

The first mechanism is storage. Abdominal fat “sequesters” circulating vitamin D and holds it within adipocytes, or fat cells, preventing the vitamin from reaching the bloodstream in useful quantities.

“This means that although the body may have the vitamin stored in fat, it isn’t freely available in the blood to perform vital functions in other organs and systems,” he says.

In other words, a blood test may show deficiency even where the body’s total stores are not depleted, because the vitamin is effectively locked away where it cannot be used.

The second mechanism concerns metabolism. People with obesity have lower expression of the enzymes needed to metabolise vitamin D, which further reduces the amount available to the body.

The consequences then loop back on themselves. “Abdominal obesity reduces circulating vitamin D, and that deficiency impairs the immune system, exacerbating the chronic inflammation caused by excess fat and drastically increasing the risk of mortality,” Alexandre explains to Agência FAPESP.

Ageing, inflammation and a loss of regulation

The picture is complicated further by the biology of ageing itself. Later life is naturally marked by a process known as inflammaging – a state of low-grade chronic inflammation that develops with age.

Vitamin D ordinarily acts as a brake on that process. Where levels fall and abdominal fat is present, that brake is weakened at precisely the point where it is most needed.

“Under normal conditions, vitamin D acts as a regulator of the immune system, preventing inflammation from getting out of control. When vitamin D levels are low and there’s excess abdominal fat, an unfavorable systemic environment develops that accelerates cardiovascular and metabolic diseases, as well as muscle loss,” he stresses.

Part of a wider cascade

This study is the most recent in a series by the same group investigating the role of vitamin D in ageing, and its findings sit alongside earlier work linking deficiency to functional decline.

“In previous studies, we identified a cascade effect. Vitamin D deficiency leads to a loss of strength, which results in reduced walking speed, causing a loss of independence and greater dependence in daily activities,” Alexandre explains.

A further study by the group found that vitamin D deficiency increases the risk of cognitive decline.

Taken together, these strands describe a hormone with a reach that extends well beyond bone health.

“Vitamin D is a hormone with various functions. It plays a role in regulating blood pressure, heart rate, the central nervous system, the immune system and the endocrine system. Therefore, when its levels are low, several essential bodily functions are compromised,” he says.

What this means for practice

For healthcare professionals working with people over 50, the practical implication is a case for looking at these two markers together rather than in isolation. A raised waist circumference and a low vitamin D level each warrant attention on their own terms, but the study suggests that the presence of one should prompt closer interest in the other.

It also reinforces the value of waist circumference as an assessment measure in its own right, given that it is central adiposity – rather than body weight alone – that drives the inflammatory and metabolic processes described here.

Building that broader assessment skill set, and the confidence to act on it as part of whole-person care, is the focus of professional training such as the College of Contemporary Health’s Obesity Essentials, a CPD-accredited online short course covering the assessment and management of overweight and obesity.

As Alexandre puts it, monitoring vitamin D levels and treating excess abdominal fat are essential measures to prevent premature death after the age of 50 – two simple assessments that, on this evidence, carry considerable weight together.

CCH insight

This is an interesting study. At CCH we have held a longstanding interest in the wide- ranging functions of vitamin D, especially its role in immune function. These results suggest that vitamin D status should be checked routinely in patients with abdominal obesity, and any deficiency should be treated immediately. This would be a simple and inexpensive protocol and could significantly reduce premature death in this group.

Findings like these are a reminder that excess abdominal fat rarely acts alone – its metabolic and inflammatory effects reach into hormone regulation, immune function and, ultimately, life expectancy. CCH’s Obesity Essentials CPD short course (10 CPD hours, fully online, CPD-accredited) helps healthcare professionals assess and manage patients living with overweight and obesity using a rounded, evidence-based approach that looks beyond a single number on the scale to the wider systemic picture.

Explore Obesity Essentials →

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Sensing, Liking and Wanting: Why Food Feels Different on GLP-1RAs

Key Takeaways: 

• A Frontiers in Nutrition review finds that altered eating experience on GLP-1 receptor agonists (GLP-1RAs) reflects changes in food reward rather than impaired taste function.
  
• The authors separate three processes: sensing food, liking it, and wanting it.
  
• The evidence is heterogeneous and largely observational, so the framework is a conceptual model, not proof of causality.
  
  
  

Why reports of “taste changes” may not be about taste at all

Some people taking GLP-1RAs report that their favourite foods become less enjoyable or tempting, without this necessarily reflecting impaired basic taste function. That distinction sits at the centre of a recent review published in the journal Frontiers in Nutrition, in which the authors conducted a structured narrative review of current evidence on how glucagon-like peptide-1 receptor agonists influence sensory perception, food enjoyment and food motivation, using a sensory-liking-wanting framework.

Obesity is a chronic, progressive metabolic disease with growing global prevalence, which increases the demand for effective long-term treatment options. GLP-1RAs are widely used in obesity treatment because they enhance satiety, delay gastric emptying, reduce energy intake and support meaningful weight loss. Alongside those effects, some people also report that food tastes different, feels less enjoyable, or no longer seems tempting. These experiences are often described as “taste changes”, but the review argues that they may reflect several biological processes rather than a single taste disorder. Further research is needed to understand these mechanisms and to improve nutritional care during treatment.

Looking beyond appetite suppression

GLP-1RAs have changed the way obesity is managed by reducing energy intake and supporting meaningful weight loss. Growing clinical experience, however, shows that their effects extend beyond a simple reduction in hunger.

Some people describe food tasting different, reduced pleasure in eating, or lower cravings for high-calorie foods. The review suggests that these experiences should not be treated as simple taste disturbances, but as a combination of three components related to eating behaviour: sensory perception, liking and wanting.

The three components of eating behaviour

Eating begins with sensory perception, which includes detecting taste, smell and food texture. This stage determines how food is initially recognised.

The second component is liking, defined as the subjective pleasure or hedonic value associated with eating. It is influenced by flavour, prior experience, context, cognitive factors and physiological state.

The third component, wanting, describes the motivation or craving to seek out and consume food. Separating these components helps explain why reports of “taste changes” may in fact reflect different biological processes.

How GLP-1RAs may influence food reward and the eating experience

The review sets out how GLP-1RAs may influence eating behaviour through interconnected biological pathways rather than by directly changing taste. Preclinical studies indicate that endogenous glucagon-like peptide-1 (GLP-1) is produced by some mammalian taste bud cells and may modulate taste signalling. Those findings do not establish that GLP-1RA treatment directly alters taste in humans, and the limited human studies available have produced inconsistent results.

Taste signals are integrated in the nucleus of the solitary tract (NTS) before reaching brain regions involved in appetite and reward. Human studies have associated GLP-1RA treatment with reduced craving and weaker neural responses to calorie-dense food cues in some participants. Those findings are more consistent with altered food valuation and motivation than with impaired basic taste.

Gastrointestinal effects, including nausea and early satiety, may also reduce the pleasure of eating, which makes it difficult to distinguish altered food reward from genuine changes in taste perception.

What the clinical evidence does and does not show

Randomised controlled trials usually focus on body weight and metabolic outcomes. Eating-related experiences are rarely included as prespecified measures and are more often captured sporadically as adverse events.

Patient-reported outcome questionnaires may provide a more sensitive window into changes in food enjoyment and preference, but assessment methods vary considerably between studies. Real-world evidence presents additional challenges, as reports of “taste alterations” may encompass several distinct sensations, including olfactory changes, dry mouth, gastrointestinal discomfort and other symptoms that are difficult to distinguish clinically.

Spontaneous reporting databases can identify safety signals but cannot establish incidence or risk. Cohort studies, by contrast, provide better-defined populations and follow-up, yet remain vulnerable to subjective reporting and confounding.

Because this was a narrative review rather than a systematic review or meta-analysis, the authors did not conduct a formal risk-of-bias assessment.

A framework for understanding what people report

According to the review, alterations in the eating experience during GLP-1RA treatment should not be regarded solely as a biological phenomenon, but understood as the interaction between different processes.

Peripheral taste pathways, brainstem integration, central reward networks, interoceptive state and learned behaviour may all contribute. Their relative importance may differ between individuals and across treatment stages. A person’s report of a “taste change” may therefore not correspond to a clinically defined gustatory disorder.

The authors also note that alternative explanations should be considered when interpreting eating-related changes, including nausea, delayed gastric emptying, altered satiety, behavioural adaptation and medication adherence.

The framework additionally accommodates limited treatment response, persistent appetite, weight regain after treatment withdrawal or interruption, and rare atypical or paradoxical responses.

Clinical relevance and a possible stage-dependent pattern

The review highlights that reported changes in eating experience should not automatically be classified as taste abnormalities. Healthcare professionals may find it useful to establish whether a person is describing altered taste perception, reduced satisfaction from eating, or diminished interest in food, as these experiences can reflect distinct processes. Distinguishing between them well depends on the quality of the conversation in the consultation, and supporting people through the eating-related changes that accompany GLP-1RA treatment is the focus of professional training such as the College of Contemporary Health’s GLP-1RAs in Practice: Supporting Patients During Treatment, a CPD-accredited online short course.

The authors present these points as translational implications rather than formal clinical recommendations. They also propose a stage-dependent pattern in which these experiences may change over time.

Early in treatment, gastrointestinal discomfort and enhanced satiety may reduce the appeal of food, whereas later stages may involve a more persistent reduction in motivation towards highly rewarding foods in some individuals.

Why this matters for nutrition and obesity management

The proposed sensory-liking-wanting framework has practical implications for obesity treatment and nutritional counselling. Understanding whether someone is experiencing altered sensory perception, reduced enjoyment of food, or lower motivation towards food may support more individualised dietary guidance and improve communication between people receiving treatment and the professionals caring for them.

The review also highlights that the existing body of evidence is heterogeneous, owing to differences in endpoint definitions, measurement methods, populations, drugs, doses and follow-up periods. Much of the human evidence is observational, secondary or exploratory, and many studies were not designed to separate sensory function from liking and wanting. Current findings are therefore better interpreted as a conceptual framework for organising available evidence than as proof of a single causal pathway.

Future studies using standardised, multimodal assessments and longer follow-up may help clarify how these eating-related changes influence food preferences, dietary behaviour, long-term weight management and treatment adherence.

Conclusion

The review concludes that altered eating experiences during GLP-1RA therapy are more consistent with changes in food reward, hedonic evaluation and motivational drive than with a uniform impairment of taste function, although modulation of peripheral taste pathways may contribute in some cases.

Current evidence supports interpreting reported “taste changes” within a sensory-liking-wanting framework that distinguishes sensory perception from food enjoyment and craving. Because responses vary between individuals and the available evidence remains heterogeneous, the proposed framework should be considered a conceptual model rather than definitive proof of causality.

Longitudinal, multimodal human studies measuring sensory function, hedonic response, motivational drive and state-related symptoms in parallel are needed to clarify these effects and their implications for nutrition, dietary behaviour, treatment adherence and long-term obesity management.

CCH insight: 

When someone says food no longer tastes right on a GLP-1RA, the clinically useful question is which part of eating has changed: the sensing, the liking or the wanting. Each points towards different advice, and each can shift as treatment progresses. CCH’s GLP-1RAs in Practice: Supporting Patients During Treatment CPD short course (2 CPD hours, fully online, CPD-accredited) equips healthcare professionals to have exactly those conversations – recognising what people are really describing, adapting dietary and nutritional support through the course of treatment, and monitoring for the changes that matter. 

Explore GLP-1RAs in Practice: Supporting Patients During Treatment →

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One Avocado a Day May Lower a Hidden Heart Disease Risk in Adults Living With Obesity

Key Takeaways:

• Adults living with obesity who ate one avocado a day for six months showed a fall of 49 nanomoles per litre in LDL particle concentration – equivalent to roughly a 4% reduction in heart disease risk.
  
• LDL particle number is a risk factor distinct from LDL cholesterol itself, and it tends to be higher in people with abdominal obesity, meaning two people with identical cholesterol readings can carry very different levels of risk.
  
• The benefit appeared consistently across sex, race, ethnicity, age and body mass index, suggesting that a single, sustainable dietary addition can shift a meaningful cardiometabolic marker without any wider change to diet or activity.
  
  
  

A single dietary change, made in the real world

Adding one avocado to the daily diet may reduce heart disease risk in adults living with obesity, according to research led by the Penn State Department of Nutritional Sciences and published in the Journal of Clinical Lipidology.

The team found that regular avocado consumption was associated with a lower concentration of low-density lipoprotein (LDL) particles – the protein particles that transport cholesterol around the body – in the blood. That reduction corresponded to an approximate 4% decrease in heart disease risk.

What distinguishes the finding is its modesty. Rather than testing a wholesale dietary overhaul, the researchers examined what happens when people make one addition and otherwise carry on as normal.

“If people want to improve the quality of their diet, making one small change might be a more feasible strategy than attempting to change their entire diet,” said Janhavi Damani, postdoctoral scholar at Penn State and first author of the study. “For people with obesity, including avocados in their daily diet might be a good starting place.”

Why particle number matters, not just cholesterol

LDL particles represent a risk factor for heart disease that is separate from LDL cholesterol – the so-called “bad cholesterol” that is itself a significant contributor to risk. The risk posed by LDL particles is typically higher in people with abdominal obesity, the researchers noted.

The distinction rests on a point of basic physiology that standard lipid panels do not capture. LDL cholesterol cannot travel through the body unaided; it must be carried by a protein particle. When a greater number of protein particles are involved in transporting the same quantity of cholesterol, heart disease risk rises – even though the measured cholesterol figure is unchanged.

Damani illustrated the point directly.

“Imagine two people with the same high levels of LDL cholesterol,” Damani said. “Person A carries their cholesterol in fewer, larger LDL particles, and Person B carries their cholesterol in more, smaller LDL particles. Person B’s heart disease risk would be higher because their overall particle count is higher even though a test of their LDL cholesterol would look identical.”

How smaller particles do more damage

Those smaller particles penetrate artery walls more easily and contribute to the accumulation known as plaque, Damani explained.

Plaque raises heart disease risk through two mechanisms working together. It narrows the space available for blood to pass through a vessel, and it reduces the vessel’s flexibility. The consequence becomes clearest under load: when a person’s heart is working hardest – through exertion, heat, stress or any other cause – their blood pressure rises more sharply than it otherwise would, because the vessel can no longer expand to accommodate the increased demand. That failure to compensate can be enough to trigger a cardiac event such as a heart attack.

This mechanistic detail matters clinically, because it explains why particle count can carry prognostic weight even when a patient’s cholesterol result looks reassuring. Practitioners working in weight management and cardiometabolic care increasingly need to interpret markers of this kind alongside anthropometric measures, and this is territory that CCH’s CPD short course provision in obesity care covers in some depth.

Inside the Habitual Diet and Avocado Trial

For this analysis, the researchers drew on data originally collected from 786 participants in the Habitual Diet and Avocado Trial, a six-month study of adults aged 25 years and older.

Eligibility was defined by waist circumference. Men qualified if their waist circumference exceeded 102 centimetres (40 inches); women qualified if theirs exceeded 89 centimetres (35 inches).

Participants were divided into two groups. Half were instructed to maintain their usual diet and activity levels. The other half were provided with one avocado to consume each day and were also instructed to maintain their usual diet and activity levels. No other dietary guidance or restriction was applied.

The original Habitual Diet and Avocado Trial had already established that adding avocado to the diets of people living with obesity did not alter weight or waist circumference, but could reduce levels of LDL cholesterol.

What the blood samples showed

In the current study, the researchers compared blood samples collected at the start and at the end of the six-month period.

Across the study, LDL particle levels in the avocado-per-day group fell by 49 nanomoles per litre. That change corresponded to an approximate 4% reduction in heart disease risk, according to the researchers.

The team was careful to set this figure in proportion.

“Four percent is a modest reduction compared with the 14% to 29% lower heart disease risk associated with improving the overall diet,” Damani said. “However, it is a step in the right direction.”

A consistent effect across the study population

One of the more notable findings concerned who benefited. Regardless of participants’ sex, race, ethnicity, age or body mass index, they were equally likely to experience improvements in LDL particle levels.

The researchers took this to indicate that anyone living with obesity could benefit from avocado consumption. They added a clear caveat, however: people should speak to a registered dietitian nutritionist or their physician for personalised, expert guidance on improving their diets.

From controlled conditions to unpredictable lives

The study’s most significant contribution may lie less in the size of the effect than in the setting in which it was demonstrated.

“Penn State researchers demonstrated several years ago that avocado consumption could reduce LDL cholesterol and levels of LDL particles,” said Kristina Petersen, associate professor of nutritional sciences and senior author of this study. “But in that study, the researchers controlled participants’ entire diets throughout the experiment. This study demonstrated benefits in the real world, where people’s diets are much less predictable. In the course of people’s normal lives, avocado consumption still contributes to a healthier diet.”

That shift – from a tightly controlled feeding study to free-living participants managing their own meals – is what makes the result relevant to everyday practice. A 4% reduction achieved under laboratory conditions tells clinicians relatively little about what patients will actually sustain. A comparable reduction achieved by people eating as they normally do, with one addition, is a different kind of evidence.

What this means for practice

For healthcare professionals supporting people living with obesity, the findings reinforce a familiar principle with fresh quantitative backing: incremental, achievable changes can move clinically meaningful markers. They also underline the value of looking beyond standard lipid measurements when assessing cardiovascular risk in patients with abdominal obesity, where LDL particle number may reveal risk that a conventional cholesterol result conceals.

None of this positions a single food as a substitute for comprehensive care. The researchers’ own framing is deliberately measured – a step in the right direction, not a solution. But in a field where adherence often determines outcomes more than the theoretical strength of an intervention, feasibility is itself a clinical variable worth taking seriously.

CCH insight

It is always re-assuring to hear about studies which show clear benefits of foods we associate with good health, so this is great news for people who eat avocados regularly and a nice reminder for others to maybe eat them more often. However, high cholesterol and other risk factors for cardiometabolic diseases are most common in populations of high deprivation, who are unable to buy avocados regularly due partly to access but mainly due to cost.

This study’s practical value lies in feasibility – one addition, sustained over six months, moving a real marker of cardiovascular risk. Translating that kind of evidence into advice patients will actually follow is the core skill of nutritional care in obesity management. CCH’s Nutrition & Weight Management Essentials (6 hours, fully online, CPD-accredited) gives healthcare professionals a solid grounding in fundamental nutrition concepts, the factors driving weight gain, and evidence-based approaches to both weight loss and long-term maintenance, with real-life case studies throughout.

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Intermittent Fasting Maintains Long-Term Weight Loss Irrespective of Meal Timing, Study Shows

Key Takeaways: 

• Adults living with overweight or obesity who followed a 16:8 fasting pattern for 12 weeks kept off significantly more weight a full year after the intervention ended.
  
• The benefit held whether the eight-hour eating window fell early or late in the day, giving people the freedom to fit fasting around their own routines.
  
• One in three participants chose to carry on fasting unprompted during the follow-up year, pointing to a habit that is relatively easy to sustain.
  
  
  

A twelve-week habit with lasting results

New research has shown that confining daily food intake to an eight-hour window helps people living with overweight or obesity maintain their weight loss 12 months after a structured intervention comes to an end. The work was carried out by scientists from the University of Granada (UGR), the Granada Institute for Biomedical Research (ibs.GRANADA), the Public University of Navarra and the Biomedical Research Networking Center (CIBER), and was recently published in the journal Clinical Nutrition.

The trial followed 99 adults, half of them women, all of whom were living with overweight or obesity. It focused on intermittent fasting, and specifically the approach widely known as 16:8, in which people fast for 16 hours and eat only during the remaining eight. The findings indicate that this pattern is an effective way to hold on to weight loss over the medium term.

Crucially, the researchers found that the benefits endured a year later regardless of when the eating window fell. Whether participants ate early in the day, between 9 a.m. and 5 p.m. (early fasting), or later on, between 1 p.m. and 9 p.m. (late fasting), they fared better than people who kept to their usual routine of eating across a window of 12 hours or more. Both the early- and late-fasting groups sustained significantly greater weight loss at 12 months, and the early-fasting group also held on to a greater reduction in fat mass. According to the team, this suggests that the approach is not only feasible and effective in the short term but also produces effects that last.

Body composition assessed one year later

For the first 12 weeks, participants were split into four groups, each of which took part in a Mediterranean diet education programme. A control group kept its usual eating window of 12 hours or longer. An early-fasting group used an eight-hour window that began before 10 a.m., while a late-fasting group used an eight-hour window that started after 1 p.m. A fourth, self-selected group chose its own eight-hour window.

Weight, fat mass and fat-free mass were measured before and after the 12-week intervention, and again a year after the study finished. The work forms part of a larger project whose principal results appeared in the journal Nature Medicine. That analysis found that people who practised time-restricted eating (TRE), whatever their eating schedule, lost an average of 3–4 kilograms (6.6–8.8 pounds) more than those given nutritional advice alone.

Dr Alba Camacho Cardeñosa, a researcher at the University Joint Institute for Sport and Health (iMUDS) at the University of Granada and a postdoctoral fellow at ibs.GRANADA in the Endocrinology and Nutrition Department at San Cecilio University Clinical Hospital, is the study’s first author. She explains that “to date, although we knew that intermittent fasting promotes modest weight loss in the short term, it was unclear whether its effects were sustained over time. By evaluating the participants 12 months after the intervention ended, we demonstrated that the changes in body weight persist.”

The researchers also point to the strength of ongoing adherence, noting that “a very positive finding is that one in three people decided to continue practicing intermittent fasting on their own during that year of follow-up, suggesting that it is a relatively easy habit to integrate into daily life.”

A flexible strategy against obesity

The study was led by researchers from ibs.GRANADA belonging to the PROFITH CTS-977 research group at the University of Granada, headed by Professor Jonatan Ruiz Ruiz. It was conducted in collaboration with the San Cecilio University Clinical Hospital and the Virgen de las Nieves University Hospital in Granada, the Public University of Navarra, the CIBER on Obesity (CIBEROBN) and the CIBER on Frailty and Healthy Aging (CIBERFES).

The team emphasises that as little as 12 weeks of intermittent fasting may serve as an effective medium-term strategy for weight management in adults living with overweight or obesity. Because both early- and late-day regimens proved effective, the findings give people the flexibility to choose the schedule that best fits their lifestyle, which may in turn improve adherence and support more successful obesity treatment.

CCH insights:

These are very encouraging results for the use of time-restricted eating (TRE) as a strategy for weight loss maintenance. It would be good to now see research into the use of TRE as a tool to prevent weight regain after cessation of GLP-1 therapy. If TRE is adopted during GLP-1RA treatment, and continued after stopping the medication, could it help maintain weight loss and cardiometabolic gains?

Helping patients hold on to their gains — during treatment and in the months after it ends — is exactly the terrain of our two-hour CPD course GLP-1RAs in Practice: Supporting Patients During Treatment, which covers nutrition, monitoring and preparing patients for life after treatment for any clinician managing the full arc of GLP-1RA care.

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AI Finds Simple Food Swaps That Make Meals Healthier and Cheaper

Key Takeaways:

• A new artificial intelligence framework can identify just one to three ingredient swaps that make a meal meaningfully more nutritious and noticeably less expensive, without overhauling it entirely.
  
• In testing, AI-generated meals sat 47% closer to United States Department of Agriculture (USDA) nutritional targets than the real meals they were modelled on, while staying close to people’s actual eating habits in type and flavour.
  
• Applying one to three swaps lifted nutritional quality by roughly 10% and cut modelled meal costs by 19 to 32%, most often by adding vegetables or legumes and removing high-sodium or processed items.
  
  
  

Turning nutrition science into practical meals

A new artificial intelligence framework that recommends as few as one to three ingredient swaps can make everyday meals meaningfully more nutritious and less expensive. That is the central finding of a study published on 28 May in the open-access journal PLOS Digital Health by PhD student Trevor Chan and Professor of Computer Science Ilias Tagkopoulos of the University of California, Davis.

The challenge the researchers set out to tackle is a familiar one. The dietary guidelines that help reduce people’s risk of conditions such as diabetes and cardiovascular disease are well established, yet turning that nutrition science into day-to-day meals remains difficult for most people. Many existing diet recommendation tools ask people to change too much all at once, which can lead to practices that are hard to sustain or leave people unsure how to put the advice into action.

How the study worked

To build their framework, the researchers drew on data from the What We Eat in America study, analysing 135,491 meals logged by 55,228 adults. From this, they identified common meal patterns across breakfast, lunch and dinner.

They then trained a generative AI model to create realistic meals that followed those patterns, while also adjusting serving sizes. Crucially, the team tested whether the model could pinpoint one, two or three ingredient swaps within each meal that would further improve both its nutritional value and its cost.

What the AI achieved

The results were striking. Compared with real meals in the same dietary pattern, the AI-generated meals were 47% closer to USDA nutritional targets, while remaining close in overall meal type and flavour to what people actually eat.

When ingredient substitutions were applied, swapping just one to three foods improved nutritional quality by approximately 10%, while reducing modelled meal costs by between 19 and 32%. The most common substitutions the system identified involved adding vegetables or legumes, and swapping out high-sodium or processed items.

Improving eating habits

The trained model also outperformed an unspecialised model. Set against GPT-4o, the purpose-built system produced meals that came closer to USDA guidelines on macronutrients.

The authors are careful to note the limits of the work. The evaluation is entirely computational and has not yet been tested with real users. Even so, they suggest the approach could help people find simple ways to improve their eating habits.

As the authors write: “By turning dietary guidelines into realistic, budget-aware meals and simple swaps, this framework can support public-health programs and consumer apps.”

Chan and Tagkopoulos summarise the thinking behind the study: “Dietary guidelines often tell people what a healthy diet should look like, but they do not always show how to get there from the meals people already eat. Our study shows that it is possible to translate dietary standards into practical meal-level changes by identifying a small number of ingredient substitutions that can make meals healthier and cost-effective, while keeping them recognizable…[w]hat we found most interesting is that improving meals does not necessarily require a complete redesign. In many cases, targeted substitutions may be enough to move a meal closer to dietary recommendations, which could make healthy eating feel more practical and achievable.”

They add: “Healthier eating does not have to mean giving up the meals people already enjoy. With AI, we can identify small ingredient substitutions that preserve taste, while are better for our health and our pocket.”

Funding

The work was supported by grants from the U.S. Department of Agriculture and the National Science Foundation.

Source: UC Davis College of Engineering

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Four Weeks of Tomato-Soy Juice Lowered Inflammation in Adults with Obesity

Key Takeaways:

• In a four-week study, a tomato-soy juice rich in lycopene and soy isoflavones significantly reduced three blood markers of systemic inflammation in healthy adults with obesity, while a control tomato juice lacking those compounds did not.
  
• The researchers chose a low-carotenoid tomato juice as the comparison drink, rather than water, so they could isolate the effects of the lycopene and isoflavones rather than the effects of tomato juice in general.
  
• Building on these results and supporting animal data, the team has secured federal funding for a pilot clinical trial examining whether the same juice can ease inflammation in people living with pancreatitis.
  
  
  

A food-based approach to inflammation

Drinking a tomato-soy juice packed with plant compounds previously shown in animal studies to support health lowered pro-inflammatory proteins in healthy adults with obesity after four weeks, according to a new study. The researchers say the findings point to the juice’s potential as a functional food that could help rein in the persistent, unchecked inflammation that underpins a wide range of chronic conditions.

The juice was formulated to deliver high levels of two plant-based compounds, lycopene and soy isoflavones, both of which earlier research suggests have antioxidant and anti-inflammatory properties. Measured against a control tomato juice that lacked these compounds, the tomato-soy juice produced a significant drop in the blood levels of three proteins that serve as markers of systemic inflammation.

“The idea is, can we use food-based interventions to modulate inflammation?” said lead author Jessica Cooperstone, associate professor of horticulture and crop science at The Ohio State University. “And can we test this in a rigorous way so that we can really see this is affecting inflammation, versus just saying something is anti-inflammatory?”

The study was published recently in the journal Molecular Nutrition & Food Research.

What is in the juice

Lycopene is a carotenoid, the class of pigments responsible for the colours of tomatoes and various other vegetables. Soy isoflavones are flavonoids that mimic the action of the hormone oestrogen. Both are phytochemicals, naturally occurring compounds that help plants thrive.

Years ago, drawing on studies that linked diets rich in either tomato products or soy with a reduced risk of prostate cancer, Ohio State researchers developed the tomato-soy juice. It was made using tomatoes bred to contain a high concentration of lycopene – varieties also developed and grown at Ohio State – and then enriched with a soy isoflavone extract.

Subsequent research at the university connected a higher intake of the tomato-soy juice with reduced prostate-specific antigen levels in some men with prostate cancer. Studies conducted elsewhere have likewise suggested that tomatoes and soy, whether eaten separately or together, can influence inflammatory and metabolic pathways tied to obesity and other chronic illnesses.

“There’s been enough compelling evidence that compounds from tomatoes and soy might be modulating inflammation that we decided to test this in people,” Cooperstone said.

How the study was carried out

For the new study, 12 healthy adults with obesity drank two 6-ounce cans of the tomato-soy juice every day for four weeks. Following a washout period, the same participants then consumed the low-carotenoid control tomato juice for a further four weeks.

The choice of comparison drink was deliberate. Rather than pitting the juice against plain water, the team selected a tomato juice stripped of the key compounds so that any difference could be attributed to those compounds specifically.

“The hypothesis is that it’s the lycopene from the tomatoes and the isoflavones from the soy that’s inducing the effect, so we didn’t want to have a control that’s just water,” Cooperstone said.

What the blood tests showed

Before and after each four-week period, the researchers collected blood samples and tested them for cytokines, the pro-inflammatory proteins produced by the immune system. Only the tomato-soy juice produced significant reductions, and it did so in three cytokines: interleukin (IL)-5, IL-12p70 and granulocyte-macrophage colony-stimulating factor (GM-CSF). The juice was also associated with a downward trend in tumour necrosis factor alpha (TNF-a), although that particular change did not reach statistical significance.

Clues from the urine analysis

The team also examined participants’ urine before and after each trial period, looking for changes in metabolites. Metabolites are the molecular products of the biochemical reactions that break down nutrients to generate energy and carry out other essential functions in the body.

The analysis revealed that both the tomato-soy juice and the control tomato juice prompted some of the same shifts in metabolite profiles, indicating that certain tomato-driven effects occurred even in the absence of lycopene. Among the changes specifically induced by the tomato-soy juice, shifts in soy isoflavone metabolites stood out. The researchers note that, while more investigation is warranted, these changes offer further evidence that the food-based intervention is acting on human biology.

“This is probably a function of the fact that there’s more to our intervention agents than just these two compounds,” Cooperstone said. “Ultimately, we want to have a better understanding of how the foods that we eat are relating to our health. And when we really want to be sure, we need to test them in clinical trials. And that’s what we’re doing here.”

Next steps: a pancreatitis trial

On the strength of these results and additional data, Cooperstone and her colleagues have received funding from the National Institute of Diabetes and Digestive and Kidney Diseases for a pilot clinical trial. That trial will test whether consuming the same tomato-soy juice reduces inflammation in people living with pancreatitis.

The team has also gathered evidence from an animal model suggesting that the tomato-soy juice can lessen both inflammation and the severity of chronic pancreatitis. Those findings support the central prediction behind the new clinical trial, namely that the intervention could improve outcomes for people with the condition.

“Care for patients with pancreatitis is palliative, focused on controlling pain and GI symptoms. Our hypothesis is that the tomato-soy juice may serve as an intervention to decrease inflammation and hopefully increase patients’ quality of life,” Cooperstone said.

Funding and contributors

The work was supported by the U.S. Department of Agriculture, the National Institutes of Health, the Lisa and Dan Wampler Endowed Fellowship for Foods and Health Research, and the Foods for Health Initiative at Ohio State.

Co-authors include first author Maria Sholola, along with Jenna Miller, Emma Bilbrey, David Francis and Thomas Mace, all of Ohio State, and Janet Navotny of the USDA. Mace is the lead principal investigator on the pancreatitis trial. Cooperstone, Philip Hart and Kristen Roberts of Ohio State are also principal investigators on that trial.

Source: Eureka Alert!

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Carbohydrate-Rich Diets May Promote Weight Gain Even Without Higher Calorie Intake

Key Takeaways: 

• A new mouse study found that carbohydrate-rich foods such as bread, wheat flour, and rice flour promoted weight gain and fat accumulation even when total calorie intake did not significantly increase.
  
• Researchers observed that the weight gain appeared to be linked more closely to reduced energy expenditure and metabolic changes than to overeating.
  
• Scientists say future human studies will explore how factors such as whole grains, fibre content, food processing, meal timing, and combinations with protein and fat influence metabolic responses to carbohydrates.
  
  
  

Bread and carbohydrates under renewed scrutiny

Bread has served as a central part of human diets for centuries and remains a staple food in many cultures around the world. Foods such as bread, rice, noodles, and other carbohydrate-rich staples continue to form the foundation of everyday meals for billions of people.

However, as rates of overweight and obesity continue to increase globally, researchers are re-examining how modern dietary patterns may influence body weight and metabolic health. While high-fat diets have traditionally received much of the attention in obesity research, scientists are now taking a closer look at the role carbohydrates may play in weight regulation.

A new study led by researchers at Osaka Metropolitan University suggests that certain carbohydrate-heavy eating patterns may contribute to weight gain in ways that are not solely explained by consuming more calories.

The findings were published in Molecular Nutrition & Food Research. 

Obesity research has traditionally focused on fat intake

Obesity is associated with a broad range of chronic conditions and lifestyle-related diseases, including type 2 diabetes, cardiovascular disease, and metabolic dysfunction. Because of this, understanding the drivers of weight gain has become an increasingly important area of scientific research.

Historically, many obesity studies have focused primarily on dietary fat as the main contributor to excess weight gain. This is reflected in the widespread use of high-fat diets in animal research investigating obesity and metabolism.

At the same time, carbohydrate-rich foods remain deeply embedded in daily diets across the world. Despite their prominence, the metabolic effects of staple carbohydrates such as bread, rice, and noodles have not always been explored in the same depth.

Public perceptions around carbohydrates also remain widespread. Beliefs such as “bread makes you gain weight” or “carbohydrates should be restricted” are common, yet researchers say it has remained unclear whether such effects are driven by the foods themselves, overall dietary habits, eating behaviour, or broader metabolic responses.

Researchers investigated how carbohydrate-rich foods affect metabolism

To better understand the relationship between carbohydrates and weight gain, researchers led by Professor Shigenobu Matsumura at Osaka Metropolitan University’s Graduate School of Human Life and Ecology conducted a series of experiments in mice.

The study examined whether mice would preferentially select carbohydrate-rich foods over standard laboratory chow and how those dietary choices would affect body weight, metabolism, and energy expenditure.

The mice were separated into several dietary groups, including:

• Chow
• Chow + Bread
• Chow + Wheat Flour
• Chow + Rice Flour
• High-fat diet (HFD) + Chow
• High-fat diet (HFD) + Wheat Flour

Researchers monitored multiple metabolic indicators throughout the study, including:

• Body weight
• Fat mass
• Energy expenditure
• Blood metabolites
• Liver gene activity
  
  
  

Mice preferred carbohydrate-rich foods

The researchers found that mice consistently showed a strong preference for carbohydrate-rich foods. Animals given access to bread, wheat flour, or rice flour largely abandoned their standard chow diet in favour of these carbohydrate sources.

Importantly, the researchers reported that overall calorie intake did not increase substantially despite this dietary shift. Nevertheless, mice consuming the carbohydrate-rich diets still experienced increases in body weight and fat mass.

Rice flour produced similar effects to wheat flour, suggesting the observed metabolic changes were not specific to wheat itself.

Interestingly, mice in the High-fat diet (HFD) + Wheat flour group gained less weight than those in the High-fat diet (HFD) + Chow group, indicating that the interaction between fat and carbohydrate intake may be more complex than previously assumed.

“These findings suggest that weight gain may not be due to wheat-specific effects, but rather to a strong preference for carbohydrates and the associated metabolic changes,” said Professor Matsumura.

Reduced energy expenditure appeared to play a key role

To investigate why the mice gained weight without substantially increasing calorie intake, the researchers carried out further metabolic analysis using indirect calorimetry and respiratory gas measurements.

The findings suggested that the weight gain was not primarily caused by overeating. Instead, the animals appeared to experience reduced energy expenditure, meaning they were burning fewer calories.

Researchers also identified several metabolic changes in the mice consuming the carbohydrate-rich diets.

Blood analysis showed:

• Increased fatty acid levels
• Reduced levels of essential amino acids

Meanwhile, examination of the liver revealed:

• Greater fat accumulation
• Increased activity of genes involved in fatty acid synthesis
• Increased activity of genes associated with lipid transport

Together, these findings suggest that carbohydrate-heavy dietary patterns may alter how the body processes and stores energy.

Metabolic changes improved when carbohydrates were reduced

The researchers also observed that removing wheat flour from the diet rapidly improved both body weight and several metabolic abnormalities.

According to the authors, this finding suggests that moving away from a highly carbohydrate-focused dietary pattern and towards a more balanced eating pattern may help improve metabolic regulation.

However, the researchers emphasised that additional work is needed to determine how these findings translate to human diets and real-world eating behaviour.

Future studies will explore human dietary patterns

The research team says the next phase of investigation will focus on understanding whether similar metabolic effects occur in people.

“Going forward, we plan to shift our research focus to humans to verify the extent to which the metabolic changes identified in this study apply to actual dietary habits,” stated Professor Matsumura.

“We also intend to investigate how factors such as whole grains, unrefined grains, and foods rich in dietary fiber, as well as their combinations with proteins and fats, food processing methods, and timing of consumption, affect metabolic responses to carbohydrate intake. In the future, we hope this will serve as a scientific foundation for achieving a balance between ‘taste’ and ‘health’ in the fields of nutritional guidance, food education, and food development.”

The researchers noted that future studies examining food quality, fibre content, food combinations, and meal timing may help provide a more nuanced understanding of how carbohydrates influence metabolism and body weight.

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Breastfeeding for Three Months or More Linked to Lower Long-Term Weight Gain in Women

Key Takeaways: 

• Women who breastfeed for at least three months may gain significantly less weight later in life, with differences observed decades after childbirth.
  
• The strongest long-term effect is seen in women who had overweight or obesity before pregnancy.
  
• Breastfeeding appears to influence energy balance, although individual responses vary and support remains essential.
  
  
  

Long-term impact of breastfeeding on weight

Breastfeeding has long been associated with short-term postpartum weight changes, but new research suggests its effects may extend much further. A study conducted by researchers at the University of Oslo indicates that women who breastfeed for at least three months may experience lower weight gain even decades later.

According to the findings, women gained up to 6.5 kilograms less on average later in life if they breastfed for a minimum of three months. This extends the understanding of breastfeeding beyond its immediate postpartum benefits, highlighting its potential role in long-term weight trajectories.

Previous research has largely focused on weight changes in the first one to two years after childbirth. In contrast, this study followed women for up to 50 years after they had stopped breastfeeding, offering a rare insight into lifelong health patterns. The findings are expected to inform further research into maternal cardiovascular risk.

Large-scale study provides robust data

The analysis drew on data from the Women and Health Study, which includes more than 170,000 women in Norway. The results were published in the American Journal of Clinical Nutrition. 

This large cohort allowed researchers to examine how breastfeeding duration relates to weight development across different groups of women, while accounting for factors such as education, physical activity, and smoking.

Strongest effect seen in women with overweight

The most pronounced differences were observed among women who had overweight or obesity in early adulthood, prior to pregnancy.

“We compared women in this group who were otherwise similar in terms of education level, physical activity and smoking. We then found that those who breastfed for three to 15 months gained on average up to 6.5 kilos less from young adulthood to middle age, compared with those who breastfed little,” says Thorbjørn Brun Skammelsrud.

Skammelsrud is completing his doctoral research at the Department of Nutrition, Institute of Basic Medical Sciences at the University of Oslo.

More modest differences in women with normal weight

Among women who had a normal weight in early adulthood, the long-term effect of breastfeeding was still present but less pronounced. Those who breastfed for three to 15 months gained up to 3 kilograms less compared with those who breastfed for shorter periods.

For women who had been underweight before pregnancy, breastfeeding appeared to have little influence on long-term weight outcomes.

Biological mechanisms and individual variation

The study also highlights the complex relationship between breastfeeding and energy balance.

“Breastfeeding increases energy expenditure, so in theory breastfeeding should contribute to weight loss. But precisely because energy expenditure increases, some women will also experience increased appetite when they are breastfeeding,” Skammelsrud explains.

This means that while breastfeeding may support weight regulation at a population level, individual experiences can differ significantly.

Implications for public health

The study included women who had children as early as the 1940s, although the association between breastfeeding and lower weight was strongest among those who gave birth after 1980. This group is considered more representative of current maternal behaviours, particularly in terms of diet and breastfeeding practices.

In Norway, national guidance generally recommends partial breastfeeding for one year or longer, provided both mother and infant are comfortable. Breastfeeding rates in Norway are relatively high compared with many other countries.

“This is positive for public health. At the same time, the study shows that some women may need extra follow-up after giving birth, particularly those with overweight or obesity,” Skammelsrud says.

Offering that kind of tailored follow-up draws on a solid grounding in nutrition and weight management – the focus of professional training such as the College of Contemporary Health’s Nutrition & Weight Management Essentials, a CPD-accredited online short course.

Supporting women who choose to breastfeed

The findings reinforce the importance of enabling and supporting breastfeeding where desired.

“In this study, we see that breastfeeding for at least three months has a positive effect on women’s weight later in life. It is therefore important that breastfeeding is facilitated, and that women who wish to breastfeed are offered qualified support,” the researcher says.

Ensuring access to appropriate guidance and support may help maximise both short-term and long-term health outcomes for women.

CCH insight

As this study shows, supporting women’s weight – particularly those with overweight or obesity – calls for a firm grasp of nutrition and energy balance across the life course. CCH’s Nutrition & Weight Management Essentials CPD short course (10 hours, fully online, CPD-accredited) gives healthcare professionals a solid grounding in the fundamentals of nutrition and the practical methods that help patients achieve and sustain a healthier weight.
Explore Nutrition & Weight Management Essentials →

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