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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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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