Obesity Care

New study reveals half of calories in US households come from ultraprocessed foods

A recent study conducted by researchers at the Johns Hopkins Bloomberg School of Public Health has revealed that more than half of the calories consumed at home by adults in the United States originate from ultraprocessed foods. The findings underscore the significant role these products play in shaping dietary habits and health outcomes.

Ultraprocessed foods are characterised by their inclusion of additives with minimal or no nutritional value, such as colourings, emulsifiers, artificial flavourings, and sweeteners. These foods encompass a wide variety of items, ranging from crisps and hot dogs to prepackaged meals. While it has been well understood that ultraprocessed foods constitute a substantial portion of the American diet, the context of where these calories are consumed had remained less clear until now.

The consumption of ultraprocessed foods has been linked to numerous chronic health conditions, including cardiovascular disease, obesity, and colorectal cancer. The new study highlights the pressing need for strategies to encourage the consumption of healthier alternatives, especially for meals prepared at home.

Key Findings and Insights

Published online in the Journal of Nutrition on December 5, the study utilised data from the National Health and Nutrition Examination Survey (NHANES), which involved more than 34,000 adults over 20 years of age between 2003 and 2018. Participants were asked on two separate occasions about the foods they had consumed in the preceding 24 hours and where those foods were eaten—either at home or away from home.

Using the Nova Food Group Classification, a widely respected framework for categorising foods by their level of processing, the researchers grouped foods into four categories: unprocessed or minimally processed, processed culinary ingredients, processed, and ultraprocessed. Examples of ultraprocessed foods included fast foods, prepacked meals, and products with artificial additives, while minimally processed foods comprised fresh fruits, vegetables, and other whole foods.

The results were striking. Over the 15-year study period, ultraprocessed foods consistently made up more than half of all calories consumed at home, rising from 51% in 2003 to 54% in 2018. Interestingly, the study observed only minor differences in these trends across demographic variables such as sex, age, race/ethnicity, income, and education. Notably, ultraprocessed food intake at home was slightly lower among individuals from higher-income households and Hispanic communities, though it still represented nearly half of their at-home calorie consumption.

Additionally, about one-third of all calories came from foods consumed away from home. For individuals with less than a high school education, the proportion of away-from-home calories derived from ultraprocessed foods increased by nearly eight percentage points, reaching 67.1% in 2018. Among those with a high school diploma or higher, this proportion remained steady at approximately 60%.

Over the same period, the proportion of calories derived from minimally processed foods fell significantly, declining from 33.2% in 2003 to 28.5% in 2018. This decrease was observed both at home and away from home, reflecting broader challenges associated with accessing and preparing fresh, minimally processed ingredients like vegetables, meats, and fish. By contrast, ultraprocessed foods are typically more affordable, have longer shelf lives, and require less preparation time.

Expert Perspectives

Dr Julia Wolfson, the study’s lead author and an associate professor in the Bloomberg School’s Department of International Health, commented on the findings, “The perception can be that ‘junk food’ and ultraprocessed foods are equivalent. Yet ultraprocessed foods encompass many more products than just junk food or fast food, including most of the foods in the grocery store. The proliferation and ubiquity of ultraprocessed foods on grocery store shelves is changing what we are eating when we make meals at home.”

Dr Wolfson emphasised the need for actionable measures to help individuals reduce their reliance on ultraprocessed foods, both at home and when dining out, “We need strategies to help people choose less processed foods and avoid unhealthy ultraprocessed foods for foods purchased for both at-home and away-from-home consumption. Additionally, strong nutrition labels warning of high ultraprocessed food content may be warranted.”

Study Limitations

The authors acknowledged certain limitations in their research, including potential reporting bias, as participants may have underreported their consumption of foods they perceived as unhealthy. Additionally, the study did not account for changes in eating habits that may have occurred during the COVID-19 pandemic, which has likely influenced patterns of at-home food consumption.

Call to Action

The findings of this study highlight the growing dominance of ultraprocessed foods in American diets and the challenges of promoting healthier eating habits. Addressing these issues will require comprehensive strategies, including improved labelling, public health campaigns, and increased accessibility to minimally processed food options.

Reducing BMI in adults associated with lower healthcare costs, study suggests

A recent study published in JAMA Network Open highlights the potential for significant healthcare savings when adults with a higher body mass index (BMI) achieve weight loss. The researchers analysed healthcare expenditures for adults with overweight or obesity who were covered either by Medicare or employer-sponsored insurance. Their findings reveal compelling evidence that weight reduction could lead to substantial savings, particularly for individuals with chronic health conditions.

Background

The prevalence of obesity among adults in the United States increased dramatically between 2000 and 2020, rising from 31% to 42%. This trend means that approximately 73% of adults would need to lose weight to meet recommended BMI levels. Excess weight is a well-documented risk factor for numerous chronic diseases, including pulmonary disease, osteoarthritis, cancer, heart disease, hypertension, and type 2 diabetes.

Obesity-related conditions contribute significantly to rising healthcare costs. In 2016, obesity was linked to more than $260 billion in healthcare expenditures, a figure projected to increase to $385 billion by 2024. Most of these costs are borne by employer-sponsored insurance, with Medicaid and Medicare accounting for roughly 25% of the total.

In the workplace, obesity has been shown to lead to increased health-related expenses and workplace accidents. Employees with obesity file double the number of workers’ compensation claims, take three times as many days off due to injury, and have medical claims costs seven times higher than their peers. Additionally, indemnity claim costs for employees with obesity are 11 times higher.

From a health risk perspective, individuals with a BMI over 35 are more than 70% more likely to develop type 2 diabetes during their lifetime. Furthermore, every five-point increase in BMI raises the likelihood of heart failure by about 30%. Excess weight also increases the risk of hypertension by 65% to 78%.

Several interventions aim to address these risks. Lifestyle programmes can achieve weight reductions of 5% to 7% and are considered cost-effective. While bariatric surgery is highly effective, it is also expensive and carries risks, including the need for follow-up procedures. Medicare currently covers bariatric surgery for individuals with a BMI of 35 or higher who have a related comorbidity, as well as those with a BMI over 40. More recently, glucagon-like peptide-1 (GLP-1) medications have emerged as an effective treatment option, with the potential to reduce weight by up to 12%. Around one-quarter of individuals using these medications achieve weight loss of over 20%.

About the Study

The study explored the relationship between weight loss and healthcare cost savings, including Medicare spending. Researchers analysed data from cross-sectional surveys conducted between 2001 and 2020. These surveys provided nationally representative data, including self-reported information on healthcare usage, insurance coverage, and medical conditions.

The analysis focused on adults aged 24 to 64 with a BMI of 25 or higher. Exclusions included individuals with annual healthcare expenditures exceeding $506,000, pregnant individuals, and adults with a BMI over 80. The study also considered participants’ household composition, region, education, race, gender, and age. Specific medical conditions examined included arthritis, heart disease, asthma, mental health disorders, hypertension, hyperlipidaemia, and diabetes.

Using this data, researchers estimated healthcare costs associated with varying levels of BMI reduction (5%, 10%, 15%, 20%, and 25%).

Key Findings

The study included 13,435 adults with employer-sponsored insurance and 3,774 Medicare beneficiaries, all with a BMI of 25 or higher. The findings demonstrated a strong link between higher BMI and increased healthcare costs.

For individuals with employer-sponsored insurance, each 1% increase in BMI above 30 corresponded to an additional $326 in annual healthcare costs. For Medicare beneficiaries, the cost increase was $633 per 1% BMI increase. Racial disparities were noted, with Hispanic and non-Hispanic Black participants incurring lower costs than non-Hispanic White participants.

Savings Associated with Weight Loss:

1. A 5% reduction in BMI led to annual savings of $670 (8%) for individuals with employer-sponsored insurance and $1,262 for Medicare beneficiaries.
2. A 25% reduction in BMI resulted in savings of $2,849 (34%) for employer-sponsored insurance participants and $5,442 (31%) for Medicare beneficiaries.

These savings were particularly significant for individuals with higher baseline BMIs and chronic health conditions. For example:

1. Among participants with arthritis and employer-sponsored insurance, a 15% BMI reduction resulted in savings of $4,950.
2. For Medicare beneficiaries with hypertension, a 15% BMI reduction led to savings of $3,709.

Overall, the research underscores that reducing BMI, particularly in people with chronic conditions, could substantially lower healthcare costs for both employer-sponsored insurance and Medicare populations.

Conclusions

This study highlights the significant potential for annual healthcare savings through weight loss, particularly for individuals with higher baseline BMI levels and those managing chronic health conditions. However, the research does not account for potential savings from preventing obesity-related conditions in the first place.

Implications for Policy and Practice:
Improving access to effective weight-loss treatments, including lifestyle interventions and GLP-1 medications, could help alleviate the economic burden of obesity on healthcare systems. These findings make a strong case for prioritising weight management strategies as part of broader public health and insurance policies.

As the prevalence of obesity continues to rise, adopting and promoting effective interventions could not only improve health outcomes but also drive meaningful reductions in healthcare spending.

Whole milk tied to lower obesity risk and improved weight profiles

Regular consumption of whole milk may contribute to maintaining a healthier body weight, according to a recent study. The research suggests that individuals who frequently drink whole milk may experience a lower risk of obesity, challenging long-held beliefs about full-fat dairy products.

The study, conducted in the United States, analysed data from 43,038 adults participating in the National Health and Nutrition Examination Survey (NHANES). Overweight and obesity were categorised using standard definitions: a body mass index (BMI) of ≥25 kg/m² for overweight and ≥30 kg/m² for obesity.

The findings revealed that drinking one cup of whole milk daily was associated with a 0.5 kg/m² reduction in BMI, an average decrease of 1.5 kg in body weight, and a waist circumference reduction of 1.1 cm. These results suggest that whole milk could play a role in weight management.

The researchers propose several mechanisms through which whole milk may influence body weight. Whole milk’s nutrient profile could promote feelings of fullness (satiety) and delay gastric emptying, reducing overall food intake. Additionally, whole milk might replace higher-calorie sugary beverages in the diet, leading to a net decrease in calorie consumption.

The study also highlighted differences in milk consumption patterns among age groups. While over 80% of children consume milk daily, only 50% of adults report drinking milk regularly. This discrepancy suggests an opportunity for public health strategies to encourage milk consumption across all age groups.

Notably, these findings contradict earlier research that linked high intake of full-fat dairy products to weight gain. The authors of the study commented, “These results could potentially inform future dietary guidelines and public health strategies. Further exploration into the mechanisms behind whole milk’s effects on weight and long-term clinical trials across diverse populations is necessary to validate these findings.”

Obesity, which affects over one billion individuals globally, is a significant public health challenge. It is associated with an increased risk of developing chronic conditions such as heart disease, type 2 diabetes, and certain types of cancer.

As dietary guidance continues to evolve, this study adds to the growing body of evidence supporting the potential benefits of whole milk. For those interested in further details, the full study is available in the journal Nutrition Research.

High blood sugar impairs brain health even without diabetes

A groundbreaking study by Baycrest has revealed that elevated blood sugar levels may negatively impact brain health even in individuals without a diabetes diagnosis. While the relationship between blood sugar and brain health is well-established in people living with diabetes, this research is the first to explore this connection in individuals who are not diagnosed with the condition.

“Our results show that even if someone does not have a diabetes diagnosis, their blood sugar may already be high enough to be negatively impacting their brain health,” explained Dr. Jean Chen, senior author of the study and Senior Scientist at the Rotman Research Institute, part of the Baycrest Academy for Research and Education (BARE). “Blood sugar exists on a spectrum – it isn’t a black-and-white categorisation of healthy or unhealthy.”

The study, titled “The associations among glycemic control, heart variability, and autonomic brain function in healthy individuals: Age- and sex-related differences,” was recently published in the journal Neurobiology of Aging. Researchers examined data from 146 healthy adults aged 18 and older. For each participant, blood sugar levels were assessed alongside brain activity, measured through magnetic resonance imaging (MRI), and heart rate variability, analysed using electrocardiogram (ECG) readings.

Key Findings:

1. Cognitive Networks Affected
   Higher blood sugar levels were linked to reduced connectivity within brain networks essential for cognition, including memory, attention, and emotion regulation.
   “The findings highlight the importance of managing your blood sugar through healthy diet and exercise, not only for your body but also for your brain,” said Dr. Chen, who also serves as Baycrest’s Canada Research Chair in Neuroimaging of Aging and Professor of Biomedical Physics at the University of Toronto. She added, “It’s also important to get regular checkups and to work with a healthcare provider, especially if you have been diagnosed with pre-diabetes.”
2. Stronger Effects in Older Adults
   Although the negative impact of elevated blood sugar on brain networks was observed across all age groups, it was more pronounced in older adults, who generally exhibited higher blood sugar levels compared to younger participants.
3. Greater Vulnerability in Women
   Women showed a stronger association between elevated blood sugar and brain network connectivity decline compared to men, highlighting potential sex-based differences in vulnerability.
4. Link to Heart Rate Variability
   The research also uncovered a relationship between higher blood sugar and lower heart rate variability – the measure of beat-to-beat changes in heart rate. Lower heart rate variability is associated with poorer brain health, while higher variability has been linked to better cognitive outcomes in prior studies.

Future Directions:

The researchers noted that heart rate variability, unlike blood sugar, may be a more accessible target for intervention in non-diabetic individuals. Modifying heart rate variability could potentially offer a pathway to enhancing brain health without requiring substantial changes in blood sugar levels.

Study Details and Support:

This research utilised data from the Leipzig Study for Mind-Body-Emotion Interactions (LEMON) dataset. Funding for the study was provided by the Canadian Institutes of Health Research and the Natural Sciences and Engineering Research Council of Canada.

This work underscores the importance of proactive blood sugar management for maintaining brain health across the lifespan, even in those without diabetes. For individuals, adopting a healthy diet, staying physically active, and seeking regular medical assessments can be crucial steps toward safeguarding both physical and cognitive well-being.

Obesity-related immune dysfunction linked to increased cancer risk

Researchers at Saint Louis University’s (SLU) School of Medicine have revealed a critical link between immune system dysfunction and an elevated risk of cancer in people living with obesity. The team found that T-cell dysfunction, a key component of immune health, plays a central role in this heightened risk.

T cells, a type of white blood cell classified as lymphocytes, are essential to the body’s immune system, defending against infections and cancer. Dr Ryan Teague, professor of molecular microbiology and immunology at SLU, and his research team are investigating how obesity impacts T-cell function and impairs immune surveillance—the body’s ability to detect and eliminate malignant cells before they develop into tumours.

The team’s findings, published in Nature Communications, were the result of a study led by Dr Teague and co-authored by Alex Piening, an M.D./Ph.D. candidate at SLU. The study demonstrated that obesity-related T-cell dysfunction prevented these immune cells from recognising and attacking tumour cells, resulting in a higher susceptibility to cancer in mice with obesity exposed to carcinogens. Now, the researchers are working to pinpoint the specific metabolic mechanisms associated with obesity that impair T-cell function.

Dr Teague’s lab focuses on identifying obstacles to effective cancer immunotherapy and developing strategies to overcome them, with the goal of improving outcomes for individuals undergoing these treatments. His team is particularly interested in understanding how obesity affects the efficacy of immunotherapies.

“Immunotherapy boosts a patient’s immune system by targeting T cells and reinvigorating them. Paradoxically, immunotherapy is often more successful in patients with obesity, where the immune system isn’t functioning quite as well,” Dr Teague explained. “Our research explains this paradox by showing that, in the context of obesity, developing tumours are only required to evade a weakened immune system. These tumours, therefore, are not as well adapted to escape the reinvigorated T cells stimulated during immunotherapy, making them more vulnerable to destruction.”

The study also highlights the role of advanced technology in achieving these findings. Single-cell RNA sequencing, a technique that allows researchers to examine the activity within individual immune cells, was instrumental in uncovering the details of T-cell dysfunction.

“We learned that the dysfunction in these T cells lies in their inability to kill tumours. The genes responsible for this activity were not being activated,” Dr Teague noted. “Additionally, the cells lacked the ability to acquire the metabolic functions required to sustain anti-tumour activity.”

SLU’s investment in single-cell RNA sequencing technology has been a driving force behind these discoveries. The Department of Molecular Microbiology and Immunology is leveraging this cutting-edge approach to advance its understanding of cancer and the immune system, bringing researchers closer to innovative treatments and potential cures.

This research underscores the complexity of the relationship between obesity, immune function, and cancer risk, while also offering hope for improved immunotherapy strategies tailored to individuals living with obesity.

Study finds physical activity boosts brain health and cuts dementia risk

Staying physically fit can significantly lower the risk of developing dementia and delay its onset by nearly 18 months, according to new research highlighting the critical role of exercise in boosting brain health. The findings offer hope, even for those genetically predisposed to dementia, revealing that maintaining a high level of fitness can reduce their risk by up to 35%.

The study, published in the British Journal of Sports Medicine, underscores the importance of physical fitness across a lifetime as a key strategy to lower the likelihood of developing dementia. It found that individuals with the highest levels of cardiorespiratory fitness (CRF)—a measure of the body’s ability to deliver oxygen to muscles during exercise—had better cognitive function and a lower risk of dementia compared to those with lower fitness levels.

Study Details

The research analysed data from 61,214 participants aged 39 to 70 who joined the UK Biobank study between 2009 and 2010. At the time of enrolment, none of the participants had been diagnosed with dementia. Over a follow-up period of up to 12 years, the researchers monitored their health outcomes.

To assess their physical fitness, participants completed a six-minute stationary bike test, measuring their CRF levels. Cognitive function was evaluated through neuropsychological tests, and genetic predisposition to dementia was calculated using a polygenic test for Alzheimer’s disease risk.

The study’s authors wrote, “Our study shows that higher CRF is associated with better cognitive function and decreased dementia risk. Moreover, high CRF may buffer the impact of genetic risk of all dementia by 35%.”

The researchers also noted that individuals with high CRF experienced a delay in dementia onset of approximately 1.48 years. The study was led by Professor Weili Wu from the Ageing Research Centre at the Karolinska Institute in Stockholm, Sweden.

Implications for Dementia Prevention

The findings provide further evidence supporting the role of a healthy lifestyle in reducing dementia risk. Organisations dedicated to dementia care emphasised the study’s importance in showing how physical activity can be a protective factor against cognitive decline.

“This research emphasises that exercise is an important part of maintaining a healthy lifestyle and could reduce the risk of developing dementia later in life,” said Dr Richard Oakley, Associate Director of Research and Innovation at the Alzheimer’s Society. “What is particularly promising about this study is that exercise also appears to reduce dementia risk in people who have a higher genetic risk of developing Alzheimer’s disease.”

The Lancet Commission on dementia, in its July report, identified physical inactivity as one of 14 modifiable risk factors for dementia. Other factors include hearing loss, low levels of education, air pollution, social isolation, and depression.

Dr Jacqui Hanley, Head of Research at Alzheimer’s Research UK, commented, “This new research highlights how good cardiorespiratory fitness, a key measure of overall physical health, could help lower the risk of developing dementia in the future. However, it is important to note that we don’t know if there is a direct link between cardiorespiratory fitness and reduced dementia risk. More research is needed to find out exactly how it affects the brain.”

Observational Nature of the Study

The researchers emphasised that their findings were observational and do not definitively establish a causal relationship between higher CRF and reduced dementia risk. Nevertheless, they suggest that improving cardiorespiratory fitness could be a viable strategy for preventing dementia, even in individuals with a high genetic predisposition for Alzheimer’s disease.

“Enhancing CRF could be a strategy for the prevention of dementia,” the authors concluded, adding weight to the growing body of evidence that physical activity plays a critical role in supporting cognitive health.

Call to Action

Dementia charities and health experts encourage people to adopt a proactive approach to reducing their dementia risk by incorporating regular exercise into their lives, avoiding smoking, limiting alcohol intake, and maintaining overall physical and mental health.

This study provides yet another compelling reason to make fitness a priority—not just for physical well-being but also for preserving cognitive health in the years to come.

Kimchi found to significantly reduce body fat and help tackle obesity

Obesity, a significant global health challenge, affects approximately 16% of the world’s population—equivalent to around 890 million individuals. Recognised by the World Health Organization (WHO) as a critical health issue, obesity is linked to a diminished quality of life and adverse effects on overall health. To address this pressing concern, researchers at the World Institute of Kimchi in South Korea have been actively studying the potential health benefits of kimchi, a traditional Korean fermented food. Their findings, published in leading international journals, including the Journal of Functional Foods, highlight kimchi’s promising role in reducing body fat and its potential as a dietary strategy for obesity management.

Evidence from Preclinical Studies

Initial investigations into the anti-obesity effects of kimchi yielded striking results. In animal models of obesity, diets incorporating kimchi led to a remarkable 31.8% reduction in body fat. These findings underscore kimchi’s potential as a functional food for managing body weight.

Insights from Longitudinal Population Studies

Data from the Korea Genome and Epidemiology Study (KoGES), a 13-year longitudinal research effort involving a large cohort, further reinforced kimchi’s benefits. Among middle-aged males, appropriate consumption of kimchi was associated with a 15% reduction in body mass index (BMI) and a 12% decrease in obesity incidence. This study was published in Food & Function and BMJ Open and received international attention, including coverage by NBC News.

Clinical Trial: Kimchi and Gut Health

A recent clinical trial led by Dr. Sung-Wook Hong from the Kimchi Functionality Research Group, in collaboration with Pusan National University Hospital, investigated the effects of kimchi on body fat and gut microbiomes. The trial involved 55 adults with overweight (both males and females) with BMIs ranging from 23 to 30 kg/m². Over three months, participants consumed 60g of kimchi daily via capsules containing freeze-dried cabbage kimchi fermented at 4℃ for two weeks.

The results were compelling:

1. Participants consuming kimchi experienced a 2.6% reduction in body fat.
2. By contrast, those in the control group saw a 4.7% increase in body fat.

This difference was statistically significant, indicating the efficacy of regular kimchi consumption.

Gut Microbiome Modulation

The trial also revealed notable changes in gut microbiota. Participants who consumed kimchi showed:

1. An increase in Akkermansia muciniphila, a beneficial bacterium associated with gut health and reduced obesity risk.
2. A decrease in Proteobacteria, which are linked to obesity.

These findings suggest that kimchi’s anti-obesity effects may be mediated through gut microbiota modulation, providing a dual benefit for weight management and gastrointestinal health.

Expert Commentary and Future Directions

Dr. Hae-Choon Chang, Director of the World Institute of Kimchi, emphasised the importance of these findings:
“The results of a preclinical study and a clinical trial have systematically verified the anti-obesity effects of kimchi and present scientific evidence that would help to make the excellent properties of kimchi widely known, thereby laying the foundation for the growth of kimchi as a health food well recognised around the world.”

She added: “We will continue to devote our time, effort, and resources towards scientific research to reinforce the health-functional properties of kimchi, in improving gastrointestinal health in addition to its immune-enhancing and anti-cancer effects, thus firmly establishing the role of kimchi as a global health food.”

The findings from this clinical trial were published in the October 2024 issue of the Journal of Functional Foods.

Kimchi: A Cultural and Health Icon

In recognition of its cultural and health significance, South Korea designated 22 November as “Kimchi Day” in 2020. This commemorative day celebrates kimchi as the first Korean food to gain such recognition for its unique health properties. Since then, Kimchi Day has been celebrated internationally, with festivals held in countries including the U.S., U.K., Argentina, and Brazil.

Kimchi’s established benefits and increasing global recognition underscore its potential as a dietary staple for promoting health and combating obesity. With ongoing research, this traditional food is poised to play a central role in global health strategies.

Effective screen time rules reduce obesity risk in children, research confirms

Families are being urged to establish clear and consistent screen-time rules for their children to promote healthier habits, improve sleep, and reduce the risk of obesity, according to new research from the University of Auckland and St George’s, University of London.

The study, published in the European Journal of Public Health, highlights that family screen-time rules are an effective tool for reducing young children’s screen use and ensuring they get adequate sleep—both of which are linked to a lower risk of developing obesity.

“These findings suggest that promoting family screen-time rules is a helpful strategy to support healthier habits in children and address obesity on a larger scale,” says lead author Dr Ladan Hashemi, an honorary senior researcher in social and community health at Waipapa Taumata Rau, University of Auckland.

The researchers advise parents and caregivers to establish straightforward screen-time rules early in a child’s life. These guidelines should focus on three key areas:

1. Quality: Limiting the types of programmes children are permitted to watch.
2. Quantity: Setting clear limits on the amount of time children can spend using televisions, tablets, and other devices.
3. Timing: Defining specific times when children can and cannot use screens, such as avoiding screens before bedtime.

“Our findings suggest that having all three rules in place is most effective in encouraging healthier habits, like reducing screen time and supporting better sleep,” explains Dr Hashemi. “These simple but combined actions can have a lasting, positive impact on your child’s overall health and help lower their risk of obesity.”

The Broader Impact of Excessive Screen Time

Research has repeatedly shown that excessive screen time, especially at a very young age, is associated with a range of adverse outcomes. These include shortened attention spans, emotional and behavioural challenges, language development delays, disrupted sleep patterns, and increased obesity risk.

The new study was motivated by the growing prevalence of childhood obesity in New Zealand and globally. It underscores the importance of improving sleep as part of addressing the obesity epidemic. Prior research has established a strong link between insufficient sleep and obesity, with children who spend less time on screen devices generally experiencing better sleep. The researchers noted that families with screen-time rules often have corresponding guidelines around bedtimes, further supporting improved sleep quality for children.

Study Methodology and Findings

The study analysed data from 5,733 children and their mothers who participated in the Growing Up in New Zealand longitudinal study. It specifically examined the impact of family screen-time rules implemented when children were two years old on their obesity outcomes at four-and-a-half years old.

The findings revealed that screen-time rules were associated with reduced screen use and better sleep in children, both of which contribute to healthier weight outcomes. However, the study also identified significant socio-economic factors—such as poverty and food insecurity—that influenced screen use and childhood obesity. When these factors were accounted for, the direct association between screen time and obesity weakened.

Addressing Underlying Issues

The researchers emphasised that tackling childhood obesity requires more than just screen-time guidelines. Broader societal challenges, such as poverty and food insecurity, play a pivotal role in determining children’s health outcomes. Families facing financial hardship often struggle to access nutritious food and other resources needed to establish healthy routines, including screen-time rules.

“Programmes that offer resources and support to financially disadvantaged families, like those that improve access to healthy foods, are essential for helping these families establish and maintain effective screen-use guidelines,” says Dr Hashemi.

This research underscores the need for a multi-faceted approach to combat childhood obesity—one that combines practical strategies like screen-time rules with broader efforts to address the socio-economic factors driving the epidemic.

By taking these steps, families can not only improve their children’s overall health but also contribute to a wider societal effort to reduce childhood obesity rates.

Epigenetic changes in fat cells shed light on why weight loss is hard to sustain

Even after significant weight loss, fat cells retain a ‘memory’ of obesity, according to groundbreaking research published in Nature. This discovery sheds light on why maintaining weight loss can be so challenging, underscoring the need for long-term support for individuals who achieve significant weight reductions.

The Epigenetic Memory of Obesity

The study reveals that obesity triggers changes in the epigenome—chemical modifications to DNA and proteins that regulate gene activity. These epigenetic alterations disrupt the normal functioning of fat cells, impairing their ability to operate as they would in a body without obesity. Crucially, these changes persist even after weight loss brings body weight to a healthy level.

This persistence highlights the complexity of obesity as a condition, suggesting that maintaining weight loss often requires more than personal effort. Co-author Laura Hinte, a biologist at ETH Zurich, explained that the findings emphasise the need for additional support. “It means that you need more help, potentially,” she said, adding that this reinforces the idea that “it’s not your fault.” By uncovering the molecular underpinnings of this phenomenon, the study offers an explanation for the enduring challenges many individuals face after weight loss.

Exploring the Molecular Mechanisms

To investigate why weight is often regained after loss, researchers examined fat tissue from individuals with severe obesity and compared it to fat tissue from people who had never experienced obesity. They discovered significant differences in gene activity: some genes were more active in the fat cells of individuals with obesity, while others were less active.

Even after weight-loss surgery, the genetic activity in fat cells from participants with a history of obesity remained altered. Two years post-surgery, despite substantial weight reductions, the fat cells still displayed an obesity-linked pattern. Similar results were observed in mice, further supporting the findings.

The Lasting Impact of Obesity on Fat Cells

The research pinpointed specific genes that were affected by obesity. Genes that promote inflammation and fibrosis (the formation of stiff, scar-like tissue) were dialled up, while those essential for normal fat cell function were suppressed. These changes were traced to alterations in the epigenome, which dictate whether specific genes are switched on or off.

The durability of this ‘memory’ was tested by placing mice with obesity on a diet. Despite becoming lean again, their fat cells continued to exhibit obesity-related epigenetic changes months later. Co-author Ferdinand von Meyenn, an epigenome specialist at ETH Zurich, noted that while it is unclear how long the body retains this memory, “there may be a time window when this memory will be lost,” although “we don’t know” for certain. This lingering effect demonstrates how deeply obesity can alter the body at the cellular level.

Effects of Fat Cell Memory on Metabolism

The persistent memory of obesity has profound implications for metabolism. Fat cells from mice formerly with obesity absorbed more sugar and fat than those from control mice that had never had obesity. Moreover, when placed on a high-fat diet, the mice formerly with obesity regained weight more quickly than their counterparts who had never had obesity.

While these findings are striking, the study stops short of proving a direct causal link between epigenetic changes and altered fat cell function. Scientists such as Evan Rosen, a biologist at Beth Israel Deaconess Medical Center in Boston, pointed out that although the research provides a valuable list of epigenetic alterations, determining which changes drive the fat cells’ lingering memory will be challenging. Von Meyenn acknowledged this limitation, stating that “it’s not yet a causal link,” but rather “correlation” that his team continues to explore.

Implications for Weight Loss and Obesity Stigma

The study’s findings have broader implications for addressing obesity-related stigma. They suggest that the biological changes caused by obesity create long-term challenges that cannot simply be overcome with willpower alone. Von Meyenn stressed the importance of preventing obesity in the first place, explaining that while people who lose weight can remain lean, “it will require a lot of effort and energy to do that.”

By uncovering the epigenetic mechanisms that underlie obesity and its lingering effects, the research may pave the way for improved treatments and support systems. This, in turn, could help reduce stigma and foster greater understanding of the biological challenges faced by individuals seeking to manage their weight long-term.

Stress hormones may be the key to understanding how obesity causes diabetes, researchers reveal

A groundbreaking study from Rutgers Health, in collaboration with several institutions, suggests that stress hormones, rather than impaired cellular insulin signalling, might be the primary cause of obesity-related diabetes. This research, published in Cell Metabolism, challenges the traditional view of how obesity-induced insulin resistance develops and introduces novel perspectives on potential treatment approaches.

“We have been interested in the basic mechanisms of how obesity induces diabetes. Given that the cost of the diabetes epidemic in the U.S. alone exceeds $300 billion per year, this is a critically important question,” said Christoph Buettner, chief of endocrinology, metabolism, and nutrition at Rutgers Robert Wood Johnson Medical School and the senior author of the study.

Challenging Long-Standing Beliefs About Obesity and Diabetes

Historically, scientists have attributed the development of diabetes in people with obesity to disrupted insulin signalling within liver and fat cells. However, this new study offers an alternative explanation, highlighting the role of the body’s sympathetic nervous system (SNS) – commonly associated with the “fight or flight” response. According to the researchers, overeating and obesity stimulate this system, leading to increased levels of the stress hormones norepinephrine and epinephrine, which seem to interfere with insulin’s effects. Importantly, they observed that this interference occurs even when cellular insulin signalling remains intact.

Through experiments on mice, the researchers found that overeating rapidly increases the stress hormone norepinephrine within days, indicating just how quickly excess food can stimulate the SNS.

The Role of Stress Hormones in Disease Development

To better understand how this hormone surge influences disease progression, the researchers used a new type of genetically engineered mice that are identical to regular mice except for one critical difference: they are unable to produce catecholamines, the primary stress hormones, outside their brain and central nervous system.

The study showed that when these genetically modified mice were fed an obesity-inducing, high-fat and high-sugar diet, they gained just as much weight as their regular counterparts. Yet, they did not develop metabolic diseases typically associated with obesity.

“We were delighted to see that our mice ate as much because it indicates that the differences in insulin sensitivity and their lack of metabolic disease are not due to reduced food intake or reduced obesity but due to the greatly reduced stress hormones. These mice cannot increase stress hormones that counteract insulin; hence, insulin resistance does not develop during obesity development.”

Explaining the Variation in Diabetes Development

The findings may provide insight into why some people living with obesity develop diabetes while others do not, and why stressful conditions can worsen diabetes, even without significant weight gain. Buettner noted: “Many types of stress – financial stress, marital stress, the stress associated with living in dangerous areas or suffering discrimination or even the physical stress that comes from excessive alcohol consumption — all increase diabetes and synergize with the metabolic stress of obesity.”

He added, “Our finding that even obesity principally induces metabolic disease via increased stress hormones provides new insight into the common basis for all these factors that increase the risk of diabetes. Stress and obesity, in essence, work through the same basic mechanism in causing diabetes, through the actions of stress hormones.”

A Paradigm Shift in Understanding Insulin Resistance

While it has long been recognised that catecholamines can impair insulin action, this study suggests that heightened activity of these stress hormones might be the fundamental driver of insulin resistance in obesity. Stress hormones increase glucose and lipid levels in the bloodstream, while insulin typically works to lower them. The study reveals that insulin signalling remains intact in many cases of insulin resistance associated with obesity. Instead, the heightened presence of stress hormones acts like an “accelerated gas pedal,” pushing blood sugar and fat levels up, despite insulin’s continued attempts to reduce them.

“Some colleagues are at first surprised that insulin resistance can exist even though cellular insulin signalling is intact,” Buettner explained. “But let’s not forget that the gas pedal effects of stress hormones are exerted through very different signalling pathways than insulin signalling. That explains why the ability of insulin to ‘brake’ and reduce the release of sugar and fat into the bloodstream is impaired even though insulin signalling is intact because stress signalling is predominant.”

Potential for New Treatments

These findings open the door to considering medications that reduce catecholamines – encompassing all stress-related hormones produced by the SNS and adrenal glands – as a possible treatment for diabetes. However, medicines currently used to block catecholamines for high blood pressure have not shown significant benefits for diabetes, possibly due to their inability to target the relevant receptors or their complex interactions within the brain and body.

Buettner and Kenichi Sakamoto, the study’s first author and an assistant professor of endocrinology at Robert Wood Johnson Medical School, are now preparing to validate these findings in human studies. They are also exploring the role of the SNS in other forms of diabetes, including Type 1 diabetes. “We would like to study if short-term overfeeding, as some of us experience during the holidays by gaining five to 10 pounds, increases insulin resistance with heightened sympathetic nervous system activation,” Buettner said.

A New Direction for Diabetes and Metabolic Disease Research

Ultimately, this research could lead to a new focus on reducing stress hormones as a therapeutic strategy to tackle insulin resistance, diabetes, and metabolic diseases, shifting away from targeting insulin signalling alone.

“We hope this paper provides a different take on insulin resistance,” Buettner concluded. “It may also explain why none of the drugs currently used to treat insulin resistance, except insulin itself, directly increases cellular insulin signalling.”

By highlighting the potential for stress hormone reduction to prevent or treat diabetes, these findings represent a substantial step forward in understanding and addressing the complex relationship between obesity and diabetes.

Study finds weight-loss surgery in adolescents leads to major long-term health benefits

A landmark study spanning 18 years and costing $29 million has found that weight-loss surgery in adolescents with severe obesity can lead to long-lasting health improvements, particularly in the remission of type 2 diabetes. The research, funded by the National Institutes of Health (NIH) and published in the New England Journal of Medicine, highlights how surgical interventions in young people bring about more sustained benefits compared to adults who undergo the same procedures.

With a rising prevalence of severe obesity in young people, researchers underscore the need to understand the benefits and risks of medical and surgical options. “These findings are essential as effective treatment options for severe paediatric obesity remain rare,” said Dr Thomas Inge, the study’s principal investigator and surgeon-in-chief at Lurie Children’s Hospital in Chicago. “Robust data on the outcomes of modern bariatric procedures are invaluable for clinicians and families considering ways to support adolescents facing obesity, especially in cases of rapid weight gain,” added Dr Inge, who also directs the hospital’s bariatric surgery programme.

The trial, which ran from 2006 to 2012, included approximately 260 adolescents aged 13 to 19, who underwent bariatric surgery at one of five centres in the United States, including Cincinnati Children’s, Texas Children’s Hospital in Houston, Children’s Hospital of Alabama in Birmingham, the University of Pittsburgh Medical Center, and Nationwide Children’s Hospital in Columbus, Ohio.

Adolescents with severe obesity who had bariatric surgery before age 19 experienced sustained weight loss a decade later. Additionally, they showed significant resolution of obesity-related health conditions, including type 2 diabetes, hypertension, and elevated cholesterol. Researchers reported that participants maintained substantial reductions across these conditions, with an average 20% decrease in body mass index (BMI), a 55% reduction in type 2 diabetes, a 57% decrease in hypertension, and a 54% improvement in abnormal cholesterol.

The benefits of surgery appeared similar between those who underwent gastric bypass and those who received sleeve gastrectomy, indicating both procedures are effective in treating obesity-related health issues in young people.

Importantly, the study found that the 55% reduction in type 2 diabetes in adolescents following surgery was far greater than that observed in adults who had undergone the same procedures. Recent NIH-funded studies in adults showed only an 18% decrease in diabetes after seven years and 12.7% after 12 years. Given the rapid progression of type 2 diabetes in young people, this study demonstrates the considerable long-term health benefits of bariatric surgery when undertaken during adolescence.

“This study underscores that surgical treatment should be considered earlier in the course of severe obesity,” Dr Inge remarked. However, he highlighted a critical barrier to access: fewer than 1% of eligible adolescents with severe obesity receive surgery due to parental reservations and other factors. “We should advocate for early intervention and ensure that adolescents have access to effective therapies to mitigate the progression of obesity-related conditions, such as type 2 diabetes and hypertension,” Dr Inge emphasised. In addition to his role at Lurie Children’s Hospital, Dr Inge serves as a professor of surgery and paediatrics at Northwestern University Feinberg School of Medicine in Chicago.

The study has received praise from other experts in adolescent weight management, who recognise the growing importance of effective interventions for severe obesity in young people. “The rate of obesity continues to rise in children, threatening to impact future life expectancy and healthcare costs,” noted Dr Kirk Reichard, surgical director of the bariatric surgery programme at Nemours Children’s Hospital in Wilmington, Delaware. Although not directly involved in the study, Dr Reichard underscored the critical need to address paediatric obesity. “While efforts to address prevention are critical, the reality is that 20% of American children are now affected by obesity and need our help,” said Dr Reichard, who is also a clinical professor of surgery and paediatrics at Sidney Kimmel Medical College of Thomas Jefferson University in Philadelphia.

Another expert, Dr Andrea Coviello, an endocrinologist and director of the weight management programme at the University of North Carolina School of Medicine in Chapel Hill, pointed out that long-term data on bariatric surgery in younger patients has been limited. “There has been a lack of long-term data on the benefits and risks of bariatric surgery in younger patients,” Dr Coviello said, adding that “this study helps to fill in knowledge gaps that may help healthcare providers and parents to make informed decisions about healthcare options for children with obesity and obesity-related conditions such as type 2 diabetes.”

Dr Coviello encouraged parents to seek guidance from paediatricians and weight-loss specialists if their children are affected by obesity, particularly if they experience related health issues such as type 2 diabetes or high blood pressure. “Appropriate care and weight loss earlier may significantly improve their child’s health in the longer term,” she noted.

The findings of this study hold significant implications for addressing severe obesity in adolescents, demonstrating that early surgical intervention can lead to sustained health improvements and potentially prevent the worsening of obesity-related conditions later in life.

Surge in endometrial cancer among younger women linked to rising obesity rates

Endometrial cancer, historically more prevalent in post-menopausal women, has seen a significant and concerning rise in cases among women under the age of 40. This trend has puzzled reproductive health experts, prompting urgent research into its causes.

Researchers from UCI Health now report a strong correlation between this surge in endometrial cancer among younger women and the rapidly increasing obesity rates. They argue that this trend demands immediate public health interventions to reverse the alarming trajectory.

Between 2001 and 2018, cases of endometrial adenocarcinoma—the most common form of endometrial cancer—rose by 137% among women aged 20 to 29, and by 71% among those aged 30 to 39, according to data presented at a recent American Society of Clinical Oncology (ASCO) conference. The increases were even more pronounced among younger Black women and Latinas.

Over the same period, obesity rates surged, rising by 7.5% per year among women aged 20 to 29, and by 4.5% annually among those aged 30 to 39, the study revealed.

A Public Health Emergency

“Endometrial cancer is the most common gynaecological cancer encountered in the United States,” notes Dr Krishnansu Tewari, a UCI Health gynaecologic oncologist and co-author of the study.

Once primarily seen in older women, endometrial adenocarcinoma is now the sixth most common cancer in women overall, and it is becoming increasingly deadly. It is projected to cause more than 13,000 deaths this year, up from 3,000 annual deaths in the late 1980s.

“This represents a public health emergency,” states Dr Alex Francoeur, the lead author of the study. Francoeur emphasises the need for a concerted effort to educate women and healthcare providers about the risks posed by obesity in developing endometrial adenocarcinoma.

Analysing Two Decades of Data

The retrospective study analysed data from more than 580,000 cases of endometrial adenocarcinoma in the U.S. over the last two decades. Researchers then compared these findings with data on obesity rates among women over the same period.

The results revealed a particularly strong link between rising obesity rates and increased incidences of cancer in younger women, especially women of colour.

“When examining trends by race and ethnicity, we found that the rate of endometrial cancer in Black women has increased by 25% since 2001, and by 17% in Hispanic women,” says Francoeur, who is a gynaecologic oncology fellow at the UCI School of Medicine’s Department of Obstetrics & Gynaecology.

Although further research is needed to establish a direct causal link, the study’s data strongly suggest the need for targeted public health initiatives aimed at educating women and reducing obesity rates.

Raising Awareness is Key

“Action is needed to address the impact of obesity on endometrial cancer,” Francoeur stresses. She advocates for the following measures:

1. Raising awareness: “Sharing this information with gynaecology patients and providing early education on the risk factors associated with obesity and reproductive health is crucial.”
2. Encouraging weight management: “Discussions about weight should become a routine part of health maintenance, similar to the way cervical cancer screenings and mammography are standard components of preventive care.”

Francoeur highlights that there are many ways for individuals to receive support, including consulting a dietitian, considering medications that target weight loss, and exploring surgical options to manage obesity.

Fertility-Sparing Treatment Options

For individuals of childbearing age diagnosed with endometrial cancer, surgery is not always the only treatment option.

“With early-stage endometrial cancers, we can often manage the disease with hormone therapy, allowing patients to preserve their ability to conceive,” explains Tewari, who is also a professor and chief of the Division of Gynaecologic Oncology in the Department of Obstetrics & Gynaecology.

Progestin therapy, a hormone treatment, can sometimes be used to shrink or eliminate the cancer temporarily in those wishing to maintain fertility. The most commonly used medications in this treatment are:

1. Medroxyprogesterone acetate, administered as an injection or a pill.
2. Megestrol acetate, available as a pill or liquid.

However, Tewari cautions that this approach is not yet a standard treatment and may increase the risk of cancer progression. “It’s vital to confirm the grade of the cancer with a gynaecologic oncologist and a pathologist, and to consult with a fertility specialist before beginning progestin therapy,” he advises.