Glucagon-like peptide-1 receptor agonists (GLP-1 RAs) are now widely used to treat overweight, obesity and type 2 diabetes (T2DM), with growing evidence of benefits that extend beyond blood sugar control.

In asthma, where overweight, obesity and metabolic dysfunction can lead to increased severity of symptoms and adverse events such as acute exacerbations, the authors suggest that GLP-1 RAs may improve asthma outcomes through weight loss, modulation of airway inflammation, and improvements in metabolic functions. Reductions in occurrence of asthma exacerbations are likely to reduce systemic corticosteroid exposure (a common treatment for acute asthma exacerbations orally or intravenously) and thus may reduce the risk of corticosteroid exposure-associated adverse events such as osteoporosis or new-onset T2DM. As such, as the clinical use of GLP-1 RAs expands, reliable estimates of their impact on asthma control are needed for individuals living with both asthma and overweight, obesity or T2DM.

The researchers conducted a nationwide self-controlled cohort study using linked Danish health registers. Adult individuals with a prior asthma diagnosis or ≥2 asthma inhaler prescriptions redeemed within 12 months) were included on the date of their first GLP-1 RA dispensing (index date). Eligible individuals had continuous registration data for at least 12 months before and after the index date.

Individuals with COPD or patients with severe asthma treated with new and relatively expensive biologic drugs within 12 months before or after the index date were excluded. Overweight or obesity was defined using ICD-10 codes for those conditions. Those who had no evidence of T2DM – with no diagnosis recorded or no evidence of other first line diabetes drugs prescribed – were also placed in the with obesity/overweight group. Those with a T2DM diagnosis or prescriptions recorded for first line diabetes drugs such as metformin were placed in the T2DM group.

The primary outcome was exacerbations, defined as an inpatient asthma hospital contact(s) and/or systemic oral or intravenous corticosteroid course(s). Secondary outcomes were the use of rescue medication (inhaled short-acting β2-agonists), inhaled corticosteroid exposure, and chest infection events defined as redemption of antibiotics commonly used for lower airway infections

The cohort comprised 27,523 individuals (mean age 54 years, 66% female) with asthma and comorbid overweight or obesity (49%) or T2DM (61%) and 26% recorded as having both conditions. Around 50% of the GLP-1 prescriptions were liraglutide, 48% semaglutide, and 2% others (exenatide, dulaglutide, lixisenatide).

Compared with the year before GLP-1 RA treatment, GLP-1 RA treatment was associated with a 26% lower exacerbation rate overall; and 28% lower in men compared with 23% lower in women. When stratified according to GLP1 RA treatment indication, the analysis showed individuals with asthma and comorbid overweight or obesity and individuals with asthma and comorbid T2DM had similar effect estimates – a 22% reduction in those with overweight or obesity and a 26% reduction in those with T2D.

Reliever medication use fell by 14% overall, suggesting fewer symptoms despite daily inhaled corticosteroid exposure also decreasing by 23% (inhaled corticosteroids are used to prevent exacerbations and treat symptoms in asthma). Furthermore, pneumonia events were reduced by 10%. People also living with allergic rhinitis saw similar decreases (23%) in exacerbations to those living without allergic rhinitis (28%). The authors are also working on updated analyses to show differences between men and women for these specific outcomes.

The authors conclude: “In this nationwide cohort of over 27,000 individuals with asthma and also overweight, obesity or type 2 diabetes, use of GLP-1 drugs  was associated with significant reductions in exacerbation burden as well as reliever use, exposure to inhaled corticosteroids and pneumonia events, irrespective of whether the drugs were being used to treat obesity or type 2 diabetes.”

The authors explain that their study did not have access to clinical records (just if people had used GLP-1 and hospital admissions), so data on BMI and weight loss for participants were not available.

But Dr Håkansson says: “There’s a high chance that the weight loss is a major contributor to these results. A common symptom in both asthma and obesity is shortness of breath, and the presence of excess fatty tissue creates a pro-inflammatory state in the body in general. There’s also evidence from other studies suggesting that the inflammation caused by excess adipose tissue is distinct from the ‘classic’ asthma inflammation which often is driven by allergies or cells called eosinophils.”

And he adds: “As the use of GLP-1 therapies increase, researchers are finding an increasing number of effects outside of weight loss.”

Obesity has a wide range of potential underlying causes, including mental and psychosocial factors. These factors include financial difficulties, mental stress and loneliness. This study aimed to examine whether these factors occur differently between people with normal weight, overweight or obesity.

The authors used data from the Dutch version of the online screening tool CheckCausesObesity.com This screening tool identifies possible underlying causes of obesity based on international guideline- and evidence-based algorithms. This is an online screening tool that helps identify the underlying causes of obesity in an individual. It systematically maps lifestyle factors, biological, psychological, social, and medication-related factors, as well as more rare medical (eg genetic) causes and also comorbidities, using guideline-based algorithms. All factors are explored in depth through detailed patient input. As part of a comprehensive assessment of multiple lifestyle factors, hormonal, genetic and medical factors which can contribute to overweight, this tool also includes questions about financial problems, loneliness and stress, as well as sex, weight, height and birthyear, enabling the researchers to calculate BMI and age. Patients complete the questions in this screening tool at home, and the results support a more personalized and medically informed treatment approach.

Statistical modelling was performed to explore the associations between financial problems, loneliness, stress and BMI classes (normal weight (BMI 20-24.9 kg/m²), overweight (BMI 25-29.9 kg/m²), obesity class 1 (BMI 30-34.9 kg/m²), obesity class 2 (BMI 35-39.9 kg/m²), and obesity class 3 (BMI ≥40 kg/m2)). Thereafter, statistical analyses were performed, adjusting for age and sex. Finally, potential sex differences in the results were assessed.

The screening tool was completed by 44.407 adults, between June 2024 and November 2025. Mean age was 52 years and the majority were female (76.7%). All the results reported below were statistically significant. The authors looked first at financial difficulties, which were present in 5.4% of the respondents with no difference between men and women. A higher proportion of respondents indicated having financial problems with increasing BMI (normal weight: 4.3%, overweight: 4.7%, obesity class 1: 5.0%, obesity class 2: 6.0% and obesity class 3: 7.2%). Respondents without financial problems had a lower BMI than those indicating they had financial problems (mean BMI: 33.2 kg/m² and 34.5 kg/m²). The association between financial issues and BMI was comparable between men and women.

Secondly, they examined stress, which was reported more frequently by women (34.5%) than by men (22.5%). Respondents experienced more stress with increasing BMI (normal weight: 27.5%, overweight: 28.6%, obesity class 1: 31.2%, obesity class 2: 34.3% and obesity class 3: 37.3%). Accordingly, respondents indicating experiencing stress had a higher mean BMI compared to those without stress (mean BMI: 34.0 kg/m² and BMI: 33.1 kg/m² respectively). This association did not differ between men and women. To explore the reasons underlying respondents’ stress, participants could elaborate on their stress experiences. These qualitative responses were analysed and organised into clusters representing the most frequently reported stress domains. According to these clusters, the three most experienced stress domains were work-related, focused on general well-being or concerns about family-members.

Thirdly, loneliness was more often reported in women (8.7%) than in men (6.3%), and more prevalent among respondents with increasing class of obesity (normal weight: 7.7%, overweight: 7.0%, obesity class 1: 7.6%, obesity class 2: 8.5%, obesity class 3: 11.7%). In addition, individuals who reported loneliness had a higher BMI (mean BMI 34.5 kg/m²) than those without loneliness (mean BMI 33.3 kg/m²). Interestingly, the results suggest that loneliness is more strongly associated with a higher BMI in men than in women.

The authors conclude: “This study shows that higher BMI is associated with more financial problems, loneliness, and stress. These relationships may be bidirectional. On the one hand, higher BMI may contribute to stigma and social isolation, reduced work capacity, and increased healthcare costs. On the other hand, financial strain, chronic stress and social isolation may influence lifestyle coping behaviours, and even biological processes that promote weight gain. Broader environmental factors may further reinforce these patterns. Further research is needed to better understand these mechanisms and to inform prevention and support strategies for individuals facing financial difficulties, mental stress, and loneliness in the context of obesity.

The warning label currently required on alcohol containers in the United States has not changed since its adoption in 1988, despite new evidence linking alcohol to several diseases. The label states the risks of drinking during pregnancy and while driving or operating machinery and warns generally that drinking alcohol “may cause health problems.” The label often goes unnoticed and unremembered by consumers.

“We wanted to test whether new warnings could better inform consumers about alcohol’s harms and better encourage people to consider cutting back on their drinking,” says lead author Anna H. Grummon, Ph.D., M.S.P.H., assistant professor at the Stanford University School of Medicine. The study was conducted as part of a larger project co-led with Marissa G. Hall, Ph.D., associate professor at the University of North Carolina.

Designed to compare the effects of differently worded and designed warning labels, the study recruited a nationally representative sample of 1,036 adults of legal drinking age (21 and older) who reported drinking at least once a week.

Participants viewed 10 messages — one control, eight new warning labels, and the current U.S. warning label — in random order. They then rated each message on how well it encouraged them to drink less alcohol, reminded them of alcohol’s harms, and informed them of something new.

“Each participant rated multiple warnings covering a range of health harms — such as cancer, liver disease, hypertension, and dementia, among others — so we could make direct, apples-to-apples comparisons between them,” says Grummon.

All the new alcohol warnings in the study outperformed the current U.S. warning label, but those highlighting cancer risk were particularly effective. This finding is notable as policymakers in the United States and abroad debate whether to adopt a cancer warning on alcohol products.

“Ireland, for example, is set to require cancer warnings on alcohol containers in the coming years, and Alaska already requires a cancer warning to be posted in bars, restaurants, and liquor stores where alcohol is sold,” says Grummon. “Our findings suggest these policies could help people understand the risks of drinking and potentially reduce consumption.”

Study participants also rated the effectiveness of warning icons and label design. Triangles and octagons were perceived as more effective and attention-grabbing than other icons, such as a magnifying glass.

More research is underway. Grummon and Hall are currently running a randomized trial to test whether new alcohol warnings effectively lead people to drink less. The study will also measure whether the warnings improve knowledge of alcohol-related harms over time.

“We know from tobacco control that well-designed warnings can inform consumers and encourage healthier choices,” says Grummon. “Given that alcohol-related deaths are increasing, we hope policymakers will consider whether updating alcohol warnings should be part of a broader strategy to address alcohol-related harms.”
—–
Grummon, A. H., Lee, C. J. Y., Campos, A. D., Lazard, A. J., Brewer, N. T., Whitesell, C., Ruggles, P. R., Greenfield, T. K., & Hall, M. G. (2026). New alcohol warnings outperform the current U.S. warning in a national survey experiment. Journal of Studies on Alcohol and Drugs, 87(3), 433-443. https://doi.org/10.15288/jsad.25-00226

By W.B. Kagan

image: “Government warning” alcohol label

View more Credit: Journal of Studies on Alcohol and Drugs

The purchasing and consumption of foods high in energy, saturated fat, free sugars, and salt, is associated with an increased risk of obesity and diet-related non-communicable diseases. In recent years, the UK Government has set a series of voluntary targets for manufacturers, retailers, and restaurants to reduce the sugar, salt, and calorie content of food. The sugar targets were intended to be met by 2020, the salt targets by 2024, and the calorie targets by 2025. Few studies have assessed the nutritional quality of foods in the restaurant sector, despite an increasing percentage of weekly food intake coming from takeaway or restaurant meals.

In the new study, researchers gathered nutritional information from the 21 highest-grossing restaurant chains in the UK in 2024, using PDF menus or nutritional information on restaurant websites. They calculated the proportion of menu items from each restaurant and food subcategory that met the nutritional targets. Nine of the 21 restaurants had more than half of their menu items meeting all applicable targets. Menu items from Papa John’s were the lowest adhering to the calorie (35%) and salt (8%) targets, while menu items from Burger King, KFC, Nando’s, and Vintage Inns had zero adherence to the sugar targets.

Food within the same subcategory varied in adherence to the targets, with salads and breakfast items having the highest overall adherence, and desserts and pizzas the lowest. However, there were examples of companies across all subcategories performing well, indicating that performance is not constrained by the type of cuisine being offered.

“Our findings demonstrate that there was low adherence to the UK Government’s sugar, salt, and calorie reduction targets in 2024,” the authors say. “This is consistent with other research that finds limited effectiveness of voluntary regulation on reformulation, suggesting that mandatory regulation may be a more effective approach to improving the nutritional quality of out-of-home food.”

Alice O’Hagan adds, “Our study shows that the UK Government’s voluntary sugar, salt, and calorie reduction targets were not being met consistently across the highest-grossing UK restaurant chains, in 2024. Only 43% of menu items met all of the targets they were eligible for, and adherence to the targets varied widely between restaurants and food categories, showing that healthier menus are achievable but are not yet the norm.”

“Interestingly, restaurants with similar menu styles performed quite differently in meeting the targets. This shows the nutritional quality of menus is not fixed by cuisine type, making the shift towards healthier menus a more attainable goal for food companies.”

Co-author Lauren Bandy adds, “Voluntary targets alone are not delivering consistent improvements in the salt, sugar or calorie content of food items on offer in UK restaurants. Our findings highlight the potential value of stricter regulation in the out-of-home sector, and show that improving transparency and accountability of individual food companies will be key in supporting healthier food provision for the UK population.”

Freely available paper in PLOS Medicine: https://plos.io/4bNeHl9

Citation: O’Hagan A, Pechey R, Forde H, Bandy L (2026) Adherence to voluntary UK sugar, salt, and calorie reduction targets in the highest-grossing restaurant chains: A cross-sectional study. PLoS Med 23(5): e1004681. https://doi.org/10.1371/journal.pmed.1004681

Author countries: United Kingdom

Funding: AOH and RP are supported by the NIHR Oxford Health Biomedical Research Centre (https://oxfordhealthbrc.nihr.ac.uk/). RP is also supported by the Royal Society and Wellcome Trust (Sir Henry Dale fellowship; 222566/Z/21/Z; https://www.royalsociety.org/grants/henry-dale/). HF is funded by the SHIFT: Sustainable and Healthy Interventions for Food Transitions project, which is funded by the Wellcome Trust (grant reference 227132/Z/23/Z; https://wellcome.org/research-funding/funding-portfolio/funded-grants/shift-sustainable-and-healthy-interventions-food), and by the COPPER project, which is funded by the National Institute for Health and Care Research (NIHR) Public Health Research programme (grant reference NIHR133887; https://fundingawards.nihr.ac.uk/award/NIHR133887). LB is supported by the NIHR Applied Research Collaboration (ARC) Oxford and Thames Valley (https://www.arc-oxtv.nihr.ac.uk/). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.

Image: Dan Gold, Unsplash (CC0, https://creativecommons.org/publicdomain/zero/1.0/)

Individuals in Cluster 5 Remain at High Diabetes Risk Despite Lifestyle Changes

The study was based on data from the Tübingen Lifestyle Intervention Program (TULIP). Participants with an increased risk of type 2 diabetes completed a two-year lifestyle intervention and were subsequently followed for approximately nine years. The analysis focused on individuals who were able to achieve substantial and sustained long-term weight reduction.

“We were particularly interested in whether individuals in risk clusters 3 and 5 differed from those in other clusters with regard to improvements in blood glucose levels and the prevention of type 2 diabetes,” explains Professor Norbert Stefan, the lead author of the study. “We were very surprised to find that, despite a large and sustained weight loss of 8% and after a very long follow-up period of 9 years, individuals in risk cluster 5 showed increasing blood glucose levels, declining insulin secretion, and a persistently high risk of type 2 diabetes.”

Fatty Liver and Insulin Resistance May Explain the Findings

Why does lifestyle intervention protect individuals in risk cluster 5 less effectively against diabetes? The authors examined mechanisms that could explain the unfavorable metabolic trajectory observed in this group. Their data suggest that insulin resistance—most likely caused by pronounced fatty liver disease and fatty liver–related impairment of insulin secretion from pancreatic beta cells—led to rising blood glucose levels in individuals in cluster 5.

These findings are consistent with earlier observations showing that fatty liver disease and insulin resistance are the dominant pathophysiological mechanisms in individuals classified in Tübingen’s type 2 diabetes risk cluster 5, making them particularly susceptible to type 2 diabetes and cardiovascular disease.

Precision Prevention Strategies Are Needed

The present results indicate that individuals in risk cluster 5 do not benefit to the same extent from lifestyle interventions as those in other clusters, even with significant and sustained weight loss—particularly with respect to glucose metabolism. If these findings are confirmed in a prospective study, a more tailored approach to diabetes prevention will be required, in which high-risk phenotypes such as cluster 5 may need more intensive or targeted interventions.

* Wagner R, …, Häring HU, Fritsche A. Pathophysiology-based subphenotyping of individuals at elevated risk for type 2 diabetes. Nat Med. 2021 Jan;27(1):49-57. doi: 10.1038/s41591-020-1116-9. Epub 2021 Jan 4. PMID: 33398163.

In 2024, the FDA updated the definition of the term “healthy” as it relates to how manufacturers can use the word on food packages. The new definition replaced one from 1992 and is consistent with current nutrition science and federal dietary guidance.

Also for the first time, the agency proposed an “FDA healthy” label icon for food packages, which is still undergoing approval.

The new study, led by researchers at Oregon State University and Tufts University, examined consumer purchasing preferences for snack products with and without healthy labels, focusing on the new FDA definition and healthy symbol to understand how endorsement from a regulator, such as the FDA, shapes consumer choices.

“Our main finding is that trust in government was an important part for people and that they were willing to pay more for that label,” said lead author Katherine Fuller, an assistant professor at Oregon State University who studies consumer behavior, particularly in the context of food and sustainability.

Fuller noted that the finding mirrors past research related to the USDA “organic” label, which has also been associated with a premium price.

For the new study, published in Food Quality and Preference, the researchers conducted an experiment in 2023 with 267 shoppers in person at six grocery stores in the Boston area. In the stores, participants were given tablets and shown pictures of 15 real-world products, nine of which were considered healthy and six that were not.

Participants first viewed products without any special healthy label and then viewed the same products, with those products meeting the new FDA “healthy” standards bearing either a generic healthy label or the FDA-healthy label. Participants received $5 in cash and a $10 gift card from the store. They were informed that the $5 could be applied toward the purchase of a product they selected in one of the scenarios they were presented. This procedure ensured the participants’ decisions had real economic consequences.

“Giving study participants purchasing power in a setting that mirrored a real shopping experience let us better observe how the labels might influence behavior,” said senior author Sean Cash, chair of the Division of Agriculture, Food and Environment at the Gerald J. and Dorothy R. Friedman School of Nutrition Science and Policy at Tufts University and an economist studying food policy and consumer behavior.

Each participant also completed a survey providing information about their demographics, knowledge of healthy food options and levels of generalized trust and trust in government.

Research findings from the study included:

• Consumers were more likely to choose the healthy snacks over unhealthy options.
• Consumers’ preference for healthy snacks increased when products were labeled with healthy icons. While the FDA and generic labels were associated with higher selection of healthy snacks, only the FDA label had a statistically significant effect.
• Prior findings that consumers are willing to pay more for labeled healthy foods were confirmed, and, additionally, the new results showed that adding a healthy label increases this premium further. For example, consumers were willing to pay 59 cents more on average for a healthy product with an FDA-endorsed label compared to a product with no label.
• The stronger effect of the FDA label reflects the role of perceived institutional credibility. These results are consistent with previous studies that demonstrate institutionally credible labels more effectively shape consumer decisions.
• The effectiveness of the FDA’s healthy label varied with the degree to which consumers indicated they trusted the government.

“Our findings demonstrate that labels act as signals for consumers, and policy can shape how well those signals work,” said Cash. “When labels are viewed as credible, such as when they have the endorsement of a government agency, they are more likely to influence eating patterns and purchasing habits.”

“Right now, there is a lot of misinformation about what is healthy and what isn’t healthy,” Fuller added. “Having a clear label, supported by scientific research, saying this is healthy because we checked, is important.”

Co-authors of the paper are Julia Reedy Sharib, Bingbing Fan and Dariush Mozaffarian, of the Friedman School at Tufts University, and Jennifer L. Pomeranz, of New York University.

Citation and Disclaimer: Research reported in this article was supported by the National Institutes of Health’s National Heart, Lung, and Blood Institute under award number R01HL115189. Complete information on authors, funders, limitations, methodology and conflicts of interest is available in the published paper. The content is solely the responsibility of the authors and does not necessarily represent the official views of the funders.

Diabetes and obesity have long been linked to an increased risk of mental health symptoms. Similarly, individuals with mental disorders have an elevated risk of metabolic diseases such as obesity and diabetes. Researchers have working to disentangle the connections between these conditions.

Previous evidence on the effects of GLP-1 medications on anxiety and depressive disorders has been somewhat inconsistent, but it has been largely based on small studies. The new paper, published in The Lancet Psychiatry, includes data from nearly 100,000 participants, over 20,000 of whom had used GLP-1 medications to treat diabetes and obesity. Participants were followed through Swedish national registers between 2009 and 2022.

The results showed that the use of GLP-1 medications – particularly semaglutide – was associated with a reduction in workplace absence and in lower rates of hospital care for psychiatric issues. During periods of semaglutide use, the reduction was 42% compared with periods when GLP-1 medications were not used. For depression, the risk was 44% lower, and for anxiety disorders, 38% lower.

In addition, semaglutide use was associated with a lower risk of substance use disorders: hospital care and sickness absence related to substance use were 47% lower during periods of semaglutide use compared with periods without GLP-1 medication. The use of GLP-1 receptor agonists was also associated with a reduced risk of suicidal behaviour.

One of the study’s authors, Professor Mark Taylor from Griffith University, says such results were to be expected: ‘An earlier study examining Swedish registers found the use of GLP-1 medications to be associated with a reduced risk of alcohol use disorder. Alcohol-related problems often have downstream effects on mood and anxiety, so we expected the effect to be positive on these as well.’

However, the magnitude of the association surprised the researchers. ‘Because this is a registry-based study, we cannot determine exactly why or how these medications affect mood symptoms, but the association was quite strong,’ says Prof Markku Lähteenvuo from the University of Eastern Finland. ‘It is possible that, in addition to factors such as reduced alcohol consumption, weight loss-related improvements in body image, or relief associated with better glycaemic control in diabetes, there may also be direct neurobiological mechanisms involved – for example, through changes in the functioning of the brain’s reward system.’

Sugary drink taxes have been adopted in several U.S. jurisdictions as a public health strategy to curb sugar consumption and improve dietary behaviors. Research on the impact of these taxes on grocery stores purchases attribute sugary drink taxes to an estimated 15% decrease in sales. However, whether this translates to an impact in restaurant sales has not been well studied.

Researchers analyzed six years of sales data (2015–2020) from more than 7,300 Taco Bell locations nationwide, focusing on drive‑through purchases. The study compared beverage calories per transaction at 60 restaurants across five jurisdictions with sugary drink taxes—Albany, California; Cook County, Illinois; Oakland, California; Philadelphia, Pennsylvania; and Seattle, Washington—with a matched group of similar restaurants in areas without such taxes.

Overall, the analysis found no significant association between sugary drink taxes and beverage calories per transaction, suggesting that sugary drink taxes of this size or alone may not substantially reduce beverage calorie consumption in fast food restaurant settings.

The authors note that consumer behavior in restaurants—such as choosing combo meals or prioritizing convenience—may limit the effectiveness of these policies.

Elbel adds, “Using millions of transactions from six years of sales data, we found that sugary beverage taxes did not influence beverage calories when implemented in five cities in the U.S.”

Rummo notes, “These results suggest that sugary drink taxes may not be effective in reducing beverage calorie consumption in fast food restaurants, as compared to supermarkets. This could be because the sizes of sugary drink taxes in the U.S. are too small for consumers or that they just aren’t responsive to price changes in these settings, among other reasons.”

In your coverage, please use this URL to provide access to the freely available paper in PLOS Medicine: https://plos.io/4sFufx5

Citation: Rummo PE, Echenique JA, Wu E, Mijanovich T, Desai SM, Bragg MA, et al. (2026) Impact of sugary drink taxes on beverage calories purchased in a national fast food restaurant chain: A quasi-experimental study. PLoS Med 23(4): e1004642. https://doi.org/10.1371/journal.pmed.1004642

Author countries: United States of America

Funding: This work was supported by the National Heart, Lung, and Blood Institute of the National Institutes of Health, grant number 5R01HL147474 (PER, JAE, EW, TM, SM, MAB, BCW, BE). The funder had no role in the study design, data collection and analysis, decision to publish, or preparation of the manuscript. Taco Bell was aware of the research question before agreeing to data sharing but did not sponsor this study and had no role in the study design, data collection and analysis, decision to publish, or preparation of the manuscript.

In the past few years there has been a lot of criticism of the BMI system due to its inability to accurately capture body fat percentage or distribution, in order to correctly categorise weight status based on adiposity explains Professor Marwan El Ghoch, of the Department of Biomedical, Metabolic and Neural Sciences, University of Modena and Reggio Emilia, Modena, Italy.  He adds that, despite these concerns, BMI as a weight classification system continues to be used in the general population in primary healthcare (i.e. general practitioners) and non-clinical (i.e. policy and health insurance) settings.

In this new study, Professor El Ghoch and researchers from the University of Verona in Italy and Beirut University in Lebanon set out to determine the validity of the BMI classification system, specifically regarding its ability to identify correctly those with overweight and obesity, in a sample of the general population who had all had their body fat measured using DXA. With DXA, the person’s age and body fat percentage is used to decide their weight status category according to their level of adiposity.*

The study included 1351 adults of mixed gender aged between 18 and 98 years (60% female) all of whom were referred to the Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, Verona, Italy. All the participants in this study where White Caucasian (due to BMI variations in different ethnicities).

According to the WHO BMI system, among these participants there were 19 (1.4%) underweight individuals (BMI under 18.5), 787 (58.3%) normal weight (BMI 18.5-25), 354 (26.2%) with overweight (BMI 25-30), and 191 (14.1%) with obesity (BMI over 30). The overall prevalence of approximately 41% for overweight and obesity combined is consistent with the local population in the Veneto region of Italy. Participants were then re-categorised according to adiposity based on body fat percentage (BF%) measured by DXA.

DXA revealed that more than one third (34%) of those with obesity defined by BMI had been misclassified and should be in the overweight category. For those with an overweight BMI, DXA showed that more than half – 53% – had been misclassified – three quarters of those misclassified fall into the normal weight category, while the other quarter should have been classified as having obesity.

BMI and DXA had better agreement when considering those with a normal weight BMI (18.5 to 25), with DXA agreeing in 78% of cases. But 22% of those with normal weight were given a different category with DXA (9.7% underweight, 11.4% overweight and 0.8% obesity). Finally, despite the small absolute numbers, the biggest BMI-DXA disagreement was found in the underweight group – two thirds (13 of 19; 68.4%) in the underweight category defined by BMI (under 18.5) were in the wrong category when analysed by DXA – and should have been classified as having normal weight.

With all the correct and misclassifications combined, the DXA analysis found that the prevalence of overweight and obesity across the cohort was at around 37% overall (23.4% overweight, and 13.2% obesity, compared to 26.2% and 14.1% with BMI).

Professor El Ghoch, who led the study, says: “Our main finding highlights the fact that a large proportion of individuals, exceeding one-third of adults among the Italian general population, is misclassified and placed in an incorrect weight status category, when relying on the traditional WHO BMI classification resulting in an overestimation of the prevalence of underweight, overweight, and obesity when compared to the classification based on body fat percentage as measured by the gold standard technique of dual-energy X-ray absorptiometry (DXA).”

Study co-author, Professor Chiara Milanese, of the University of Verona, adds: “Another key finding of our study is that, even though both systems identify a similar overall prevalence of overweight and obesity,  we are talking in some cases about different people – or in other words the individuals identified by DXA are not all the same as those from BMI classification. This is due to the disagreement between WHO BMI and DXA-derived BF% classification systems in determining weight status in the general population among body weight ranges and age groups of both genders.”

Accordingly, the authors conclude: “Public health guidelines in Italy need to be revised to consider combining direct body composition or their surrogate measures such as skinfold measurement or body circumference – such as the waist-to-height ratio – with BMI while assessing weight status in the general population. We believe a similar level of misclassification can be expected in White Caucasian populations in other countries in Europe and Worldwide. However, to confirm this, and if a similar effect exists in other ethnicities, future research should extend the aim of our analysis to other countries across Europe and globally, as well as seeing if such misclassification occurs in people of other ethnicities.”

Professor Marwan El Ghoch, University of Modena and Reggio Emilia, Modena, Italy. T) +39 0592055371 E) m.elghoch@unimore.it

Tony Kirby in the ECO Media Centre. T) +44 7834 385827 E) tony.kirby@tonykirby.com

The authors confirm no conflicts of interest.

This press release is based on oral presentation 0360 at the European Congress on Obesity (ECO) in Istanbul, Turkey, 12-15 May. The material has been peer reviewed by the congress selection committee. The full paper has been published in the journal Nutrients. As such, the full paper is provided in place of the abstract.

The following thresholds are used in DXA – body fat values to give weight status:

For males:

18–39 years BF% < 8% (underweight); ≥8% (normal weight); ≥21% (overweight); ≥26% (obesity); 40–59 years BF% < 11% (underweight); ≥11% (normal weight); ≥23% (overweight); ≥29% (obesity) 60–98 years BF% < 13% (underweight); ≥13% (normal weight); ≥25% (overweight); ≥31% (obesity).

For females:

18–39 years BF% < 21% (underweight); ≥21% (normal weight); ≥33% (overweight); ≥39% (obesity); 40–59 years BF% < 23% (underweight); ≥23% (normal weight); ≥35% (overweight); ≥41% (obesity); 60–98 years BF% < 26% (underweight); ≥26% (normal weight); ≥36% (overweight); ≥41% (obesity).

For full paper, click here

The study, published in the journal Health Psychology, found that adults who followed more routine eating patterns, such as repeating the same meals and keeping calorie intake steady over time, lost more weight during a 12-week behavioral weight loss program than those who ate a more varied diet.

“Maintaining a healthy diet in today’s food environment requires constant effort and self-control,” said lead author Charlotte Hagerman, PhD, of the Oregon Research Institute. “Creating routines around eating may reduce that burden and make healthy choices feel more automatic.”

Researchers analyzed detailed, real-time food logs from 112 overweight or obese adults who were enrolled in a structured behavioral weight loss program. Participants were asked to track everything they ate each day using a mobile app, along with daily weigh-ins using a wireless scale. To ensure the data reflected consistent habits, researchers focused on the first 12 weeks of the program — a period when participants are typically most engaged and accurate in tracking their food intake.

The researchers then measured how “routinized” each person’s diet was in two ways. First, they looked at caloric stability, or how much a person’s daily calorie intake fluctuated from day to day and between weekdays and weekends. Second, they examined dietary repetition, tracking how often participants logged the same meals and snacks over time, rather than constantly choosing new foods.

In the end, those who repeated many of the same foods rather than eating a wide variety lost an average of 5.9% of their body weight, compared with 4.3% among those whose diets were more varied. The study also found that greater day-to-day calorie consistency was linked to better results. For every 100-calorie increase in daily fluctuation, weight loss decreased by about 0.6% over the study period.

The findings suggest that simplifying food choices, such as creating a rotation of go-to meals and maintaining a steady calorie intake, may help people build sustainable habits in a challenging food environment. However, the researchers caution that the study shows a correlation, not cause and effect, and that factors like motivation or self-discipline may also play a role.

The authors also acknowledge that previous research has linked dietary variety with better health status. However, these studies have mostly focused on dietary variety within healthy food groups, like fruits and vegetables. “If we lived in a healthier food environment, we might encourage people to have as much variety in their diet as possible,” Hagerman said. “However, our modern food environment is too problematic. Instead, people may do best with a more repetitive diet that helps them consistently make healthier choices, even if they might sacrifice some nutritional variety.”

One unexpected finding of the study was that participants who logged higher calorie totals on weekends compared with weekdays also lost more weight. Hagerman said this most likely reflects stronger tracking habits rather than higher food intake, since people often are not as consistent with their tracking on weekends.

Still, says Hagerman, the takeaway is straightforward: when it comes to weight loss, consistency may matter more than variety.

Article: “Do Routinized Eating Behaviors Support Weight Loss? An Examination of Food Logs from Behavioral Weight Loss Participants,” by Charlotte Hagerman, PhD, Oregon Research Institute; Asher E. Hong, B.S., Drexel University; Nicole T. Crane, PhD, Drexel University; Meghan L. Butryn, PhD, Drexel University; Evan M. Forman, PhD, Drexel University. Health Psychology, published online March 26, 2026.

Contact: Charlotte Hagerman, PhD, can be reached at chagerman@ori.org.

The American Psychological Association, in Washington, D.C., is the largest scientific and professional organization representing psychology in the United States. APA’s membership includes 190,000 researchers, educators, clinicians, consultants and students. Through its divisions in 54 subfields of psychology and affiliations with 60 state, territorial and Canadian provincial associations, APA works to advance the creation, communication and application of psychological knowledge to benefit society and improve lives.

The research, published in the Journal of Medical Internet Research, established a significant and consistent association between Problematic Smartphone Use (PSU) – whereby an individual becomes behaviorally or psychologically reliant on their smartphone – and eating disorder symptom severity. Researchers argue this highlights the need for early intervention strategies specific to excessive phone use for young people displaying eating disorder symptoms.

While there has been research conducted into the negative impact that problematic internet usage, exposure to social media, and harmful online content can have on body image and body dysphoria in both clinical and non-clinical populations, none have specifically examined PSU.

Researchers identified 35 studies in which to include in this systematic review. The studies were from across the globe and provided researchers with a sample size of 52,584 participants with an average age of 17.

Their analysis of the data found that higher daily smartphone use was also related to greater food addiction symptoms, broader disordered eating behaviours like uncontrolled eating or emotional overeating, and body dissatisfaction in people with no diagnosis of an eating disorder. The association was particularly strong in those who use their phones for more than seven hours a day.

Ben Carter, Professor of Medical Statistics at King’s IoPPN and the study’s senior author said, “Smartphones have become ubiquitous in our everyday lives. It is apparent from our study that, even for people without a diagnosis of an eating disorder, the overuse of a smartphone is associated with poor body satisfaction and altered eating behaviours, and is a potential source of distress”

Dr Johanna Keeler, a Visiting Lecturer at King’s IoPPN and the study’s first author said, “Adolescence is a key stage of development as individuals evolve their sense of self by observing others. While smartphones might present an easy way for this to happen, being consistently exposed to idealised images can lead them to compare their own appearance with these “standards”, leading to poor self-esteem and appearance dissatisfaction – both risk factors for the development of an eating disorder.”

For more information, please contact Patrick O’Brien (Media Manager) on +44 020 7848 5377.

Problematic smartphone use and smartphone screen time are associated with eating disorder psychopathology in non-clinical samples: a systematic review (DOI )(Keeler, Carter et al) was published in the Journal of Internet Medical Research.

1. “Problematic Smartphone Use” is not “smartphone addiction” and should not be used interchangeably. While smartphone users can demonstrate addictive behaviours, significantly more research is required before the “addiction” moniker can be applied.

About King’s College London and the Institute of Psychiatry, Psychology & Neuroscience

King’s College London is amongst the top 35 universities in the world and 5th best in the UK (QS World University Rankings 2026), and one of England’s oldest and most prestigious universities. With an outstanding reputation for world-class teaching and cutting-edge research, King’s maintained its sixth position for ‘research power’ in the UK (2021 Research Excellence Framework).

King’s has more than 42,000 students (including more than 12,800 postgraduates) from some 190 countries worldwide, and 8,500 staff.

For nearly 200 years, King’s students and staff have used their knowledge and insight to make a positive impact on people, society and the planet. Focused on delivering positive change at home in London, across the UK and around the world, King’s is building on its history of addressing the world’s most urgent challenges head on to accelerate progress, make discoveries and pioneer innovation. Visit the website to find out more about Vision 2029, which sets out bold ambitions for the future of King’s as we look towards our 200th anniversary. World-changing ideas. Life-changing impact: kcl.ac.uk/news

In a large, randomized trial, researchers at Mass General Brigham have found that high-dose vitamin D3 did not reduce COVID-19 infection severity, but may impact long COVID outcomes. Results of the study are published in The Journal of Nutrition.

“There’s been tremendous interest in whether vitamin D supplements can be of benefit in COVID, and this is one of the largest and most rigorous randomized trials on the subject,” said senior author JoAnn Manson, MD, DrPH, of the Mass General Brigham Department of Medicine. “While we didn’t find that high-dose vitamin D reduced COVID severity or hospitalizations, we observed a promising signal for long COVID that merits additional research.”

Vitamin D has been hypothesized to boost immune health, but clinical evidence in the context of COVID-19 has been mixed. The Vitamin D for COVID-19 (VIVID) Trial aimed to provide clarity by rigorously evaluating high-dose vitamin D3 supplementation among newly diagnosed COVID-19 patients and their household contacts. Across the United States and Mongolia, 1,747 adults who had recently tested positive for COVID-19 and 277 household contacts were randomized to receive either daily vitamin D3 (9,600 IU/day for two days followed by 3,200 IU/day) or daily placebo for four weeks. The U.S. trial was conducted from December 2020 to September 2022 while the Mongolia trial ran from September 2021 to April 2022. The median time between the participants’ positive COVID-19 tests and the initiation of vitamin D supplementation or placebo was three days.

Alongside Manson, lead authors Davaasambuu Ganmaa, Kaitlyn Cook and team used stratified randomization and statistical weighting to ensure factors that can affect COVID-19 outcomes (including age, sex, body mass index, race/ethnicity and COVID-19 vaccination status) were balanced between the two groups.

The rate of healthcare utilization (including hospitalizations, in-person or virtual clinic visits, and emergency visits) or death did not differ between the vitamin D and placebo groups over a four-week period. Similarly, no significant differences were found in symptom severity. Taking high-dose vitamin D also didn’t reduce the rate at which household contacts contracted COVID-19.

However, an analysis of the participants who adhered to the vitamin D regimen demonstrated a signal that they were less likely to experience long COVID symptoms at eight weeks than those who took placebo pills. In the vitamin D group, 21% reported at least one persistent symptom, compared to 25% in the placebo group, a difference of borderline statistical significance.

“Long COVID, which can include symptoms of fatigue, shortness of breath, brain fog, other cognitive challenges and more, continues to significantly impact people’s lives,” said Manson. “We hope to conduct further research in larger populations on whether long-term vitamin D supplementation reduces the risks and severity of long COVID.”

Authorship: In addition to Manson and Ganmaa, Mass General Brigham authors include Allison Clar, Michael Rueschman, Aditi Hazra, Howard D. Sesso, Valerie E. Stone, Patricia Copeland and Georgina Friedenberg. Additional authors include Cook, Polyna Khudyakov, Dorjbal Enkhjargal, Tsolmon Bilegtsaikhan, Kenneth H. Mayer, Raji Balasubramanian, Douglas C. Smith, Quanhong Lei, Todd Lee, Emily G. McDonald, Tserenkhuu Enkhtsetseg, Erdenebaatar Sumiya, Yansanjav Narankhuu, Myagmarsuren Erdenetuya, Dalkh Tserendagva, Rikard Landberg, Niclas Roxhed and Susanne Rautiainen.

Disclosures: Roxhed is a founder and shareholder of Capitainer AB, a company commercializing the blood collection devices used in this study. All other authors declare no conflicts of interests.

Funding: The study received anonymous foundation support and philanthropic support from Jon Sabes of Minneapolis, Minn. The authors also acknowledge support from the Tishcon Corporation, which donated the vitamin D and placebo study capsules; Takeda; and Capitainer cards. The authors have not declared a specific grant for this research from any funding agency in the public, commercial or nonprofit sectors.

Paper cited: Ganmaa, D., et al. “A Randomized Trial of Vitamin D Supplementation and COVID-19 Clinical Outcomes and Long COVID: The VIVID Trial.” The Journal of Nutrition. DOI: 10.1016/j.tjnut.2026.101398