weight loss Tag

Immune Cells May Keep a Biological Memory of Obesity

Key Takeaways: 

• Mice lacking a protein called CWC22 in their fat tissue immune cells struggled to lose weight on a reduced-fat diet.
  
• Over half of the obesity-related genetic changes in these cells persisted after weight loss, suggesting a biological “memory” of obesity.
  
• Correcting one of those changes restored normal cell function and helped the mice shed fat again.
  
  
  

Why weight loss can become harder after obesity

According to the World Health Organization, one in eight people worldwide lives with obesity. Yet despite the volume of health education programmes, books, articles and treatments available, many people continue to find weight loss extremely difficult once obesity has developed. Precisely why the body resists losing weight, and why lost weight is so often regained, remains a complex puzzle for researchers.

A new study published in the journal Science Translational Medicine may offer part of the answer. The research points to changes in a particular type of immune cell known as an adipose tissue macrophage (ATM). In mice, these changes appeared to make weight loss harder, because the cells seem to carry a biological “memory” of obesity that outlasts the obesity itself.

What the researchers did

Researchers from several institutions across Japan set out to study ATMs directly. These immune cells help regulate fat tissue health in a number of ways, one of the most important being the safe removal of dying cells from the tissue.

The team fed laboratory mice a high-fat diet for 12 weeks until the animals developed obesity, then switched them to a low-fat diet for a further six weeks. When they compared the animals, they noticed a pattern: the mice that lost the least weight after the dietary switch had lower levels of a protein called CWC22 in the nucleus of their ATM cells. This suggested that CWC22 might play a role in helping the body shed weight.

To test that idea, the researchers genetically modified a group of mice so that they lacked the CWC22 gene in a group of immune cells that includes macrophages. Under normal circumstances, CWC22 helps cells splice messenger RNA, the editing process that RNA undergoes before it is used as a template to make proteins.

A clean-up failure in fat tissue

When the modified mice were placed on a weight-loss diet, they struggled to shed fat. Their ATMs could not clear away dead cells effectively, and as a result dead cells accumulated in the fat tissue.

Closer analysis of these immune cells revealed the mechanism. The absence of the Cwc22 gene caused a splicing error involving a gene called Scarb1. Because of that error, the macrophages destroyed their own clean-up receptors before those receptors could reach the cell surface, leaving the cells without the tools they needed to do their job.

The knock-on effect involved a chemical messenger. Because the macrophages were less able to clear dead cells, they released less inosine. Inosine normally acts as a signal instructing fat cells to break down their stored fat, so with less of it available, fat breakdown was impaired.

A memory that persists after weight loss

Perhaps the most striking finding concerned how long these changes lasted. The research team found that 51.9% of the genes showing obesity-induced RNA splicing changes in these immune cells remained altered even after the animals had lost weight.

In other words, the immune cells retained a biological record of the period of obesity, including alterations that continued to impair their normal clean-up duties long after the diet had changed.

“These findings reveal that aberrant alternative splicing in macrophages underlies resistance to postobesity weight loss,” commented the study authors in their paper.

Rewriting the memory

Encouragingly, at least one component of that memory appears to be reversible. When the scientists corrected the Scarb1 splicing error using a synthetic genetic patch, the clean-up receptors were restored. This in turn increased the amount of inosine available and helped the mice to lose fat once again.

“Our study suggests that specific alternative splicing events can shape macrophage phenotypes under defined environmental conditions.”

What this could mean for people living with obesity

The findings may eventually help inform treatments for people who struggle to lose weight after developing obesity. When the team analysed human tissue samples, they found abundant CWC22 in the nuclei of immune cells taken from people who were lean, but reduced levels in samples from people living with obesity. That parallel between the mouse and human findings is what makes the work potentially translatable.

It is worth keeping the limitations in view. The functional experiments were carried out in mice, and the human element of the study was limited to tissue analysis rather than any test of treatment. No synthetic genetic patch has been trialled in people, and there is a considerable distance between correcting a splicing error in a mouse model and offering a therapy in clinical practice.

Even so, the study adds to a growing body of evidence that weight regain is not simply a matter of behaviour or willpower. Biological adaptations in fat tissue, appetite regulation and now immune cell function all appear to work against sustained weight loss. Clinicians who want to explore these mechanisms and their practical implications in more depth may find it useful to look at structured CPD, such as the College of Contemporary Health’s Obesity Essentials short course, which covers the biological, clinical and behavioural drivers of obesity and weight management.

For people living with obesity, findings like these carry a useful message: the difficulty of maintaining weight loss has measurable biological underpinnings, and understanding them may in time lead to better-targeted support.

CCH insight

Understanding why the body resists weight loss is central to supporting people living with obesity well. Our Obesity Essentials CPD short course explores the physiology, clinical management and behavioural dimensions of obesity, giving healthcare professionals a grounded, evidence-informed basis for the conversations they have every day.

Explore Obesity Essentials

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GLP-1 Medications May Reshape Obesity Care, but Clinicians Still Have Questions

Key Takeaways: 

• Staff saw injectable GLP-1 medications as a valuable middle option between behavioural support and bariatric surgery.
  
• Their strongest concerns centred on what happens after treatment stops, particularly weight regain and masked behavioural patterns.
  
• Most had learned about these medications from patients rather than through formal training.
  
  
  

A service preparing for a change it had not yet made

A qualitative study published in Obesity Science & Practice set out to capture something rarely documented: what healthcare professionals think about injectable GLP-1 medications before their service begins prescribing them. The researchers interviewed staff at a United Kingdom Tier 3 weight management service that had applications for approval in place but was not yet prescribing, giving an unusually clean view of expectations, hopes and anxieties uncoloured by direct prescribing experience.

The timing matters because these medications are moving quickly into routine obesity care. One in eight people worldwide lives with obesity, a scale that demands sustained attention from health authorities. In England, weight management is organised across four tiers, running from population-level prevention and lifestyle services through to specialist multidisciplinary care and bariatric surgery. Injectable GLP-1 medications, including semaglutide and tirzepatide (a dual glucose-dependent insulinotropic polypeptide/glucagon-like peptide-1 receptor agonist), are increasingly built into these pathways. Semaglutide is recommended for eligible patients within specialist services, while tirzepatide can also be prescribed in NHS primary care.

How the study was carried out

Participants were recruited from a Tier 3 service in England providing interpersonal nutritional advice and behavioural support to people with a body mass index above 40 kg/m², or between 35 and 39.9 kg/m² alongside a weight-related comorbidity.

Interviews took place between 20 June and 19 July 2024. Eligible participants were behavioural change advisors or nutrition advisors, and importantly, none of them held prescribing privileges. Staff were invited by email and completed an information sheet, an electronic consent form, a demographic questionnaire and an interview-date selection.

The research team developed a semi-structured interview schedule, refining it after a pilot interview. Questions covered knowledge of semaglutide, perceived benefits, concerns, possible psychological consequences, long-term outcomes, service integration and information needs. Interviews were audio-recorded and transcribed verbatim, then analysed using Braun and Clarke’s six-stage reflexive thematic analysis. Transcripts were read repeatedly and coded in NVivo 14, with preliminary themes developed, discussed, revised, mapped, defined and named. Analysis was predominantly inductive, with a deductive element used to group themes according to the research questions, and the dataset was interpreted through a constructivist lens.

The recruitment email reached 17 healthcare professionals. Thirteen expressed interest and 11 completed interviews, comprising six nutrition advisors and five behavioural change advisors. Interviews ran from 34 to 62 minutes, with a mean of 46 minutes. Sample size was guided by information power rather than a fixed target. Thirteen themes emerged, organised into four clusters: knowledge and information needs, perceived benefits, concerns, and service provision considerations.

Learning from patients rather than from training

One of the more striking findings concerns where knowledge was coming from. Participants had mainly learned about injectable GLP-1 medications through patients who had purchased them privately. Most did not feel confident in their current understanding, reported little formal training, and often sought out information independently, though lack of time limited how far they could go.

That said, the baseline was not zero. All participants knew the medications could facilitate weight loss, and most recognised appetite suppression as an important mechanism, although understanding of how the drugs work varied considerably. A few had deeper knowledge of semaglutide’s physiological effects. Gastrointestinal effects were widely mentioned, including nausea, constipation and diarrhoea.

It is a gap that structured continuing professional development is well placed to close. CCH’s GLP-1RAs in Focus short course was built for professionals in exactly this position, including non-prescribers supporting people on GLP-1RA pathways who want a working grasp of the underlying physiology and pharmacology rather than a patchwork assembled from patient conversations.

Seen as a middle path, not a shortcut

Most participants held positive views and regarded injectable GLP-1 medications as a useful weight-loss tool. Several felt that early weight loss could boost patients’ confidence in their own ability to lose weight, and in turn encourage greater engagement with behavioural support.

Many framed the medications as a valuable middle ground between behavioural support and bariatric surgery, particularly for people with complex needs or those who did not want surgery. At the same time, participants were clear that the drugs were not a substitute for a patient’s own efforts. Where lifestyle change alone was achievable, it was generally the preferred route, partly because it could help people feel more in control of their own progress.

Concerns clustered around what happens next

The dominant concern was not the treatment period itself but what follows it. Most participants worried about weight regain after discontinuation, particularly where behavioural changes had not become established during treatment.

Closely linked to this was a worry about masking. Participants feared that appetite suppression could obscure emotional eating, stress eating, unhelpful habits and other behavioural patterns, making it harder to tell which changes were driven by the medication and which by behavioural support. There was also concern that successful weight loss could create a false sense of security, reduce engagement with lifestyle advice, or foster reliance on medication.

Some participants raised possible mental health risks, including disordered eating or worsening difficulties among people with eating disorders, psychological trauma or a history of self-harm. It is worth being precise here: these were concerns held by participants rather than harms they had observed, and the authors noted that current evidence does not support a causal relationship between GLP-1 medications and suicidal or self-injurious thoughts or actions.

Where behavioural support should sit in the pathway

Many participants favoured offering behavioural and lifestyle support before prescribing begins, giving time to understand individual needs and to manage expectations about what the medication can and cannot do. Almost all supported providing that help alongside treatment, though views differed on how often and for how long.

Some also argued for support during dose reduction and for a few months after treatment ends, precisely because of the regain risk they had identified. The introduction of GLP-1 prescribing into their own service was viewed by some as experimental and as a learning process, and participants anticipated that their professional roles and responsibilities would shift as a result.

What this study cannot tell us

The authors were candid about the limits. The study included 11 professionals from a single Tier 3 service that had not yet started prescribing injectable GLP-1 medications, so the findings may not generalise to other services or to professionals with direct prescribing experience. The interviewer also worked within the same service, which may have shaped how freely participants expressed their views.

What it means for practice

Taken together, the picture is of a workforce that is broadly positive about injectable GLP-1 medications and sees a clear clinical niche for them, but that is thinking hard about continuity of care. The concerns raised, weight regain after discontinuation, reduced engagement with behavioural support, masked behavioural patterns and possible mental health risks, are perceived rather than demonstrated harms, but they point to real design questions for services.

The authors conclude that further research is needed on combining injectable GLP-1 medications with interpersonal behavioural support, and on how that integration can best sustain patients over time. In the meantime, the most actionable finding may be the simplest one: the staff closest to patients wanted better information and had few structured routes to get it.

CCH insight

This study lands on something many services will recognise: the staff supporting people on GLP-1RA pathways are often the least formally trained in how these medications work, and the anxiety sits not in the prescription itself but in the months that follow it.

GLP-1RA Therapy: The Complete Programme (Ozempic, Wegovy & Mounjaro) is built around that full sequence, covering the science, safe prescribing and the long-term care that protects the result, from nutrition and lean mass through to plateaus and when to refer. Seven CPD hours, three Certificates of Completion, and the CCH Advanced Certificate in GLP-1RA Therapy on passing the capstone. Open to prescribers and non-prescribers alike.

Explore GLP-1RA Therapy: The Complete Programme →

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Novo Nordisk Launches Late-Stage Trial to Find the Lowest Effective Dose of Oral Wegovy

Key Takeaways: 

• Novo Nordisk has begun OASIS-5, a 60-week late-stage trial testing lower maintenance doses of the oral Wegovy pill.
  
• The trial will enrol 450 adults with a BMI of 30 or above, or 27 with a weight-related health condition.
  
• Interest in lower dosing reflects real-world practice, where cost and side effects already drive some people to take reduced doses.
  
  
  

A trial built around dose flexibility

Danish drugmaker Novo Nordisk has started testing smaller doses of its Wegovy pill in a new late-stage study designed to identify the lowest dose that still supports weight loss, according to a listing on a US clinical trials database.

The study, known as OASIS-5, began on 12 August and is scheduled to run until 2028. It will examine lower strengths of the daily maintenance dose – the dose used to sustain weight loss once it has been achieved, rather than the escalating doses used at the start of treatment. At present, the approved long-term dose of the Wegovy pill is 25 milligrams.

“Having a broader range of maintenance doses could provide greater flexibility in treatment and optimising the patient experience,” Novo said in an emailed statement to Reuters.

Novo has not specified which new dose strengths are being tested. The Wegovy pill is also approved in doses of 1.5 mg, 4 mg and 9 mg.

What OASIS-5 will measure

The 60-week trial will recruit 450 adult participants who have previously struggled to lose weight, with a Body Mass Index of 30 or above, or 27 in combination with a weight-related health issue.

The primary objective is to establish whether lower doses of oral semaglutide – the active ingredient in Wegovy – produce greater weight loss than placebo over the 60-week period. Secondary objectives include changes in waist circumference, other health benefits and the side effect profile at these reduced strengths.

The study will exclude people living with diabetes, those who have experienced recent major weight changes, and anyone currently being treated with GLP-1 medications.

Seeking health benefits beyond weight loss

The trial arrives against a backdrop of dosing behaviour that is already happening outside clinical protocols. Some people taking GLP-1 medicines, including Wegovy and Lilly’s Zepbound injections, are microdosing or otherwise taking lower-than-approved doses. The practice has become popular largely because of the high cost of the medicines and the side effects associated with them.

“People are using low dosages of these products… they just decide on their own,” Novo CEO Mike Doustdar told Reuters in an interview last week, noting that patients often seek health benefits beyond weight loss.

That observation points to a broader question facing prescribers: what people hope to gain from GLP-1 therapy is not always confined to the number on the scales. Understanding the pharmacology behind dose escalation and maintenance, and being able to discuss the trade-offs between efficacy, tolerability and cost, is increasingly central to safe prescribing. It is a theme covered directly in the College of Contemporary Health’s CPD short course GLP-1RAs in Practice: Prescribing, which examines dose titration, monitoring and shared decision-making in day-to-day clinical settings.

Competitive pressure in a growing market

Novo is under pressure after losing ground to US rival Eli Lilly in an obesity drug market projected to exceed $100 billion by 2030. Investors are watching the Wegovy pill closely; it generated second-quarter sales of 3.22 billion Danish kroner ($499.89 million).

Doustdar expects market segmentation to prevent a winner-take-all contest with Lilly – a view consistent with a future in which different doses, formulations and treatment goals serve different groups of people rather than a single product dominating.

Lilly did not immediately respond to a Reuters request for comment on whether it plans to test smaller doses of its oral drug Foundayo, which has lowest approved doses of 0.8 mg and 2.5 mg.

What this could mean for practice

If OASIS-5 demonstrates that lower maintenance doses deliver meaningful weight loss, it would give clinicians a wider set of options for people who cannot tolerate higher strengths, who are managing the cost of long-term therapy, or who have reached a weight they wish to maintain rather than continue reducing. It would also bring an existing real-world practice within the evidence base, replacing self-directed dose reduction with an approved, monitored alternative.

Results are not expected until 2028, so any change to prescribing practice remains some way off. In the meantime, conversations about dosing, expectations and adherence will continue to sit with the healthcare professionals supporting people through treatment.

CCH insight

Dose selection, titration and tolerability are among the most common practical challenges in GLP-1 prescribing. The College of Contemporary Health’s CPD short course GLP-1RAs in Practice: Prescribing covers dose escalation and maintenance, managing side effects, patient selection and monitoring – equipping healthcare professionals to make confident, evidence-based decisions as the treatment landscape evolves. 

Explore GLP-1RAs in Practice: Prescribing →

Source: Reuters

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Surgery Plus Medication Outperforms Surgery Alone in Young People

Key Takeaways: 

• Young people who restarted obesity medication a median of one month after sleeve gastrectomy lost more weight at 12 months than those who had surgery alone.
  
• Improvements in eating behaviours, including hunger scores, were significantly greater in the early reinitiation group.
  
• Rates of postoperative complications, readmissions, emergency department visits and reoperations did not differ between the two groups.
  
  
  

Combining pharmacotherapy with surgery in adolescent obesity care

Restarting obesity medication, including glucagon-like peptide-1 (GLP-1) receptor agonists, shortly after sleeve gastrectomy is associated with greater weight loss at one year than surgery alone in adolescents, according to a research letter published online on 22 July in JAMA Surgery.

The finding speaks to a question that has become increasingly pressing as both metabolic and bariatric surgery and highly effective obesity pharmacotherapy have become available to younger patients: whether the two should be sequenced, or used together.

What the researchers set out to examine

Dr Alaina P. Vidmar, of Children’s Hospital Los Angeles, and colleagues evaluated the 12-month safety, weight trajectory and eating behaviour outcomes associated with early reinitiation of obesity medication following metabolic and bariatric surgery.

The analysis included 99 young people aged 7–20 who underwent sleeve gastrectomy between November 2023 and February 2026.

Half the cohort restarted medication within a month of surgery

Of the 99 young people in the cohort, 53 reinitiated obesity medication, with a median time to reinitiation of 1.0 month.

Among those who restarted treatment, most resumed the same class of medication they had been prescribed before surgery. Postoperative regimens were nonetheless generally consolidated, with fewer young people requiring multiagent therapy after their operation than before it.

Weight trajectories diverged after the six-month mark

Through the first six months, the two groups experienced similar early postoperative weight loss.

The picture changed by the end of the first year. The early reinitiation group achieved a greater mean reduction in body mass index (BMI) percentage at 12 months than the group who had surgery alone, at −29.3% versus −25.5%. The same pattern held for excess BMI loss percentage, at −53.6% versus −45.7%.

Eating behaviours improved more with combined treatment

Improvements in eating behaviours were significantly greater in the early reinitiation group at 12 months than in the surgery-only group. Median hunger scores on the Adult Eating Behaviour Questionnaire, for example, fell by 3.5 points in the early reinitiation group, compared with a rise of 0.2 points among those treated with surgery alone.

This behavioural dimension is a reminder that appetite regulation after surgery is not a fixed quantity, and that the interaction between pharmacological and surgical mechanisms is an area where prescribing clinicians increasingly need structured, up-to-date grounding. The College of Contemporary Health addresses precisely this territory in its GLP-1RA Complete Programme, which covers the pharmacology, patient selection, monitoring and behavioural support that underpin safe long-term use of these agents.

Safety outcomes were comparable between the groups

There was no difference between the groups in postoperative complications, including biliary events requiring cholecystectomy, readmissions, emergency department visits and reoperations.

A lifespan view of severe obesity

The authors frame the results as support for treating severe obesity in young people as a chronic condition requiring more than one modality.

“Bariatric surgery is the most durable and effective treatment for severe obesity, but for youth with severe disease, we need a multimodal approach, which means combining medication and surgery over the lifespan,” Vidmar said in a statement.

CCH insight

For clinicians supporting young people through and beyond metabolic and bariatric surgery, findings like these shift the practical question from whether to prescribe to when, what and for how long. Confidence with GLP-1 receptor agonists, and with the behavioural and monitoring work that surrounds them, is becoming a core competency rather than a specialist interest.

The College of Contemporary Health’s GLP-1RA Complete Programme is designed for healthcare professionals who want that grounding: mechanisms of action and the wider incretin landscape, patient selection and contraindications, dose escalation and adverse effect management, and the behaviour change support that helps people sustain outcomes over time. It is CPD-accredited and studied entirely online, so it fits around clinical commitments.

Explore the GLP-1RA Complete Programme →

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Weight Bias at Work: What New GLP-1 Research Reveals About Women’s Employment Prospects

Key Takeaways: 

• Women who were unemployed when they started GLP-1 medications saw their employment rate rise by nearly 27 percentage points over 18 months, according to a 2026 NBER working paper.
  
• The gains appeared only among women entering the workforce – those already employed saw no rise in pay or promotion, pointing to perception rather than capability.
  
• The findings echo long-standing evidence on the financial cost of weight bias, from documented pay gaps to hiring professionals’ judgements based on photographs alone.
  
  
  

A new way to measure an old problem

For years, economists have documented what they call the “obesity penalty” – the social and financial disadvantages people can face because of their weight. It has been a difficult phenomenon to measure cleanly, because the factors that shape someone’s body weight also tend to shape their income, health and opportunities.

The rapid uptake of GLP-1 medications has given researchers something closer to a natural experiment. When large numbers of people begin treatment within a short window, and others who want the same treatment have not yet been able to start, it becomes possible to compare two otherwise similar groups and observe what changes.

That is the approach taken in a 2026 working paper published by the National Bureau of Economic Research, in which Harvard economist Rebecca Diamond examined what happened to women’s employment after they began taking GLP-1 medications.

What the researchers did

Diamond looked at survey data from around 15,000 people. She compared women who had started taking GLP-1 medications with similar women who wanted to take them but had not yet started. The two groups were matched on factors including income, race, body mass index and overall health, so that the comparison was not simply between people in very different circumstances to begin with.

The design matters. Because the comparison group consisted of women who also wanted the medications, the study is less vulnerable to the criticism that people who seek treatment are systematically different in motivation from those who do not.

The result that stands out

Among women who were unemployed at the point they began treatment, the employment rate rose by nearly 27 percentage points over the following 18 months, compared with the matched group who had not yet started.

To put that figure in context, it is a larger gap than the difference in employment between American women with a high school diploma and those holding a university degree. In other words, an 18-month change in body weight was associated with a bigger shift in employment than several years of formal education.

The research does not suggest that losing weight made these women more intelligent, more capable or better qualified for work. Nothing about their skills, experience or credentials changed. What the study raises is a different and more uncomfortable question: whether a change in appearance alters how women are perceived by employers.

Changes beyond the workplace

The effects were not confined to employment. The study also found that single women taking GLP-1 medications were nearly 29 percentage points more likely to get married or move in with a partner than similar women who had not started treatment.

Taken together, the employment and partnership findings describe something broader than a labour market effect. They describe a shift in social response.

The financial cost of weight bias

GLP-1 medications have moved quickly into the mainstream. In 2026, 11% of US adults said they were currently taking one to lose weight, up from just 3% in 2024, according to Gallup.

But the question of how weight shapes women’s working lives long predates the current wave of prescribing. Research was already pointing in this direction well before GLP-1 medications entered the cultural conversation.

What hiring professionals saw

A report from Fairygodboss, an employer review site for women, offered a particularly troubling look at how appearance can shape hiring decisions. In one study, hiring professionals were shown images of women with different body types and asked to evaluate them.

The woman pictured at the highest body weight was judged far more harshly than the others. Twenty percent of respondents described her as “lazy”, a label applied less frequently to every other woman pictured. Just 18% said she appeared to have leadership potential, while 21% described her as “unprofessional”.

These are judgements made on the basis of a photograph alone, with no information about experience, qualifications or performance.

Earnings gaps documented long before GLP-1 medications arrived

The pay data tells a similar story. In 2011, the Federal Reserve Bank of St Louis cited research finding that white women living with overweight earned about 4.5% less than white women whose BMI fell within what researchers classified as the normal range. White women living with obesity earned nearly 12% less.

Two caveats are important here. Those figures were specific to white women and do not apply to everyone. They also say nothing about anyone’s value, ability or contribution. What they suggest is that weight-related bias was already showing up in some women’s pay long before GLP-1 medications became widely available.

When appearance pays

The argument that appearance carries an economic premium is not new, and it is sometimes made bluntly. Codie Sanchez, CEO and founder of Contrarian Thinking, has said that women who wear makeup to work earn about 30% more on average than women who do not.

“Pretty privilege is very real,” she said on an episode of The Burnouts Podcast. “And you can either say ‘That’s not fair, so I’m not doing it.’ or you can win.”

Sanchez acknowledged that the advantage is unfair, but argued that women should use it rather than ignore it. “If it’s going to make me more money to paint my face, clown me up,” she said.

Diamond’s findings suggest weight bias may operate along similar lines. The women who benefited most were those seeking to enter the workforce, where first impressions carry disproportionate weight and where an employer’s judgement is formed quickly and on limited information. For women already in a job, whose managers had direct evidence of their performance, the effect disappeared.

Why this matters in clinical practice

For healthcare professionals, findings like these complicate the consultation room. People starting GLP-1 medications may be motivated by clinical goals, social goals, economic goals, or some mixture of all three, and those motivations shape expectations, adherence and how someone responds if treatment is paused or stopped.

Understanding the pharmacology well enough to have that conversation credibly is increasingly part of everyday practice rather than a specialist concern. Building that grounding is the focus of professional training such as the College of Contemporary Health’s GLP-1RAs in Focus – Why Drugs Like Ozempic Work, a CPD-accredited online short course covering GLP-1 physiology and pharmacology for prescribers and non-prescribers alike.

An uncomfortable conclusion

Losing weight does not make a person more intelligent, more capable, harder working or better qualified for a job. But it may change how other people perceive them.

That is precisely what makes Diamond’s findings difficult to sit with. If some women gain access to more opportunities after losing weight while their underlying abilities remain exactly the same, then the economic benefit is not really a benefit at all. It is a measure of how heavily appearance still shapes the way women are perceived and treated – and of how much value has been withheld from them beforehand.

The medication changed the response. It did not change the woman.

CCH insight 

Findings like these are a reminder that GLP-1 medications carry social and economic weight as well as clinical effect – and that patients arrive at the consultation with motivations shaped by far more than a treatment target. CCH’s GLP-1RAs in Focus – Why Drugs Like Ozempic Work CPD short course (2 CPD hours, fully online, CPD-accredited) builds the foundation in GLP-1 physiology and pharmacology that healthcare professionals need to explain the science clearly, set realistic expectations and contribute confidently to treatment discussions, whether or not they prescribe. 

Explore GLP-1RAs in Focus →

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

Key Takeaways: 

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

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

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

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

Looking beyond appetite suppression

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

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

The three components of eating behaviour

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

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

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

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

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

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

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

What the clinical evidence does and does not show

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

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

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

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

A framework for understanding what people report

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

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

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

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

Clinical relevance and a possible stage-dependent pattern

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

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

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

Why this matters for nutrition and obesity management

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

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

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

Conclusion

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

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

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

CCH insight: 

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

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

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Ozempic and Mounjaro Linked to Modest Rise in Hair Loss Risk, BMJ Study Finds

Key Takeaways: 

• Adults living with type 2 diabetes taking GLP-1 receptor agonists developed alopecia more often than those taking SGLT-2 inhibitors (37% higher risk) or DPP-4 inhibitors (68% higher risk), a BMJ study reports.
  
• Absolute risk stayed low, at 6.91 cases per 1,000 person years for GLP-1 receptor agonists against 5.04 for SGLT-2 inhibitors and 3.89 for DPP-4 inhibitors.
  
• The association was confined to non-scarring alopecia, where the follicle stays intact and regrowth remains possible.
  
  
  

A modest signal, but one worth discussing in the consultation

Medications from the GLP-1 receptor agonist class, now widely used in the management of type 2 diabetes and obesity, may be associated with a modest increase in hair loss. The finding comes from a study published by The BMJ on 22 July 2026.

The class includes semaglutide, marketed under brand names such as Ozempic and Wegovy, and tirzepatide, marketed as Mounjaro and Zepbound. Researchers found that adults living with type 2 diabetes who were treated with GLP-1 receptor agonists went on to develop alopecia more frequently than people prescribed two other commonly used classes of diabetes medication.

Although the relative increase was significant, the researchers emphasised that the absolute risk of hair loss remained low. Even so, awareness of the possible adverse effect could help people and their clinicians reach better informed treatment decisions together.

Reports of hair loss with semaglutide and tirzepatide

Hair loss has been reported before as a possible adverse effect of GLP-1 receptor agonists, particularly with medications containing semaglutide or tirzepatide. What has been missing is research that directly compares the risk among people taking these medicines with the risk among people taking alternative diabetes treatments.

To address that gap, the research team analysed electronic health records from the University of Pennsylvania Health System (Penn Medicine). They compared rates of alopecia among adults living with type 2 diabetes who began treatment with GLP-1 receptor agonists, SGLT-2 inhibitors or DPP-4 inhibitors.

The analysis covered people treated between January 2019 and September 2024. One comparison included 12,004 people taking GLP-1 receptor agonists and 15,221 taking SGLT-2 inhibitors. A second, separate comparison included 11,964 people taking GLP-1 receptor agonists and 11,233 taking DPP-4 inhibitors.

Accounting for differences between the treatment groups

The groups differed in several important respects before the researchers adjusted their results.

Compared with people taking SGLT-2 inhibitors, those taking GLP-1 receptor agonists were younger (mean age 58 v 65), had a higher body mass index (36.2 v 32.3), and had lower rates of cardiovascular disease and chronic kidney disease.

A similar pattern was seen in the comparison with DPP-4 inhibitors. People taking GLP-1 receptor agonists were again younger (mean age 58 v 67) and had a higher body mass index (36.2 v 31.3).

To limit the influence of these imbalances, the researchers adjusted for factors that might otherwise have shaped the findings, including age, sex, ethnicity, pre-existing conditions, use of other medications, and body mass index.

Higher rates of alopecia after adjustment

Once those adjustments were made, use of a GLP-1 receptor agonist was associated with a 37% higher risk of alopecia than use of an SGLT-2 inhibitor (6.91 v 5.04 per 1,000 person years).

The difference was larger in the second comparison. Risk was 68% higher among people taking GLP-1 receptor agonists than among those taking DPP-4 inhibitors (6.53 v 3.89 per 1,000 person years).

Further analysis indicated that the association was limited to non-scarring alopecia, the form in which hair follicles remain intact and the potential for regrowth is preserved. For this type of hair loss, risk was 53% higher among people taking GLP-1 receptor agonists than among those taking SGLT-2 inhibitors, and 72% higher than among those taking DPP-4 inhibitors.

Why rapid weight loss might disturb the hair cycle

The study did not establish why GLP-1 medications might be connected to hair loss, but the authors set out several plausible explanations.

Rapid weight loss is a well established cause of increased hair shedding. It may also contribute to iron or zinc deficiency, either of which can interfere with the normal hair growth cycle. Hormonal changes related to weight loss or to treatment itself could play a part as well, although further research will be needed to identify the mechanisms at work.

Important questions that remain open

The researchers acknowledged a number of limitations. The available clinical records did not contain enough detail to determine the severity, extent or duration of the alopecia. Nor could the team assess whether hair grew back after people stopped taking the medication.

Because the study was observational, it cannot demonstrate that GLP-1 medications directly caused the hair loss. Other factors that were not measured may have influenced the results.

Set against that, the authors described their work as rigorous, drawing on high quality data from a large and representative group of patients. The findings also held up across additional analyses, which supports their reliability.

What the findings mean for practice

For clinicians, the practical value of a study like this lies less in the headline percentages than in what it adds to the conversation before and during treatment. Anticipating adverse effects, recognising them early and folding them into shared decision-making are core parts of the GLP-1 consultation – the ground covered by CPD courses such as the College of Contemporary Health’s GLP-1RAs in Practice: How to Safely Prescribe Ozempic, Wegovy & Mounjaro, which works through initiation, titration and the avoidance of adverse reactions.

The researchers concluded: “Our findings extend previous anecdotal safety signals and provide more systematic evidence to inform clinical awareness of this potential adverse effect.”

CCH insight

This may seem like an odd perspective, but this could be a good thing if it means that people considering taking GLP-1 medications for vanity reasons (to slim down to their perfect weight when they do not have obesity or type 2 diabetes) are put off, leaving better availability for those who genuinely need it. I am sure that for most people living with obesity or diabetes, a small increased risk of alopecia is worth taking when balanced against the huge health benefits that these drugs usually bring.

Hair loss is unlikely to change prescribing decisions on its own, but it is exactly the kind of adverse effect that patients notice, worry about and sometimes stop treatment over. Knowing how to raise it, put the absolute risk in context and respond if it appears is part of delivering GLP-1 therapy well. CCH’s GLP-1RAs in Practice: How to Safely Prescribe Ozempic, Wegovy & Mounjaro (Or Any Other Weight Loss Drug) is a two-hour, CPD-accredited online course covering every stage of the consultation, from patient selection and titration through to managing adverse reactions, grounded in current NICE guidance and the ADA 2026 Standards of Care.

Find out more about GLP-1RAs in Practice →

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Study Identifies Which Patients With Obesity Respond Best to GLP-1-Based Treatment

Key Takeaways: 

• A Mayo Clinic study has identified a distinct biological subtype of obesity – a form of the “hungry gut” phenotype – that responds especially well to tirzepatide.
  
• People in this subgroup lost an average of 21.5% of their body weight after six months on tirzepatide, roughly double the 11.7% seen in other subtypes.
  
• The lower appetite-hormone levels traced back to reduced hormone production in the intestine rather than differences in the gut microbiome.
  
  
  

A step towards precision medicine for obesity

Why do some people lose a substantial amount of weight on GLP-1-based medications while others see far more modest results? A new Mayo Clinic study offers a potential answer, identifying a distinct biological subtype of obesity that responds especially well to tirzepatide – a medication that mimics two naturally occurring hormones involved in appetite and blood sugar regulation. The finding moves the field a step closer to precision medicine for obesity, where treatment is matched to an individual’s underlying biology rather than applied uniformly.

The research, published in the journal Gastroenterology, points to a future in which clinicians could predict, rather than simply hope, that a given therapy will work for a given person.

What the researchers found

The team studied 483 adults living with obesity and identified three distinct biological types of the disease. About one in four participants produced lower levels of GLP-1 and other hormones that help people feel full after eating.

This subgroup saw markedly better results on treatment. Patients in this group lost an average of 21.5% of their body weight after six months of tirzepatide, compared with 11.7% for patients in the other groups – losing nearly twice as much weight over the same period.

“Obesity is a complex disease driven by different biological mechanisms,” says senior author Andres Acosta, M.D., Ph.D., a gastroenterologist and the Delaney Family Director of the Nutrition Obesity Research Program at Mayo Clinic in Minnesota. “Our findings suggest we can begin identifying which patients are most likely to respond to specific therapies rather than treating obesity as a single disease.”

Understanding the “hungry gut” subtype

The subgroup that responded so strongly to tirzepatide shares a recognisable biological signature: people in this group produce lower levels of natural appetite-regulating hormones, experience faster stomach emptying and report greater hunger after meals.

Researchers describe this as a form of the “hungry gut” obesity phenotype, which is characterised by an abnormal duration of fullness. Rather than eating unusually large amounts at any one sitting, people with hungry-gut obesity may eat normal portion sizes but find themselves snacking more frequently, because the sense of fullness does not last as long as it should.

Because tirzepatide acts on the same appetite pathways that are underactive in this group, it appears especially well suited to addressing the biology that drives their eating patterns.

Why the underlying biology matters

The study also sheds light on why hormone levels differ in this subgroup. The researchers found that the reduced hormone levels were associated with decreased hormone production in the intestine itself, rather than with differences in the gut microbiome. That distinction offers new insight into the biology underlying this subtype and helps explain where the difference in treatment response originates.

Identifying the right therapy sooner could carry significant long-term benefits. Because obesity increases the risk of diabetes, heart disease, certain cancers and many other serious chronic conditions, matching people to the treatment most likely to help them – rather than relying on a one-size-fits-all approach – could improve long-term health outcomes.

What this means for clinical practice

The findings support growing efforts to personalise obesity treatment based on an individual’s biology. For clinicians, interpreting studies like this one increasingly depends on a firm grasp of how GLP-1-based medications act on appetite hormones and gastric emptying in the first place – the kind of grounding offered by CPD courses such as the College of Contemporary Health’s GLP-1RAs in Focus, which examines why some people respond more strongly to these treatments than others. Still, the authors are careful to note the limits of the current work. They caution that prospective studies are needed before this approach can be incorporated into routine clinical practice.

Even so, the results represent an important step towards more precise, individualised treatment for obesity – and towards a future in which people are guided to the therapy most likely to work for them from the outset.

Studies like this one land almost weekly, and making sense of them starts with understanding how GLP-1 receptor agonists actually work – from gut hormones and appetite regulation to why some people respond far more strongly than others. CCH’s GLP-1RAs in Focus – Why Drugs Like Ozempic Work is a two-hour, CPD-accredited online course created by Prof. Mike Bewick and Nigel Hinchliffe that builds exactly this foundation, whether or not you prescribe. Explore the course and interpret the next headline with confidence.

Source: Mayo Clinic

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GLP-1 Medicines for Weight Loss Reach Record Use Among US Adults

Key Takeaways: 

• Eleven per cent of US adults report currently taking GLP-1 medicines for weight loss in 2026, a substantial rise from three per cent in 2024.
  
• Awareness of GLP-1 medicines intended for weight loss has increased to 91 per cent, while the US adult obesity rate has declined from its 2022 peak of 39.9 per cent to 36.4 per cent so far in 2026.
  
• Brand-name GLP-1 medicines remain the most commonly used option, but cost and insurance coverage appear to be driving some people towards compounded or custom-mixed versions.
  
  
  

GLP-1 use for weight loss continues to rise

The proportion of US adults who say they are currently taking GLP-1 medicines for weight loss has reached a new high in 2026, according to data from the Gallup National Health and Well-Being Index.

Eleven per cent of US adults now report current use of these medicines for weight loss purposes. This represents a significant increase from 2024, when three per cent reported current use. Lifetime use has also risen, with 15 per cent of US adults saying they have taken a GLP-1 medicine for weight loss at some point. This is an increase of nine percentage points.

The findings are based on a web survey of 5,065 US adults conducted between 28 May and 5 June 2026. The survey used the probability-based Gallup Panel, which includes respondents from all 50 US states and the District of Columbia.

How Gallup measured GLP-1 use

To assess whether people had ever used GLP-1 medicines for weight loss, Gallup asked respondents:

“Have you ever taken weight loss medications such as semaglutide (brand names Ozempic and Wegovy), liraglutide (brand name Saxenda) or tirzepatide (brand names Mounjaro and Zepbound)?”

People who answered “yes” were then asked a follow-up question to determine whether they were currently taking one of these medicines:

“Are you currently taking weight loss medications such as semaglutide (brand names Ozempic and Wegovy), liraglutide (brand name Saxenda) or tirzepatide (brand names Mounjaro and Zepbound)?”

These questions allowed Gallup to distinguish between lifetime use and current use among US adults.

FDA approvals have expanded the market

The rise in GLP-1 use follows the approval of several medicines for weight loss in the US. The Food and Drug Administration approved Novo Nordisk’s Wegovy, which contains semaglutide, for weight loss in 2021.

Since then, additional options have become available. Eli Lilly’s Zepbound, which contains tirzepatide, received FDA approval in November 2023.

As more treatment options have entered the market, public awareness has also increased. Gallup reports that 91 per cent of Americans are now aware of GLP-1 medicines intended for weight loss, up from 80 per cent in 2024.

Adult obesity has declined from its 2022 peak

Gallup’s latest findings show that the US adult obesity rate has continued to fall after reaching a record high of 39.9 per cent in 2022. So far in 2026, the adult obesity rate stands at 36.4 per cent.

Gallup describes this as a statistically meaningful decline. The trend has continued to move in the opposite direction to national GLP-1 use, which has increased over the same period.

Gallup calculates obesity using the federal standard of a body mass index of 30 or higher. BMI is calculated using respondents’ self-reported height and weight.

The organisation notes that self-reported data may produce somewhat lower estimates than studies based on randomised clinical measurements of height and weight. Gallup suggests that a “vanity effect” in how people report their own height and weight may help explain this difference. However, because Gallup has used a consistent method over time, the data still provides useful information about changes in the adult obesity rate.

Diabetes diagnoses have levelled off

While obesity levels have declined, the proportion of US adults who report having been diagnosed with diabetes has remained steady since 2023. This follows 15 years of gradual increases that occurred alongside rising obesity rates.

Gallup notes that a falling obesity rate would be expected to stabilise, but not necessarily reduce, the proportion of adults who have ever been diagnosed with diabetes. Diabetes is described in the original analysis as a lifelong disease that can be managed but not cured.

To measure diabetes prevalence, Gallup asked US adults:

“Has a doctor or nurse ever told you that you have diabetes?”

The diabetes rate includes people with Type 1 diabetes and people with Type 2 diabetes. The 2026 figures for obesity and diabetes are based on 10,091 respondents from surveys conducted from 18 February to 3 March and from 28 May to 5 June 2026.

Brand-name GLP-1 medicines remain the most common option

Among adults currently taking GLP-1 medicines for weight loss, brand-name options remain the most common.

Gallup found that 68 per cent of current use involves brand-name GLP-1 medicines such as Ozempic or Wegovy. By comparison, 19 per cent of current use involves compounded or custom-mixed versions of the medicine.

A further 12 per cent of people currently taking a GLP-1 medicine for weight loss are unsure whether they are using a brand-name medicine.

People using compounded versions report slightly higher effectiveness

Gallup also compared perceived effectiveness between people taking brand-name GLP-1 medicines and those taking compounded or custom-mixed versions.

People using compounded or custom-mixed GLP-1 medicines were slightly more likely to describe the medicine as “extremely effective”. Thirty-nine per cent of people in this group gave that response, compared with 32 per cent of people using brand-name GLP-1 medicines.

However, both groups generally regarded the medicines as effective. Seventy-seven per cent of people using compounded or custom-mixed versions said the medicine was either “effective” or “extremely effective”. Among people using brand-name GLP-1 medicines, the figure was 74 per cent.

Some people are switching from brand-name to compounded GLP-1 medicines

Although brand-name medicines continue to account for most current GLP-1 use, Gallup’s findings suggest that compounded or custom-mixed versions are gaining ground.

Among people currently using compounded or custom-mixed GLP-1 medicines, 35 per cent report having switched from a brand-name medicine. By contrast, 10 per cent of people currently using brand-name GLP-1 medicines say they switched from a compounded or custom-mixed version.

This suggests that movement towards compounded or custom-mixed GLP-1 medicines is greater than movement in the opposite direction.

Cost and insurance coverage appear to be major factors in this shift. Among people who switched from a brand-name GLP-1 medicine to a compounded version, 66 per cent cited cost or insurance coverage as their main reason for switching. Among those who switched from a compounded version to a brand-name medicine, 34 per cent cited cost or insurance coverage as the primary reason.

Wider implications for obesity and diabetes trends

The growing use of GLP-1 medicines for weight loss may point to broader health implications for adults in the US. Gallup’s analysis indicates that increased use of these medicines has coincided with a decline in the adult obesity rate and a levelling off in diabetes diagnoses after years of increases.

Previous research cited in the original analysis has shown a general alignment between GLP-1 use and declining obesity rates across age groups. One exception is adults aged 65 and older, among whom the reported effectiveness of GLP-1 medicines is lower.

Brand-name GLP-1 medicines still lead the market by a wide margin. However, the lower cost of compounded or custom-mixed versions appears to be contributing to a shift away from brand-name options for some people. This may be expanding access to GLP-1 medicines across broader sections of the population, although access remains limited.

Gallup suggests that this broader availability may be one factor helping to drive overall GLP-1 use higher in the US.

Source: Gallup

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

Key Takeaways: 

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

A twelve-week habit with lasting results

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

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

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

Body composition assessed one year later

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

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

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

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

A flexible strategy against obesity

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

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

CCH insights:

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

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

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Many Who Stop GLP-1 Medications Restart Within a Year, Study Finds

Key Takeaways: 

• Around 4 in 10 people with type 2 diabetes stopped their GLP-1 medication within the first year, rising to nearly 6 in 10 by the end of two years.
  
• Of those who stopped, more than half restarted within a year and nearly two-thirds within two years, suggesting use is often start-and-stop rather than permanent.
  
• Newer medications, a prescription from an endocrinologist, and fewer stomach-related side effects were all linked to a lower likelihood of stopping.
  
  
  

Use is more start-and-stop than assumed

People prescribed GLP-1 medications are more likely to start and stop treatment than many assume, according to a study being presented on Sunday at ENDO 2026, the Endocrine Society’s annual meeting in Chicago, Illinois.

“Our study asked two questions that haven’t been well answered until now: How many people with type 2 diabetes taking GLP-1 medications actually stop using them? And how many restart them?” said Sainikhil Sontha, M.S., a research associate at Boston University School of Public Health in Boston, Massachusetts.

How the study was carried out

The researchers ran a retrospective cohort study using Komodo Health US claims data covering January 2019 to June 2025. The group included adults aged 18 to 64 years with a BMI of 25 kg/m² or above and type 2 diabetes who had started liraglutide, semaglutide, or tirzepatide, and who had previously enrolled within the last year with more than six months of follow-up.

Discontinuation was defined as a gap of more than 60 days in filling a GLP-1 prescription. Obtaining a new fill after discontinuation was counted as reinitiation.

How many people stopped

“Using insurance records from more than 60,000 Americans with type 2 diabetes, we found that about 4 in 10 patients stopped their GLP-1 medication within the first year, and nearly 6 in 10 had stopped by the end of two years,” Sontha said.

But the team also found something more encouraging.

How many people restarted

“More than half of those who stopped restarted therapy within a year (41.5%), and nearly two-thirds did so within two years (58%),” Sontha said. “This suggests that for many patients, these medications aren’t being abandoned permanently; use is more start-and-stop than most people assumed.”

Who was more likely to stop

Using Cox proportional hazards models, the researchers also accounted for sociodemographic, clinical, and provider-level predictors.

Sontha and colleagues found that people on Medicaid or Medicare, people who are Black, and those experiencing nausea or other stomach-related side effects (37%) were more likely to discontinue a GLP-1 medication within a year.

What was linked to staying on treatment

People were 10% less likely to stop if their first GLP-1 medication was prescribed by an endocrinologist.

The type of medication also made a difference. People taking newer medications such as tirzepatide were 41% less likely to discontinue than those taking older drugs such as liraglutide, while people taking semaglutide were 28% less likely to discontinue anti-obesity medication use than those on older medications.

Why it matters

“This research matters because consistent use of these medications is what produces their protective effects,” Sontha said. “Stopping early may mean missed opportunities to prevent heart attacks, kidney disease progression and other complications.”

The researchers hope the findings give providers, insurers, and policymakers a clearer picture of which patients need more support to stay on GLP-1 medications.

CCH insights:

This study suggests most patients see GLP-1 medications as a temporary treatment to lose weight, rather than a long-term treatment for obesity and cardiometabolic health. It also suggests patients are not getting good advice regarding GLP-1 therapy. In the long-term, patients should be advised to reduce down to the minimum dose that enables them to maintain weight loss and also maintain gains in metabolic markers and improvements in cardiovascular risk factors, rather than stopping and restarting treatment.

Getting that judgement right – knowing when to hold a dose, when to step down rather than stop, how to keep a patient nourished when side effects bite, and how to prepare them for the long term – is exactly what our two-hour CPD course GLP-1RAs in Practice: Supporting Patients During Treatment is built around, for any clinician supporting patients across the full arc of therapy.

Source: Endocrine Society

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A Simple Blood Test Could Identify the Most Effective Obesity Medication

Key Takeaways: 

• A hypothesis-generating pilot study suggests that fasting blood levels of two incretin hormones – GLP-1 and GIP – may help predict how well people with severe obesity respond to semaglutide and tirzepatide.
  
• Low fasting GIP was linked to an optimal response to tirzepatide, while low GLP-1 combined with intermediate-to-high GIP was linked to an optimal response to semaglutide.
  
• The researchers stress that the findings are preliminary and should not guide prescribing until confirmed in larger, adequately powered randomised trials.
  
  
  

A step towards matching patients with the right medication

A straightforward fasting blood test may one day help clinicians decide which obesity medication is most likely to work for an individual patient. That is the tentative conclusion of a new hypothesis-generating pilot study published in the journal Diagnostics, which reports that fasting blood levels of glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP) may help predict the therapeutic response to semaglutide and tirzepatide in people living with severe obesity.

Why obesity medications produce different responses

Obesity, characterised by excessive fat accumulation in the body, has become a global epidemic, affecting more than 650 million adults worldwide. The condition is associated with a significantly increased risk of cardiovascular disease, type 2 diabetes, certain cancers, and all-cause mortality.

Among the pharmacological options, glucagon-like peptide-1 receptor agonists (GLP-1RAs) such as semaglutide, and dual GIP/GLP-1 receptor co-agonists such as tirzepatide, have shown considerable promise in addressing this challenge. One major limitation of these medicines, however, is the marked variability in response between individuals, which has prompted interest in identifying the biological mechanisms that drive this variation.

GLP-1 and GIP are the two principal incretin hormones, secreted by intestinal cells after food is eaten. GLP-1 suppresses appetite and promotes satiety through central nervous system pathways, whereas GIP regulates adipose tissue metabolism and energy expenditure. Acting synergistically, these hormones help to regulate glucose metabolism and appetite, giving them a major role in the management of obesity and type 2 diabetes.

Because the incretin system is frequently dysregulated in obesity, researchers at the University of Catania and MEDISAN, both based in Italy, designed the study to investigate whether fasting blood levels of GLP-1 and GIP could help identify people more likely to respond to semaglutide and tirzepatide.

How the pilot study was designed

The study enrolled 90 adults with a BMI greater than 40 kg/m² (class III obesity). Fasting blood samples were collected to measure each participant’s GLP-1 and GIP levels.

Each hormone was independently divided into low, intermediate, and high tertiles – a statistical division of a dataset into three equal parts – based on its distribution across the study population. Combining the GLP-1 and GIP tertiles produced nine distinct hormone profiles, each containing 10 participants. Within every profile, participants were randomly assigned to receive either semaglutide or tirzepatide, with five people allocated to each medicine per profile.

Response to treatment was assessed at six months. A reduction in body weight of less than 5% was classed as a low response, a reduction of 5–15% as an intermediate response, and a reduction of more than 15% as an optimal response.

Low incretin levels shaped treatment outcomes

The analysis showed that participants in the three profiles characterised by the low GIP tertile achieved an optimal response to tirzepatide, regardless of their GLP-1 levels. This suggests that low fasting GIP was associated with greater responsiveness to exogenous GIP receptor agonists such as tirzepatide.

For semaglutide, participants in two profiles – those characterised by a low GLP-1 tertile combined with an intermediate-to-high GIP tertile – were the only ones to achieve an optimal response. This may indicate that low endogenous GLP-1 availability leaves more GLP-1 receptors free for activation by exogenous semaglutide. The intermediate-to-high levels of endogenous GIP, meanwhile, may point to intact or compensatory incretin secretory capacity that does not interfere with the efficacy of a GLP-1 receptor agonist.

Participants in the profile characterised by high GLP-1 and high GIP tertiles achieved only a low response to both medicines. The authors suggest this may reflect a dysregulated incretin system that was not overcome by pharmacological doses within six months. They note, however, that fasting hormone measurements alone cannot distinguish between incretin secretory deficiency and receptor resistance, making this interpretation speculative.

On the clinical side, participants who achieved an optimal response to either medicine experienced significant reductions in waist circumference and improvements in insulin sensitivity. These changes paralleled the weight-loss patterns observed across the response groups, indicating clinically meaningful improvements in central adiposity and metabolic health.

How receptor occupancy may explain the findings

The observed variation in response may be explained through incretin receptor occupancy. Tirzepatide, as a dual GIP/GLP-1 receptor co-agonist, activates both receptor systems simultaneously. When GIP is present at low abundance (low fasting levels), it cannot fully occupy its receptor, potentially leaving that receptor available for exogenous tirzepatide. Once bound and activated, tirzepatide may then exert greater therapeutic effects by regulating adipose tissue metabolism, energy expenditure, and potentially central appetite regulation.

Semaglutide, which binds and activates the GLP-1 receptor exclusively, may exert its greatest effects when GLP-1 receptors are relatively unoccupied because of low levels of endogenous GLP-1. In these conditions, semaglutide may more effectively restore GLP-1 receptor signalling and deliver its anorectic, insulinotropic, and metabolic effects.

What this could mean for personalised prescribing

Taken together, the study suggests that fasting blood levels of GLP-1 and GIP were associated with the therapeutic response to semaglutide and tirzepatide in people with severe obesity, and may help identify those more likely to respond to treatment. Specifically, low GIP levels were associated with an optimal tirzepatide response, whereas low GLP-1 levels combined with intermediate-to-high GIP levels were associated with an optimal semaglutide response.

Because a single-timepoint measurement of GLP-1 and GIP cannot reveal receptor resistance, the researchers recommend treating these observations as hypothesis-generating, and highlight the need for mechanistic validation through dynamic measurements of incretin levels and receptor activity. Overall, the findings offer preliminary clinical evidence for incretin-guided, personalised pharmacotherapy that could improve treatment outcomes in obesity management.

Limitations and next steps

Several important caveats apply. This was a small, single-centre, open-label pilot study, with only five participants per treatment arm within each hormone profile. In addition, fasting hormone measurements cannot distinguish incretin secretory deficiency from receptor resistance. The authors therefore emphasise that the findings are preliminary and should not guide clinical practice until they are confirmed in larger, adequately powered randomised trials.

CCH insights:

This was a very small scale pilot study, so we can’t draw any conclusions, but it is an important step towards developing tests or measurements that can improve the personalisation of obesity care and improve the efficiency and effectiveness of obesity treatment.

Making sense of early findings like these – and understanding the incretin physiology that explains why semaglutide and tirzepatide can behave so differently from one patient to the next – is exactly what our two-hour CPD course GLP-1RAs in Focus – Why Drugs Like Ozempic Work is built for, giving any clinician the grounding to weigh new GLP-1RA evidence on its merits rather than its headlines.

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