The problem we already know

GLP-1 response varies enormously. Across studies, a meaningful minority of people do not reach the typical response threshold of at least 5% body weight loss. In one semaglutide analysis, 32% of people achieved less than 5% loss from baseline or gained weight, while 5% lost more than 25%. That’s a wide disparity in outcomes from the same class of drug.

What this study found

Researchers at the 23andMe Research Institute ran a genome wide association study across 27,885 people who had used semaglutide or tirzepatide.

Two key findings emerged:

• A variant in the GLP1R gene (the gene encoding the receptor these drugs target) was associated with greater weight loss. Each copy of the variant contributed roughly an additional 0.76 kg of weight loss. Those with two copies of the gene lost around 1.5 kg more than those without. That might sound modest in isolation, but it did represent over 10% of the total weight loss for those with two copies of the GLP1R variant.

• A variant in the GIPR gene was linked to increased nausea and vomiting, specifically in people taking tirzepatide. This makes biological sense: tirzepatide is a dual GLP-1/GIP receptor agonist, and the variant is a known partial loss of function mutation. The researchers suggest that when the GIP component can’t function as effectively, it may be less able to buffer the nausea inducing effects of GLP-1 receptor activation. Recent preclinical work supports this theory.

Notably, the GLP1R variant linked to better weight loss was also associated with more nausea and vomiting. And people who were homozygous for risk alleles at both genes faced a roughly 15-fold increased odds of vomiting on tirzepatide. That’s a striking signal for side effect risk.

How much does genetics actually explain?

The study also built a combined prediction model using genetics alongside demographic and clinical factors (age, sex, BMI, drug type, T2D status, and others). The model explained about 25% of the variance in weight loss, with genetics contributing a modest but meaningful slice on top of non-genetic predictors. It was validated against electronic health records from a separate cohort, and people predicted to lose more weight did indeed lose more weight over time.

A few caveats worth noting for your clinical lens. The side effect prediction models performed at 65-68% AUC, which is statistically meaningful but not yet at a level that would change individual patient decisions.

The study also relied heavily on self-reported data from 23andMe participants, who skewed female (82%) and European ancestry (78%). Self-reported weight loss was significantly higher than EHR data showed for the same individuals, so the absolute numbers should be interpreted carefully.

What does this mean for practice right now?

Genetic testing for GLP-1 response isn’t part of standard clinical practice, and we’re not close in terms of actionable, guideline level recommendations. But this study adds weight to the case that personalised approaches to GLP-1 prescribing may be on the horizon. It’s also a useful conversation starter with patients who feel like they’ve “failed” on a GLP-1, when in reality, their response may have been shaped by factors completely outside their control.

You can read the full study in Nature here

References

Su, Q.J., Ashenhurst, J.R., Xu, W., Tran, V., Wu, R.R., Weldon, C.H., Shi, J., Hicks, B., 23andMe Research Team, Abul-Husn, N.S., Aslibekyan, S., Holmes, M.V., Koelsch, B.L. and Auton, A. (2026) ‘Genetic predictors of GLP1 receptor agonist weight loss and side effects’, Nature. doi: 10.1038/s41586-026-10330-z.​

Oral GLP-1 maintenance after injectable weight loss

Eli Lilly has reported positive topline Phase 3 results from ATTAIN-MAINTAIN, a trial designed to answer a very practical question: after achieving weight loss on injectable therapies, can patients maintain that loss by switching to a once-daily oral GLP-1?

Trial Design and Methodology

The 52 week trial involved 376 adults with obesity or overweight and related comorbidities. All participants had previously completed the 72 week SURMOUNT-5 trial, where they reached a weight plateau (defined as <5% change between weeks 60 and 72) using the highest tolerated doses of injectable Wegovy or Zepbound

Participants were re-randomised to receive either orforglipron (oral GLP-1) or a placebo as an adjunct to lifestyle interventions

Primary and Secondary Outcomes

Orforglipron met its primary endpoint, demonstrating superior maintenance of body weight reduction compared to placebo at 52 weeks. Key data includes:

• Participants who transitioned from Wegovy to orforglipron maintained their weight within an average difference of 0.9 kg.

• Participants transitioning from Zepbound to orforglipron maintained their weight within an average difference of 5.0 kg.

• In post hoc analyses at 24 weeks, those switching from Wegovy to orforglipron saw a weight change of -0.1 kg, compared to a 9.4 kg gain in the placebo group. Similarly, those switching from Zepbound saw a 2.6 kg change versus a 9.1 kg gain for placebo.

Safety and Tolerability

The safety profile was consistent with previous Phase 3 studies of orforglipron. The most frequently reported adverse events were gastrointestinal-related, typically mild to moderate in severity. Discontinuation rates due to adverse events ranged from 4.8% to 7.2% for those on orforglipron, depending on their previous injectable therapy.

Clinical Implications and Patient Access

As a once daily oral alternative, orforglipron addresses barriers for needle averse patients. This small molecule formulation allows for flexible dosing without food or water restrictions, and it’s scalability could support improved global affordability and treatment access. Having been submitted to the U.S. Food and Drug Administration for regulatory approval under an expedited review process, orforglipron is being evaluated as a practical oral option for chronic weight management and long term maintenance

Ready to Go Beyond the Basics?

The GLP-1 Handbook is your go to reference, filled with clear guidance and patient ready resources designed for immediate application in your consults.

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Navigating Weight Loss Medications: A Short Course for Dietitians

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Learn More

References

Eli Lilly and Company (2025) Lilly’s orforglipron helped people maintain weight loss after switching from injectable incretins Available at: https://investor.lilly.com/news-releases/news-release-details/lillys-orforglipron-helped-people-maintain-weight-loss-after (Accessed: 15 December 2025).

Some of these approaches are supported by emerging evidence, while others remain largely anecdotal. For health professionals, understanding the range of strategies patients are exploring, as well as the evidence (or lack thereof) behind them, is vital to guiding safe and effective care.

The next section explores these approaches in detail.

Current Long Term Options For Patients

Maintaining the current dose

The Approach

Maintaining the current dose means continuing the patient on their established, well tolerated GLP-1 regimen on an ongoing basis to manage obesity and any related chronic conditions. The aim is to preserve achieved weight loss and glycaemic improvements while avoiding unnecessary dose changes. This approach might suit patients with a stable or satisfactory response, good tolerability and no pressing safety, access, or cost concerns.

What Some Of The Evidence Shows So Far

The SURMOUNT 1 study has highlighted the effectiveness of tirzepatide in managing overweight and obesity long term. Participants on the highest dose (15 mg) achieved an average weight reduction of 22.9% over three years, marking one of the longest documented sustained weight loss effects in obesity pharmacotherapy.

Notably, nearly 99% of participants remained free from diabetes at the 176-week mark. Beyond weight loss, tirzepatide also demonstrated significant improvements in fasting insulin, blood pressure, lipid profiles, and overall glycaemic control, reinforcing its potential role in long-term metabolic health management.

Gradual taper of dose

The Approach

For patients who want to find the lowest effective dose or to discontinue completely, a gradual taper means stepping the GLP-1 dose down in small, planned increments (typically using the same titration steps as initiation, but in reverse) to test whether benefit can be maintained with less medication or none at all.

What Some Of The Evidence Shows So Far

Emerging evidence shows that patients who are weaned off GLP1s over several weeks (with progressively lower doses) experience less rebound hunger and can better maintain weight loss. In a real world study, patients who tapered down to zero over 9 weeks (while receiving lifestyle coaching) actually continued to lose a small amount of weight during the taper, and 6 months after stopping, their weight remained essentially stable.

Spacing out dose frequency

The Approach

Spaced out dosing means extending the interval between GLP-1 injections beyond the approved schedule (for example, taking a weekly medicine less often than once a week). Note that this is considered ‘off label’ and risks reduced efficacy, fluctuating appetite control, weight regain, glycaemic deterioration and dosing errors.

What Some Of The Evidence Shows So Far

A 2025 brief case series using modelling examined less frequent dosing of GLP-1s for weight maintenance. Two patients who spaced doses of semaglutide or tirzepatide maintained a large proportion of their prior weight loss, illustrating feasibility in real-world settings. The simulations suggested that moving from weekly to every 14 days preserved about 70% of weight loss seen with weekly dosing, and even monthly dosing maintained roughly half of the effect. The authors noted this is an off-label strategy and called for controlled trials to validate effectiveness and define who might benefit.

Switching to an alternative (non glp-1) anti obesity medication

The Approach

Switching to a non GLP-1 anti obesity medication means replacing the GLP-1 with another approved weight loss medicine to help maintain weight loss. Research in this area remains limited but emerging evidence provides some guidance.

What Some Of The Evidence Shows So Far

A real world study from a US academic weight service followed adults who reached BMI <30 kg/m² after 12 months on GLP-1s within an 18-month “medical weight loss bundle” (12 months of fully covered anti obesity medication therapy plus 6 months of transition care), then transitioned some patients to older, generic anti obesity medicines (metformin, topiramate, bupropion, naltrexone, and phentermine). Among the 40 patients who moved to generics, weight loss achieved on GLP-1 therapy was largely maintained to 18 months and at a later follow-up (593 days) while off GLP-1s.

Microdosing

The Approach

There is no formal definition of what constitutes a “microdose” for GLP-1 medications. In the real world, it generally involves using doses lower than the established therapeutic amount needed to achieve the intended medical benefit. For example, a patient stepping down from 2 mg of semaglutide weekly might see 0.25 mg as a “microdose,” even though it is the standard approved starting dose. In comparison, someone tapering off completely might use even smaller, non standard amounts, such as 0.125 mg weekly, which is not part of approved dosing guidelines and would require manual adjustment.

What Some Of The Evidence Shows So Far

Research on microdosing is limited, with most insights coming from anecdotal accounts rather than controlled clinical trials. Some clinicians report that patients can achieve and maintain weight loss at lower doses but these observations lack formal scientific validation. One notable real world example comes from the digital weight loss clinic Embla, where patients achieved an average 14.8% weight loss at 64 weeks using a maximum mean semaglutide dose of 0.77 mg, about 36% of the standard cumulative dose, while maintaining effectiveness.

From a regulatory standpoint, microdosing is off label and not endorsed by manufacturers or health authorities. Pharmaceutical companies do not provide instructions for altered dosing, regulators have not included it in approved guidelines, and prescribers may assume greater liability if harm occurs.

Common microdosing methods

Some patients adjust doses by counting the audible “clicks” on injection pens such as Ozempic or Wegovy, allowing for smaller dose changes than officially prescribed. For single dose pens like Mounjaro or Zepbound, some will attempt to extract partial doses by breaking open the device, bypassing its built in precision and safety mechanisms. Others using vials, either compounded or branded, may draw up custom doses with a syringe.

Note that each of these methods carries accuracy and safety risks and manufacturers strongly advise against this due to the risk of inaccurate dosing and medication waste.

Cycling on and off GLP-1s (stopping treatment with planned restart)

The Approach

Cycling on and off GLP-1s means taking a planned break from treatment for a defined period, then re-starting on a schedule agreed in advance. This is an off label strategy and differs from spacing doses or tapering because it includes time completely off treatment.

What Some Of The Evidence Shows So Far

To date, there are no randomised or prospective studies testing GLP-1 cycling for weight maintenance or long term management. Published trials evaluate withdrawal or continuation, not planned breaks with re-initiation. Most information comes from patient forums and social media, where reports are mixed: some describe renewed appetite suppression on re-start, while others report weight gain during breaks and significant nausea on resuming previous doses, often requiring a full re-titration.

Completely Stopping GLP-1s

The Approach

Completely stopping means ceasing the medicine with no maintenance dose or planned re-start. It is usually considered for patients who have reached their goals and prefer to trial life off medication, those with ongoing intolerance, new contraindications, pregnancy plans, access or cost barriers, or a change in clinical priorities. In the real world, this is usually done with or without a tapering off plan.

What Some Of The Evidence Shows So Far

Stopping GLP-1 therapy often leads to weight regain. Multiple studies have documented that patients tend to regain a substantial portion of the weight lost once the medication is discontinued. For example, in the STEP 1 trial extension, patients who stopped semaglutide after 68 weeks of treatment regained about two thirds of the weight they had lost within one year of discontinuation. Similarly, the STEP 4 trial found that patients who discontinued semaglutide and switched to a placebo for 48 weeks regained 6.9% of their body weight.

A 2025 systematic review mapped weight change after stopping anti-obesity medicines across 11 RCTs. On average, there was no significant regain at four weeks versus controls, indicating early weight loss was largely maintained at that point. By week 8, regain had begun and was significant (+1.50 kg versus control), rising to +2.50 kg by week 20; thereafter the trajectory plateaued. Regain was observed across subgroups, with significant regain at 12 weeks in trials of GLP-1s. By 52 weeks, despite some regain versus controls, mean weight still remained below baseline.

Keep in mind that individual outcomes after discontinuation will vary. Not everyone regains all the weight immediately. Some real world data shows promise that a few may maintain their full weight loss for at least one year after stopping GLP-1 therapy, especially if they continue with lifestyle improvements.

Additional Factors in Long Term Outcomes

Exercise could play a key role in weight maintenance

A study examining long-term weight loss maintenance after stopping liraglutide therapy found that combining medication with supervised exercise led to significantly better outcomes compared to using GLP-1s alone or a placebo. One year after discontinuation, those who followed a combined exercise and GLP-1 approach regained less weight (7.1 kg) than those who relied solely on GLP-1s (9.6 kg).

Additionally, participants who engaged in both exercise and GLP-1 therapy saw greater improvements in body fat percentage and waist circumference, indicating better long term body composition maintenance.

Discontinuation rates

A retrospective cohort study of over 125,000 U.S. adults found that nearly two thirds of non-diabetic patients (64.8%) discontinued their GLP-1 therapy within one year. Among patients with type 2 diabetes, discontinuation remained high at 46.5% within the first year. Notably, up to 47% of T2D patients and 36% of non-T2D patients restarted their medication within the same timeframe.

Withdrawal effects

When GLP‑1s are stopped, patients may experience a range of physical symptoms. Appetite and food cravings often return within days or weeks. Some individuals describe hypoglycaemia like effects such as weakness, blurred vision or heart palpitations. Gastrointestinal symptoms including nausea, constipation or diarrhoea are also commonly reported.

There can be notable psychological effects too. Many report heightened anxiety, mood fluctuations or a resurgence of persistent thoughts about food. In some cases, users describe experiences of depression or irritability following cessation.

Frameworks To Consider For Long Term Use and Offboarding

Several professional bodies have developed frameworks to guide clinicians in supporting patients who want to consider long term use or discontinuing GLP-1s altogether. The following summary highlights recommendations from the National Institute for Health and Care Excellence (NICE) and a joint advisory from leading U.S. medical societies, offering structured approaches to follow up care, lifestyle planning, and long term weight management.

National Institute for Health and Care Excellence (NICE)

Quality statement on the advice and support people should receive after stopping weight management medicines.

Ensure that people stopping medicines for weight management:

• Receive feedback and monitoring at regular intervals for a minimum of 1 year so they can get help if they are not maintaining changes

• Have well rehearsed action plans (such as 'if–then' plans) that they can easily put into practice if they are not maintaining changes

• Have thought about how they can make changes to their own immediate physical environment to prevent weight regain

• Have the social support they need to maintain changes

• Are helped to develop routines that support the new behaviour

• Are offered a range of options for follow-up sessions after an intervention active phase

Ensure that weight management interventions encourage people to make lifelong behavioural changes and prevent future weight gain, by:

• Fostering independence and self-management (including self-monitoring)

• Encouraging dietary behaviours that support weight maintenance and can be sustained in the long term

• Emphasising the wider benefits of keeping up levels of physical activity over the long term

• Discussing strategies to overcome any difficulties in maintaining behavioural changes

• Encouraging family-based changes

• Discussing sources of ongoing support once the intervention or referral period has ended

Read more here

American College of Lifestyle Medicine, the American Society for Nutrition, the Obesity Medicine Association, and The Obesity Society

While specific nutritional and other behaviours that contribute to weight maintenance after stopping GLP-1 therapy have not been rigorously studied, a joint advisory from several leading American medical societies highlights that other observational data can show general predictors for successful long term weight reduction.

Recommendations include:

• Lay the groundwork early. Establish nutrition and lifestyle habits during GLP-1 use so they are easier to sustain if treatment stops.

• Make maintenance a primary goal. Aim to preserve health gains for as long as possible.

Predictors of success to reinforce:

• Eat at consistent times, including a regular breakfast.

• Choose mostly minimally processed foods that are rich in protein and fibre.

• Limit sugary drinks, highly processed foods and habitual snacking.

• Allow flexibility with portion controlled treats to avoid rigid restriction.

Supportive behaviours to encourage:

• Target about 60 minutes of physical activity per day, accumulated across the week.

• Monitor weight, food intake and activity consistently.

• Keep discretionary screen time under 10 hours per week.

• Use social support, advance planning and problem-solving to stay on track.

Read more here

Real World Perspectives on Long Term Use

Discussions about GLP-1s in online communities and patient groups reveal a growing acceptance of these medications as ongoing treatment rather than short term interventions. Many clinicians frame obesity as a chronic condition, and this view has filtered into patient conversations, with some describing GLP-1s as part of a permanent lifestyle plan. References to evidence of weight regain after stopping treatment often reinforce this perspective, although sentiment varies widely based on personal experience, cost, and access.

Patient forums such as Reddit and Facebook provide a window into real world management strategies and underline that there is no single agreed upon maintenance pathway. Users often share practical approaches, experimenting with dosing schedules to balance appetite control, side effects, and affordability. Some report success maintaining weight through lifestyle changes alone, but most highlight a rapid return of hunger and weight regain if medication is stopped abruptly, underscoring the need for structured support when adjusting or discontinuing treatment.

Below is a tiny sample of Reddit and Facebook threads that capture common themes from patients and clinicians navigating long term GLP-1 use:

Closing Thoughts

Long term use and discontinuing GLP-1s is unlikely to follow a single, uniform pathway. Patient experiences show that cost, tolerability, lifestyle, and personal goals all influence whether they continue, taper, cycle, or stop altogether. While the evidence base for some of these approaches is developing, clinicians play an incredibly important role by providing structured monitoring, reinforcing sustainable lifestyle practices, and tailoring support to individual needs. Future research will be critical in shaping how health professionals support patients to make confident, informed choices about their long term options.

Ready to Go Beyond the Basics?

The GLP-1 Handbook is your go to reference, filled with clear guidance and patient ready resources designed for immediate application in your consults.

Learn More

Navigating Weight Loss Medications: A Short Course for Dietitians

Want to build a deeper, strategic understanding? This structured course offers theory and real world learning to solidify your expertise and help you navigate GLP-1s with confidence.

Learn More

References

Jastreboff, A.M., Aronne, L.J., Ahmad, N.N., Wharton, S., Connery, L., Alves, B., Kiyosue, A., Zhang, S., Liu, B., Bunck, M.C. and Stefanski, A., 2022. 'Tirzepatide Once Weekly for the Treatment of Obesity'. New England Journal of Medicine, 387(3), pp. 205–216. DOI: 10.1056/NEJMoa2206038.

Gudbergsen H, et al. Embla Clinic study (ECO 2024) – EASO Conference Abstract – Personalized dosing and tapering of semaglutide for weight maintenance (Is coming off semaglutide slowly the key to preventing weight regain? - EASO).

Wu CC, Cengiz A, Lawley SD. Less frequent dosing of GLP-1 receptor agonists as a viable weight maintenance strategy. Obesity (Silver Spring). 2025 Jul;33(7):1232-1236. doi: 10.1002/oby.24302. Epub 2025 May 25. PMID: 40415172; PMCID: PMC12210098.

Paddu NU, Lawrence B, Wong S, Poon SJ, Srivastava G. Weight maintenance on cost-effective antiobesity medications after 1 year of GLP-1 receptor agonist therapy: a real-world study. Obesity (Silver Spring). 2024 Dec;32(12):2255-2263. doi: 10.1002/oby.24177. Epub 2024 Nov 18. PMID: 39558626; PMCID: PMC11589535.

Wilding JPH, Batterham RL, Davies M, Van Gaal LF, Kandler K, Konakli K, Lingvay I, McGowan BM, Oral TK, Rosenstock J, Wadden TA, Wharton S, Yokote K, Kushner RF; STEP 1 Study Group. Weight regain and cardiometabolic effects after withdrawal of semaglutide: The STEP 1 trial extension. Diabetes Obes Metab. 2022 Aug;24(8):1553-1564. doi: 10.1111/dom.14725. Epub 2022 May 19. PMID: 35441470; PMCID: PMC9542252.

Wu, H., Yang, W., Guo, T. et al. Trajectory of the body weight after drug discontinuation in the treatment of anti-obesity medications. BMC Med 23, 398 (2025). https://doi.org/10.1186/s12916-025-04200-0

The Lancet. (2025) 'Healthy weight loss maintenance with exercise, GLP-1 receptor agonist, or both combined followed by one year without treatment: a post-treatment analysis of a randomised placebo-controlled trial' [Accessed 19 Jan. 2025].

Rubino D, Abrahamsson N, Davies M, et al. Effect of Continued Weekly Subcutaneous Semaglutide vs Placebo on Weight Loss Maintenance in Adults With Overweight or Obesity: The STEP 4 Randomized Clinical Trial. JAMA. 2021;325(14):1414–1425. doi:10.1001/jama.2021.3224

Rodriguez PJ, Zhang V, Gratzl S, et al. Discontinuation and Reinitiation of Dual-Labeled GLP-1 Receptor Agonists Among US Adults With Overweight or Obesity. JAMA Netw Open. 2025;8(1):e2457349. doi:10.1001/jamanetworkopen.2024.57349

NICE (2025) Quality statement 7: Advice and support after stopping medicines for weight management or completing behavioural interventions (Accessed: 10 August 2025).

Mozaffarian D, Agarwal M, Aggarwal M, Alexander L, Apovian CM, Bindlish S, Bonnet J, Butsch WS, Christensen S, Gianos E, Gulati M, Gupta A, Horn D, Kane RM, Saluja J, Sannidhi D, Stanford FC, Callahan EA. Nutritional priorities to support GLP-1 therapy for obesity: A joint Advisory from the American College of Lifestyle Medicine, the American Society for Nutrition, the Obesity Medicine Association, and The Obesity Society. Obesity (Silver Spring). 2025 May 30. doi: 10.1002/oby.24336. Epub ahead of print. PMID: 40445127.

Key Findings: Most Patients Stop Within a Year

A retrospective cohort study of over 125,000 U.S. adults found that nearly two thirds of non-diabetic patients (64.8%) discontinued their GLP-1 therapy within one year. Among patients with type 2 diabetes, discontinuation remained high at 46.5% within the first year. Notably, up to 47% of T2D patients and 36% of non-T2D patients restarted their medication within the same timeframe.

So why are so many people stopping? The study highlights several key reasons:

• Gastrointestinal Side Effects: Patients who experienced moderate to severe nausea, bloating, or other GI symptoms were significantly more likely to stop treatment.

• Cost & Accessibility: Income played a role, patients earning less than $30,000 (USD) per year were far more likely to discontinue compared to higher income individuals.

• Weight Loss Impact: The more weight a patient lost, the less likely they were to stop. For every 1% of weight lost, the likelihood of discontinuing decreased by 3%.

What This Means for You

With many patients stopping and restarting GLP-1 therapy, dietitians can play a pivotal role in providing long term support and improving outcomes.

Here are five big opportunities:

1. Offboarding: Guide patients through a structured transition to prevent rapid weight regain post medication.

2. Reinitiation: Assist those restarting GLP-1s by addressing previous challenges.

3. Medication Adherence: Offer accountability and problem solving through regular check-ins.

4. Side Effect Management: Support with the gold standard in managing nausea, bloating, and constipation through education and lifestyle strategies.

5. Cost Effective Alternatives: Help patients explore lower cost medication options or adjust nutrition strategies to sustain weight loss without ongoing GLP-1 use.

Trends to Watch: Could GLP-1 Prices Be Changing?

Liraglutide, the daily GLP-1 injectable sold as Victoza and Saxenda, has officially come off patent, with generic versions recently available in the USA. In Australia, two generic applications are currently awaiting approval. This is a promising step toward reducing costs and increasing accessibility for patients. While the price drop won’t happen overnight, as more manufacturers introduce liraglutide generics, we could see significant savings over time.

For now, newer weekly GLP-1s like semaglutide and tirzepatide remain under patent protection, meaning these generics are still many years away, unless you're in Brazil or China. But this shift with liraglutide could be a sign of what’s ahead!

Thanks for reading!

Leif

Got feedback? Email leif@glp1dietitianhub.com, I'd love to hear from you.

Note: This newsletter is for educational purposes only and should not be considered medical advice. Always consult a qualified healthcare professional for personalised guidance.

Subscribe for free to receive new posts and support my work

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Bridging Nutrition Shortfalls on GLP-1 Therapy

Recognise the Challenge

Patients on GLP-1 medications often experience a significant loss of appetite, which may lead to inadequate nutritional intake. Even when dietitians raise concerns, some patients dismiss under eating because they see rapid weight loss as a success. Acknowledging this mindset is the first step in creating a supportive plan that balances safe weight reduction with optimal nutrition.

Assess Readiness to Change & Use Motivational Interviewing

Before suggesting interventions, identify where the patient may be in their willingness to consider change. Motivational interviewing underpins these conversations by helping patients explore the benefits of adequate nutrition and any ambivalence they might have. Through open-ended questions, reflective listening, affirmations, and summarising, you can guide patients toward recognising the importance of meeting their nutritional needs.

Highlight the Importance of Nutrient Intake

Many patients become more open to change when they understand how nutrition supports their overall health and goals:

• Link nutrition to medication efficacy: Balanced intake can optimise GLP-1 results, stabilise energy levels, and protect metabolic function.

• Explain health risks: Under eating can lead to nutrient deficiencies, fatigue, and muscle loss, which can undermine long term weight management.

• Quantify progress: Encourage baseline and follow up blood tests and consider body composition tools like DEXA scans to track changes beyond the scales.

Offer Practical Strategies

Even if patients are reluctant, small, targeted steps can prevent nutrient shortfalls:

• Protein first approach: Suggest starting meals with a high-protein food, especially if appetite is low.

• Liquid nutrition: For those who find solid food too filling, encourage nutritionally complete shakes or soups fortified with protein and micronutrients.

• Supplement guidance: Consider multivitamins or specific supplements based on lab results and dietary intake.

Individualise Goals and Follow-up

Set realistic expectations and schedule regular reviews:

• Collaborative goal setting: Work with the patient to define “success,” balancing their desire for weight loss with the need to maintain adequate nutrition.

• Frequent feedback: Monitor changes in muscle mass, body composition, and blood tests. Celebrate small wins, such as stable muscle mass or improved lab results.

• Adapt as necessary: If patients show minimal progress or disengagement, move toward a harm reduction approach
  

Respect Autonomy While Providing Guidance

Some patients remain unconcerned about inadequate intake. Continue to provide education and open communication:

• Empowerment: Offer accurate information so patients can make informed decisions, even if they opt not to change.

• Supportive environment: Avoid guilt or shame. Emphasise your role in helping maintain health alongside weight management goals.

When to Refer

If you suspect disordered eating or other mental health barriers, consider referring the patient back to their prescriber. Collaboration with psychologists and other healthcare professionals also promotes comprehensive support.

Key Takeaways

Balancing readiness to change with motivational interviewing can help uncover the reasons behind patients’ reluctance to address their reduced intake. Encouraging baseline and follow-up blood tests, as well as body composition assessments, offers tangible evidence of how low intake may affect their health and goals. By focusing on practical nutrition strategies, ongoing monitoring, and open communication, dietitians can support patients in protecting both their progress and their overall well-being.

Thanks for reading!

Leif

Got feedback? Email leif@glp1dietitianhub.com, I'd love to hear from you.

Note: This newsletter is for educational purposes only and should not be considered medical advice. Always consult a qualified healthcare professional for personalised guidance.

Subscribe for free to receive new posts and support my work

Subscribe

What exactly is Orforglipron?

Orforglipron is a once daily, oral GLP-1 receptor agonist. Unlike typical GLP-1 drugs, which are large molecules, Orforglipron is a small molecule. This structural difference is thought to enhance its absorption within the body, enabling it to be taken orally and offering increased convenience compared to injectable GLP-1s.

What's the latest research saying?

Recent Phase 3 trial results (ACHIEVE-1), released this month, have been very encouraging. They showed significant reductions in HbA1c levels by 1.3% to 1.6% compared to placebo. Participants on the highest dose (36 mg) lost an average of approximately 16 pounds (7.3 kg), representing about 7.9% of their body weight after 40 weeks. This weight loss is comparable to Novo Nordisk’s Ozempic injections but slightly lower than Eli Lilly’s own injectable GLP-1 therapy, Zepbound. As with other GLP-1 medications, side effects primarily involved mild to moderate gastrointestinal issues, including nausea and diarrhoea.

Why is this important?

The introduction of Orforglipron could change how we approach obesity and type 2 diabetes management. Compared to weekly injections, its ease of use and cost effectiveness may improve patient adherence and satisfaction. This could, in turn, broaden the patient base for GLP-1 therapies.

When will it be available?

Eli Lilly plans to submit Orforglipron for weight management approval later this year and expects to submit for type 2 diabetes approval in 2026. Analysts anticipate availability in the US by the second half of next year if the FDA review goes smoothly.

How much will it cost?

Pricing isn't confirmed yet, but US industry experts predict a monthly sticker price just under $1,000, potentially lower than current injectables like Wegovy. Real world costs to patients will likely be lower, considering insurance coverage and patient assistance programs. It's worth mentioning that pricing outside the US is expected to be significantly less.

What more can we expect to learn?

Additional studies involving over 10,000 patients are underway, exploring Orforglipron's effectiveness in broader populations, including those with concurrent obesity, diabetes, cardiovascular disease, and sleep apnoea. More detailed data will be presented at upcoming medical conferences and published in peer reviewed journals throughout this year and next.

What's the impact for dietitians?

As dietitians, this is an exciting opportunity to re evaluate patient education and management strategies around GLP-1 therapies. Easier adherence and potentially fewer barriers to treatment initiation mean that nutritional counselling and lifestyle support could play even more significant roles in patient success. Preparing now by staying updated on this emerging therapy will empower us to best support our patients when Orforglipron hits the market.

References

Melson, E., Ashraf, U., Papamargaritis, D. et al. What is the pipeline for future medications for obesity?. Int J Obes 49, 433–451 (2025). https://doi.org/10.1038/s41366-024-01473-y

Eli Lilly and Company. (2024, April 22). Lilly’s oral GLP-1, orforglipron, demonstrated statistically significant and clinically meaningful reductions in A1C and body weight in adults with type 2 diabetes.

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Leif

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Let’s get into it!

Study Overview

This large retrospective study analysed claims data from over 460,000 US adults newly prescribed GLP-1s between 2017-2022. The majority had type 2 diabetes (80.5%), obesity (44.9%), and were female (56.3%). Researchers tracked nutritional deficiencies for 12 months after starting GLP-1 therapy.

Key Findings

Deficiency Rates Are Substantial:

• 12.7% developed nutritional deficiencies within 6 months

• 22.4% developed deficiencies within 12 months

• Vitamin D deficiency was most common (7.5% at 6 months, 13.6% at 12 months)

The Dietitian Paradox

Here's what's surprising: Patients who saw a dietitian within 6 months were more likely to be diagnosed with nutritional deficiencies:

• 18.5% vs 12.2% at 6 months

• 29.8% vs 21.8% at 12 months

The authors suggest this reflects increased screening and detection rather than dietitian care being harmful, patients referred to dietitians likely had higher baseline risk.

Comparison with Non-GLP-1 Users

When compared to matched patients taking only metformin, GLP-1 users showed higher rates of several deficiencies at 12 months, particularly:

• Vitamin D deficiency

• B vitamin deficiencies

• Thiamine deficiency

Other interesting notes from the study

• 92% of patients hadn't seen a dietitian in the 6 months before starting GLP-1s

• The average time to first dietitian visit was 128 days (over 4 months)

• The authors note that GLP-1s can reduce energy intake by up to 39%, and also stress the importance of hydration monitoring (GLP-1s may suppress thirst).

• B12 testing may be complicated by semaglutide interfering with assay results

Clinical Implications

This study starts to validate what we've observed in practice:
GLP-1s create predictable nutritional challenges that demand proactive, not reactive, intervention. With 1 in 5 patients developing deficiencies within a year, the current "wait and see" approach isn't serving our patients.

Next Steps

Build your referral case: Use this evidence to advocate for dietetic referrals at GLP-1 initiation. The 20% deficiency rate within 12 months provides data to support systematic referral protocols.

Strengthen monitoring protocols: This research reinforces the need for comprehensive baseline assessments and regular follow-up testing. Position yourself as the professional who catches these issues before they become problems.
​
​Elevate your clinical narrative: Frame your services around preventing the documented nutritional complications, not just treating them after they occur. This shifts the conversation from optional to essential.

Read the full study here

Reference

Butsch, W.S., Sulo, S., Chang, A.T., Kim, J.A., Kerr, K.W., Williams, D.R., Hegazi, R., Panchalingam, T., Goates, S. and Heymsfield, S.B., 2025. Nutritional deficiencies and muscle loss in adults with type 2 diabetes using GLP-1 receptor agonists: A retrospective observational study. Obesity Pillars, 15, p.100186. doi: 10.1016/j.obpill.2025.100186.

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Leif

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What exactly is microdosing?

Microdosing involves using doses lower than the established therapeutic amount needed to achieve the intended medical benefit. Originally, the term "microdosing" was associated primarily with psychedelic substances like psilocybin. Today, the concept extends broadly to include small or subtherapeutic amounts of medications, alcohol, supplements, or even certain foods.

The definition of a "microdose" for GLP-1 medications varies based on an individual's treatment stage and prior dosage. For example, a patient who was previously on 2 mg of semaglutide weekly might consider 0.25 mg a microdose, whereas for a new patient just starting treatment, 0.25 mg is the standard introductory dose. Similarly, someone transitioning off the medication might use 0.125 mg weekly as a microdose to gradually taper down.

Reasons people microdose

• Cost Management: GLP-1 medications are expensive, prompting some patients to microdose to stretch medication supplies.

• Medication Shortages: Supply disruptions have led individuals to microdose in order to extend their medication availability.

• Reducing Side Effects: Lower doses may help patients better tolerate common side effects such as nausea or gastrointestinal discomfort.

• Personalised Treatment Approach: Some patients and providers believe that standard dosing increments do not suit every individual and prefer more tailored dosing.

Common microdosing methods

Click Counting (Ozempic and Wegovy)

Some patients microdose by counting "clicks" on their injection pens, which represent incremental dosing adjustments smaller than those officially prescribed. For example, an Ozempic pen produces an audible click with each incremental adjustment. However, manufacturers strongly discourage this practice due to dosing inaccuracies and potential medication waste. Patients choosing this method should always consult closely with a clinician.

Breaking Open Pre-filled Pens (Mounjaro and Zepbound)

For medications only available in single dose pens, patients might manually extract smaller doses by breaking open pre-filled pens. This method bypasses the device's intended precision and safety mechanisms.

Using Vials (Compounded or Brand name)

For vials of GLP-1 medication, people have been manually drawing doses of any size with a syringe.

Is microdosing safe or effective?

Currently, microdosing lacks extensive clinical evidence. Potential concerns include:

• Reduced medication effectiveness from underdosing.

• Increased risks of dosing inaccuracies and contamination.

• Potential for unknown long term health consequences.

Regulatory perspective

Microdosing is considered an off-label practice and is not endorsed by drug manufacturers or regulatory bodies. This means:

• Pharmaceutical companies do not provide guidance or support for these dosing modifications.

• Healthcare providers prescribing off-label doses may assume liability if adverse effects occur.

• Regulatory bodies do not include these strategies in approved guidelines for GLP-1 medications.

Personalising GLP-1 dosing: Insights from recent research

A recent real-world study from Denmark suggests that a personalised approach to semaglutide dosing may help patients achieve significant weight loss while reducing side effects and medication costs. Instead of following the standard dosing schedule, patients in this study were given the lowest effective dose, with increases only if progress stalled.

Key Findings:

• The average maximum dose used was 0.77 mg, significantly lower than the standard dosing for Ozempic and Wegovy.

• Patients lost an average of 14.8% of their body weight at week 64.

• Patients used only around one-third of the typical cumulative dose at week 64 (36.1%).

• Reported symptoms were generally mild

Such findings highlight the potential benefits of personalised dosing strategies, including improved patient outcomes and resource management.

Recommendations for health professionals

Health professionals can play an essential role in patient education by:

• Understanding the rationale behind microdosing.

• Clearly communicating the potential risks and limitations of these practices.

• Encouraging patients to consult their healthcare provider before making dosing adjustments.

• Promoting evidence-based practices to ensure safe, effective patient care.

Microdosing of GLP-1 medications is increasingly common but remains controversial. Staying informed ensures dietitians can provide accurate guidance, support patient safety, and contribute positively to treatment discussions.

Reference

Gudbergsen H, et al. Embla Clinic study (ECO 2024) – EASO Conference Abstract – Personalized dosing and tapering of semaglutide for weight maintenance (Is coming off semaglutide slowly the key to preventing weight regain? - EASO).

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Leif

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Common deficiencies associated with rapid weight loss

• Protein

• Vitamin D

• B12

• Iron

• Calcium

Products that can help fill nutritional gaps

Protein Shakes: Useful for patients struggling to meet protein needs due to reduced appetite.

Nutritionally Complete Meal Replacements: Best used short-term or as a structured part of a meal plan, not a long-term solution.

Multivitamins: Should not replace a food-first approach but can be useful when deficiencies are likely.

Other Commonly Marketed Supplements

These products are widely available, but their necessity and effectiveness vary by individual needs:

Hydration Products

Electrolyte-enhanced drinks can support hydration, particularly for patients experiencing nausea or low fluid intake.

Fibre Supplements

Can be helpful for managing constipation, a common side effect of GLP-1 medications.

Probiotics

May help support gut microbiome balance, especially in patients with digestive discomfort.

Hair, Skin, and Nail Supplements

Often contain biotin, collagen, zinc, and antioxidants, but their role in GLP-1 patients is unclear.

Final Considerations

A food first approach remains best practice, but where intake is insufficient, targeted supplementation can play a valuable role in optimising health and preventing deficiencies. As more evidence emerges, recommendations may evolve. Until then, dietitians should continue to use clinical judgment and a person centred approach.

Thanks for reading!

Leif

Got feedback? Email leif@glp1dietitianhub.com, I'd love to hear from you.

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One of the strangest (and most fascinating) examples I’ve come across was a patient who for years used to compulsively play the chess app on his phone anytime he had a spare second. After starting GLP-1s, he completely stopped. No effort, no decision. Just… gone.

Stories like this might sound unusual, but they’re becoming increasingly common, and researchers are starting to take notice.

What some of the early science suggests

There’s a growing body of research exploring how GLP-1s may influence the brain’s reward system, particularly dopamine signalling in areas like the nucleus accumbens and ventral tegmental area. These pathways are central to both food and substance related reward, which helps explain why GLP-1s might reduce more than just hunger.

In preclinical models, GLP-1s have been shown to reduce alcohol, nicotine, opioid, and cocaine intake, and not just consumption, but also the drive to seek those substances out. In humans, the evidence is still emerging, but what we’ve seen so far is promising.

Alcohol intake declines on GLP-1s

A 2025 study observed the real world effects of GLP-1s (liraglutide and semaglutide) on alcohol use in people with overweight or obesity. Among regular drinkers, average alcohol intake dropped by nearly two thirds after starting GLP-1 treatment, with no participants reporting increased consumption. High consumers reduced their intake from 23 to 8 units per week on average, and low consumers saw their intake halve. While more research is needed, these findings support the idea that GLP-1s may dampen the brain’s reward response to alcohol in much the same way they appear to reduce cravings for food.

Behavioural Addictions

This is where it gets really interesting, although formal research is sparse. Anecdotal evidence, largely from online forums and patient reports, is accumulating. People are sharing stories of unexpectedly losing interest in or stopping behaviours such as:

• Compulsive shopping

• Gambling

• Excessive internet or app usage (just like my chess playing patient!)

The Takeaway

The potential for GLP-1s to influence addictive behaviours is a rapidly evolving area. While preclinical data and compelling anecdotal reports suggest a genuine effect, robust clinical evidence from ongoing trials is needed before these become tools for addiction treatment.

It's definitely something to keep an eye on! Hearing these stories first hand reminds us how complex the interplay between metabolism, brain chemistry, and behaviour truly is.

References

Hornsby, C., Bains, J. S., & Yeo, B. K. (2021). Can GLP-1 Be a Target for Reward System Related Disorders? A Qualitative Synthesis and Systematic Review Analysis of Studies on Palatable Food, Drugs of Abuse, and Alcohol. Frontiers in Psychiatry, 11, 615332

O'Farrell, M., Almohaileb, F. I., & le Roux, C. W. (2025). Glucagon-like peptide-1 analogues reduce alcohol intake. Diabetes, Obesity and Metabolism, 27(3), 1601-1604.

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Leif

Got feedback? Email leif@glp1dietitianhub.com, I'd love to hear from you.

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What Current Research Says

Hair loss, or alopecia, has been reported in clinical trials for GLP-1 medications approved for obesity, though typically not as a common side effect (<5%).

• Semaglutide (Wegovy): Trials showed hair loss in 3% of adults (vs. 1% placebo) and 4% of adolescents (vs. 0% placebo).

• Tirzepatide (Zepbound): Trials reported hair loss in 4-5% of participants (vs. 1% placebo). Notably, this was more frequent in females (7.1%) compared to males (0.5%), though no participants discontinued the trials due to hair loss.

• Tirzepatide (Mounjaro): While not listed as an adverse effect in the official package insert, one 2022 study observed alopecia in 4.9% to 5.7% of users (vs. 0.9% placebo).

Emerging Research & FDA Oversight

Recent pre-print research suggests GLP-1 users might have a higher risk of hair loss compared to those on older weight loss medications like Contrave, particularly women. This potential difference is hypothesised to relate to the greater amount and speed of weight loss often achieved with GLP-1s.

Given the increased attention on GLP-1 side effects generally, the FDA is actively investigating various reports, including hair loss, as part of its ongoing safety monitoring (pharmacovigilance).

Understanding the Causes

The prevailing expert opinion is that hair loss experienced during GLP-1 therapy is not typically a direct pharmacological effect of the drug itself. Instead, it's largely attributed to:

Rapid Weight Loss: This is a well established trigger for a condition called Telogen Effluvium (TE), the most common form of hair loss reported in this context. TE is a temporary condition where hair sheds diffusely across the scalp. It's triggered when major body stress, such as rapid weight loss, causes a high number of hair follicles to prematurely enter their resting state (the telogen phase) instead of their active growing state (the anagen phase). These resting hairs eventually fall out, leading to increased shedding usually seen about three months after the stress started.

Nutritional Factors: Appetite suppression with GLP-1s can lead to reduced overall energy intake and potentially inadequate intake of key nutrients vital for hair health. Deficiencies in protein, iron, zinc, B vitamins (especially B12 and folate), and potentially Vitamin D can contribute to or exacerbate hair thinning.

Lessons from Bariatric Surgery

The experience following bariatric surgery provides a strong parallel. Hair loss is a known and anticipated side effect, generally beginning at 3 months post-surgery. It's linked directly to the rapid weight loss, associated hormonal shifts, and potential nutrient deficiencies. Crucially, in most bariatric cases, hair regrows as weight stabilises and nutritional status improves.

Takeaways for Health Professionals

Hair loss can be distressing for people and potentially impact their adherence and overall wellbeing during their weight management journey.

Here’s a few key areas where we can provide support:

• Inform: Educate patients about potential temporary hair loss associated with GLP-1 medications.

• Reassure: Help patients understand that this hair loss is usually transient and should improve as weight and nutritional status stabilises

• Nutrition guidance: Stress the importance of adequate protein intake and essential micronutrients (especially iron, zinc, B12, folate and vitamin D) during weight loss.

• Advise on Supplementation: Recommend a standard multivitamin or appropriate supplement if dietary intake is compromised (note that over supplementation of Vitamin A has been reported to increase hair loss).

• Refer: If hair loss is causing psychological distress, refer back to prescriber.

References

Diet and hair loss: effects of nutrient deficiency and supplement use - PMC, accessed on 23 March 2025, pmc.ncbi.nlm.nih.gov/articles/PMC5315033

Mounjaro (tirzepatide) prescribing information. Eli Lilly. Indianapolis, IN. Revised July 2023. Accessed March 2025 at uspl.lilly.com/mounjaro/mounjaro.html#pi

Wegovy (semaglutide) prescribing information. Novo Nordisk. Bagsvaerd, Denmark. Revised July 2023. Accessed March 2025 at novo-pi.com/wegovy.pdf

Zepbound (tirzepatide) prescribing information. Eli Lilly. Indianapolis, IN. Revised November 2023. Accessed March 2025 at accessdata.fda.gov/drugsatfda_docs/label/2023/217806s000lbl.pdf

Do Ozempic, Wegovy, Mounjaro & Zepbound cause hair loss?, accessed on 23 March 2025, drugs.com/medical-answers/ozempic-wegovy-mounjaro-cause-hair-loss-3575019medrxiv.org, accessed on 23 March 2025, medrxiv.org/content/10.1101/2025.02.23.25322568v2.full.pdf

Ozempic, Wegovy side effects: Suicidal ideation, hair loss – Medical News Today, accessed on 23 March 2025, medicalnewstoday.com/articles/ozempic-wegovy-side-effects-suicidal-ideation-hair-loss

Telogen Effluvium – British Association of Dermatologists, accessed on 23 March 2025, bad.org.uk/pils/telogen-effluvium/

Thanks for reading!

Leif

Got feedback? Email leif@glp1dietitianhub.com, I'd love to hear from you.

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This week's focus is an important study by Bartel et al. (2024), exploring how GLP-1s, like semaglutide, might impact individuals with eating disorders.

The authors discuss concerns that GLP-1s may unintentionally worsen or even trigger ED behaviours. They point out that increased feelings of fullness and common side effects like nausea or stomach upset could lead to increased dietary restriction, potentially exacerbating ED symptoms. Furthermore, the study raises a critical point about how GLP-1s might complicate standard ED treatment protocols, which generally involve regular meal patterns.

Interestingly, current research into using GLP-1s specifically for binge eating disorder is mixed, often limited by methodological issues. Consequently, there's not yet strong evidence supporting the use of GLP-1s for treating binge eating or other ED symptoms.

The authors suggest several research avenues, advocating for longer-term studies to identify delayed ED symptoms, better measures distinguishing harmful dietary restriction from healthy restraint, and exploration into personalised treatment approaches.

For clinicians, the article provides practical guidance for discussing GLP-1s with patients, emphasising informed decisions, understanding potential risks, and addressing how these medications might interact with ED treatment.

In summary, while GLP-1s offer substantial benefits in managing diabetes and supporting weight loss, dietitians should carefully consider the potential impacts on eating behaviours, particularly among clients who might be vulnerable to EDs.

Read the full study 👇

https://onlinelibrary.wiley.com/doi/10.1002/eat.24109

Reference

Bartel S, McElroy SL, Levangie D, Keshen A. Use of glucagon-like peptide-1 receptor agonists in eating disorder populations. Int J Eat Disord. 2024 Feb;57(2):286-293. doi: 10.1002/eat.24109. Epub 2023 Dec 22. PMID: 38135891.

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Leif

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Choosing the Right Measurement

Measuring body composition isn't a one size fits all approach. It's essential to consider three main factors when deciding which method suits your practice best:

• Cost: Balancing affordable options versus more precise, higher-cost methods.

• Accuracy and Precision: Ensuring reliable and repeatable results.

• Feasibility for Clinical Implementation: Choosing methods that seamlessly integrate into your workflow.
  

In everyday clinical practice, some of the most practical methods include:

• Circumference measurements: Quick, easy, and inexpensive.

• Skinfold assessments: Reliable when performed consistently, though they require practice.

• Bioelectrical Impedance Analysis (BIA): Improved accuracy in recent years, makes it a viable clinical option.

• DEXA (Dual-energy X-ray absorptiometry) remains the gold standard for its precision but can be trickier to use and recommend due to cost/availability.

Understanding Lean Mass Changes with GLP-1s

One of the key topics discussed was the nature of lean mass loss on GLP-1 medications. Weight loss with these medications often involves a higher proportion of lean mass compared to diets alone, such as modest calorie restriction or very low-energy diets (VLED). However, an important nuance highlighted was that lean mass loss doesn't automatically equate to muscle loss. You can indeed experience a reduction in lean tissue but still see improvements in muscle strength.

The primary concern arises if lean tissue reduction is accompanied by a decrease in muscle strength, which could negatively impact health and function. This combination is what truly warrants close monitoring.

When to Measure and How to Use the Data

Before undertaking body composition measurements, clearly define your clinical goal. Ask yourself:

• Why am I measuring body composition?

• How will the results influence clinical decisions or patient recommendations?

Remember, a change greater than 4% in body composition is considered significant, as this surpasses the typical error margin inherent in measurement techniques.

Rethinking Assessment: What Dietitians Can Do Next

There's currently a gap in high quality research assessing muscle changes specifically related to GLP-1s, including how exercise might influence these outcomes. This might present an opportunity for dietitians to contribute through practice. Simple strength assessments, like hand grip tests or validated lower body strength measures, can provide meaningful, functional data alongside body composition measurements. Some may wonder whether this type of assessment falls outside of scope. But with the right upskilling, I believe it's well within reach and well worth incorporating into routine care.

Personally, I believe DEXA remains the ideal method for measuring body composition if it's accessible and affordable, particularly as costs decrease and standalone scanning options become more widespread. If DEXA isn't feasible, BIA is a strong alternative given its practicality and improving accuracy. Incorporating basic strength assessments, along with regular baseline and follow up testing, should become standard practice when managing patients on GLP-1 medications.

Reference

Academy of Nutrition and Dietetics. (2025). Considerations for Body Composition, Physical Activity and Nutrition with Use of Obesity Medications [Accessed 25 May 2025].

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Leif

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Why Might GLP-1 Medications Boost Fertility?

Current consensus is that two primary mechanisms may explain the "Ozempic babies" phenomenon:

Improved Fertility Through Weight Loss

The most significant factor appears to be the relationship between weight loss and fertility improvement. For individuals with obesity, this significant weight loss can lead to:

• Restored ovulation and more regular menstrual cycles

• Rebalanced hormone levels, particularly estrogen, which rises with obesity and can diminish fertility

• Improved symptoms of conditions like PCOS that often coincide with obesity and fertility issues

Medical experts note that each BMI point above 29 decreases female fertility by approximately 5%, making the weight loss effects of these medications potentially significant for fertility.

Potential Interference with Oral Contraceptives

The second mechanism involves how GLP-1 medications might affect the efficacy of hormonal birth control, particularly oral contraceptives:

• The slowing down of gastrointestinal transit time, could affect the absorption of oral medications, including birth control pills

• Side effects like vomiting and diarrhea, could further reduce the effectiveness of oral contraceptives if pills are not properly absorbed

Anecdotally, the risk appears to be highest during titration weeks when patients increase their dosage. However, it's worth noting that while this mechanism is frequently discussed on social media, there is limited published research specifically exploring the relationship between semaglutide and the effectiveness of oral birth control.

Clinical guidance

Regulatory bodies have issued warnings about using GLP-1 medications before and during pregnancy:

• The FDA recommends discontinuing these medications at least two months before a planned pregnancy

• The UK's Medicines and Healthcare Products Regulatory Agency (MHRA) has issued alerts regarding contraception and weight loss injections, stating these drugs must not be taken during pregnancy, while trying to get pregnant, or during breastfeeding

• If unexpected pregnancy occurs, immediate discontinuation of the medication is advised, and patients should seek prompt medical evaluation and regular antenatal care.

• Encourage a conversation with prescriber about non-oral contraceptive methods, especially during titration periods.

Your Conversations Matter

The "Ozempic babies" phenomenon underscores the important role you play in guiding patient decisions about contraception, fertility, and GLP-1 medication use. By fostering open, informed discussions, you can help patients make safe, personalised choices.

As these medications continue to grow in popularity, understanding their full range of effects, including their potential impact on fertility, will remain an important area for ongoing research and public health communication.

References

Cleveland Clinic. (2025). Ozempic Babies. Available at: https://health.clevelandclinic.org/ozempic-babies [Accessed 22 June 2025].

Frank, A. (2024). Ozempic babies: are weight loss drugs leading to unintended pregnancies? BMJ, 388, q2440. doi: https://doi.org/10.1136/bmj.q2440

GOV.UK. (2023). Women on “skinny jabs” must use effective contraception, MHRA urges in latest guidance. Available at: https://www.gov.uk/government/news/women-on-skinny-jabs-must-use-effective-contraception-mhra-urges-in-latest-guidance#:~:text=Women on “skinny jabs” must,in latest guidance - GOV.UK [Accessed 22 June 2025].

University of Texas Southwestern Medical Center. (2025). Surprise Ozempic babies underscore links between obesity and fertility. Available at: https://utswmed.org/medblog/surprise-ozempic-babies-underscore-links-between-obesity-and-fertility/#:~:text=The FDA recommends that people,before becoming pregnant if possible. [Accessed 22 June 2025].

Women's Health. (2025.). Why Are So Many People Getting Pregnant On Ozempic?. Available at: https://www.womenshealthmag.com/weight-loss/a62932157/ozempic-birth-control-fertility-pregnancy/ [Accessed 22 June 2025].

Thanks for reading!

Leif

Got feedback? Email leif@glp1dietitianhub.com, I'd love to hear from you.

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As more patients turn to GLP-1 medications to manage obesity, structured nutrition and lifestyle support has never been more important. A new joint advisory from the American College of Lifestyle Medicine, the American Society for Nutrition, the Obesity Medicine Association, and The Obesity Society offers clear priorities to help clinicians optimise outcomes and mitigate risks.

Here’s a practical summary of key points to apply in practice:

Initiation of GLP-1 therapy with a patient centred approach

Start with a thorough, patient-centred discussion. Ensure patients understand that GLP-1s are an adjunct to lifestyle changes, not a standalone solution. Explore their goals beyond weight alone (e.g. improved energy, mobility, health markers), and screen for barriers such as food insecurity or mental health concerns. Screening for eating disorders is important, noting that restrictive eating disorders are generally a contraindication for GLP-1 use.

Completion of baseline nutritional assessment and screening

A full medical and nutritional assessment should precede initiation. Key checks include: current dietary habits, nutritional status, risk of deficiencies, sarcopenia/osteopenia risk, GI conditions, and psychosocial factors that affect eating behaviour. This is also a time to address any existing nutrient insufficiencies and set realistic expectations for how their appetite and food preferences may change.

Management of gastrointestinal side effects

GI symptoms are common, especially during dose escalation. Proactively counsel patients on smaller, more frequent meals, adequate hydration, and temporary adjustments to food choices to ease nausea and bloating. For constipation, consider increasing fluids and fibre gradually, and using magnesium or other supplements if needed. Help patients avoid the cycle of skipping meals due to nausea, which can worsen symptoms and nutrient intake.

Navigation of dietary preferences and intakes

Expect appetite and food preferences to shift, often away from high fat, high sugar, and ultra processed foods. This can support healthier eating patterns, but reduced interest in food can also risk inadequate nutrition. Encourage nutrient-dense choices and regular eating patterns, and monitor for food aversions or disinterest that could compromise intake. Patients may need support to adjust to their changing relationship with food.

Prevention and mitigation of nutrient deficiencies

Rapid calorie reduction increases the risk of micronutrient deficiencies. Prioritise a diverse diet rich in whole plant foods, lean protein, and healthy fats. Recommend supplementation (e.g. vitamin D, calcium, B12, iron, and multivitamins) as needed, based on individual risk. If appetite is low, small nutrient-dense meals, smoothies, and fortified products can help. Monitor nutrient status regularly.

Preservation of muscle and bone mass

Lean mass loss is a known risk with GLP-1-induced weight loss. To prevent this, protein intake should be optimised with recommendations ranging from 1.2-1.6 g/kg/day during active weight reduction. Some experts suggest 1.5 g per kilogram of lean body mass daily for greater precision. Alternatively, an absolute target of 80-120 grams per day (or 16-24% of total calories on a 2000 calorie diet) may be easier to follow while ensuring adequate intake.

Prioritise high quality protein sources and counsel patients to consume protein first at meals. Equally important is resistance training, at least 3 sessions per week should be encouraged, ideally alongside at least 150 minutes per week of moderate aerobic activity, to preserve muscle and bone health.

Maximisation of weight reduction efficacy

Structured nutrition and lifestyle programs enhance the weight loss effects of GLP-1s. Trials show that intensive lifestyle interventions alongside GLP-1s achieve the greatest weight reductions. Encourage a dietary pattern focused on minimally processed, nutrient dense foods, regular exercise, and behaviour change support (self-monitoring, stress management, sleep optimisation).

Promotion of other supportive lifestyle measures

Don’t forget broader lifestyle factors

• Sleep: Poor sleep undermines GLP-1 efficacy, assess and address where needed.

• Stress management: Chronic stress can drive weight regain; consider CBT or mindfulness based interventions.

• Substance use: Screen for and address alcohol or other substance use that may interact with GLP-1 therapy.

• Social support: Foster social connection through group visits, peer support, or structured programs, as isolation is a risk factor for poor outcomes.

The opportunity for dietitians

With structured nutritional care still underutilised alongside GLP-1s, this is a key opportunity for dietitians to lead. Nutrition counselling can enhance efficacy, prevent side effects, preserve lean mass, and support long term maintenance after medication is tapered or stopped. GLP-1 therapy without this support risks weight regain, nutrient issues, and poor patient experience.

Read the full paper 👇

https://onlinelibrary.wiley.com/doi/10.1002/oby.24336

Reference

Mozaffarian D, Agarwal M, Aggarwal M, Alexander L, Apovian CM, Bindlish S, Bonnet J, Butsch WS, Christensen S, Gianos E, Gulati M, Gupta A, Horn D, Kane RM, Saluja J, Sannidhi D, Stanford FC, Callahan EA. Nutritional priorities to support GLP-1 therapy for obesity: A joint Advisory from the American College of Lifestyle Medicine, the American Society for Nutrition, the Obesity Medicine Association, and The Obesity Society. Obesity (Silver Spring). 2025 May 30. doi: 10.1002/oby.24336. Epub ahead of print. PMID: 40445127.

Thanks for reading!

Leif

Got feedback? Email leif@glp1dietitianhub.com, I'd love to hear from you.

Note: This newsletter is for educational purposes only and should not be considered medical advice. Always consult a qualified healthcare professional for personalised guidance.

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