GLP-1 and Nutrition: A balanced view with everything you need to know
Introduction
GLP-1 medications such as Ozempic®, Wegovy® and Mounjaro® are transforming the landscape of obesity treatment. Yet while the results can be dramatic, they also raise new concerns. From our growing reliance on injections, often without sustainable dietary change, to ensuring adequate protein, fibre and micronutrient intake while on them, and supporting people to come off these drugs safely. With prescriptions now easier to access than ever, it’s never been more important to balance medical intervention with real food education.
How do they work?
The medications work by mimicking the action of the natural hormone GLP-1 and GIP, which helps regulate appetite by normalising our blood sugar response, slowing how quickly food leaves the stomach, and reducing appetite, making people feel fuller sooner and eat less. Although originally created for type 2 diabetes, they are now widely used for weight loss because reduced appetite and slower digestion can lead to significant weight loss.
Tirzepatide (Mounjaro®) is a dual agonist that activates both GIP and GLP-1 receptors, leading to even greater weight loss than GLP-1 only drugs.
What does it all mean?
Originally developed for Type 2 diabetes, Glucagon-Like Peptide-1 (GLP-1) and Gastric Inhibitory Polypeptide (GIP) are receptor agonists that mimic the action of the hormones GLP-1 and GIP that are released by your gut after eating to help control blood sugar by stimulating insulin release in the pancreas and reducing another hormone called glucagon (which can increase our blood sugar), while increasing fullness to reduce appetite. The receptor agonists have also been used by millions of people worldwide to improve blood sugar control and help combat obesity in a bid to prevent comorbidities such as high blood pressure, cardiovascular disease and metabolic disorders.
The medication Semaglutide is licensed under the brand names Ozempic® (for diabetes) and Wegovy® (for weight management), while Tirzepatide is licensed as Mounjaro® for obesity and weight loss.
I have also heard about drugs called DPP4- inhibitors. What are these?
DPP-4 inhibitor medications are sometimes used in Type 2 diabetes to SLOW down the breakdown of GLP-1 making it active for LONGER. An example would be Sitagliptin or Linagliptin. It is estimated that GLP-1 can circulate for around 2-3 times longer with this drug and it is ONLY licensed for Type 2 diabetes, rather than weight loss. DPP-4 drugs have less side effects than Semaglutide but are also less effective when it comes to weight loss. They might be used as an alternative to Semaglutide, but are not used alongside.
When might weight loss injections be recommended?
Weight loss injections are prescribed for people with Type 2 diabetes and obesity, or those with a high BMI who may have tried and struggled with diet-only approaches. For these people, injections can be life-changing because they make blood sugar control easier, support weight loss, and protect the heart and kidneys, helping people feel healthier, more energised, and back in control of their lives.
What are the NICE* guidelines for prescribing
Weight Loss: GLP-1 treatment is generally considered for individuals with a BMI over 35, or occasionally at a lower BMI if weight reduction would significantly improve other health conditions, such as hypertension, Type 2 diabetes or increased risk of cardiovascular disease. They should be used alongside a specialist dietary therapy for a maximum of 2 years. These medicines are therefore most effective when used alongside lifestyle changes, including healthy eating and physical activity.
Type 2 Diabetes: The latest NHS and National Institute for Health and Care Excellence (NICE) guidance says that GLP-1 medicines, like Ozempic® and Wegovy®, can be prescribed for people with Type 2 diabetes when other treatments aren’t working effectively or can’t be tolerated. They’re designed to help the body manage blood sugar more effectively but they can also support weight loss.
NICE has also indicated that GLP-1 medicines may in future be offered earlier, rather than as a final option. This reflects emerging research showing that these medicines can help protect the heart and kidneys in addition to managing blood glucose levels, marking an important development in the long-term management of Type 2 diabetes.
(*NICE guidelines are evidence-based recommendations from the National Institute for Health and Care Excellence for health and social care in England and Wales).
The challenges and side effects
There can be downsides of using these medicines as many users report side effects such as nausea, diarrhoea, constipation, and abdominal discomfort, and in some cases gallbladder disease or pancreatitis. These often decrease over time, but can persist in some people.
A significant drawback is that much of the weight lost can include muscle mass, with estimates of muscle mass accounting for up to 25–45% of total weight lost, which is mostly higher than with diet alone and can affect long-term health, metabolism, and strength.
The reality is that while weight loss injections help reduce food intake, unless eating habits adapt, weight regain is highly likely once medication stops. Eating half of our favourite foods now can mean going back to old portion sizes later, once appetite returns.
Users of weight loss jabs are advised to eat a healthy, balanced diet focusing on protein (meat, fish, eggs, dairy, plant-based options), fibre-rich foods (vegetables, beans, whole grains), and healthy fats (nuts, seeds, avocado, olive oil), while limiting ultra-processed foods, refined carbs, sugary snacks, and alcohol.
How they affect appetite and food choices
Taking these types of medication helps the body regulate hunger and fullness more effectively, which can make managing food choices and maintaining a healthy weight more achievable. However, here’s how that might affect our appetite and what we choose to eat.
1. Reduces appetite
Ozempic® and other similar medications activate receptors in the brain that respond to GLP-1, helping people feel satisfied sooner after eating. Many individuals report a noticeable reduction in hunger and food-related thoughts, making it easier to manage portion sizes and avoid unnecessary snacking.
2. Slows digestion
It also slows the rate at which food leaves the stomach. This delay helps maintain a feeling of fullness for longer, which can naturally reduce overall food intake throughout the day.
3. Alters food preferences
Some people find that they crave healthier foods and smaller meals while taking the medication, whereas others find that their food choices unintentionally become less healthy. This is often because healthier foods (that are rich in fibre and protein) are more filling and can therefore make people feel overly full.
BANT’s Key Recommendations
BANT is the British Association for Nutrition and Lifestyle Medicine, the UK’s professional body that sets standards, provides guidance and supports safe, evidence-informed practice for registered nutritional therapists. It’s the body that I am registered with as a Nutritionist.
The following is just part of the guidance that BANT recommend on all GLP-1 weight-loss medications, which includes Wegovy®, Ozempic® and Mounjaro®.
1. Personalised Support
Work with a registered Nutritionist, Dietician or Nutritional Therapist to review eating habits, health history, and any emotional triggers around food. Ongoing support helps people make lasting changes.
2. Manage Side Effects
Nausea, constipation, or bloating are common early on. Eating small, balanced meals, staying hydrated, and avoiding large or high-fat meals can help ease symptoms. Ginger or peppermint tea may help to reduce nausea.
3. Eat for Nourishment
As appetite often decreases, focus on quality over quantity.
BANT identifies key nutrients at risk, including:
- Iron – important for energy and preventing anaemia
- Calcium – for bone strength and muscle function
- Magnesium – supports energy production and bowel regularity
- Zinc – needed for immune function, wound healing, and taste
- Vitamins A, D, E, and K – fat-soluble vitamins often reduced with low food or fat intake
- B vitamins, particularly B1 (thiamine) and B12 – essential for energy and nerve health
- Vitamin C – supports the immune system and iron absorption
Choose nutrient-dense foods with plenty of protein, fruit, vegetables, and whole grains. Aim for 30g fibre a day (veg, beans/lentils, fruit, whole grains, nuts/seeds) which helps feelings of fullness, gut health, and blood sugar balance. Eating sufficient fibre wtih adequate hydration may also help reduce constipation.
Every mouthful counts on these medications as less food equals less nutrients so nutrition needs to be BETTER than ever.
Avoid relying on processed, sugary, or energy-dense snacks which are mostly high in sugar and salt, high in free carbohydrates and food additives, and often low in protein, fibre and nutrients.
Consider a multivitamin or key nutrient supplements if intake is low.
4. Protect Muscle and Bone Health
Aim for 80–120 g of protein per day and include regular strength-building exercise at least three times a week. Too little protein does not just lead to muscle and bone loss it affects nearly every system in the body. Protein provides the building blocks for every single body cell, enzymes, neurotransmitters, and hormones, all of which are essential for healthy brain function and balanced mood. Many hormones and antibodies are made from proteins, so a lack of protein can also weaken the immune system. Proteins are vital for cell repair, regeneration, and the countless chemical reactions that keep the body functioning well every day.
5. Maintain Healthy Habits
Good sleep, stress management, physical activity, and positive social connections all support sustainable weight management and overall wellbeing.
6. Ongoing Monitoring
Regular check-ins and progress tracking help prevent nutrient deficiencies, ensure safe weight loss, and reduce the risk of weight regain when medication stops.
What is microdosing?
Microdosing weight loss jabs refers to people taking smaller doses of GLP-1 medications (like Ozempic®, Wegovy®, or Mounjaro®) than the amounts used in standard treatment plans. This is still seen as a newer area of science and while this is being used, we still lack sufficient research and protocols of how to do this. Microdosing normally involves using the lowest dose of the medication and sometimes leaving longer gaps in-between doses than would usually be recommended. We currently have very little clinical data on the lower dose use of these medications and how effective they might be. As a result microdosing is not currently an approved practice prescribed by the NHS in the UK.
Why people do it
To reduce side effects: Some people find nausea, constipation, or fatigue easier to manage with a lower dose.
To maintain weight loss: Some use smaller “maintenance doses” after reaching their goal weight to try to prevent regain, although we do not have much data to show that this is effective.
To save money: Because these injections can be expensive, some stretch out pens or use smaller self-administered doses to make them last longer.
Why doctors are cautious
It’s still off-label: Dose changes outside a prescribed plan aren’t medically approved or well-researched.
Effectiveness drops: Too small a dose may not produce the same appetite or metabolic effects seen in clinical trials.
Safety concerns: Dosing errors can happen easily with self-adjustment, and long-term impacts of microdosing haven’t been studied.
So while the idea of “microdosing” sounds appealing, experts currently advise against doing this unless under medical supervision.
Personalised Nutrition and why it makes all the difference
GLP-1 medications are powerful tools, but they work best when combined with nutrition and lifestyle changes. Without these, individuals risk regaining weight when treatment stops. A balanced, protein and fibre-rich diet enhances the body’s natural GLP-1 response and supports long-term metabolic resilience.
Think of the injection as one tool – not the whole plan. The real magic happens when it’s paired with the right nutrition and lifestyle support. Nutritional therapy can play a huge role here.
A well-qualified nutrition professional can help you design meals that keep your blood sugar stable, protect your muscle mass, and ensure you’re still getting enough protein, fibre, and micronutrients — even when your appetite drops.
After taking these medications people are anxious to come off and unless they have learned a NEW way of eating that supports healthy eating, people are likely to gain more weight again afterwards.
Working with a nutrition professional while taking GLP-1 medication can also:
- Reduce the risk of nutritional deficiencies.
- Help manage or prevent side effects like nausea or constipation.
- Support you emotionally as eating patterns change.
- Guide you through a gradual transition off injections, helping you build lasting food habits that make weight regain far less likely.
Because ultimately, when medication stops, food has to take over again — and that’s where a personalised nutrition plan becomes your safety net.
Things to watch out for
Some people taking GLP-1 medications may find it harder to eat sufficient high-fibre or protein-rich foods, as these can feel too filling. While some people do manage to eat a healthy diet and manage to meet their macro and micronutrient requirements, it is also common to crave less filling carbohydrate rich foods, or to feel a bit more relaxed about food choices, knowing that the medication alone will lead to weight loss. However, maintaining a balanced, nourishing diet remains just as important for long-term health.
These medicines can help reduce appetite and support weight loss, but without careful support, people can risk losing muscle and bone mass, missing out on key nutrients, or regaining weight once treatment stops.
Foods that naturally raise GLP-1
Did you know that eating the right foods can naturally increase your GLP-1?
We have cells called L-cells that are mainly located in the distal ileum and colon which are a bit further down in our gut. These cells ‘sense’ our food and can produce GLP-1 when we consume sufficient fibre, amino acids, fatty acids and whole food carbohydrates. These digest slowly and are more likely to reach the specialised L-cells in the gut.
Fibre rich foods like beans, lentils, vegetables, nuts, seeds, and whole grains help the gut microbes produce short-chain fatty acids that also stimulate GLP-1, making fibre a key player in GLP-1 secretion.
GLP-1 secretion is greatest when meals contain sufficient proteins, such as fish, poultry, eggs, dairy, soy, and legumes, along with healthy fats from oily fish, olive oil, avocado, nuts, and seeds, which also encourage its release.
Having a slower and more sustained digestion alongside a diverse microbiome is also important.
These foods can help to regulate our appetite naturally by giving our brain the correct hunger and satiety cues; can improve our metabolic health, help us maintain our muscle mass as well as creating a healthy gut microbiome. All of these are powerful tools for natural, sustainable weight management.
Ultra processed foods, snack foods, or foods rich in refined carbohydrates and sugars digest rapidly in the gut. This means that they can bypass the L-cells lower down in the gut and lead to lower GLP-1 release and greater hunger.
How a nutritional approach can help
For some people medication is necessary, however here is how a nutrition approach might be helpful.
- Food First – if you have less than 2 stone/12 kg to lose, always try a food first approach first.
- Follow a structured plan while you are taking medication to support muscles, bones, energy and nutrients.
- Get support when you come off the drugs so that your diet takes over.
There are lots of nutrition plans available, however one approach might be Renew Reset Recharge®.
Renew Reset Recharge® is a science led programme which combines the latest research alongside 20 years of clinical know-how. Many people join who have tried other programmes and find that this programme delivers while also being easy to follow and with nutrient dense foods.
Renew Reset Recharge® teaches long-term healthy eating principles such as:
- Eat 3 nutrient dense meals a day
- Fast 12-14 hours overnight to rest digestion and support fat burn
- Stop eating 3-hours before bed to allow food to leave stomach
- Leave 4-5 hours between meals to digest and metabolise foods
- Prioritise a balanced plate at each meal
- The programme naturally includes protein and fibre to support our natural GLP-1 and uses real food so that you feel satisfied and nourished.
Renew Reset Recharge® resets your appetite and reduces cravings in 80% of participants and a weight loss average of between 3-4kg in 28 days.
People say Renew Reset Recharge® is not only the easiest programme they have ever followed, but it is so popular because it supports many areas of your health simultaneously.
What it is NOT…
- Just another programme with a calorie deficit.
- A yoyo diet plan where you end up heavier that when you started
- A plan that only supports you in weight loss
What it IS…
- A science led nutrition programme to transform your health and change the way you eat forever.
- A programme that fits easily into everyday and family life.
- A programme that intuitively becomes a beautiful way of eating for the rest of your life – no restriction, just a handful of principles that work.
- It’s like a magic key to your metabolism, you will learn how to lose weight easily and maintain your weight effortlessly.
- A healthy eating nutrition programme, based on simple principles that you can use anywhere – no number crunching / no calculations
A programme ALSO created to:
- Support healthy blood sugar control
- Improve energy, mood and sleep
- Support better digestion and less bloating
- Reset your appetite and control food cravings
- Reduce pain and inflammation
- Reframe your relationship with food – take the STRESS out of eating
- It is fantastic as a stand alone programme to lose weight and reset. You will be in a GROUP which develops a sense of community during your journey AND you will have access to Dominique for weekly group ZOOM calls where you can ask all your questions to help you stay on track.
You can join the zoom calls longer term if you choose, or if you have a goal that will exceed 28 days – you will soon become your own nutrition expert.
Click HERE to find out all you need to know about Renew Reset Recharge®
References:
Ahrén, B. et al., 2017. Efficacy and safety of once-weekly semaglutide versus once-daily sitagliptin as an add-on to metformin, thiazolidinediones, or both, in patients with type 2 diabetes (SUSTAIN 2): A 56-week, double-blind, phase 3a, randomised trial. The Lancet Diabetes & Endocrinology, 5(5), pp.341–354.
BANT (British Association for Nutrition and Lifestyle Medicine), 2024. Guidance for Supporting Clients Using GLP-1 Weight-Loss Medications. London: BANT.
Brown, E., Wilding, J.P.H. & Barber, T.M., 2021. Glucagon-like peptide-1 receptor agonists for obesity: Guideline-aligned clinical use. Diabetes, Obesity and Metabolism, 23(4), pp.761–777.
Carbone, S., Dixon, D.L. & Canada, J.M., 2023. Off-label use and dosing uncertainties of GLP-1 receptor agonists. Journal of Clinical Endocrinology & Metabolism, 108(2), pp.345–356.
Chambers, E.S., Viardot, A. & Psichas, A., 2015. Effects of dietary fibre on short-chain fatty acid production and GLP-1 release in humans. Nature Communications, 6, pp.1–10.
Corbin, K.D. et al., 2020. Dietary fibre intake improves glycaemia via mechanisms involving GLP-1. Diabetes Care, 43(6), pp.1295–1302.
Fardet, A., 2016. Minimally processed foods versus ultra-processed foods: Implications for satiety and gut signalling. Nutrients, 8(12), pp.1–17.
Frias, J.P. et al., 2018. Tirzepatide versus dulaglutide in type 2 diabetes: A randomised, phase 2 trial. The Lancet, 392(10160), pp.2180–2193.
Gade, J., Beck, A.M. & Christensen, R., 2021. Changes in lean body mass with GLP-1 receptor agonist therapy: A systematic review and meta-analysis. Diabetes, Obesity and Metabolism, 23(4), pp.1001–1012.
Gallwitz, B., 2019. Clinical use of DPP-4 inhibitors and their effect on endogenous GLP-1 activity. Diabetes, Obesity and Metabolism, 21(S1), pp.3–11.
Gerstein, H.C. et al., 2019. Dulaglutide and cardiovascular outcomes in type 2 diabetes (REWIND). The Lancet, 394(10193), pp.121–130.
Hall, K.D. et al., 2019. Ultra-processed diets cause excess calorie intake and weight gain: A controlled inpatient trial. Cell Metabolism, 30(1), pp.67–77.
Hallberg, S.J. et al., 2023. Weight regain trajectories after GLP-1 receptor agonist discontinuation. Obesity, 31(6), pp.1188–1196.
Hursel, R. & Westerterp-Plantenga, M.S., 2016. Appetite suppressants and risk of micronutrient inadequacy. Obesity Reviews, 17(4), pp.319–329.
Jastreboff, A.M. et al., 2022. Tirzepatide once weekly for the treatment of obesity. New England Journal of Medicine, 387(3), pp.205–216.
Johansson, L. et al., 2022. Effects of semaglutide on eating behaviour, appetite, and food choices. Diabetes, Obesity and Metabolism, 24(3), pp.340–349.
Kuhre, R.E. et al., 2016. Fatty acids stimulate GLP-1 secretion via G-protein coupled receptors in human L-cells. Endocrinology, 157(1), pp.282–294.
Lean, M.E.J. et al., 2019. UK obesity management: Evidence and guidance update. Obesity Reviews, 20(1), pp.12–27.
Lee, Y.H. et al., 2022. GLP-1 receptor agonists and risk of gallbladder or biliary diseases: A systematic review and meta-analysis. JAMA Internal Medicine, 182(5), pp.513–519.
Leidy, H.J. et al., 2015. Higher protein intake preserves lean mass during weight loss. American Journal of Clinical Nutrition, 101(6), pp.1320–1329.
Liu, J. et al., 2020. GLP-1 receptor agonists and pancreatitis risk: Updated meta-analysis. Diabetes, Obesity and Metabolism, 22(6), pp.1008–1018.
Mulvihill, E.E. & Drucker, D.J., 2016. Pharmacology, physiology and mechanisms of action of DPP-4 inhibitors. Endocrine Reviews, 37(6), pp.734–772.
Nauck, M.A. & Meier, J.J., 2018. Incretin hormones: Their role in health and metabolic disease. Diabetes, Obesity and Metabolism, 20(S1), pp.5–21.
NICE (2024). GLP-1 Receptor Agonists. [online] NICE. Available at: https://cks.nice.org.uk/topics/diabetes-type-2/prescribing-information/glp-1-receptor-agonists/
Nuttall, J.P. et al., 2021. Dietary protein and amino acids stimulate GLP-1 secretion and improve appetite regulation. Nutrients, 13(12), p.4448.
Phillips, S.M. et al., 2016. Protein intake to support metabolic health and muscle preservation during weight loss. Advances in Nutrition, 7(3), pp.620S–628S.
Reynolds, A. et al., 2019. Carbohydrate quality and human health: Systematic review and meta-analysis. The Lancet, 393(10170), pp.434–445.
Rubino, D. et al., 2022. Weight regain and cardiometabolic effects after withdrawal of semaglutide. Diabetes, Obesity and Metabolism, 24(9), pp.1553–1564.
van Can, J. et al., 2019. GLP-1 receptor agonists reduce hunger and influence food preference in humans. International Journal of Obesity, 43(2), pp.315–323.
Wilding, J.P.H. et al., 2021. Once-weekly semaglutide for weight management in adults with obesity. New England Journal of Medicine, 384(11), pp.989–1002.
Wharton, S. et al., 2022. Gastrointestinal tolerability and side-effect profile of GLP-1 receptor agonists: Systematic review. Obesity Reviews, 23(3), p.e13355.
Zhou, Y. et al., 2021. Body composition effects of GLP-1 receptor agonists: Meta-analysis. Obesity Reviews, 22(10), e13388.
Disclaimer:
Features published by Dominique Ludwig are not intended to treat, diagnose, cure or prevent any disease. Always seek the advice of your GP or another qualified healthcare provider for any questions you have regarding a medical condition, and before undertaking any diet, exercise or other health-related programme. Please refer to our Terms and Conditions and Medical Disclaimer for more information as well as our Website Terms and Conditions.
Written by Dominique Ludwig and supported by Lyndsey Mayhew
