GLP-1 diet: what to eat on Mounjaro, Wegovy or Ozempic, meal by meal

A few weeks in, the scene keeps repeating: dinner arrives, you eat half of it, and you put your fork down without a struggle. That is the medicine doing what it is meant to do. It is also the moment many people type "GLP-1 diet" or "what to eat on Mounjaro" into a search engine, because nobody told them what to do with that half-plate.

The question is more serious than it sounds. When you eat less, everything left on the plate counts for more. The papers published over the past two years say much the same thing: quantity takes care of itself, and it is the make-up of meals that needs attention.

There is no official GLP-1 diet

No health authority has published a diet specific to these medicines, and the product information for Ozempic (semaglutide), Wegovy (semaglutide) and Mounjaro (tirzepatide) contains no meal plan. For weight management, the licences describe the treatment as an addition to a reduced-calorie diet and increased physical activity, and leave it there. NICE uses the same form of words.

The gap has been filled by doctors and dietitians. In 2024, a group led by Jaime Almandoz and Thomas Wadden published a review in Obesity of the nutritional guidance to give patients. In 2025, four American learned societies, among them the Obesity Society and the American Society for Nutrition, signed a joint advisory in the same journal (Obesity, 2025). Both texts rest on expert opinion more than on trials comparing one diet with another. For want of anything better they serve as the reference, and this guide draws on them.

What gets called a GLP-1 diet therefore comes down to a few words: ordinary food, dense in nutrients, served in small portions. Nothing is forbidden. No food speeds up the effect of the medicine.

Less room on the plate, the same needs

People on treatment eat markedly less: a review in Obesity Pillars, 2024 gathered the studies that measured it and found a 16 to 39% drop in calories consumed. Almost none of them looked at what was on the plate.

Yet the need for protein, vitamins and minerals does not shrink with appetite. A meal cut by half supplies half the calcium, iron and vitamin B12, unless its composition changes. The 2025 advisory places the zone of caution below 1,200 kcal a day for women and 1,800 kcal for men, thresholds under which it becomes hard to cover your needs from food alone.

Nobody needs to count calories for all that. It is usually enough to start with what nourishes, and never mind if you are full before you get to the bread.

Protein first

This is the first piece of advice in every reference text, because rapid weight loss does not only take fat. In the body composition sub-study of the STEP 1 trial, lean mass accounted for 5.3 of the 13.6kg lost on semaglutide, according to the figures quoted in the 2025 advisory. With tirzepatide, the equivalent analysis from SURMOUNT-1 puts it at about a quarter (Diabetes, Obesity and Metabolism, 2025). Lean mass is not the same thing as muscle, and we go through those numbers in our article on muscle loss on Ozempic and similar medicines.

For a healthy adult, the UK reference nutrient intake is 0.75g of protein per kilo of body weight a day. During weight loss, the experts aim higher. The 2024 review recommends at least 60 to 75g a day, and the 2025 advisory cites a range of 1.2 to 1.6g per kilo, while admitting that it is unclear which weight to base the sum on in someone living with obesity.

In practice that means a source of protein at every meal, breakfast included, and eating it first, before fullness arrives. Eggs, fish, chicken, dairy, beans and lentils, tofu: the choice is wide, and a tin of sardines or a pot of cottage cheese counts as much as a chicken breast.

On days when nothing will go down, liquids are often better tolerated than solids. A glass of milk, a drinking yoghurt, a smooth lentil soup or a bowl of Greek-style yoghurt are all ways of getting there.

Fibre and fluids, without rushing your gut

Constipation is one of the very common side effects listed for Wegovy, meaning it affects more than one person in ten.

Fibre helps, as long as you go gently. The UK recommendation is 30g a day for adults, and the NHS notes that most of us average about 20g. On treatment it is wiser to approach it in steps, with cooked vegetables, fruit, porridge oats and small amounts of pulses. The 2025 advisory even suggests limiting very high-fibre foods in the first days after a dose increase, when nausea dominates.

Fluid goes with it. The 2024 review settles on more than 2 to 3 litres of drinks a day. The figure looks high when you are eating little, because people who eat little often drink little too. A water bottle within reach, small sips between meals in place of large glasses with them, and you get close.

What goes down badly, and why

A stomach that empties slowly copes poorly with big meals and fatty meals. Most digestive discomfort on treatment comes from that, and most of it eases by adjusting the volume and texture of meals more than by cutting foods out.

The advice on nausea, constipation and alcohol comes from the 2025 joint advisory; the rest reflects the everyday experience of clinicians. All of it describes tendencies, and everyone then discovers their own limits. The wider picture of what these medicines can do to digestion is in our guide to GLP-1 side effects.

Alcohol deserves a word of its own. The experts recommend keeping it to a minimum, because it can add to nausea and reflux and supplies calories with nothing else attached. We look at the question in detail in Mounjaro and alcohol.

Repeated vomiting, severe or persistent abdominal pain, being unable to keep fluids down: these are not matters for the kitchen. They need reporting promptly to your prescriber, GP or NHS 111.

What a day looks like

Three small meals and one or two snacks often suit people on treatment better than a conventional lunch and dinner. The 2025 advisory mentions regular eating at set times, every three to four hours, for those who can no longer manage much at one sitting.

In the morning, Greek-style yoghurt with porridge oats and a piece of fruit, or two boiled eggs and a slice of wholemeal toast. At lunch, a palm-sized portion of fish or chicken, cooked vegetables, two or three spoonfuls of rice or potato. Mid-afternoon, a yoghurt and a few nuts. In the evening, a red lentil soup or a leek omelette.

For anyone who prefers a ready-made plan, we have put together a 7-day GLP-1 diet plan with portions, a shopping list and the protein supplied by each day.

Vitamins and minerals, the quiet watch

Eating less for months on end can leave intakes of some micronutrients short, and the experts ask for them to be monitored. The 2025 advisory names iron, calcium, magnesium, zinc and several vitamins, D and B12 among them.

The first answer is variety: dairy or calcium-fortified alternatives, oily fish, eggs, green vegetables, pulses, fruit. The second is medical follow-up, since only a blood test can tell whether a deficiency exists. If you are worried that you are eating very little, ask your prescriber or a registered dietitian before buying a supplement.

Movement counts as much as the menu

Protein alone will not keep your muscles: they also need to be used. The American societies recommend pairing treatment with a structured exercise programme, with strength training at least three times a week and at least 150 minutes of moderate aerobic activity. The NHS guideline for all adults points the same way: 150 minutes of moderate activity a week, plus strengthening activities on at least two days.

Strength work does not require a gym. Squats, press-ups against a wall or resistance bands are enough to begin with, provided the effort is regular.

What to eat on Mounjaro, Wegovy or Ozempic: the same framework

The guidance does not change from one medicine to the next. Semaglutide and tirzepatide reduce appetite and slow the stomach by closely related routes, and none of the reference texts varies its dietary advice by molecule.

What does change is each person's situation. Someone with diabetes, someone whose kidneys work poorly, an older person or an athlete will not have the same needs or the same precautions to take. Protein amounts in particular should be discussed with a doctor or dietitian if you have kidney disease. This guide describes a general framework and is not a prescription.

Then there is what comes next. The extension of the STEP 1 trial showed that part of the weight returns after semaglutide is stopped (Diabetes, Obesity and Metabolism, 2022), a subject we cover in coming off Mounjaro or Wegovy. Knowing how to put together a small, complete plate is more or less the one thing you take with you.

Frequently asked questions

What diet should you follow on a GLP-1 medicine?

No particular diet is required. Experts recommend varied, nutrient-dense food, with a source of protein at each meal, fibre increased gradually and enough to drink. Portions shrink of their own accord as appetite falls.

What foods should you avoid on Mounjaro, Wegovy or Ozempic?

No food is off limits. Fatty meals, fried food and large portions are the ones most often poorly tolerated, especially after a dose increase. Alcohol is best cut back, because it can add to nausea and reflux.

How many meals a day should you eat?

There is no rule. Three small meals and one or two snacks, at regular times, suit many people who can no longer eat large amounts. Skipping meals mostly makes it harder to get enough protein.

What should you eat when you really are not hungry?

Small amounts of protein-rich foods that are easy to swallow: yoghurt, cottage cheese, an egg, lentil soup, fish, a glass of milk. Spreading them over five or six small helpings makes it easier to reach your intake without forcing yourself.

Can you do keto or intermittent fasting on weight loss injections?

The reference texts do not recommend it, and no trial shows a benefit from stacking another restriction on top. A diet that cuts out whole food groups raises the risk of falling short when you are already eating little. It is a decision to take with your doctor.

This article is for information only and is no substitute for advice from a healthcare professional. Never change your treatment without talking to your doctor.