What to eat on Ozempic, Wegovy or Mounjaro: protein, small meals and side effects

Semaglutide (Ozempic, Wegovy), tirzepatide (Mounjaro, Zepbound) and the other GLP-1 medicines change eating more than any diet does. Hunger goes quiet, a few bites can feel like a full meal, and foods you loved may suddenly not appeal. That is how they work — and it brings a new question: when you eat much less, how do you still eat well?

This article is general information, not medical advice. Your prescriber and, if you have one, your dietitian decide what is right for you.

Why eating feels so different

GLP-1 medicines act on appetite in the brain and slow down how fast the stomach empties. Food stays longer, fullness comes sooner and lasts longer. In the large trials people ate markedly less without trying and lost around 15% of their weight over well over a year on semaglutide, more on tirzepatide.

The slower stomach also explains the most common side effects: nausea, a heavy feeling, reflux, constipation or diarrhoea. They are usually worst in the first weeks and after each dose increase, and often ease with time.

The part people miss: muscle

When weight comes off quickly, not all of it is fat. In trials of these medicines a meaningful part of the weight lost was lean mass, including muscle. Muscle keeps you strong, steady on your feet and helps blood sugar — losing too much of it is not a good trade.

Two things protect it best, and both are in your hands:

• Enough protein. A joint advisory from four obesity and nutrition societies suggests aiming for roughly 1.2–1.6 g of protein per kg of body weight a day (on an adjusted weight if your BMI is high). For many people that is 80–120 g a day.
• Strength exercise. Two or three sessions a week — weights, bands, body-weight exercises — tell the body the muscle is still needed.

Our protein calculator works out a range for your weight, with a GLP-1 option.

How to eat when you are not hungry

• Protein first. Start the plate with fish, chicken, eggs, tofu, Greek yoghurt, cottage cheese or lentils, while you still have room.
• Small and often. Three small meals and a snack sit better than two big ones. Use a smaller plate; stop at the first sign of fullness rather than finishing.
• Slowly. Fullness arrives late on these medicines. Put the fork down between bites.
• Go easy on fat and sugar. Fried, very fatty and very sweet foods are the usual triggers of nausea and a heavy stomach.
• Drink through the day. Eating less also means drinking less from food. Sip water between meals rather than a lot with them.
• Fibre, gradually. Vegetables, fruit, oats and beans help constipation — add them step by step, with enough water.

Don’t let the plate get too small

With very little food, vitamins and minerals can fall short as well as protein. A varied plate — vegetables, fruit, whole grains, legumes, dairy or alternatives — matters more than ever. If you eat very little for a long time, ask your doctor whether you need a blood test or a supplement.

Keeping track without obsessing

On GLP-1 medicines the useful questions change. Not “did I stay under my calories?” — you probably did — but “did I get enough protein?”, “am I drinking enough?”, “which foods make me feel sick?”

foodoo has a GLP-1 mode for this: your medicine and dose schedule with reminders, a daily protein floor worked out from your weight, a short daily check-in about nausea and other symptoms, links between foods and how you felt (only when the data really supports them), and a report you can show your doctor. It can hide calories altogether if numbers don’t help you.