Protein & food on a GLP-1

What to eat

Build meals around protein and fibre, with plenty of vegetables.

• Lean protein at every meal: chicken, turkey, fish, eggs, lower-fat dairy, beans, lentils, tofu.
• Plenty of vegetables: aim for about half your plate.
• High-fibre carbohydrates: wholegrains (oats, brown rice, wholemeal bread), beans and pulses.
• Fruit, especially higher-fibre choices like berries, apples, pears and (for constipation) prunes.
• Nuts and seeds in small amounts, and plant oils.

Aim for about 30 g of fibre a day (build it up slowly to avoid bloating), and drink about 8 to 10 glasses a day (roughly 1.5 to 2 litres) while you’re on an injection, and more if you have sickness or diarrhoea.

What to ease off, and why

A GLP-1 slows how fast your stomach empties, so these tend to make side effects worse.

Fatty and fried foods, creamy sauces, pastry

fat slows the stomach further and can worsen nausea

Large meals and big portions

sickness is more likely after a large meal, so eat small and stop when full

Very sugary foods and drinks

can worsen nausea and diarrhoea

Fizzy drinks

add to reflux and burping

Alcohol

irritates the gut and adds empty calories, so keep it minimal

Caffeine and spicy food

can worsen reflux, burping and stomach upset for some people

Tips that help

• Eat your protein first, so you get it in before you feel full.
• Have small, regular meals, roughly every 3 to 4 hours, and don’t skip meals.
• Eat slowly and stop as soon as you feel full.
• For nausea, try cold foods and ginger or peppermint tea; avoid fatty and spicy meals.
• For reflux, sit upright and don’t lie down straight after eating.
• For constipation, build up fibre and fluid gradually and keep moving.

Common questions

How much protein should I eat on Mounjaro or Wegovy?

During active weight loss, the 2025 joint clinical advisory suggests about 1.2 to 1.6 g of protein per kg of body weight a day, or roughly 80 to 120 g a day for most adults, with a floor of about 60 g. Because carrying extra weight inflates the per-kg figure, the exact basis isn’t settled, so this calculator uses a healthy or adjusted body weight to avoid overstating your needs. Ask a dietitian for a personal figure if you have kidney disease or diabetes.

Why does protein matter so much on a GLP-1?

Rapid weight loss on a GLP-1 can include a lot of muscle, not just fat. Eating enough protein, together with strength training, helps protect muscle while the fat comes off. Protein on its own isn’t enough: the advisory is clear that it needs pairing with resistance exercise.

What should I eat on a GLP-1?

Lean protein at every meal (chicken, fish, eggs, lower-fat dairy, beans, tofu), plenty of vegetables, and high-fibre carbohydrates like wholegrains and pulses. Aim for about 30 g of fibre a day and keep well hydrated. Eating your protein first helps you get it in before you feel full.

What foods should I avoid?

Fatty and fried foods, very large portions, very sugary foods and drinks, fizzy drinks and alcohol tend to worsen the common side effects (nausea, reflux, diarrhoea), because a GLP-1 slows how fast your stomach empties. You don’t have to cut them out entirely, but easing off usually settles your stomach.

I can’t eat much. How do I still get enough protein?

Eat protein first, have small protein-rich meals and snacks through the day, and use easy options like Greek yoghurt, milk, cottage cheese or a protein shake when a full meal feels like too much. If you’re regularly struggling to eat, tell your prescriber.

Do I need to count calories?

The medicine reduces your appetite, so many people don’t. The bigger risks are losing muscle and missing nutrients, so the priority is hitting your protein and fibre, eating a variety of foods, and considering a daily multivitamin. Your prescriber can advise on blood tests.