What should I eat first at a meal on a GLP-1?

The protein. You may only manage a third of what you used to, so whatever is eaten first is what you actually get. Protein, then vegetables and fibre, then the starch.

How much protein do I need on these drugs?

Expert guidance for weight loss on GLP-1 therapy converges on roughly 1.2 to 1.6 g per kg of body weight a day, higher if you are training for muscle. Work your own figure out with the protein calculator; the harder part is hitting it when four bites fill you up.

Should I use protein shakes?

They are a reasonable tool rather than a requirement. When solid food is unappealing or you cannot physically fit enough in, liquid protein is the easiest way to close the gap. Food first where you can manage it.

Do I still need to count calories?

Usually much less than before, because the drug is doing the intake restriction for you. The risk on these medicines tends to be eating too little and too little protein, not too much, so counting protein is more useful than counting calories.

What to Eat on GLP-1 Medication

Protein first, small and often, fibre and fluid on purpose: what to put on a plate you may not finish.

Read this first: food advice, not medical advice

These are prescription medicines. Everything here is about what and how to eat while you are on one; nothing here is dosing, titration or prescribing guidance, and none of it replaces your prescriber, GP or dietitian.
Persistent vomiting, an inability to keep fluids down, or severe stomach pain that spreads to your back and does not go away are reasons to seek medical help the same day, not to adjust your diet and hope.
If you also take insulin or a sulfonylurea, eating much less can drop your blood sugar too low. Your prescriber needs to know before you cut your intake.
Buying these compounds outside a pharmacy, including anything sold as a research peptide, means no guarantee of purity, dose accuracy or sterility, and no clinician watching what happens next.
If you are pregnant, trying to conceive or breastfeeding, or have a history of pancreatitis, gallbladder disease or an eating disorder, talk to your clinician before changing how you eat on these drugs.

The problem these drugs create at the dinner table

GLP-1 medicines work by turning appetite down and slowing how fast your stomach empties. That is the point of them, and it is also the whole nutritional problem: you now have a fraction of the appetite you used to have, and every mouthful has to earn its place.

Nothing here is about restriction. The drug is doing the restricting. Your job is to make sure that what you do eat is worth eating, because the two things that go wrong on these medicines are almost never eating too much. They are eating too little protein, and eating too little fibre and fluid.

Five principles, in order of how much they matter

1. Protein goes in first. Whatever is eaten first is what you actually get, because you may finish a third of the plate. Protein, then the vegetables and fibre, then the starch. Expert guidance for weight loss on GLP-1 therapy lands at roughly 1.2 to 1.6 g of protein per kg of body weight per day, and higher if you are resistance training. Work out your own number with the protein intake calculator, then plan meals backwards from it.

2. Small and often beats three meals. Four to six small meals fit a slow stomach far better than three normal ones. Eat slowly, put the fork down between mouthfuls, and stop at the first sign of fullness, because the signal arrives late and arrives hard.

3. Fat is the dial to turn down, not food groups. Fat slows stomach emptying more than protein or carbohydrate, and your stomach is already slow. A fried or heavily creamy meal is the most reliable way to feel sick. The same food, grilled or poached, is usually fine.

4. Fibre and fluid have to be deliberate now. Eating far less food means far less of both, which is most of why constipation is so common. The UK recommendation is 30 g of fibre a day, and the NHS suggests 6 to 8 glasses of fluid daily. Build fibre back up gradually, with fluid alongside, or you trade constipation for bloating. The water intake calculator gives you a starting figure.

5. Drink between meals, not with them. Fluid competes with food for a stomach that has very little room. Push it into the gaps.

A day that works

A workable structure is a protein-led breakfast (eggs, Greek yoghurt, or porridge made with milk), a small protein-and-vegetable lunch, a mid-afternoon protein snack, and an evening meal finished two to three hours before bed so it is not sitting there when you lie down. Nothing on that list is exotic. The discipline is the timing, not the menu.

If you physically cannot fit enough in, a protein shake or a glass of milk is a legitimate tool rather than an admission of defeat. Liquid protein occupies less space and needs no chewing on the days when chewing is the barrier.

When intake is very low for months

At a genuinely small daily intake, micronutrients stop taking care of themselves. Calcium, iron, B12 and vitamin D are the usual gaps, and the UK advice to consider a vitamin D supplement in autumn and winter applies to you more than most. This is a good reason to ask for a referral to a dietitian rather than to guess.

The tables

The lists below come from the same food dataset as the rest of the food reference section, so the protein and calorie figures match what you will find there. They are grouped by the job the food is doing: getting protein in, getting through a bad day, fixing the fibre, and packing something into a meal you cannot finish.

Protein first, every meal

The single highest-value habit on these drugs: eat the protein on the plate before anything else, because you may not reach the rest of it. These are the densest sources in a small portion.

Food	Typical portion	Protein (g)	Calories (kcal)	Why it earns the space
Greek yoghurt (low-fat)	1 pot (170 g)	17	100	Soft, cold and high in protein per spoonful, and usually tolerated on the days when nothing else appeals.
Chicken breast (cooked)	1 breast (120 g)	37	198	The most protein per gram of any everyday food here; keep it moist (poached, in a sauce) as dry meat is hard work on a slow stomach.
Cod (cooked)	1 fillet (140 g)	32	147	Lean, low-fat and light, so it leaves the stomach faster than red meat or anything fried.
Egg (whole)	1 large egg (50 g)	7	78	Small, soft, cheap and complete; scrambled eggs are a reliable meal when appetite has vanished.
Cottage cheese	1 serving (100 g)	11	98	High protein, no cooking, and easy to eat in the small amounts that actually get finished.
Firm tofu	1/2 block (150 g)	18	180	The densest plant protein in this dataset per calorie, and it takes on whatever flavour still tastes right to you.
Tuna, canned in water	1 small tin (100 g)	26	116	Store-cupboard protein with almost no fat, for days when cooking is beyond you.
Prawns (cooked)	1 serving (100 g)	24	99	Very lean, quick to eat, and light enough not to sit heavily.

Gentle on a slow stomach

For the first days after a dose change, when nausea and early fullness peak. Moist, low-fat, mild and preferably cool: fat is the single biggest trigger, because it slows an already-slow stomach further.

Food	Typical portion	Protein (g)	Calories (kcal)	Why it earns the space
Oats (dry)	1 serving (50 g)	7	190	Made into porridge it is soft, warm and mild, and it brings soluble fibre for the constipation side.
Skimmed milk	1 glass (200 g)	7	70	Protein in liquid form when solids are unappealing; the fat-free version empties from the stomach faster.
Potato (boiled)	1 medium (150 g)	3	116	Bland, starchy and easy, the classic settle-your-stomach carbohydrate. Leave the skin on for fibre when you can face it.
Banana	1 medium (120 g)	1	107	Portable, mild and gentle, and useful when you need something in you before you can face a meal.
Greek yoghurt (low-fat)	1 pot (170 g)	17	100	Cold foods carry less aroma, and aroma is half of what triggers the nausea.
Lentils (cooked)	1 serving (150 g)	14	174	In a thin soup it is protein, fibre and fluid in one bowl, which is exactly the shape of an easy meal here.

Fibre, for the constipation

Eating far less food means eating far less fibre, and that is most of why constipation is so common. Build these back in gradually, with fluid alongside, rather than all at once.

Food	Typical portion	Protein (g)	Calories (kcal)	Why it earns the space
Chia seeds	1 tbsp (12 g)	2	58	Very high fibre in a tablespoon, and it absorbs water into a gel, so it works with your fluid intake rather than against it.
Baked beans	1/2 tin (200 g)	10	188	Half a tin is a genuinely useful fibre dose and needs no cooking skill.
Wholemeal bread	1 slice (40 g)	4	99	The easiest one-for-one swap there is: same slice, more fibre.
Black beans (cooked)	1 serving (150 g)	14	198	Fibre plus a useful amount of plant protein in the same spoonful.
Broccoli	1 serving (90 g)	3	31	High fibre for very few calories; steam it soft if raw vegetables feel heavy.
Spinach	1 handful (30 g)	1	7	Wilts down to nothing, so it adds fibre and micronutrients without taking up stomach space.

When you cannot finish a meal

Some weeks the problem is the opposite one: you cannot eat enough to hit your protein target or your micronutrients. These pack the most into the fewest mouthfuls. Use them deliberately, not by default.

Food	Typical portion	Protein (g)	Calories (kcal)	Why it earns the space
Peanut butter	1 tbsp (16 g)	4	94	Protein and calories in a tablespoon; stir it into porridge or yoghurt rather than eating a fatty meal.
Cheddar cheese	1 matchbox (30 g)	8	121	A matchbox piece is real protein, useful when a whole meal is not happening.
Almonds	1 handful (28 g)	6	162	A handful is protein, fibre, vitamin E and magnesium, which matters when total intake is low.
Pumpkin seeds	1 handful (28 g)	8	157	The most protein-dense seed here, and easy to scatter over food you are already eating.
Whole milk	1 glass (200 g)	7	122	Drinkable calories and protein for the days when chewing is the barrier.
Avocado	1/2 avocado (100 g)	2	160	Calorie-dense and soft, though the fat load means it suits the settled days better than the nauseous ones.

Protein and calorie figures are for the typical portion shown, from the same approximate food-composition dataset as the food reference tables.

Sources

Work out your numbers

Frequently asked questions

What should I eat first at a meal on a GLP-1?: The protein. You may only manage a third of what you used to, so whatever is eaten first is what you actually get. Protein, then vegetables and fibre, then the starch.
How much protein do I need on these drugs?: Expert guidance for weight loss on GLP-1 therapy converges on roughly 1.2 to 1.6 g per kg of body weight a day, higher if you are training for muscle. Work your own figure out with the protein calculator; the harder part is hitting it when four bites fill you up.
Should I use protein shakes?: They are a reasonable tool rather than a requirement. When solid food is unappealing or you cannot physically fit enough in, liquid protein is the easiest way to close the gap. Food first where you can manage it.
Do I still need to count calories?: Usually much less than before, because the drug is doing the intake restriction for you. The risk on these medicines tends to be eating too little and too little protein, not too much, so counting protein is more useful than counting calories.

Written and reviewed by Mathew Beale, MSc Biotechnology, University of Reading.

Last reviewed: 29 July 2026