How much protein do you need on a GLP-1?
Aim for 1.2 to 1.6 g of protein per kilogram of body weight per day on a GLP-1. For a 90 kg person that is 108 to 144 g daily, or roughly 30 to 45 g at each of three meals. This matters more on these medicines than on any other approach to weight loss, because appetite suppression makes undereating protein almost effortless. Body composition studies across the GLP-1 trials suggest that without adequate protein and resistance training, around 30 per cent of what you lose can be lean mass rather than fat.
The number, and how to work out yours
The working range is 1.2 to 1.6 g per kilogram of body weight per day. Take your weight in kilograms and multiply. At 75 kg that is 90 to 120 g. At 100 kg it is 120 to 160 g.
Two refinements worth knowing. If you are training with resistance two or three times a week, aim at the upper end. And if you are carrying a great deal of excess weight, some clinicians calculate from a target or adjusted body weight rather than current weight, because the raw figure becomes impractical. That is a conversation for a dietitian rather than a rule of thumb.
Why this matters more on a GLP-1 than on a diet
All weight loss costs some lean mass. What is different here is the mechanism and the speed.
These medicines suppress appetite without any regard for what you were going to eat. Protein is the most filling macronutrient and the least appealing when you are not hungry, so it is the first thing people quietly drop. Meanwhile the rate of loss is faster than most dietary approaches produce, and faster loss means a higher lean mass cost unless it is actively defended.
What lean mass loss actually costs you
It is not about appearance. Muscle is metabolically active tissue, and losing it lowers your resting energy expenditure, which is the number of calories you burn doing nothing.
The practical consequences arrive later: a lower metabolic floor makes maintaining your new weight harder, and if you eventually come off treatment, regain is faster onto a body that burns less than it used to. There is also the plain question of physical function, which matters increasingly from middle age onward.
This is the strongest argument for taking protein seriously rather than treating it as optional advice. A 6 per cent weight loss with muscle intact is a better clinical outcome than 9 per cent without, even though the scale says otherwise.
How to hit the target when you are not hungry
The target is genuinely hard on a suppressed appetite. These are the things that work.
- Protein first, every meal. If you stop eating early, you have already had it.
- Front-load breakfast. Appetite is often best in the morning and worst in the evening. Use the window you have.
- Drink some of it. Milk, yoghurt drinks and protein shakes bypass the chewing problem entirely.
- Choose density over volume. A tin of tuna delivers what a large plate of vegetables cannot.
- Track it for three days. Not forever. Just long enough to learn what your normal intake actually is, because almost everyone overestimates.
What 30 to 40 grams looks like
- Chicken breast, 150 g: about 35 g protein.
- Salmon fillet, 150 g: about 32 g.
- Three eggs: about 18 g. Add a slice of cheese or some beans to close the gap.
- Greek yoghurt, 200 g: about 20 g.
- Tin of tuna or mackerel: about 25 g.
- Cottage cheese, 200 g: about 25 g.
- Whey or plant protein scoop: 20 to 25 g, and the most reliable option on a bad day.
Vegetarian and vegan sources
Achievable, but it needs more planning, because plant proteins are generally less dense and less complete.
Tofu, tempeh, seitan, lentils, chickpeas, black beans, edamame, Greek yoghurt and eggs if you eat them, plus a plant protein powder to cover the shortfall. Combining sources across the day matters more than at every meal. If you are vegan and on a GLP-1, a dietitian referral is genuinely worth asking your GP for rather than a nice-to-have.
Protein alone is not enough
Protein gives your body the raw material to hold onto muscle. Resistance training is what tells it to.
Two or three sessions a week is sufficient, and it does not require a gym membership. Bodyweight work, resistance bands or a couple of dumbbells at home all count. Without the training stimulus, a good chunk of the protein you are working so hard to eat gets used elsewhere.
Can you eat too much protein?
For most healthy people, intakes in this range are well tolerated and there is no good evidence of harm to normal kidneys.
The exception matters: if you have reduced kidney function, chronic kidney disease, or you have had kidney problems in the past, protein targets should be set by your doctor rather than by an article. Kidney function is one of the things baseline bloods check before starting a GLP-1, which is a good reason not to skip them.
Protein on a GLP-1: common questions
Between 1.2 and 1.6 grams per kilogram of body weight per day. At 90 kg that is 108 to 144 grams, or roughly 30 to 45 grams at each of three meals. Aim at the upper end if you are doing resistance training.
Body composition sub-studies suggest that without adequate protein and resistance training, roughly 30 per cent of total weight lost can be lean mass. With both in place that typically falls to around 10 to 15 per cent.
Not necessarily, but they are the most reliable option when appetite is suppressed. Liquid protein bypasses the difficulty of chewing through a meal you do not want, and one shake can close a 25 gram gap in seconds.
You lose a greater proportion of lean mass, which lowers resting energy expenditure. That makes maintaining your new weight harder, makes regain faster if you stop treatment, and reduces physical function over time.
Yes, but it takes planning. Tofu, tempeh, seitan, lentils, chickpeas, edamame, dairy and eggs all contribute, usually with a plant protein powder to cover the shortfall. A dietitian referral is worth requesting if you are vegan.
For people with normal kidney function there is no good evidence of harm at these intakes. If you have reduced kidney function or a history of kidney disease, your protein target should be set by your doctor. Kidney function is one of the things baseline bloods check before starting.