When a GLP-1 medicine suppress appetite, people eat less of everything, protein included. That matters, because caloric restriction can lead to muscle catabolism. [1] In a US survey of people on GLP-1 therapy, average intake was about 77 g a day, yet fewer than half reached 1.2 g per kilogram of body weight. [2]
A clear, personal protein target is one of the simplest ways to close that gap.
How much is enough?
The everyday recommendation of 0.8 g per kilogram was set for healthy adults and is now under review. For people actively losing weight, experts point to a higher range of 1.2-1.6 g per kilogram a day. [3] Older adults may need more, because protein needs rise with age. [4] There are limits at both ends: intake should not fall below 0.4-0.5 g per kilogram, and long periods at 2 g per kilogram or more are best avoided. [3]
Which weight should you use?
For someone living with obesity, multiplying by their actual weight can overestimate how much protein they need. [3] One option is an adjusted body weight: ideal body weight plus a quarter of the excess. [5] For example, a woman who weighs 100 kg with an ideal weight of 60 kg has an adjusted weight of 70 kg, which puts her target at roughly 85-110 g a day. If calculations feel too cumbersome, a fixed goal of 80-120 g a day is a practical alternative, [3] with at least 60-75 g a day as a reasonable intake. [4]
Making it fit a smaller appetite
The most useful habit is also the simplest: eat the protein on the plate first, so it is not the part left behind. [3,4] Spreading protein across the day helps too. Muscle uses about 20-25 g of good-quality protein at a sitting, so several moderate servings may work better than one large one, although the evidence on timing is still mixed. [1]
Small, protein-dense foods are easier to manage than big plates. Fish, eggs, Greek yogurt, cottage cheese, nuts, seeds and nut butters all pack protein into a small volume, and beans, peas and lentils are good plant sources. [3] Soups and smoothies made with milk or yogurt often go down more easily than heavier foods such as red meat, cold cuts or hard cheese, and red and processed meats are best kept to a minimum anyway. [3] Quality counts as well as quantity: proteins rich in essential amino acids, such as leucine-rich whey, do more to support muscle. [1,5]
When food alone falls short, especially in the early weeks, a shake or other meal replacement with 15–25 g of protein per serving can help. [4] Beyond meeting the target, though, no guideline currently recommends extra protein supplements. [5] And if poor appetite makes it impossible to eat enough protein, it is worth reviewing the dose. [4]
Protein needs a partner
Protein on its own is unlikely to protect muscle without structured strength training, and protein eaten beyond what the muscles can use may simply be turned into fat. [3] Exercise also raises protein needs, [5] and protein taken soon after a strength session may boost the benefit, particularly in older adults. [1]
When to take extra care
For patients with a history of kidney stones, the joint advisory suggests steering away from animal protein. High-protein and high-fat foods slow the stomach, which can make constipation worse; cutting back for a while may be needed. [3] And if a patient notices more hair loss, check for low protein intake or iron deficiency before putting it down to the medicine. [4]
Keep it going
Support makes a difference. In one study, people who received dietary counselling alongside GLP-1 therapy increased their protein intake more than those taking the medicine alone. [3] Reviewing food diaries or meal photos at follow-up shows whether the target is being met, so it can be adjusted as weight, appetite and dose change. [3] A protein prescription is not a one-off instruction. It works best as a number the patient knows, checks and comes back to.