Free tool · Reviewed July 25, 2026
Protein calculator for GLP-1 users
Most protein calculators give you a weight-loss number from trials that never involved these drugs. This one uses the GLP-1-specific guidance — and asks the kidney question the others skip.
Key takeaways
- The Obesity Society’s 2024 GLP-1 guidance is 0.8–1.5 g of protein per kilogram of body weight per day, with a stated floor of 60–75 g/day.
- That is different from the 1.2–1.6 g/kg figure most protein calculators use — that range comes from non-GLP-1 weight-loss trials.
- Targets are per KILOGRAM, not per pound. Per-pound versions of this advice land near triple the RDA.
- Kidney disease reverses the advice: KDIGO caps intake at 0.8 g/kg/day in CKD G3–G5 and warns against exceeding 1.3 g/kg/day where progression is a risk.
- Benefit for preserving fat-free mass plateaus around 1.6 g/kg — higher intakes have only been shown to help trained athletes in aggressive deficits.
- Protein matters more on a GLP-1 than on a diet alone because appetite suppression makes it easy to undereat protein without noticing.
Kidney disease changes this answer in the opposite direction to what most protein content assumes. If you have reduced kidney function, the guideline ceiling sits below the general range — tick the box above, and confirm the target with your clinician.
Targets are per kilogram of body weight, per day. Nothing you enter is stored or sent anywhere. General information, not medical advice.
Why the usual number is the wrong number here
Type “protein calculator” into any search box and you will get 1.2–1.6 grams per kilogram. That range is real, but it was measured in people losing weight through energy restriction alone. The Obesity Society issued guidance in 2024 for people losing weight on a GLP-1 specifically, and it lands at 0.8–1.5 g/kg with a hard floor stated in grams rather than per-kilo terms.
The floor matters more than the ceiling for most people. Appetite suppression makes it genuinely easy to end a day at 40 grams without noticing, and that is where lean-mass loss accelerates. If you want the full protocol rather than the number, the protein guide covers timing, food ranking by protein per calorie, and what to do when nothing appeals. For why the scale and the mirror disagree during this, see GLP-1s and muscle loss.
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Common questions about protein on a GLP-1
How much protein should I eat on a GLP-1?
The Obesity Society published GLP-1-specific guidance in 2024: 0.8 to 1.5 grams per kilogram of body weight per day, with an absolute floor of more than 60 to 75 grams a day. Note this is narrower at the top than the 1.2–1.6 g/kg range most protein calculators use, because that range comes from weight-loss trials that did not involve GLP-1s. Above 1.5 g/kg is described as an individual decision rather than a general recommendation.
Is protein per pound or per kilogram?
Per kilogram, and the distinction is not pedantic. A target of "1.0–1.2 g per pound" — which appears in a lot of fitness content and which an earlier version of our own guide got wrong — works out to roughly 2.2–2.6 g/kg. That is about triple the RDA and above anything the lean-mass literature supports for non-athletes. To convert, divide your weight in pounds by 2.2 before applying any g/kg figure.
Does protein need to change if I have kidney disease?
Yes, and it moves in the opposite direction to general weight-loss advice. The KDIGO 2024 guideline sets 0.8 g/kg/day for CKD stages G3–G5 and advises against exceeding 1.3 g/kg/day where progression is a concern — below the general range. This is the single most important reason not to take a generic protein calculator at face value. Confirm your target with the clinician managing your kidney function.
Why does protein matter more on a GLP-1?
Because the drug works by suppressing appetite, and protein is the easiest macronutrient to under-eat when you simply are not hungry. Rapid weight loss draws on both fat and lean tissue; adequate protein plus any resistance training is what shifts that balance toward fat. It is also why the scale can stall while your waist keeps shrinking — preserved muscle offsets lost fat on the scale.
Can I just drink protein shakes to hit the target?
They count, and they are genuinely useful when appetite is low, but note that whey powder is not USDA-standardised — protein per serving varies by brand, so read your own tub rather than assuming a figure. Whole foods with high protein-per-calorie, such as canned light tuna, cod, egg white, chicken breast and non-fat Greek yogurt, do the same job with more satiety per gram.
Targets from The Obesity Society (2024) GLP-1 guidance and the KDIGO 2024 CKD guideline, current as of July 2026. Screening information only — protein targets in kidney, liver or pregnancy contexts belong to your clinician, not a calculator.