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Your protein floor

For people on Ozempic, Wegovy, Mounjaro or Zepbound. It shows you where the number comes from.

Last updated 24 September 2026 · Written by Ihor, who makes Keel · General information, not medical advice

How the number is worked out

Your protein floor is the least protein to eat in a day. It is worked out from four things: your weight, your height, your age and how much you train. It is the same calculation the Keel app uses — this page imports the app's own code, so the two cannot disagree.

The number is a weight basis multiplied by a figure in grams per kilogram, then held inside two limits. Each part is explained below, with where it comes from.

For example: 183 lb (83 kg), 5′6″, 44 years old, resistance training about twice a week. The weight basis is 83 kg, the figure is 1.5 g per kg, and the floor is 125 g a day.

Grams per kilogram: five steps

The figure depends on how much you train. There are five steps, and only five:

  • Not training right now — 1.2 g per kg
  • Walking or cardio only — 1.3 g per kg
  • Resistance training about twice a week — 1.5 g per kg
  • Resistance training 3–4 times a week — 1.6 g per kg
  • More than that — 1.8 g per kg

The range recommended for people on GLP-1 medication during active weight loss is 1.2–1.5 g per kg a day (Božić et al., 2026). The two top steps, for people who train more, sit above that range and follow the resistance-training evidence (Morton et al., 2018).

Why the weight is capped at BMI 30

The calculation uses your actual weight, not a goal weight — up to a point. Above a body-mass index of 30, the weight basis stops at the weight that would put you at BMI 30 for your height. Multiplying an actual weight above that through would ask a heavier body to eat an amount that is not safe: at the lowest step, 150 kg would come to 180 g a day.

For example: 250 lb (113 kg) at 5′4″. BMI 30 at that height is about 79 kg, so the floor is worked out from 79 kg, not 113 kg — 119 g a day at 1.5 g per kg.

The cap follows Weijs (2025), cross-checked against the European Association for the Study of Obesity (EASO, 2026).

At 65 and over

Older muscle needs more protein to respond. At 65 and over, the figure is never below 1.2 g per kg, and any step at 1.5 or below rises by 0.1 — so 1.2 becomes 1.3, 1.3 becomes 1.4, and 1.5 becomes 1.6. The two top steps are already above that and do not change.

This follows the PROT-AGE group's recommendations for older adults (Bauer et al., 2013) and ESPEN's 2019 guidance, rather than the GLP-1 range above.

The limits either side

Whatever the multiplication gives, two limits hold:

  • Never below 60 g a day. A small, light body can multiply out to less than that; Keel never sets a floor lower.
  • Never above 2.0 g per kg of the weight basis. No step reaches it; it is there as a backstop.

The result is rounded to the nearest gram.

Per meal

Alongside the daily figure, Keel shows a per-meal range: 25–40 g, across three or four meals. At 65 and over the lower end is 30 g, because older muscle needs a larger amount at one sitting. This follows Moore et al. (2015).

If your clinician has given you a number

Use theirs. A target set by your clinician always overrides this calculation — in the app, entering it replaces Keel's number entirely. Keel tracks and educates. It never recommends a dose, a titration schedule or when to stop your medication — discuss those with your prescriber.

What the evidence does and does not say

No trial has yet tested a protein target in people on GLP-1 medication specifically. The floor is drawn from obesity, geriatric and sports-nutrition evidence. That is the honest state of it, and it is why the working is shown under the number rather than hidden.

What has been measured: in a 2026 paper on people taking these medications, 43% reached 1.2 g of protein per kg a day, and the average intake was 77 g a day (Božić et al., 2026).

Questions people ask

How much protein should I eat on Ozempic, Wegovy, Mounjaro or Zepbound?

There is no single number. The range recommended during active weight loss is 1.2–1.5 g per kg of body weight a day. Keel starts from that range and moves with your training, your age and, above BMI 30, your height. The calculator above works out yours. If your clinician has set a target, theirs comes first.

Is it based on my current weight or my goal weight?

Your current weight, capped at the weight that would put you at BMI 30 for your height. Using a goal weight is not what the cited research does.

How much protein should I eat per meal?

25–40 g, across three or four meals — 30–40 g at 65 and over.

Is this medical advice?

No. It is a calculation with its sources shown. It does not diagnose, treat or prescribe anything. Discuss your diet and your medication with your prescriber.

Does the calculator keep what I type?

No. It runs in your browser. Your weight, height and age are not sent anywhere.

Sources

  1. Božić et al. Metabolites 2026;16(6):364. mdpi.com
  2. Morton RW et al. Br J Sports Med 2018;52(6):376–384.
  3. Weijs PJM. Curr Opin Clin Nutr Metab Care 2025;28(1):27–32.
  4. European Association for the Study of Obesity. Obesity Facts 2026;19(4):422–437.
  5. Bauer et al. PROT-AGE Study Group. JAMDA 2013;14(8):542–559.
  6. ESPEN guidance, 2019.
  7. Moore et al., 2015.