Eliana Witchell RD - Evidence-Based Nutrition
Tool

GLP-1 Protein Calculator

Your daily protein target on a GLP-1 — based on 1.6 g per kg of ideal body weight per day

Reviewed by Eliana Witchell, MSc, RD, CDELast reviewed: Version 1.0.0

Enter your height and sex at birth. The calculator returns your daily protein target (1.6 g/kg ideal body weight) and a per-meal breakdown across two or three meals. Minimum per-meal floor is 30 grams — adjust meal distribution to hit 30 g at each meal even if daily total slightly shifts.

An evidence-based protein-target calculator for patients on Ozempic, Wegovy, Mounjaro, Zepbound, or Rybelsus. Enter your height and sex at birth to get a daily protein target based on 1.6 grams per kilogram of ideal body weight per day — the threshold supported by current research for optimizing muscle protein synthesis. The calculator also suggests a per-meal breakdown across two or three meals so you can match the distribution that works for your appetite pattern. All computation runs in your browser; nothing is stored or transmitted. Educational tool. Not a replacement for individualized guidance from a Registered Dietitian or your prescriber.

ftin

Used to compute ideal body weight (Devine formula).

Your protein target

95grams of protein per day

Based on 1.6 g of protein per kilogram of ideal body weight per day. Your calculated ideal body weight is approximately 59.3 kg.

Two meals per day
48 g
per meal
Three meals per day
32 g
per meal

Minimum floor: 30 g of protein per meal across at least two meals. If either suggested per-meal value falls below 30 g, adjust to hit 30 g at each meal even if it means slightly exceeding your daily target.

This calculator is educational. It does not replace individualized guidance from a Registered Dietitian or your prescriber. Patients with chronic kidney disease, eating-disorder history, or other specific medical conditions should discuss protein targets with their care team before adopting this target.

How to use your target

  1. Distribute, do not dump. Muscle protein synthesis responds per meal, not per day. Aim for at least 30 g of protein per meal across two or three meals.
  2. Front-load to your appetite window. For most GLP-1 patients, that means no breakfast, a first meal at 10 a.m.–noon, and dinner by 7 p.m.
  3. Drink the first meal when needed. A protein shake, high-protein yogurt, or cottage cheese smoothie counts. This is a tool, not a compromise.
  4. Prioritize density over volume. A small piece of salmon beats a large salad when stomach capacity is limited.
  5. Track for a week, then reassess. If you consistently miss your target, audit timing, sources, and textures. If it persists, bring the data to your dietitian.

Scope note

This tool is educational. The 1.6 g/kg ideal-body-weight target is a well-supported baseline for most adults. Patients with chronic kidney disease, a history of eating disorders, or conditions that alter nitrogen handling should discuss targets with their care team before adopting the output directly. If you live in Ontario, British Columbia, or Nova Scotia, individualized Medical Nutrition Therapy is available through Eliana's practice.

Common questions

What is the calculator based on?
1.6 grams of protein per kilogram of ideal body weight per day — the threshold supported by current research (Layman 2015 and subsequent) for optimizing muscle protein synthesis in adults. Ideal body weight is calculated from height using the Devine formula, a clinically common approximation.
Why ideal body weight instead of my current weight?
Patients on a GLP-1 are often above their ideal body weight when they start treatment, and their weight is actively changing during treatment. Pegging protein intake to current weight would produce a target that shifts week to week. Ideal body weight gives a stable target that protects lean mass across the whole treatment window.
Why does the calculator ask for sex at birth?
The Devine ideal-body-weight formula uses sex-specific base values (50 kg for male, 45.5 kg for female) with the same height adjustment of 2.3 kg per inch over 5 feet. This is a clinical approximation and does not affect the principle behind the protein target.
Is this the only way to calculate protein needs?
No. Registered Dietitians in clinical practice often refine the target based on body composition (lean mass), training load, and specific conditions. If you have access to a DEXA scan or a bio-impedance measurement, a protein target calculated on lean body mass is more precise. The 1.6 g/kg ideal body weight target is a well-supported working baseline when those measures are not available.
Is the data I enter stored anywhere?
No. The calculator runs entirely in your browser. Nothing you enter is sent to a server, stored in a cookie, or logged. If you refresh the page, the calculator starts over.
Why 30 grams per meal?
Muscle protein synthesis is triggered above a per-meal threshold that is in the 25–30 gram range for most adults. Below that threshold, the amino acid signal to synthesize muscle is blunted regardless of how much protein is consumed later in the day. This is why distribution across meals matters as much as the daily total.
What if the per-meal suggestion drops below 30 g?
Redistribute. If three meals drops your per-meal target below 30 g, move to two meals. If two meals takes you above what you can eat in one sitting on a GLP-1, add a protein-dense snack of at least 15–20 g alongside two meals that each hit 30 g. The floor is the 30 g per-meal signal, not the daily total.
Who should not use this target?
Patients with chronic kidney disease or reduced glomerular filtration rate should discuss protein targets with their nephrologist or prescriber before adopting this calculator's output. Patients with a history of eating disorders should work with a dietitian experienced in eating-disorder recovery rather than a generalized target.

Related in this cluster

References

  1. Layman DK, Anthony TG, Rasmussen BB, et al. Defining meal requirements for protein to optimize metabolic roles of amino acids. Am J Clin Nutr. 2015;101(6):1330S-1338S. (PubMed) (evidence entry →)
  2. Wilding JPH, Batterham RL, Calanna S, et al. Once-weekly semaglutide in adults with overweight or obesity (STEP 1). N Engl J Med. 2021;384:989-1002. (DOI) (evidence entry →)
  3. Sehgal NKR, Tronieri JS, Ungar L, Guntuku SC. Self-reported side effects of semaglutide and tirzepatide in online communities. Nature Health. 2026. Published online April 10, 2026. (DOI)
  4. Practitioner case material: Eliana Witchell, MSc, RD, CDE. Clinical notes, 2023–2026. Anonymized.

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Important Disclaimer: This program is for educational purposes only and does not replace individualized Medical Nutrition Therapy or medical care.

Personalized nutrition therapy services are available only in jurisdictions where Eliana Witchell, RD, CDE holds active licensure. Always consult with your healthcare provider before making changes to your diet, exercise, or medication regimen.

This page is for educational purposes only and does not replace individualized Medical Nutrition Therapy or medical care.