Mounjaro Protein Calculator
Find out how much protein you should aim for each day and per meal to support muscle preservation during weight loss on GLP-1 medication.
When you lose weight — especially on GLP-1 medications like Mounjaro — getting enough protein is essential for preserving muscle mass. Reduced appetite can make it harder to hit your protein targets, so planning ahead matters.
This calculator estimates your ideal daily protein intake based on your weight, activity level, and goals, then splits it across your meals.
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What this calculator does
This calculator estimates your daily protein needs using evidence-based ranges (grams per kilogram of body weight), adjusted for your activity level and goal. It then divides your target across the number of meals you eat, with practical food examples.
Who it is for
Adults using or considering Mounjaro who want to ensure they eat enough protein to preserve lean muscle mass during weight loss. Also useful for anyone on a calorie-restricted diet.
How to use it
Enter your current and target weight, sex, activity level, protein goal (general, muscle preservation, or active), and number of meals per day. Click 'See My Result' for your personalised breakdown.
How the calculation works
We use a reference weight (average of your current and target weight) and multiply it by a protein range per kg of body weight. General = 1.2–1.6 g/kg, muscle preservation = 1.6–2.2 g/kg, active = 1.4–2.0 g/kg. These ranges are adjusted upwards for higher activity levels.
Worked example
Current weight 90 kg, target 75 kg, moderate activity, general goal: Reference weight = 82.5 kg. Protein range = 1.2–1.6 g/kg = 99–132g/day. Ideal = 116g/day. Over 3 meals = ~39g per meal.
Assumptions and limitations
- Protein ranges are based on sports nutrition and clinical guidelines for weight loss
- Reference weight uses the midpoint of current and target weight
- Meal examples are illustrative and approximate
- Individual needs may vary based on medical conditions, kidney function, and other factors
- This is not medical or dietetic advice — consult a healthcare professional
Frequently asked questions
How much protein should you eat on Mounjaro?
Most guidelines recommend 1.2–2.0g of protein per kg of body weight during weight loss, depending on activity level. Higher protein intake helps preserve muscle mass, which is especially important when appetite is reduced.
What happens if you do not eat enough protein?
Insufficient protein during weight loss can lead to muscle loss, fatigue, hair thinning, and a slower metabolism. Prioritising protein at every meal helps maintain lean body mass.
What are the best sources of protein?
Lean meats (chicken, turkey), fish, eggs, Greek yoghurt, cottage cheese, lentils, beans, tofu, and protein-rich dairy are all excellent sources. Aim for a variety across the day.
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Related guides
- How Much Protein Should You Eat on Mounjaro? — Why protein matters during GLP-1 weight loss and how to hit your daily target with practical meal guidance.
- Mounjaro vs Wegovy for Weight Loss — A balanced comparison of Mounjaro (tirzepatide) and Wegovy (semaglutide) — mechanism, effectiveness, cost, and side effects.
- How Much Weight Can You Lose on Mounjaro? — A realistic look at expected weight loss on Mounjaro (tirzepatide), based on clinical trial data and practical planning advice.
- How Many Calories Should You Eat on Mounjaro? — Understanding your calorie needs during Mounjaro treatment — maintenance, deficit, and safe intake ranges explained.
- What BMI Means for Weight-Loss Injections — How BMI is used to assess eligibility for weight-loss medications like Mounjaro and Wegovy, and its limitations.
Sources and references
ESPEN guidelines on protein during weight loss, BDA protein factsheet, Mifflin-St Jeor equation for reference
Last updated
Last reviewed: 2025-04-12.