calculateCalculator Guide

GLP-1 Protein Calculator

Most weight-loss diets are protein-deficient. On a GLP-1, where 20-40% of weight lost can come from lean mass if you do nothing, hitting your protein target every day is the single biggest lever for protecting muscle.

Standard dietary protein recommendations (the 0.36g per pound RDA) were built around preventing deficiency in sedentary adults at stable weight. Those numbers do not apply when you are eating in a deep calorie deficit, losing weight fast, and at higher risk of losing lean tissue.

The working number for GLP-1 users sits much higher: 0.7 to 1.0 grams of protein per pound of goal body weight, every day. That single rule does more for body composition than any food choice, exercise plan, or supplement.

This page gives you the formula, walks through three realistic examples, and explains why the goal-weight version of the calculation works better than the more common current-weight version most calculators use.

The formula

The simplest version is goal body weight in pounds, multiplied by 0.8. That lands you in the middle of the 0.7-1.0g/lb range that the strength training and weight-loss-preservation literature points to, and it is easier to remember than fiddling with grams per kilogram.

Goal weight matters more than current weight here. If you currently weigh 240 pounds but you are heading for 170, your muscle does not need to be fed for the 240-pound body — it needs to be fed for the body you are building. Using current weight inflates your target unnecessarily early in treatment, which is the opposite of what someone with reduced appetite needs.

If you lift weights three or more times per week, push closer to 1.0g/lb. If you are completely sedentary, you can sit at 0.7g/lb without losing much muscle, but the upper end is still the safer bet given how aggressively GLP-1s shrink total intake.

The Formula

Daily protein (g) = goal body weight (lb) × 0.8

Use 0.7g/lb if sedentary, 1.0g/lb if lifting weights regularly. Goal weight, not current weight.

Worked examples

Person A: 220 lb now, goal 180 lb, lifts 2x/week

180 × 0.8 = 144g of protein per day. That is roughly four palm-sized portions of meat, fish, or Greek yogurt spread across the day.

Person B: 165 lb now, goal 140 lb, strength training 4x/week

140 × 1.0 = 140g of protein per day. The upper end of the range, because muscle-protein synthesis demand goes up with lifting volume.

Person C: 290 lb now, goal 200 lb, sedentary office job

200 × 0.7 = 140g of protein per day. The lower end of the range, because lower activity reduces muscle-protein synthesis demand, but the number is still high relative to typical Western intake.

The pattern is hard to miss: real-world targets cluster in the 120-160g range for most adults losing weight on a GLP-1, regardless of starting size. That is the lens for evaluating whether your day looks "on target" or not.

Where the calculator will live

An interactive version of this calculator — where you enter your goal weight and activity level and get a daily gram target, plus a breakdown across four meals — is on the roadmap for this site. Until it ships, the formula above is identical to what the calculator will use. For a generic protein calculator that uses similar logic, the Examine.com protein calculator is a reasonable substitute, though it defaults to current weight rather than goal weight.

Common questions

Common Concerns

Why use goal weight instead of current weight?expand_more

Using current weight inflates the protein target for the body you are leaving behind, not the body you are building. For someone with significant weight to lose, that can mean an extra 30-50g of protein per day that the body simply does not need — and is often impossible to eat anyway on a suppressed appetite.

Is 1g per pound of body weight a myth?expand_more

1g per pound of current body weight is what bodybuilding culture popularized, and it is genuinely too high for most people who are not training hard and trying to gain muscle. 0.7-1.0g per pound of goal weight is the better target for GLP-1 users in a deficit.

What if I cannot hit the target?expand_more

Many users genuinely cannot eat 140g of protein per day from whole food while on a GLP-1 — appetite suppression is the whole point of the drug. Protein shakes, Greek yogurt, cottage cheese, and protein powder mixed into oatmeal or coffee are the standard workarounds. Two shakes a day is not cheating, it is the design.

Does protein cause kidney problems?expand_more

In adults with normal kidney function, high-protein diets do not damage kidneys. If you have pre-existing kidney disease, talk to your doctor before pushing protein high — the same caution applies whether or not you are on a GLP-1.

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