Calori lator
한국어

Calculator

Calorie CalculatorTDEE CalculatorMacro CalculatorCalorie Deficit CalculatorFor Weight LossTo Gain WeightMaintenance CalculatorFor WomenFor MenBMI CalculatorBMR CalculatorProtein CalculatorIdeal Weight CalculatorWater Intake CalculatorGLP-1 Calculator
Meal Plans
Foods
Guides
About

GLP-1 Calorie & Protein Calculator

Advertisement
Units
Sex (biological, used for the formula)
Activity
Goal

Calories / day

1,806 kcal

This is not medical or dosing advice. It estimates general nutrition targets only — talk to whoever manages your prescription about the medication itself.
BMR1495 kcal
TDEE2056 kcal
Target1806 kcal
Protein target80–128g

1.0–1.6g per kg of bodyweight — the research-backed range for people on a GLP-1 medication, higher than the general 0.8g/kg minimum to help protect muscle while appetite is suppressed.

For protein spread across meals and real food examples, try the protein calculator.

Why GLP-1 medications change calorie and protein needs

GLP-1 receptor agonists (semaglutide, tirzepatide, and related drugs marketed as Ozempic, Wegovy, Mounjaro, and Zepbound) don't act on muscle tissue directly. What they reliably do is suppress appetite — often enough that people end up eating in a substantial calorie deficit without deliberately dieting at all. Whenever the body runs a sustained deficit, it draws energy from both fat and lean tissue, and low protein intake during that deficit is what lets more of the loss come from muscle rather than fat. A 2024 systematic review and network meta-analysis of GLP-1 receptor agonist trials found lean mass loss averaged about 25% of total weight lost across the studies reviewed — a pooled average, not a fixed number for any one person, since how much of your own weight loss comes from muscle depends heavily on protein intake and activity.

Why the deficit is capped at "mild"

Every Calorilator calculator treats a deficit over 750 kcal/day as an aggressive option that carries an inline caution rather than being a default. This calculator goes further: because the medication itself is already creating a deficit for most people, it only offers maintenance or a 250 kcal/day mild deficit on top — there's no "standard" or "aggressive" option to select here at all. Adding a large deliberate deficit on top of appetite-suppression-driven under-eating raises the risk of falling short on total nutrition, not just protein.

Where the 1.0–1.6g/kg protein range comes from

A systematic review of protein intake during energy deficits concluded that more than 0.8g/kg — the general adult minimum used elsewhere on this site — is necessary to limit lean mass decline during a deficit, and that intakes up to 1.6g/kg "may be preferred." One of the trials it reviewed compared a group eating roughly 1.0g/kg against a group eating roughly 2.3g/kg during a two-week calorie-restricted diet: the lower-protein group lost 1.6kg of lean mass, the higher-protein group lost only 0.3kg, with fat loss nearly identical between the two groups. The same review found a ceiling too — pushing from 1.6g/kg to 2.4g/kg preserved about the same amount of fat-free mass, with no measurable extra benefit. That's where this calculator's 1.0–1.6g/kg range comes from: enough to matter, without asking for more than the evidence supports.

Who this suits, and its limitations

This is for adults already taking, or considering, a GLP-1 or GLP-1/GIP medication who want a starting calorie and protein target rather than guessing. It is not a dosing tool, doesn't know which medication or dose you're on, and doesn't replace guidance from whoever manages your prescription. Like every calculator on this site, it uses population-average formulas with roughly ±10–15% individual variance, enforces the same 1500 kcal (men) / 1200 kcal (women) safety floor, and hides deficit goals entirely below a BMI of 18.5. If you have a medical condition affecting protein metabolism, or appetite suppression severe enough to make eating difficult, talk to a clinician rather than relying on a general calculator.

Related articles

Advertisement

Frequently asked questions

Why doesn’t this calculator offer a large calorie deficit option?

GLP-1 medications suppress appetite enough on their own to put most people into a real calorie deficit, often without deliberately dieting at all. Stacking a second, larger deliberate deficit on top raises the risk of eating too little overall and losing more muscle along with fat. That's why this calculator only offers maintenance or a mild 250 kcal/day deficit — the same aggressive-deficit caution the rest of Calorilator's calculators apply, just as the default here rather than an option you have to opt out of.

Why is the protein target higher than the usual 0.8g/kg minimum?

A systematic review of protein intake during energy deficits found that more than 0.8g/kg is necessary to limit lean mass decline, and that intakes up to 1.6g/kg “may be preferred.” A 2024 systematic review and network meta-analysis of GLP-1 receptor agonist trials found lean mass loss averaged about 25% of total weight lost across the studies reviewed — protein intake is one of the few levers that shifts that ratio back toward fat instead of muscle, which is why this calculator uses the higher 1.0–1.6g/kg range rather than the general adult floor.

Is this medical advice, or guidance about my dose?

No. This calculator estimates general nutrition targets — calories and protein — based on population-level formulas. It doesn't know your dose, your titration schedule, or your individual medical history, and it isn't reviewed by a clinician. Any decision about starting, changing, or stopping a GLP-1 medication belongs with whoever manages your prescription, not a calculator.

Does it matter which GLP-1 medication I'm on — Ozempic, Wegovy, Mounjaro, Zepbound?

Not for this calculator. It works from the shared mechanism across the GLP-1 and GLP-1/GIP class — appetite suppression leading to a calorie deficit — rather than from a specific drug or dose. It doesn't distinguish between medications, and it isn't a dosing tool for any of them.

What if I genuinely can’t eat enough protein because my appetite is too suppressed?

Get as close as consistently possible rather than treating the range as pass/fail. Protein-first eating order, smaller and more frequent meals, and protein-dense foods that don't require eating a large volume (eggs, Greek yogurt, cottage cheese, fish, protein shakes) all help close the gap. If appetite suppression is severe enough that eating enough of anything is a struggle, raise that with whoever manages your prescription rather than trying to solve it alone.

My BMI is under 18.5 — why can’t I select the mild deficit option?

Calorilator hides every weight-loss goal, on every calculator, once BMI drops under 18.5, and shows a note recommending a doctor's guidance instead. That rule applies here too — a GLP-1 medication doesn't change the underlying safety reasoning.