How Many Calories Should I Eat on Semaglutide or Another GLP-1?

On semaglutide, eat around your normal maintenance calories and let the medication do the cutting. GLP-1 medications work largely by reducing appetite and slowing gastric emptying, and they substantially reduce meal size (Fujioka, 2026). The calorie deficit is the medication's job. Your job is to make sure that what you eat is worth eating.

For most adults on semaglutide or any GLP-1, the useful reference is your maintenance level, with the reduced appetite bringing the actual number down on its own. You can estimate maintenance with the Protocol MD calorie calculator or our TDEE calculator, but treat the result as a reference point for what normal looks like, not a target to cut beneath.

Stacking a deliberate restriction on top of pharmacological appetite suppression is where people run into the problems below.

Under-eating is the bigger risk on a GLP-1 because when appetite drops sharply, it is easy to forget to eat, or to stop after a few bites, and end up well under what your body needs for weeks at a time. A 2026 review of GLP-1 nutrition notes that lean-tissue loss (including bone and muscle) and vitamin deficiencies have been reported on these medications, and calls nutritional counseling invaluable (Fujioka, 2026). Low intake can show up as:

• Muscle loss. Lean mass makes up part of the weight lost on GLP-1 medications; across trials the share ranges from about 15% or less in some studies to 40–60% in others, and lean mass includes organs and water as well as muscle (Neeland et al., 2024). Inadequate protein and total calories make it harder to protect. Our guide to body recomposition covers the training side.
• Fatigue and poor recovery. Under-fueling commonly shows up as low energy.
• Harder-to-manage GI side effects. Large meals are a common nausea trigger on a GLP-1, so skipping food and then eating a big meal tends to backfire. Eating slowly, avoiding large or high-fat meals, and stopping at the first feeling of fullness may help reduce nausea (Alhazmi et al., 2026). Keeping those smaller meals protein-forward serves the protein target covered below.
• Nutrient gaps. Eating substantially less food means fewer vitamins and minerals, unless the food is dense in them.
• Hair thinning. Telogen effluvium is associated with GLP-1 use, and researchers attribute it mainly to weight-loss-related nutritional shortfalls (Viquez Burboa et al., 2026).

None of this means the medication isn't working. It means the eating pattern around it needs attention.

On a GLP-1, prioritize protein, regular meals, nutrient-dense food, hydration and resistance training instead of a calorie number.

Protein first, every meal. When total intake drops, sustaining protein intake helps spare lean mass (Westerterp-Plantenga et al., 2009). In a meta-analysis of resistance-training studies, gains in lean mass stopped increasing at around 1.6 grams of protein per kilogram of body weight per day, roughly 0.7 grams per pound (Morton et al., 2018). That study was not done in people on GLP-1 medications, so treat it as a reference point and let your physician set your target. On a suppressed appetite that can be genuinely hard, which is why it goes first on the plate rather than last.

Eat on a schedule, not on hunger. If hunger cues are muted, waiting to feel hungry means under-eating. Regular smaller meals work better than waiting.

Make the calories count. Fewer total calories means each one needs to bring more with it: protein, fiber, vitamins, minerals. This is the moment when food quality stops being optional.

Hydrate and keep some fiber in. Both help with the gastrointestinal side of things.

Keep resistance training in. Protein gives your body the material to hold muscle; training is the signal telling it to. Neither works well alone. Those priorities do more for you on a GLP-1 than any single calorie number.

Yes, there is a calorie floor on a GLP-1, and it matters more here than in ordinary dieting because appetite suppression makes it easy to drop below it without noticing.

As a general reference, Protocol MD uses 1,200 calories per day for women and 1,500 for men as a conservative floor: below that, it becomes hard to meet protein, vitamin, and mineral needs, and intakes that low are generally used only under medical supervision. It is a rule of thumb, not a formal federal guideline. The NIDDK's description of safe weight-loss programs centers on an eating plan based on the calories and nutrients your body needs (NIDDK), and the Dietary Guidelines for Americans set out what those nutrient needs are. If you're consistently landing under that on a GLP-1, which is easy to do without realizing it, that's a conversation with your prescribing physician, not something to push through.

The Protocol MD calculators apply that same floor: if the math produces a target below it, they don't display a number, because a calculator isn't in a position to supervise anyone.

Calories on Zepbound, Wegovy or Ozempic follow the same principles, because those principles are the same across the class. Semaglutide (marketed as Ozempic® and Wegovy®) and tirzepatide (marketed as Mounjaro® and Zepbound®) all reduce appetite through related mechanisms, so “how many calories on Zepbound” and “how many calories on Wegovy” have the same answer: eat around maintenance, prioritize protein, don't chase a deficit the medication is already producing.

Protocol MD provides physician-prescribed, compounded semaglutide and tirzepatide. Compounded medications are not FDA-approved and are not the same as the brand-name products, even when they are made with the same active ingredient. If you're weighing the two molecules, we cover how semaglutide and tirzepatide compare. Whichever GLP-1 you take, the calorie answer is the same: eat around maintenance and prioritize protein.

Talk to your physician about how much you eat if you're regularly eating well under the floor above, if nausea is preventing you from eating at all, if you're losing weight much faster than expected, if you feel persistently exhausted, or if you're unsure whether what you're eating is enough. And if the scale has stalled, that's a different question with a different answer — we cover it in why you might not be losing weight on semaglutide.

If your relationship with food or with tracking feels compulsive or distressing, that's worth raising with a clinician. In the US you can text “NEDA” to 741741 to reach a trained volunteer at Crisis Text Line, any time.

The bottom line is that on semaglutide or another GLP-1, most people should eat about what they'd eat to maintain their weight — and then let the medication do the reducing. The number to watch isn't a ceiling, it's a floor: enough total food, and enough protein, to help keep the weight you lose coming mostly from fat rather than muscle. If you're routinely eating far below that floor, the answer isn't to push harder. It's to talk to your prescribing physician.