How Many Calories Should I Be Eating on a GLP-1 Medicine?

Your calorie needs depend on several factors: your current body weight, height, age, sex, and how active you are. On a GLP-1 medicine like Mounjaro (tirzepatide) or Wegovy (semaglutide), reduced appetite often means calorie intake drops naturally — sometimes significantly. That can be a useful effect, but eating too little for too long can lead to fatigue, muscle loss, and nutrient gaps, so the quality and composition of what you eat matters as much as the quantity.

A General Starting Point

General nutrition guidance suggests that a moderate calorie deficit — roughly 500 calories below your estimated daily needs — is a common target for gradual, sustainable progress. Many people on GLP-1 medicines find they land somewhere in the range of 1,200–1,800 calories per day depending on their size and activity level, though this varies widely. These are educational ranges, not personal prescriptions — your own needs may sit outside them, and any specific calorie target should be discussed with your prescriber or a registered dietitian who knows your full picture. You can explore the broader context of managing your intake in our guide to understanding calorie deficit on a GLP-1 journey.

Why Macros Matter Too

Beyond total calories, what you eat shapes how well you feel and how much of your weight loss comes from fat rather than muscle. Many people on GLP-1 medicines ask about what macros to prioritise — and protein consistently comes up as the most important. Adequate protein (general guidance often points to around 1.2–1.6 g per kilogram of body weight, though individual needs vary) helps preserve muscle mass, supports satiety, and is often harder to hit when appetite is low. For practical guidance on structuring meals, see what to eat on Mounjaro and our overview of daily calorie targets on a GLP-1 medicine.

When Appetite Is Very Low

One challenge many people face is eating too little — not through choice, but because the medicine reduces hunger so effectively. If you regularly struggle to reach even a minimal intake, this is worth discussing with your prescriber. For more on navigating this, see our page on overeating patterns on Mounjaro for context on how appetite changes across the journey.

Keeping track of calories and macros when appetite is unpredictable can be genuinely tricky — some days you barely feel hungry, others you feel more like yourself. GLP Trackr's AI food photo scan makes logging effortless: point your camera at a meal and the app estimates calories, protein, and other macros instantly, without manual searching or weighing.

From there, you can set your own calorie and protein targets inside the app and watch how your daily intake stacks up at a glance. Over time, the insights feature lets you see patterns — how your protein intake on a given week related to your energy levels or progress, for example — turning scattered data into a clear picture you can actually act on.

If you are ever unsure whether your intake is right for you, use your logged data as a starting point for a conversation with your prescriber or a registered dietitian — they can review your actual numbers and give personalised guidance that general content simply cannot. GLP Trackr is here to help you record and understand your journey, not to replace that clinical relationship.

Ready to take the guesswork out of food tracking? Download GLP Trackr on the App Store or Google Play — your first 7 days are free.