What Should My Calorie Deficit Be on Mounjaro or Wegovy?

A calorie deficit simply means consuming fewer calories than your body uses in a day. Over time, this encourages your body to draw on stored energy, which contributes to weight loss. On medicines like Mounjaro (tirzepatide) or Wegovy (semaglutide), many people find the deficit happens more naturally — reduced appetite and lower "food noise" mean eating less without as much conscious effort.

What a sustainable deficit usually looks like

General nutritional guidance suggests that a deficit of roughly 500 calories per day can support gradual, steady weight loss for many adults. Going significantly below your maintenance calories — particularly dropping under around 1,200–1,500 calories daily depending on your size and activity level — risks losing muscle mass and missing key nutrients, which can be especially important when appetite is already suppressed. These are general educational ranges, not personalised targets; always align specific numbers with your prescriber or a registered dietitian.

Why protein changes the picture

On a GLP-1 medicine, eating less overall makes it even more important that what you do eat is high quality. Prioritising protein at each meal helps preserve muscle tissue during weight loss and keeps you feeling fuller for longer. Many people find that thinking about what their calorie intake should be in terms of protein-first eating — rather than just cutting calories — leads to better results and fewer energy dips.

Calorie deficit vs calorie intake — two sides of the same question

Searching for what your calorie intake should be is really the same question approached from the other direction: once you know roughly how many calories your body needs to maintain its current weight (your Total Daily Energy Expenditure, or TDEE), subtracting your target deficit gives you a daily calorie goal. You can explore how that number is calculated on our page about understanding your calorie deficit, or get a working figure using the tool on our calorie deficit calculator.

Knowing your target deficit is one thing; consistently tracking whether you are hitting it — especially when appetite varies day to day on a GLP-1 medicine — is where most people find it hard to stay on top. That is where GLP Trackr's food logging makes a real difference.

Effortless food logging built for GLP-1 life

Instead of manually searching for every ingredient, GLP Trackr lets you point your camera at a meal and the AI photo scan returns an instant breakdown of calories, protein, and macros. A barcode scanner and a searchable food database cover packaged foods and snacks. When you are eating less than usual and every meal counts nutritionally, having a frictionless way to log what you eat means you actually do it — and you can see at a glance whether your calorie intake is sitting within your target range.

Set your targets, watch the numbers add up

You can set daily calorie and protein targets inside the app and track your progress against them throughout the day. The daily check-in feature lets you log your weight, energy, and food-noise level each morning, so over time you can see how your intake patterns connect to your results. For a fuller picture of your whole journey — not just calories — visit the calorie deficit hub for guidance on how deficits, GLP-1 appetite changes, and progress tracking all fit together.

GLP Trackr is a tracking tool, not a substitute for personalised advice. If you are unsure what calorie intake is right for your situation, speak with your prescriber or a registered dietitian — they can give guidance that takes your full health history into account.

Ready to take the guesswork out of hitting your daily targets? Download GLP Trackr on the App Store or Google Play and explore every feature free for 7 days.