How to Do a Calorie Deficit on Mounjaro or Wegovy

A calorie deficit occurs when the calories you eat and drink fall below your total daily energy expenditure (TDEE) — the amount your body burns through basic functions, movement, and activity. When that gap is sustained over time, the body draws on stored energy, which is how weight loss occurs.

How much of a deficit is typical?

General educational guidance suggests a moderate deficit — often in the range of 300–600 calories below your maintenance level — tends to support steady progress while preserving muscle and energy. These are general ranges only; what is right for you depends on your individual circumstances, activity level, and what your prescriber or healthcare team has advised.

Why protein matters more when you are in a deficit

Eating enough protein is particularly important when cutting calories. Protein helps your body hold on to lean muscle while losing fat, and it contributes to the sense of fullness that many people already notice on GLP-1 medicines. Prioritising protein-rich foods — eggs, fish, poultry, legumes, dairy, tofu — at each meal is one of the most practical steps you can take.

Keeping track of what you eat

A deficit is difficult to manage without some awareness of your intake. Learning how to count calories effectively can take some of the guesswork out of the process — even a rough log is more useful than none. If you occasionally eat more than planned, that is entirely normal; the guide on what to do if you overeat on Mounjaro has some grounding perspective on getting back on track without stress.

It is also worth being aware that drastically cutting calories is not the goal. Eating too little — especially with reduced appetite from GLP-1 medication — can leave you low on nutrients and energy. If you have any concerns about your intake, discuss them with your prescriber or a registered dietitian.

Consistency is where most people find the challenge — not understanding the concept, but keeping track of it day after day, especially when appetite is unpredictable on a GLP-1 medicine. GLP Trackr's AI food photo scan is the fastest way to log what you eat: point your camera at your meal and get an instant breakdown of calories, protein, and macros without manually searching every ingredient.

Alongside photo scanning, the barcode scanner and food search make it straightforward to log packaged foods or familiar meals. Once your daily calorie and protein targets are set inside the app, you can see at a glance how you are tracking — and the app surfaces patterns over time so you can notice what is actually moving your results.

All of this lives in one place alongside your weight log and weekly progress charts, so a calorie deficit does not feel like an isolated maths exercise — it becomes part of a broader picture of your journey. For a fuller understanding of the principles behind managing your energy intake, the complete guide to calorie deficit on GLP-1 medicines covers the topic in depth.

GLP Trackr is a tracking tool, not a medical or nutrition service — always follow the personalised guidance of your prescriber or a qualified healthcare professional when making decisions about your diet, especially if you have any underlying health conditions.

Ready to make food logging effortless? Download GLP Trackr on the App Store or Google Play and explore all its features free for 7 days.