How Many Calories Should You Eat to Lose Weight on a GLP-1 Medicine?

Your calorie needs are shaped by your Total Daily Energy Expenditure (TDEE) — the calories your body burns across all activity in a day. A deficit of roughly 500 kcal below your TDEE is commonly cited as a starting point for gradual, sustainable weight loss, but this is a general educational guideline, not a personal prescription. Your prescriber or doctor is best placed to advise on the right target for your situation.

The key factors that affect your number

• Body weight and composition: larger bodies and those with more muscle mass burn more calories at rest.
• Age: metabolic rate tends to slow gradually with age.
• Activity level: someone with a physically active job or regular exercise has a meaningfully higher TDEE than someone mostly sedentary.
• Biological sex: on average, men have higher calorie needs than women due to differences in muscle mass and body composition — many men find a deficit sits somewhere between 1,800 and 2,200 kcal, while many women find 1,400–1,800 kcal a reasonable range. These are general starting points only.
• GLP-1 appetite changes: medicines like Mounjaro (tirzepatide) and Wegovy (semaglutide) commonly reduce appetite and food noise, meaning many people naturally eat less. This is helpful, but it also makes it easy to under-eat protein without realising it.

What about macros — carbs, protein, fat?

Within your calorie target, understanding your overall calorie deficit matters more than obsessing over exact macro splits. That said, protein deserves special attention on a GLP-1 journey. Aiming for adequate protein — many general guidelines suggest around 1.2–1.6 g per kg of body weight as an educational reference — helps preserve muscle mass during weight loss. Carbohydrates are not the enemy; focusing on fibre-rich, slower-digesting carbs tends to sit better when gastric emptying is slower. Fat should not be cut too aggressively, as it supports satiety and nutrient absorption.

For a deeper look at how to work out a specific deficit figure, see how much of a calorie deficit to aim for and working out the calories needed to lose weight. If you want to explore how your daily intake fits into a longer pattern, daily calorie guidance for weight loss covers this in more detail.

Knowing your calorie target is one thing; accurately tracking what you actually eat is another — especially on a GLP-1 medicine, where portion sizes shift and appetite can be unpredictable from day to day. GLP Trackr's AI food photo scan is the easiest way to stay on top of this: point your camera at a meal and get an instant calorie, protein, and macro breakdown without manually searching for every ingredient.

Beyond the photo scan, the app lets you set your own calorie, protein, fibre, and water targets and track progress against them throughout the day. The daily check-in captures your weight, energy levels, and food-noise alongside your intake, so over time you can see how your eating patterns actually connect to your results — not just what the scales show.

GLP Trackr also includes a library of GLP-1-friendly meal plans and recipes built around protein-first, gentle-on-the-stomach options, which takes the planning effort out of hitting your targets on lower-appetite days.

Ready to take the guesswork out of eating on your GLP-1 journey? Download GLP Trackr on the App Store or Google Play — your first 7 days are completely free.

General calorie ranges here are educational references only and are not a substitute for personalised advice. Your prescriber or doctor can help you set a calorie target that suits your health history and treatment plan — always follow their guidance.