How Many Calories Do You Need to Lose Weight on Mounjaro or Wegovy?

A calorie deficit — eating less than your body uses — is the underlying driver of weight loss. How large that deficit needs to be depends on your current weight, height, age, activity level, and metabolic rate. There is no single number that works for everyone.

A general starting point

Many general health guidelines suggest a modest daily deficit in the region of 500 calories below your estimated total daily energy expenditure (TDEE) as a sustainable starting point — but this is a rough educational benchmark, not a personal prescription. Your own needs may differ, and a larger or smaller deficit can be appropriate depending on your circumstances. For a more tailored view, our guide on calorie intake for weight loss explores this in more detail, and you can also look at how large a calorie deficit supports weight loss.

Why GLP-1 medicines change the picture

Mounjaro (tirzepatide) and Wegovy (semaglutide) act on appetite-regulating pathways in the body, and a commonly reported effect is a significant reduction in hunger and "food noise". Many people find they are satisfied with much smaller portions. This is helpful for creating a calorie deficit — but it also makes it easy to eat too little, particularly of key nutrients like protein. Eating enough protein matters because it helps preserve muscle mass during weight loss, supports satiety, and keeps energy levels steadier.

Protein and quality over pure restriction

Rather than fixating on a single calorie target, most people on a GLP-1 journey benefit from thinking about what fills those calories. Prioritising protein (chicken, fish, eggs, legumes, dairy) and fibre-rich vegetables tends to support better outcomes than eating less of everything indiscriminately. Our page on how many calories to eat to lose weight covers practical ways to approach this, and if you want a breakdown specific to men's energy needs, see our guide on daily calorie needs for men.

Knowing roughly what you should eat is one thing — consistently tracking it while appetite is unpredictable is another. This is where GLP Trackr's AI food photo scan becomes genuinely useful: point your camera at a meal and get an instant calories, protein, and macro breakdown without manually searching every ingredient.

Beyond single meals, the app lets you set a daily calorie target and a protein goal, so you can see at a glance whether you are hitting a meaningful deficit or inadvertently under-eating. The barcode scanner and food search make logging quick on days when appetite is low and meals are small. Over time, the insights features surface patterns — for example, whether the days you hit your protein target tend to correlate with steadier weight progress.

For a broader look at how calorie targets fit into your overall GLP-1 journey, the calorie deficit hub brings together everything on this topic.

GLP Trackr provides general tracking and informational support — it is not a substitute for personalised advice from your prescriber or doctor. If you are unsure what calorie intake is appropriate for your health circumstances, speak with your healthcare professional before making significant changes.

Ready to take the guesswork out of food logging? Download GLP Trackr on the App Store or Google Play and explore it free for 7 days — snap a photo of your plate and your nutrition is logged in seconds.