How to Work Out Your Maintenance Calories on a GLP-1 Journey

Your maintenance calorie level — sometimes called Total Daily Energy Expenditure (TDEE) — is the point at which your calorie intake equals your calorie output. Eat below it and you are likely to lose weight over time; eat at or above it and weight tends to hold steady or rise. It is not a fixed number: it shifts with changes in body weight, muscle mass, age, and daily activity.

The main factors involved

• Basal Metabolic Rate (BMR) — the calories your body burns at complete rest, just keeping organs functioning. This is typically estimated using formulas (such as Mifflin-St Jeor) that factor in your weight, height, age, and sex.
• Activity level — a multiplier applied to your BMR to account for how much you move each day, from sedentary desk work to regular exercise.
• Body composition — muscle tissue burns more calories at rest than fat tissue, so two people with the same body weight can have quite different maintenance levels.

A practical way to estimate it

The most straightforward approach is to use a TDEE calculator that asks for your height, weight, age, and a broad activity category. The result is an estimate — individual variation means the true figure can be a few hundred calories above or below, but it gives you a useful working number to track against. You can explore what maintenance calories actually mean and how they are calculated in more detail, or use our maintenance calories guide as a companion reference.

Why this matters specifically on a GLP-1 medicine

Reduced appetite on tirzepatide or semaglutide can mean eating significantly less than before without feeling hungry. For some people that creates a large deficit without any deliberate effort; for others, especially later in a journey, knowing the maintenance number helps them understand whether a plateau is a calorie issue or something else entirely. Pairing your maintenance estimate with an understanding of how to calculate your calorie deficit gives you a clearer picture of where you are relative to your goal.

Knowing your maintenance number is only useful if you can consistently compare it to what you are actually eating — and that is where logging becomes the practical piece of the puzzle.

GLP Trackr's AI food photo scan lets you point your camera at a meal and get an instant breakdown of calories, protein, and other macros without manual searching or weighing. On days when appetite is low and meals are small and irregular, this frictionless approach makes it far more likely you will actually log what you eat. You can set a calorie target based on your maintenance estimate (or a deficit below it), and the app tracks your daily intake against that number in real time.

Over time, the insights tools show you patterns — how your intake varies across the week, how it correlates with your weight trend, and whether you are consistently hitting, exceeding, or falling short of your target. That context is genuinely hard to spot without a log, and it is exactly the kind of data that makes a conversation with your prescriber or doctor more productive. You can read more about putting your numbers into practice in our complete guide to calorie deficit on a GLP-1 journey.

General educational calorie ranges are a helpful starting point, but your ideal intake depends on your individual circumstances — always discuss specific dietary goals with your healthcare professional, especially if you have any medical conditions or are on other treatments.

Ready to put your maintenance number to work? Set your calorie target in GLP Trackr and let the AI food scanner do the tracking — available free on the App Store and Google Play, with a 7-day trial to get started.