How to Figure Out How Many Calories to Eat on a GLP-1 Journey

Your daily calorie requirement is shaped by a handful of personal factors: your weight, height, age, sex assigned at birth, and how active you are. Most approaches start with an estimate of your basal metabolic rate (BMR) — the calories your body needs just to keep basic functions running at rest — and then multiply it by an activity factor to arrive at your total daily energy expenditure (TDEE).

The basic formula in practice

Widely used equations such as the Mifflin-St Jeor formula use weight (kg), height (cm), and age (years) to estimate BMR. Once you have that figure, an activity multiplier — ranging from sedentary (roughly 1.2×) to very active (1.7×+) — gives you a TDEE estimate. Creating a modest calorie deficit below that figure is the general principle behind gradual weight loss.

It is worth keeping in mind that no formula gives a perfect number for any individual. These are starting estimates; your real-world results will tell you more than any equation can. For a practical tool you can work through yourself, visit the GLP Trackr calorie calculator to run through these variables in one place.

Why this matters differently on a GLP-1 medicine

Medicines like tirzepatide (Mounjaro) and semaglutide (Wegovy) commonly reduce appetite and food noise, which means many people naturally eat less without tracking. The risk is eating too little — particularly of protein — which can affect energy and muscle retention. Understanding your calorie target helps you make sure what you do eat is working hard for you.

For a closer look at the conversion between calories and weight change, the page on calories per pound of body weight explains the relationship in plain terms. You may also find it useful to explore practical ways to figure out your calorie needs and how to calculate your daily calorie intake for further detail on the same topic approached from different angles.

General educational ranges

As a broad educational reference, many adults in a moderate calorie deficit aim for somewhere in the range of 1,400–1,800 kcal per day, though the right figure varies considerably by individual. These are not personal targets — treat any specific number as a starting point to observe and adjust, ideally in discussion with your prescriber or a registered dietitian.

Knowing your calorie target is only useful if you can consistently measure against it — and on a GLP-1 medicine, when appetite is unpredictable and meals are smaller, manual logging can feel like more effort than it is worth. That is where GLP Trackr's AI food photo scan makes a real difference: point your phone camera at a meal and get an instant calorie and protein breakdown, no typing required.

Once you have set a daily calorie target inside the app, every meal you log — whether by photo scan, barcode, or search — feeds directly into your running total. You can also set a separate protein target, which many people on GLP-1 medicines find especially useful given reduced overall intake. The daily check-in then brings your food, weight, and energy data together so you can see at a glance how intake and results are tracking over time.

All of this data also feeds into GLP Trackr's insights features, so you can spot patterns — like whether days when you hit your protein goal tend to correlate with better energy — and bring a clear summary to your next prescriber appointment.

Any specific calorie or nutrient target should be agreed with your prescriber or a qualified dietitian based on your full health picture. GLP Trackr helps you log and observe your intake; it does not replace that professional guidance.

Ready to stop guessing and start seeing your numbers clearly? Download GLP Trackr on the App Store or Google Play — it is free to try for 7 days.