How Many Kcal Per Day Do You Need on a GLP-1 Medicine?

A daily kilocalorie estimate is built from two components: your Basal Metabolic Rate (BMR) — the energy your body burns at rest — and an activity multiplier that accounts for how much you move. Together these produce a Total Daily Energy Expenditure (TDEE) figure: a rough guide to how many kcal per day your body uses overall.

The factors that go into the calculation

• Body weight — heavier bodies generally require more energy at rest
• Height — influences the surface area and lean mass estimate
• Age — metabolic rate tends to slow gradually over time
• Biological sex — affects muscle mass distribution and baseline BMR
• Activity level — from largely sedentary to very active; this multiplier has the biggest impact on your total figure

What the number means on a GLP-1 journey

The figure a calculator produces is an estimate, not a prescription. Individual metabolism varies, and factors like medication effects, muscle mass, and health history all influence real-world energy needs. Many people on Mounjaro or Wegovy find they naturally eat well below their calculated TDEE — which is why understanding how many kcal per day is realistic on a GLP-1 medicine is a useful companion read.

If you want to explore the broader context of calorie targets, our calorie calculator hub covers the full picture, including how to interpret your result and adjust for progress. You can also compare approaches in our guide on using a calories per day calculator alongside your journey.

One practical consideration: eating too far below your needs for an extended period can reduce muscle mass and slow metabolism over time. General nutrition guidance suggests that for most adults a floor of around 1,200–1,500 kcal per day is commonly referenced, though the right range for you is something to discuss with your prescriber or doctor — they can factor in your full health picture.

Once you have a kcal per day estimate, the practical challenge is logging what you actually eat — especially when appetite is unpredictable. GLP Trackr's AI food photo scan is the fastest way to do this: point your camera at a meal and the app returns an instant calorie and macronutrient breakdown, no manual searching needed. It is particularly useful on lower-appetite days when you want to check you have eaten enough without the friction of typing everything in.

You can set a daily calorie target inside the app and track progress against it throughout the day. The morning check-in also captures energy levels and food noise alongside your food log, so you can see how your intake connects to how you feel — a pattern that is genuinely useful to bring to your next prescriber appointment.

For a closer look at how daily calorie needs differ for women specifically, the page on daily calorie needs for women on GLP-1 medicines is worth reading alongside this one.

GLP Trackr is a tracking and journaling tool, not a medical service. Any calorie target you set should be informed by your own prescriber or doctor, who knows your full health history. If you are unsure what intake level is appropriate for you, always ask them first.

Ready to put your kcal target to work? Download GLP Trackr on the App Store or Google Play and start a free 7-day trial — your camera does the food logging so you can focus on the journey.