Calorie Calculator: Understanding Your Intake on a GLP-1 Journey

A calorie estimate typically uses an equation — the most widely referenced being the Mifflin-St Jeor formula — that takes your body measurements and activity level to estimate your Total Daily Energy Expenditure (TDEE). This is the approximate number of calories your body burns across the day at rest and through movement. From that figure, you can work out a sensible intake range depending on your goal.

Why this matters specifically when you are on Mounjaro or Wegovy

Both tirzepatide (Mounjaro) and semaglutide (Wegovy) are known to reduce appetite — sometimes significantly. This is useful for reducing overall intake, but it can also mean some people unintentionally eat far too little, particularly in protein. Calculating your calorie and protein needs gives you a target to aim for, rather than simply eating whatever your appetite allows on a given day.

General educational context: many adults working toward gradual weight loss aim for a modest calorie deficit — often discussed in ranges of 300–500 kcal below TDEE — but what is appropriate for you personally depends on your health, your starting point, and the guidance of your prescriber or doctor. These figures are for general orientation, not a personal prescription.

What the calculator takes into account

• Basal Metabolic Rate (BMR): the calories your body needs at complete rest to maintain basic functions
• Activity multiplier: adjusts BMR upward based on how active you are day to day
• Goal adjustment: a further adjustment for a deficit (loss) or surplus (maintenance/muscle building)

For a deeper look at how maintenance calories are calculated, see our guide to working out your maintenance calorie needs. If you want to look up the calorie content of specific foods and meals, our food calorie calculator covers that in detail.

For further context on energy balance and nutrition, NHS guidance on understanding calories provides a clear, evidence-based overview.

Manually calculating and then tracking calories every day is where most people fall off — especially when appetite is unpredictable and meals are smaller or less structured than usual. GLP Trackr is built specifically for this challenge.

AI photo food scanning — point, snap, done

The standout feature for calorie tracking on a GLP-1 journey is the AI meal photo scanner. Rather than searching for every ingredient or estimating portions, you point your camera at your plate and the app produces an instant calorie and macro breakdown. For days when appetite is low and meals are improvised, this removes almost all friction from logging.

Set a calorie target and watch it in real time

Once you have your calorie figure — whether from the calculator here or agreed with your healthcare professional — you can set it as your daily target inside GLP Trackr. The app tracks your running total across meals and snacks, so you always know where you stand. You can also set a protein target separately, which is particularly useful given how important protein intake is when appetite is reduced.

The daily check-in and food log feed into the app's insights dashboard, which can surface patterns over time — for example, whether lower-protein days correlate with lower energy or slower progress.

You can explore the full range of tracking tools via the GLP Trackr calorie and nutrition tracking hub.

A note on targets: any specific calorie or macro goal that affects your health should be discussed with your prescriber or doctor — they know your full picture. GLP Trackr helps you record and monitor your intake so you can have more informed conversations with them; it is not a substitute for their guidance.

Ready to make food tracking effortless? Download GLP Trackr on the App Store or Google Play and explore every feature free for 7 days — no commitment needed.