How Many Calories Are You Supposed to Eat a Day?

Your daily calorie requirement is shaped by two main components: your basal metabolic rate (BMR) — the energy your body uses just to keep functioning at rest — and the calories you burn through physical activity and daily movement. Together, these make up your total daily energy expenditure (TDEE), which is the most useful starting estimate for a daily calorie target.

Key factors that influence your number

• Body size and composition: larger bodies and those with more muscle mass burn more calories at rest.
• Age: metabolic rate tends to decrease gradually with age.
• Activity level: someone with a physically active day needs meaningfully more calories than someone largely sedentary.
• Health and weight goals: a modest calorie deficit supports gradual fat loss; maintenance targets aim to match expenditure.

How GLP-1 medicines change the picture

Medicines like Mounjaro (tirzepatide) and Wegovy (semaglutide) work partly by reducing appetite and increasing feelings of fullness, which commonly leads to eating less without deliberate restriction. This is useful for weight management, but it also raises a practical challenge: when overall food intake drops, it becomes easier to fall short on protein, fibre, and key micronutrients. Many people on GLP-1 medicines find that understanding their daily calorie picture helps them eat intentionally rather than simply eating less.

General educational guidance often suggests a floor of around 1,200 calories per day for women and 1,500 for men as a rough lower limit before nutritional adequacy becomes harder to maintain — but individual needs vary, and any specific target for you should be discussed with your prescriber or a registered dietitian. For a deeper look at calculating your own number, the GLP Trackr calorie calculator hub walks through the main methods. You may also find it useful to explore how many calories you must eat in a day alongside practical guidance on what those calories should actually look like on a plate.

Knowing your target is one thing; hitting it consistently — especially when appetite is unpredictable on a GLP-1 medicine — is where most people struggle. GLP Trackr's AI food photo scan is the fastest way to close that gap: point your camera at a meal and the app returns an instant calorie and protein breakdown, no manual entry required. It also supports barcode scanning and a manual food search for when you need more precision.

Once your daily calorie goal is set inside the app, every meal you log feeds directly into your targets dashboard, so you can see at a glance whether you are on track, under, or over — across calories, protein, water, and fibre simultaneously. The daily check-in feature captures the full context around your food intake: energy, mood, sleep, and food noise, all in one 30-second log. Over time, the app's insights surface patterns you might not notice otherwise, such as how your energy on a given day relates to what you ate the day before.

GLP Trackr is a tracking and journaling tool; it does not replace the guidance of your prescriber or a registered dietitian when it comes to setting a calorie goal that is right for your individual circumstances. If you have any concerns about your nutritional intake while on Mounjaro or Wegovy, your healthcare professional is the right person to ask.

Start logging your meals and building a clearer picture of your nutrition — GLP Trackr is free to try for 7 days on the App Store and Google Play.