How to Count Calories When You're on Mounjaro or Wegovy

Every food has an energy value measured in calories (kcal). To count them accurately, you need three things: portion sizes, a reliable source of calorie data, and a consistent logging habit.

Reading food labels and weighing portions

Packaged foods list calories per 100 g and often per serving. Weighing portions — even roughly — gives you a more honest number than eyeballing. A kitchen scale makes this quick; over time you develop a feel for common portions and need it less.

How to count calories without an app

A simple notebook or spreadsheet works. Write down each food, the weight or portion, and look up the calorie content on the packaging or a reputable food database. Running totals through the day keeps you aware of where you stand. Many people find this approach helps them understand food composition even before they move to a faster method.

How to count macros alongside calories

Macros — protein, carbohydrate, and fat — make up your total calories (protein and carbs provide roughly 4 kcal per gram; fat provides roughly 9 kcal per gram). On a GLP-1 journey, protein tends to matter most: it supports muscle alongside weight change and keeps you feeling fuller on smaller meals. Tracking protein as a secondary number alongside calories gives you a more complete picture. See our guide to calorie deficit and GLP-1 weight management for more on how these numbers fit together.

Common foods to watch

• Liquid calories: juices, smoothies, and alcohol add up quickly with little satiety.
• Cooking fats: a tablespoon of oil adds around 120 kcal — easy to miss.
• Protein foods: chicken breast, eggs, Greek yoghurt, and legumes give the most protein per calorie, which matters on a GLP-1 plan.

For more practical strategies, explore ways to make calorie counting sustainable day to day.

The quickest method by far is photographing your meal and letting an AI do the work. GLP Trackr's AI photo scan identifies foods in your plate and returns an instant calorie, protein, and macro breakdown — no manual searching, no typing. For packaged foods, the barcode scanner pulls nutrition data in seconds. Manual search is also there when you need it.

Because the app is built specifically for people on Mounjaro and Wegovy, it pairs food logging with the rest of your journey. You can set a daily protein target alongside calories, and the morning check-in captures weight, energy, and food-noise level in one place — so you start to see how what you eat connects to how you feel and how your weight moves.

If you're weighing up which tool to use, our overview of good apps for counting calories on a GLP-1 plan covers what to look for, and how a dedicated calorie-counting app compares to general trackers is worth reading too.

A note on targets: calorie and protein goals vary depending on your body, activity level, and what your prescriber or doctor has discussed with you. The figures in any app — including GLP Trackr — are general guides. Always follow the personalised guidance of your healthcare professional, especially if your appetite has changed significantly on your medication.

Ready to make food logging effortless? Snap a photo of your next meal with GLP Trackr and get an instant breakdown. Available free on the App Store and Google Play — your first 7 days are on us.