Counting calories with a photo: how it works and how far to trust it

How it works

An AI looks at the photo, recognises the foods it can see, estimates the amount of each and works out calories and macros (protein, carbs and fat) from nutrition tables.

It’s the same process a person would follow looking at your plate, only faster. And as with a person, the estimate isn’t exact.

Where it tends to go wrong

• Amounts: the hardest thing to judge from a photo. A deep bowl can hide twice the rice.
• What you can’t see: cooking oil, butter or dressings can add a lot of calories.
• Mixed dishes: stews, creamy dishes or closed sandwiches are harder than a chicken breast with vegetables.

Tips to make it more accurate

• Shoot from above, in good light, with the whole plate in frame.
• Photograph one plate at a time and separate what you can tell apart.
• If the app allows it, add a short description (“with a tablespoon of oil”).
• Check the result and correct it if something looks off: what matters is the average over several days, not one meal.

What to do with the result

Use it as a guide, not as clinical data. If your goal is to lose fat, maintain or build muscle, compare the day’s total with your calorie and macro target. You can work it out with our macro calculator.

If your weight isn’t moving as you expected after two or three weeks, adjust the target instead of obsessing over one meal.

How FierFit Gym does it

In FierFit Gym you can log a meal with a photo, text or your voice. With a photo, you pick the image and the AI identifies the foods, estimates how much of each there is and shows them separately with their calories and macros. Before saving you can adjust the foods and amounts: the AI helps you log, but the decisions are yours.

The AI needs an internet connection and has limited use on the free plan.

Plan your whole week with AI

If you’d rather not decide what to eat every day, FierFit Gym can suggest a menu. You choose between one day or the full week, tell it what you need (diet, allergies, budget, cooking time) and the AI adjusts it to your calorie and protein targets.

Before saving you see the whole menu, day by day, with the calories and macros of each meal, and you can accept or discard it. If you accept, the meals are saved as planned: they appear on their day waiting for you to confirm them and don’t add to your calories until then.

Like the other AI features, each generated menu counts toward the free plan’s usage limit, and the numbers are estimates.