Technology
The most common question here is a practical one: should a calorie counting app be free or paid? Calorie counting apps: free vs paid explains why typing foods and scanning barcodes can be given away, while estimating a plate from a photo costs money every time it runs, and what to check before paying.
For the photo itself, how AI photo calorie counting works breaks it into three steps: the model recognises the foods, estimates how much of each is on the plate and converts that into calories and macros with a nutrition database. Portion size is where it slips most, so how accurate counting calories with a photo is covers what it gets right, what it misses and how to take a photo that helps. How a food scanner app works compares photo, barcode and label.
No app replaces knowing your starting point: how many calories you need a day.
Calorie counting apps: free or paid? What you are actually paying for
What is genuinely free in a calorie app, what costs money and why. The four business models, what you pay with in each — and when paying is not worth it.
How to choose a calorie counting app: 2026 guide
Not all calorie counting apps are the same. A 2026 guide to choosing well: database vs barcode vs AI photo, real accuracy, privacy.
Count calories without weighing food: methods that work
You do not need a scale to control what you eat. Methods to estimate calories and portions without weighing: your hand, the plate method.
Food diary: why logging what you eat works
Keeping a food diary is one of the most science-backed habits for losing weight. Why it works, how to do it without stress, and how to avoid abandoning it.
Food scanner app: how it works
How a food scanner app works: AI photo, barcode and label. What it recognises, where the limit is and how it saves you typing every food.
How Calorie Counting From a Photo Works: What the AI Does and How Accurate It Is
Is counting calories from a photo reliable? How the AI does it and how far off it is: in one study, the average calorie error was 35.8%. And how to correct it.
Smartwatch and health: which metrics matter and which ones fail
Steps and resting heart rate are reliable; calories are not: in a study of 7 watches, none got below 20% error. Which metrics to watch and what to do with them.
Big data, AI and personalized nutrition: what actually works
AI calorie counts from a photo were off by 36% on average in a 2025 study. What big data, DNA tests and glucose sensors really do for your diet.
Start eating better today
Snap your food and, in about 15-25 seconds, see its calories and macros.