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Is Cal AI accurate?
What an NIH test found about photo calorie apps · Last checked November 2026
Not reliably. In a 2026 NIH test, four photo calorie apps, Cal AI among them, under-counted meals by about 250–345 kcal on average. That’s a whole snack, every meal. AI is good at telling what’s on your plate, and bad at telling how much.
What the research found
- NIH, 2026: Cal AI and three other apps tested. 102 meals, every ingredient weighed to a tenth of a gram, then photographed and run through Cal AI, MyFitnessPal, Lose It! and Appediet. All four under-counted calories by about 250–345 kcal on average, and fat by about 30 g. (Early results presented at NUTRITION 2026, not yet peer-reviewed.)
- Sweden, 2025: 52 weighed food photos. ChatGPT-4o and Claude 3.5 Sonnet were off by 36% on calories on average, and Gemini 1.5 Pro by 64%. All three guessed low, and more so on bigger plates.
- Ireland, 2025: 114 photos of real meals. ChatGPT named the foods well but guessed the weight too low on 76% of photos. Large meals weighed 798 g, and it guessed 530 g.
Why a photo can’t count calories
- A camera can’t weigh food. 150 g and 250 g of rice look alike in a bowl, but they’re about 130 kcal apart.
- Hidden fat. One tablespoon of olive oil is about 120 kcal and invisible once it’s cooked in. That’s why fat was the biggest miss in the NIH test.
- Bigger plates, bigger misses. Every study found the error grows with the portion.
How to log food you can trust
- Weigh it, in grams. Weigh foods the same way every time, cooked or raw.
- Scan the barcode or type the label for packaged food. That’s the maker’s own numbers, not a guess.
- Log the oil separately.
- Save meals you repeat. Weigh once, log in one tap after that.
- Check against the scale. Weigh yourself once a week; if the trend doesn’t match the plan, adjust the plan.
How BECOME does it
- The AI never sets your numbers. Calories come from USDA food data, by the gram, ounce or kcal.
- Barcode scan, typing a label, or one tap on a planned meal.
- Saved meals and quick add for what you eat every week.
- A weekly check-in: if your weight moves slower or faster than planned, your plan changes by about 100 kcal at a time, and only when you approve it.
- No ads.
Sources
- Hengist A., Charles O. et al. (NIDDK, National Institutes of Health). Presented at NUTRITION 2026, American Society for Nutrition, July 2026. Press release
- Fridolfsson J. et al. Performance Evaluation of 3 Large Language Models for Nutritional Content Estimation from Food Images. Current Developments in Nutrition, 2025. PMC12513282
- O’Hara C. et al. An Evaluation of ChatGPT for Nutrient Content Estimation from Meal Photographs. Nutrients, 2025. PMC11858203
- USDA FoodData Central (SR Legacy): cooked white rice 130 kcal per 100 g; olive oil 884 kcal per 100 g.
Cal AI, MyFitnessPal and Lose It! are trademarks of their owners; BECOME isn’t affiliated with them. General guidance, not medical advice.