A photo-based AI calorie-tracking app estimated that a meal contained hundreds of calories less than it actually did — undercounting by roughly 250 to 345 calories and about 30 grams of fat per meal, about one-third of the true calorie and fat content.
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Expert: Aaron Hengist & Olivia Charles, NIH NIDDK researchers Aaron Hengist (postdoctoral visiting fellow, NIH NIDDK): "People using a photo-based tracking app without adjusting the portions or entering the amounts of food should take the results with a grain of salt. These apps tend to underestimate calories, especially from fats." Olivia Charles (NIDDK) presented the findings at NUTRITION 2026, the American Society for Nutrition annual meeting (July 25-28, National Harbor). The apps underestimated calories by roughly 250 to 345 per meal and fat by about 30 grams — about one-third of the actual calorie and fat content. High-fat ketogenic dishes caused the most trouble, while carbohydrates were measured more consistently. A user logging a meal could believe they ate hundreds of calories less than they actually did. Source: https://www.sciencedaily.com/releases/2026/07/260726015237.htm
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