Gut Microbes Rewrite the Calorie Count, Dethroning a 130-Year-Old Formula

A new DAMM model that accounts for gut bacteria in energy absorption outperforms the century-old Atwater factors, achieving 96% accuracy versus 88% in a small crossover trial (17 healthy adults on Western and high-fiber diets). The study suggests Atwater underestimates energy intake on Western diets because it misses microbial fatty acid production, and raises the possibility that methane-producing microbes hidden in gut biofilms skew stool-based tests. While promising for explaining individual diet differences, DAMM requires further validation for weight loss/gain and broader populations. Published in PLOS ONE (May 27, 2026) with NIH funding.