Excerpt from an article about these findings: For a more granular look, comparing individuals instead of population averages, I recently joined Luke and her te

Excerpt from an article about these findings: For a more granular look, comparing individuals instead of population averages, I recently joined Luke and her team, including Dugas, to examine activity and energy expenditure in a large, multiyear analysis known as the Modeling the Epidemiological Transition Study (METS). More than 300 participants wore accelerometers similar to a Fitbit or other fitness tracker 24 hours a day for an entire week while their daily energy expenditure was measured with doubly labeled water. We found that daily physical activity, tracked by the accelerometers, was only weakly related to metabolism. On average, couch potatoes tended to spend about 200 fewer calories each day than people who were moderately active: the kind of folks who get some exercise during the week and make a point to take the stairs. But more important, energy expenditure plateaued at higher activity levels: people with the most intensely active daily lives burned the same number of calories each day as those with moderately active lives. The same phenomenon keeping Hadza energy expenditure in line with that of other populations was evident among individuals in the study.