Our findings add to a growing body of evidence suggesting that energy expenditure is consistent across a broad range of lifestyles and cultures. Of course, if we push our bodies hard enough, we can increase our energy expenditure, at least in the short term. But our bodies are complex, dynamic machines, shaped over millions of years of evolution in environments where resources were usually limited; our bodies adapt to our daily routines and find ways to keep overall energy expenditure in check.
All of this means that if we want to end obesity, we need to focus on our diet and reduce the number of calories we eat, particularly the sugars our primate brains have evolved to love. We’re getting fat because we eat too much, not because we’re sedentary. Physical activity is very important for maintaining physical and mental health, but we aren’t going to Jazzercise our way out of the obesity epidemic. (via Debunking the Hunter-Gatherer Workout - NYTimes.com)