Obesity and Hunter-Gatherers

The New York Times ran an interesting article "Debunking the Hunter-Gatherer Workout" discussing a research article published yesterday in PLoS ONE. As we all know, obesity is on the rise, and represents a major public health concern. Why is obesity on the rise? Public health experts disagree on whether it is due to a decrease in physical activity, or an increase in calorie consumption (or a combination of both). What affects our weight more: diet or exercise?

For some reason I couldn't find a stock image of a
hunter-gatherer, but this guy has a spear , so it will have to do.

To determine how our physical activity has changed over time (as obesity has increased), the researchers studied the Hadza people of Tanzania, one of the last remaining hunter-gatherer societies. They measured the energy expenditure, amount of exercise, and diet. The results were somewhat surprising. The Hadza were more physically active than the typical American. However, the amount of calories they burn per day is no different from the typical American. Surprising!

Over years of evolution our bodies have developed ways to keep our energy expenditure constant. This was no doubt a very useful thing when we lived in environments with limited resources, and had to worry about staving off starvation. But, it's not so useful in trying to lose weight. This confirms what most people who have lost weight already know, diet is more important than exercise. Exercise definitely helps, but diet is essential.

Check it out, it's a neat paper!