Study Suggests Obesity Is Caused by Eating More, Not by Burning Less Energy

The conveniences of modern technology like cars, escalators, and more often may have people thinking that we now burn less calories than our ancestors did, but a recent study might just have put paid to this idea. Researchers who published their findings in online journal PLoS ONE learned that traditional hunter-gatherers burn just as many calories as your average modern adult—or, at least, your average American or British adult—reports MedicalNewsToday.com.

The study involved having researchers measure the daily energy expenditure (meaning calories burned per day) of a group of traditional hunter-gatherers called the Hazda. The Hazda live in the northern Tanzanian savannah and spend their days moving over great distances to hunt and forage.  The researchers, led by Herman Pontzer from Hunter College in New York, found that the differences in the numbers of calories burned in a single day were indistinguishable between the Hazda and American and British adults, even accounting for the effects of weight, body fat percentage, age, and gender.

“[Energy expenditure is] not simply a function of physical activity,” Pontzer is quoted as saying. The findings may suggest that since the results show that decreased energy expenditure is not an issue and therefore not a possible cause for the rise in cases of obesity, the added weight gain may be attributed to increased food consumption instead.

This is not to say, however, that you should give up exercise—far from it. The authors suggest that the Hazda’s higher levels of physical activity “may contribute to the health and vitality evident among older Hazda,” MedicalNewsToday.com reports. Still, these findings suggest that it would be in your best interest to pay more attention to the calories you consume, especially if you’re concerned about gaining weight. To this end, it may be a good idea to start a food journal and remember to read labels before purchasing items from the supermarket.


(Photo by Emilian Robert Vicol via Flickr Creative Commons; used for illustrative purposes only)