The Obesity Code: Unlocking the Secrets of Weight Loss (Why Intermittent Fasting Is the Key to Controlling Your Weight)

by Jason Fung

Inherent to the Calories In, Calories Out theory is the idea that reduced physical activity plays a key role in the obesity epidemic. This idea is that we used to walk everywhere, but now we drive. With the increase in laborsaving devices such as cars, our exercise has decreased, leading to obesity. The proliferation of video games, television and computers is also believed to contribute to a sedentary lifestyle. Like any good deception, this one sounds pretty reasonable at first. There is a small problem, though. It is just not true. Researcher Dr. Herman Pontzer studied a hunter-gatherer society living a primitive lifestyle in the modern day. The Hadza in Tanzania often travel 15 to 20 miles per day to gather food. You might assume that their daily energy expenditure is much higher than a typical office worker. Pontzer discusses the surprising results in a New York Times article: “We found that despite all this physical activity, the number of calories that the Hadza burned per day was indistinguishable from that of typical adults in Europe and the United States.”