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

by Jason Fung

What causes weight gain? Proximate cause: Consuming more calories than you expend. If more calories in than out is the proximate cause, the unspoken answer to that last question is that the ultimate cause is “personal choice.” We choose to eat chips instead of broccoli. We choose to watch TV instead of exercise. Through this reasoning, obesity is transformed from a disease that needs to be investigated and understood into a personal failing, a character defect. Instead of searching for the ultimate cause of obesity, we transform the problem into •eating too much (gluttony) and/or •exercising too little (sloth). Gluttony and sloth are two of the seven deadly sins. So we say of the obese that they “brought it on themselves.” They “let themselves go.” It gives us the comforting illusion that we understand ultimate cause of the problem. In a 2012 online poll,1 61 percent of U.S. adults believed that “personal choices about eating and exercise” were responsible for the obesity epidemic. So we discriminate against people who are obese. We both pity and loathe them. However, on simple reflection, this idea simply cannot be true. Prior to puberty, boys and girls average the same body-fat percentage. After puberty, women on average carry close to 50 percent more body fat than men. This change occurs despite the fact that men consume more calories on average than women. But why is this true?