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

by Jason Fung

Assumption 5: A calorie is a calorie This assumption is the most dangerous of all. It’s obviously true. Just like a dog is a dog or a desk is a desk. There are many different kinds of dogs and desks, but the simple statement that a dog is a dog is true. However, the real issue is this: Are all calories equally likely to cause fat gain? “A calorie is a calorie” implies that the only important variable in weight gain is the total caloric intake, and thus, all foods can be reduced to their caloric energy. But does a calorie of olive oil cause the same metabolic response as a calorie of sugar? The answer is, obviously, no. These two foods have many easily measurable differences. Sugar will increase the blood glucose level and provoke an insulin response from the pancreas. Olive oil will not. When olive oil is absorbed by the small intestine and transported to the liver, there is no significant increase in blood glucose or insulin. The two different foods evoke vastly different metabolic and hormonal responses.