The body is the product of what it eats. The most obvious and probably the most common nutritional defects are caused by serious calorie imbalance: too few or too many.(p.11)
If you consume more calories (units of energy) than your age, size, and life style require, you store those calories in the form of fat. If you consume fewer calories than you need, you lose fat because the body uses fat as an energy source when it runs out of calories. (p.13)
A certain number of calories are needed to sustain the basic body metabolism, which includes such functions as keeping the heart beating, breathing and maintaining a normal body temperature. Beyond that, each of your activities requires calories.(p.14)
To speed the reducing process, I have cut the fat consumption way down during the Diet period. When the body demands more fat, it pulls it our of the fat storage areas, which are plentiful in the overweight woman and man.(p.17)

The Scarsdale Medical Diet is LOW fat, LOW carbohydrates, and consequently LOW in caloric content, not NO fat, NO carbohydrates. The person in normal health gets enough complex carbohydrates in the vegetables and fruits on the diet for safe eating. He burns his own excess fat to provide the added energy while reducing.(p.37)