Here are the typical dieting rules and the physiological reasons as to why restrictive diets don’t work and why it may actually result on weight gain! 1. Restrict calories. When we artificially restrict caloric intake, when we simply don’t eat enough food, the body commonly goes into what’s called a “survival response.” This happens because the body thinks there is not enough food, “there must be a famine” which triggers the brain to signal the body to start storing to surviv