crash diet

noun

: a way of losing a lot of weight very quickly by limiting how much one eats

He went on a crash diet and lost 20 pounds in a month.

Medical Definition

crash diet

noun

ˈkrash- 

: a diet intended to help a person lose a large amount of weight in a short period of time typically by reducing the amount of food consumed to minimal levels

If you feel you need to diet, be reasonable about it. Aim to lose no more than 4 pounds per month, as crash diets are unsustainable and can cause … weight fluctuation that may damage metabolism and could lead to eating disorders.

—Runner's World

crash dieter noun

Chronic crash dieters lose muscle along with fat, and when they regain weight, they gain back mostly fat.

—Betty Weider, Shape

crash dieting noun