: 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