crash diet
US /ˈkræʃ ˌdaɪ.ət/
UK /ˈkræʃ ˌdaɪ.ət/
1.
a diet that involves eating very little food, often with the aim of losing weight quickly
:
•
She went on a crash diet to fit into her wedding dress.
•
Crash diets are often unhealthy and unsustainable.