crash diet
From Longman Dictionary of Contemporary EnglishRelated topics: Nutritioncrash dietˈcrash ˌdiet noun [countable] DFNan attempt to lose a lot of weight quickly by strictly limiting how much you eatExamples from the Corpuscrash diet• One needed to go on a crash diet, the other was in the middle of a nervous breakdown.• A crash diet will leave you hungry, you will binge and you will not get anywhere.• So to maximise the benefits to your metabolic rate, resolve never to crash diet again.