diet noun definition in Healthy eating habits topic from the Oxford Advanced Learner's Dictionary

diet

 noun: Healthy eating habits topic
1 [countable, uncountable] the food that you eat and drink regularly to have a healthy, balanced diet the Japanese diet of rice, vegetables and fish to receive advice on diet2 [countable] a limited variety or amount of food that you eat for medical reasons or because you want to lose weight; a time when you only eat this limited variety or amount a low-fat, salt-free diet diet drinks (= with fewer calories than normal) I decided to go on a diet (= to lose weight) before my holiday.