1. C 日常饮食　sort of food that is usually eaten by a person, community, etc.
2. C 规定饮食　limited variety or amount of food that a person is allowed to eat

　My diet is made up of rice and vegetables.　我日常的饮食包括米饭和蔬菜。
　The doctor put me on a low-salt diet.　医生嘱我饮食要少盐。
　Noise pollution is a daily diet in big cities.　在大城市，噪音污染是家常便饭。

 ♣ go on a diet
　用规定食谱，节食　allowed to eat only some foods or a little food, because of illness or to lose weight
　No sugar for me, please. I went on a diet.　请别给我加糖，我现在正按照规定节食。

 ♣ diet, food, provisions, rations, table
　参见food条。
 ♣ diet, meal, repast
　参见meal条。

　vt. & vi. （使）节制饮食 (cause to) restrict sb; be restricted, to a limited list of food and drink that one is allowed, especially by a doctor

　diet　的基本意思是“进特种饮食”或“节食”，多用于在医生劝导或规定之下。可用作不及物动词，也可用作及物动词，用作及物动词时，可接名词、人称代词或反身代词作宾语。

　～ strictly　严格控制饮食
　～ off　节制饮食

　He is dieting.　他在节食。
　He got so fat that he had to diet.　他太胖，需要节食。
　His doctor is dieting him strictly.　他的医生严格规定他的饮食。
　I am dieting myself on vegetation.　我在吃素。
　She became so fat that she had to diet herself.　她长得太胖，所以不得不实行节食。

　［词源］中古英语diete（饮食）