--- a healthy diet? diet和food的区别：

The doctor has ordered me a special diet. Too many sweet foods will make you fat.

diet指的是习惯性的食物或规定的事物

food是一般的词语,凡能吃的东西都可称为food

The _____ that you buy in supermarkets are high in sugar, fat and salt. Proper _____ and exercise are both important for health.

food

diet