Be careful about what you eat and drink every day.

Literal

Every-day [possessive-の] food-and-drink [topic-には] be-careful [command-なさい].

飲食物 ('food and drink items') is a formal compound — 飲 (drink) + 食 (eat) + 物 (things). 注意する takes に for the object of attention. ~なさい is the mild imperative.