食 (shí) means "food" or "to eat" and is a classical or formal term that appears in many compound words related to eating and cuisine. It is more literary than the everyday 吃 (chī) but is commonly seen in written Chinese and set phrases. Examples include 食物 (food) and 饮食 (diet).
中国的饮食文化非常丰富。
Zhōngguó de yǐnshí wénhuà fēicháng fēngfù.
China's food culture is very rich.
这家餐厅的食材都是当天新鲜的。
Zhè jiā cāntīng de shícái dōu shì dāngtiān xīnxiān de.
The ingredients at this restaurant are all fresh from the same day.
注意食品安全对健康很重要。
Zhùyì shípǐn ānquán duì jiànkāng hěn zhòngyào.
Paying attention to food safety is very important for health.