饮食 (yǐnshí) is a broad noun covering both food and drink together — your overall diet or eating habits. It's more general than 食物 (shíwù, just 'food') or 饮料 (yǐnliào, just 'beverages'), and less formal than 膳食 (shànshí, used in nutrition/health contexts). 餐饮 (cānyǐn) refers to the catering industry or restaurant meals, not personal diet.