the substances that you take into your body as food and the way that they influence your health

Good nutrition is essential if patients are to make a quick recovery. 病人如果要迅速康复，必须补足营养。

improvements in nutrition 改善营养

the process of taking in and using food, or the scientific study of this

She's a professor of nutrition at Columbia University. 她是哥伦比亚大学的营养学教授。