Principles of human nutrition

We rely on the foods we eat to provide all the building blocks for metabolism, tissue growth and reproduction, the energy required for all functions and activities, and the ‘essential’ compounds that cannot be synthesized by humans. Nutritional science covers all the processes involved in achieving a healthy balance between requirements and the supply of nutrients, at the right time and in appropriate proportions, at cellular, organ, whole body and group/population levels. Nutritional status (what we eat, what we are, what we can do) should be assessed in all patients, through awareness, simple screening, and detailed evaluation when appropriate. Nutrition is only occasionally a sole cause or treatment of disease, but is frequently an important contributor to disease aetiology and management. It is commonly affected by illness and by treatments.