Summary
Nutrition is the set of processes by which the body gets from food the energy and materials it needs to live. Food provides nutrients: carbohydrates and fats give energy; proteins build and repair the body; and vitamins and minerals, in small amounts, keep everything working. Water and fibre are essential too.
In human nutrition several systems work together. The digestive system turns food into nutrients and absorbs them; the respiratory system supplies oxygen; the circulatory system delivers them through the blood to every cell; and the excretory system removes waste. A healthy diet is varied and balanced, like the Mediterranean diet, with more fruit, vegetables and pulses than sweets and fats.
Key points
- Nutrition provides energy and materials from food.
- Carbohydrates and fats: energy. Proteins: build and repair.
- Vitamins and minerals: in small amounts, but essential.
- Water and fibre are needed too.
- The digestive, respiratory, circulatory and excretory systems work together.
- The digestive system transforms and absorbs; the circulatory delivers.
- A healthy diet is varied and balanced (the Mediterranean diet).