Food is an important source of nutrition for human and animal life. Its primary function is to support growth and essential processes in the body.
Different organisms obtain food through different means. Some animals, such as birds, eat other animals or plants. Other organisms, such as plants, take in food through photosynthesis. Plants and other organisms also absorb nutrients from water, air and soil.
The basic nutrients that plants need are carbon, nitrogen, phosphorus, magnesium and sulfur. They are needed for growth, repair and regulation of vital processes in the body. Inadequate nutrients increase the risk of future physical and cognitive problems.
Nutrition is the study of the processes involved in absorbing and using food. Dietary fibre, carbohydrates, proteins and fats are essential components. However, too many people in the developed world consume too much sugar, salt, and saturated fats.
A healthy diet contains a wide variety of foods. Vegetables, for example, contain vitamins, minerals, and fiber. Legumes, such as tofu and kidney beans, are a good source of protein.
In addition to providing energy, fats also help protect internal organs. Fish, chicken and milk are excellent sources of fats. Similarly, eggs contain high levels of fat.
Diets vary from country to country. This is partly due to geographic differences. Generally, people in cool regions depend on crops that mature quickly, whereas those living in warm, wet lowlands rely on crops that retain water.
Agricultural technology has developed improved varieties of seeds, improved ways of harvesting and processing them, and improved storage methods. These changes have made more food available to more people.