Food components of human nutrition

As a prerequisite for a healthy body plays not only the daily energy intake and the total energy content of food a role, but also the composition.
Food taken from either the animal or plant kingdom and contain a different composition of nutrients.

The nutrients include:
Protein
Fats
Carbohydrates
Vitamins
Minerals (volumes and trace elements)
Dietary fiber (cellulose, hemicelluloses, lignin)

Other food components include: Dyes (leafy greens), Fragrances (Roost staffed), Flavors, secondary plant compounds, water, cholesterol, uric acid.
Protein, fat and carbohydrates are among the vital nutrients and energies lifers den, while minerals and vitamins are vital, but without energy.
Fiber, color, fragrance and taste substances are functionally important food ingredients. But not only the eyeliner nutrients, but also the nutrient content and energy content are decisive for an evaluation of a food.

Nutrient density
The nutrient density of a food is the ratio of nutrient content in terms of energy. On the nutrient density is the quality of food and thus assess the health value. The higher the nutrient density is, the cheaper the relationship between the nutrient and energy content.

It can be calculated using the following formula:
Nutrient density (µ g mg, g) = nutrient content (g mg, µ g per 100g) / energy content (kcal). The nutrient density is an important criterion when it comes into energies berg ante nutrition (e.g. reducing food), but all the nutrients in sufficient quantity to contain. In this case to be sufficiently supplied, the menu on foods with high nutrient density.

For example, the protein content of different pieces of meat (pork tenderloin and pork belly):
# Pork fillet, 100g: 21.5 g Eiweiß/104 kcal = 0.21 g / kcal
# Pork belly, 100g: 14.0 g Eiweiß/385 kcal = 0.04 g / kcal
The nutrient density in terms of protein is pork fillet with 0.21 g / kcal higher than that of pig belly with 0.04 g / kcal.

Energy content of nutrients
The energy content of food is in kilojoules or kilocalories. If nutrients in the body “burned”, it is energy. The nutrients, proteins, fats, carbohydrates and alcohol differently are high-energy values.

1g protein = 4.2 kcal
1g fat = 9.3 kcal
1g carbohydrates = 4.2 kcal
1g alcohol = 7.0 kcal

1 gram fat provides more than twice energy as much the same amount of protein and carbohydrates!