All nutrients perform one or more of the following functions:
1. Serve as a source of energy or heat
2. Support the growth and maintenance of tissue
3. Aid in the regulation of basic body processes
These three life-sustaining functions collectively are part of metabolism, the sum of all physical and chemical changes that take place in the body. Nutrients have specific metabolic functions and interact with one another to maintain the body.
Nutrients
The science of nutrition historically has been based on the nutrients found in food. Nutrients are the chemical substances supplied by food that body needs for growth. Maintenance, and repair. Nutrients can be into six groups :
1. Carbohydrates ( often abbreviated as CHO )
2. Fats ( lipids)
3. Proteins
4. Minerals
5. Vitamins
6. Water
Nutrients are considered either essential or nonessential, depending on whether the body can or cannot manufacture them. When the body requires a nutrient for growth or maintenance but lacks the ability to manufacture it in amounts sufficient to meet bodily needs, this essential nutrient must be supplied by foods in the diet. Vitamin C, Vitamin A and calcium are 3 of the more than 40 essential nutrients. Nutrients not needed in the diet because the body can make them are called nonessential. For example, the amino acid alanine is a nonessential nutrient because the body can manufacture it from other raw materials.
Nutrition
Nutrition is a science
Stated simply, nutrition is the science that studies the relationship of humans to food. The discussion of nutrition in this text involves the following topics :
ü The chemical content of food
ü The body’s use of food
ü The relationship of food to health
ü Selection of food
ü Techniques to modify food habits
ü Diet as treatment for disease
ü The relationship between medications and food intake
As this list suggests, the science of nutrition encompasses ideas from many other sciences: biology, chemistry, economics, educational theory ,nursing, medicine, pharmacology, physiology, psychology, and sociology. This connection with other disciplines suggests the far- reaching implications of good nutrition.
