Nutrition is the provision, to cells and organisms, of the materials necessary to support life. Many common health problems can be prevented or alleviated with good nutrition.Poor diet can have an injurious impact on health, causing deficiency diseases such as scurvy, beriberi, and kwashiorkor; health-threatening conditions like obesity and metabolic syndrome, and such common chronic systemic diseases as cardiovascular disease, diabetes, and osteoporosis. There are seven major classes of nutrients: carbohydrates (saccharides), fats (triglycerides), fiber (cellulose), minerals, proteins, vitamins, and water.These nutrient classes can be generally grouped into the categories of macronutrients (needed in relatively large amounts), and micronutrients (needed in smaller quantities). The macronutrients are carbohydrates, fats, fiber, proteins and water. The other nutrient classes are micronutrients and also include antioxidants and phytochemicals.

    The macronutrients (excluding fiber and water) provide energy, which is measured in kilocalories. Carbohydrates and proteins provide four (4) Calories of energy per gram, while fats provide nine (9) Calories per gram. Vitamins, minerals, fiber, and water do not provide energy, but are necessary for other reasons.

   Molecules of carbohydrates and fats consist of carbon, hydrogen, and oxygen atoms. Carbohydrates may be simple monomers (glucose, fructose, galactose), or large polymers polysaccharides (starch). Fats are triglycerides, made of various fatty acid monomers bound to glycerol. Some fatty acids are essential, but not all. Protein molecules contain nitrogen atoms in addition to the elements of carbohydrates and fats. The nitrogen-containing monomers of protein, called amino acids, Similar to fatty acids, certain amino acids are essential.Most foods contain a mix of some or all of the nutrient classes. Some nutrients are required on a regular basis, while others are needed less frequently. Poor health can be caused by an imbalance of nutrients.


Carbohydrates may be classified as monosaccharide,    disaccharides, or polysaccharides
   Fats are composed of fatty acids bonded to a glycerol
   Dietary fiber consists mainly of cellulose, a large    carbohydrate polymer that is indigestible because
Protein is composed of
amino acids that are the body's    structural materials.
   Dietary minerals are the chemical elements required by    living organisms
deficiency or excess may yield symptoms of    diminishing health
  About 70% of the non-fat mass of the human body is    made of water
Other nutrients
Other micronutrients include antioxidants and    phytochemicals
Intestinal bacterial flora
The human digestion system contains a population of a    range of bacteria and yeast such as
   Balanced diet
Balanced diet is a diet which consists of all the essential    nutrients  in a required proportion
Malnutrition refers to insufficient, excessive, or    imbalanced      consumption of nutrients  
Food guide pyramid
The food guide pyramid suggested optimal nutrition    guidelines for each food category, per day

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