In standard units, the formula for body mass index is:

Normal BMI is considered to be 18.5 - 24.9. A BMI below that would indicate that the individual is underweight, while a higher value may indicate that the individual is overweight.  

BMI values between 30 and 39.9 indicate obesity, while a BMI over 40 could indicate that the individual is severely obese. 

Vitamin B5, or pantothenic acid, is the only water-soluble vitamin listed. Vitamins A, E, D, and K are all fat soluble and so should be consumed with fat to be absorbed.

Soluble fiber, present in oat bran, barley, nuts, seeds, and legumes, delays gastric emptying, increases satiety, and lowers LDL cholesterol by interfering with the absorption of dietary cholesterol. Insoluble fiber passes through the gastrointestinal tract relatively intact, provides bulk for stool, and reduces bowel transit time. Carbohydrates and unsaturated will not lower LDL cholesterol or delay gastric emptying, though they will increase satiety.

Vitamin D is a fat soluble vitamin, and so will be better absorbed when taken with a meal that contains fat. The other vitamins listed may be better absorbed with food, but do not require fat for transport across intestinal membranes, as they are water-soluble. 

Conditionally essential amino acids are those that can be produced by the body under normal circumstances, but may not be able to be produced during certain situations, such as certain disease states or severe catabolic stress. Arginine is the only conditionally essential amino acid listed. Histidine and methionine are both essential amino acids, while aspartic acid is a non-essential amino acid.

Vitamin C is one of the body's most important antioxidants. Antioxidants are reducing agents - that is they themselves get oxidized. Recall: OIL RIG. Thus antioxidants such as vitamin C are electron donors, able to stabilize the free radicals produced by various metabolic processes in tissues and extracellular spaces. Vitamin E (not listed) is another important antioxidant and is actually more potent than vitamin C.

While all of the substances listed are present in gastric secretions and are necessary for normal digestion, intrinsic factor is the only one that has a direct role in vitamin B12 absorption in the small intestine. Deficiencies in intrinsic factor due to genetic variation or damage to stomach lining can result in pernicious anemia, a type of anemia that is caused by insufficient levels of B12.

The digestion of dietary carbohydrates is initiated by amylase, an enzyme present in saliva. This enzyme breaks down long carbohydrate molecules into shorter units such as disaccharides. Lipase breaks down fats and is not present in the saliva, rather it is secreted by the pancreas into the duodenum. Pepsin is a protease - an enzyme that breaks down proteins. This enzyme is secreted by the chief cells of the stomach in its zymogen form (pepsinogen). It is activated by the product of the parietal cells (hydrochloric acid). Note that amylase is also secreted by the pancreas to complete the chemical digestion of carbohydrates into monosaccharides so that they can be absorbed by the brush border of the small intestine.