Nutrition Glossary

BMI (Body Mass Index)

A formula that uses weight and height to estimate body fat and gauge health risks due to carrying too much weight. The BMI is only one factor in determining a person's health risk. A BMI in the "healthy" range does not necessarily mean that you are fit and healthy!

BMI does not take into account lean body mass or body frame. A muscular, large-framed person's BMI could indicate obesity, but other indicators would show that this is not the case.

BMR (Basal Metabolic Rate)

The estimated minimum level of energy required to sustain the body's vital functions when at rest. Usually, more than half of the calories burned in a day are those burned to keep your body functioning.

Calories

The unit of measure used to refer to the amount of energy produced when food is oxidized (burned).

Carbohydrates

A source of energy for the body. Complex carbohydrates (carbs that break up into two or more sugars during digestion) are found in nearly all foods of plant origin. The best source of carbohydrates is whole grains.

Simple carbohydrates can be found in fruits and vegetables. But you should avoid the simple carbohydrates that come from processed and refined sugars. They are not very nutrient-dense.

A gram of carbohydrate is 4 calories.

Diet-induced Thermogenesis (Specific Dynamic Action (SDA))

Diet-induced thermogenesis is the energy used to digest, absorb, transport and metabolize the food that you eat. This is usually equal to about 10% of the calories that you eat.

Fat, Saturated

The "bad" fat, although there is some controversy over that. These are animal-based fats. Try to limit saturated fats to no more than 10% of total daily calories.

Fat, Trans (trans fatty acids)

Usually, man-made fats produced through hydrogenation (heating liquid vegetable oils in the presence of metal catalysts and hydrogen).

According to the Institute of Medicine, "...it is recommended that trans fatty acid consumption be as low as possible while consuming a nutritionally adequate diet."

Trans fatty acids can also be found in "milk (0.22 g/serving), butter (0.40 g/serving), and meats (0.01 to 0.21 g/serving)."

When looking at food labels, keep an eye out for the word "hydrogenated."

Fat, Unsaturated

These are plant-based fats, also known as the "good" fat.

Monounsaturated fats include olive, peanut, avocado and canola oil.

Polyunsaturated fats, such as safflower, sunflower and corn oil are also know as "good" fats. However, according to the National Library of Medicine, "a large intake of polyunsaturated fat may increase the risk for some types of cancer." Studies are not conclusive.

Fats

Dietary fats play an important role in the health of the body, by providing essential fatty acids, such as linoleic acid. They are also carriers of fat-soluble vitamins (A, D, E and K). A gram of fat provides 9 calories. It is recommended to get no more than 30% of your total daily calories from fat.

Fiber

Dietary fiber is made up of undigestable complex carbohydrates. The body does not absorb fiber, so it has no calories. Dietary fiber helps in digestion and elimination.

Fit

Sound physically and mentally.

Glycemic Index (GI)

A ranking given to foods to indicate how it affects blood sugar and insulin levels. The higher the value, the more quickly blood sugar and insulin levels will increase. However, you must consume an amount of the food that will give you 50 grams of carbohydrate in order to reach that level. Some foods, such as carrots, have a high GI (131), yet you would have to eat well over a pounds' worth to raise your blood sugar to that level. See Glycemic Load below for more details.

How the Glycemic Index is Tested

An excerpt from "Eat, Drink and Be Healthy" by Dr. Walter C. Willet, M.D.:

"The basic steps are the same. A healthy volunteer fasts overnight. The next morning he or she eats 50 grams of white bread (or, alternately, water in which 50 grams of glucose has been dissolved). Over the next two hours, blood samples are taken at regular intervals to measure the rise and fall of glucose. Another day the same volunteer eats enough of the test food -- cooked potato, potato chips, whole-grain bread, ice cream, and so on -- to consume 50 grams of carbohydrates and sits through another two hours of blood sampling. The glycemic index for that food for that individual is calculated by dividing the blood sugar response to the test food by the response to white bread or pure glucose."

Source: "Eat, Drink and Be Healthy: The Harvard Medical School Guide to Healthy Eating" by Dr. Walter C. Willet, M.D., Simon & Schuster Source, A Division of Simon & Schuster

Glycemic Load (GL)

The glycemic load will give you the ranking of a food taking into account the amount of carbohydrate actually eaten. The formula is as follows:
  GI / 100 x Carbohydrate Grams Eaten = GL

Metabolism

The process by which digested foods (nutrients) are converted into energy and used by the body for vital functions. Metabolism is measured in calories. Many things can affect your metabolism, such as the percentage of fat vs. lean muscle tissue (muscle will burn more calories than fat).

See also Basal Metabolic Rate.

Minerals

Minerals play an important role in the health of your body in terms of healthy bones, teeth, hair, nails, nerve and muscle activity and regulation of body fluids.

Protein

Plays an important role in maintaining the body's functions and is the main component of muscle tissue. A gram of protein provides 4 calories of energy. Good sources of protein include foods from animal sources and legumes, such as chickpeas (garbanzo).

Vitamins, Fat-Soluble

Vitamins A, D, E and K are fat-soluble vitamins. These vitamins are not easily excreted by the body and can build up to toxic levels over time if much more than the RDA is taken.

Vitamins, Water-Soluble

B complex and C vitamins are water-soluble and therefore can be destroyed to some degree by cooking or processing. These vitamins are eliminated through sweat or urine and only small amounts are stored in the body.