Whether you’re trying to maintain a healthy weight or lose a few pounds, knowing the definitions of terms relating to diet and exercise can help you make good choices.
Body mass index (BMI): One method of estimating body fat. (The other method is by waist circumference.) BMI is calculated by multiplying your weight in pounds by 703, and then dividing that number by your height in inches squared. You can also use a calculator, like this one from the National Heart, Lung and Blood Institute.
Calorie: A unit of measure for the amount of energy released when the body breaks down food. Carbohydrates and protein contain four calories per gram; fat, nine calories; and alcohol, seven calories.
Calorie-dense foods: Foods that provide a lot of calories relative to portion size.
Carbohydrate: Any of a large group of sugars or starches that the body uses by converting into glucose -- a simple sugar -- for fuel. Sugars and starches are compounds of carbon, hydrogen and oxygen.
Complex carbohydrates: Starches, which make up plant tissue. You can find complex carbohydrates in foods such as grains and vegetables.
Empty calories: Calories found in foods with little or no vitamins, minerals, fiber or other nutrients. Examples of foods with empty calories are soft drinks, punches, many pastries and candy.
Fat: Organic compounds made up of carbon and hydrogen that are the body’s most concentrated energy source.
Fiber: A carbohydrate found in plants that cannot be digested. Fiber comes in two forms: soluble and insoluble. Soluble fiber, found in beans, fruit and oats, dissolves in water. Insoluble fiber, found in whole grains and vegetables, doesn't dissolve in water. Both types of fiber help with digestion, lower cholesterol and help control blood sugar.
High-protein diets: Diets that recommend eating 30 percent or more of calories from protein, versus the recommended 10 to 15 percent. These diets also recommend low carbohydrate consumption and are often high in total fat.
Metabolic rate: The rate at which your body burns calories to maintain itself.
Monounsaturated fat: Found in olive oil, canola oil, olives, cashews, almonds and avocados; lowers LDL ("bad"), raises HDL ("good") cholesterol.
Nutrient: A substance found in food that is important for good health.
Omega-3 fat: Found in fish, flaxseed oil, walnuts and canola oil; has little effect on HDL or LDL cholesterol levels; lowers triglycerides (blood fats).
Polyunsaturated fat: Includes omega-3 and omega-6 fats found in corn, soybean and sunflower oils; lowers LDL, raises HDL cholesterol; reduces the risk for heart disease.
Protein: Organic compounds made up of amino acids, which in turn are composed of carbon, hydrogen, oxygen, nitrogen and, in a few cases, sulfur. Proteins form the basis of all cells in the body and play a major role in many body processes. Proteins are found in plant and animal tissues.
Saturated fat: Found in meat, poultry, whole milk and dairy products made from whole milk, eggs, coconut and palm oil; raises LDL and total cholesterol, increases risk for heart disease.
Simple carbohydrates: Sugars, including glucose, fructose, sucrose and lactose. You can find simple carbohydrates in foods such as fruit and milk.
Trans fat: Found in margarine, cookies, crackers, vegetable shortening and many fast foods. Trans fat raises LDL, lowers HDL cholesterol and is linked to an increased risk for heart disease. Trans fat is contained in partially hydrogenated and hydrogenated fat or oil; is a form of artificial saturated fat.
Triglyceride: A type of fat that is solid at room temperature. Most of your body's fat is stored as triglycerides.
Vitamin: An essential compound required for good health. Vitamins are needed in trace, or minute, amounts for a variety of body processes. You need vitamins A, B series, C, D, E and K. A person deficient in a vitamin can develop disease.