Minimum Body Fat Percentage
The minimum body fat percentage considered safe is five percent for males and twelve percent for females. The average adult body fat considered healthy is 15 to 18 percent for men and 22 to 25 percent for women.
Several methods are available for assessing body fat:
WAIST TO HIP RATIO.. Simply divide waist circumference by hip circumference. A ratio greater than eight tenths of a percent (0.8) is considered to be a health risk for women. For men, a ratio of 95 hundredths of a percent (0.95) or higher is considered a health risk.
SKINFOLD MEASUREMENT. Approximately 50 percent of fat is stored under the skin. Measurement of the skin thickness at several areas of the body using calipers can indicate the overall body fatness.
BIOELECTRICAL IMPEDANCE. A low level of electrical current is passed though a person's body by electrodes placed on a wrist and ankle. The greater the resistance to the current flow, the greater the percentage of body fat.
HYDRODENSITOMETRY. Fat is less dense than water. The difference between your weight on dry land and your weight when you are submerged in water is the estimate of your total body fat. This test is a very accurate measure of total body fat.
How Fats are Stored
Fats are stored more easily as body fat than protein or carbohydrate because they have the lowest thermic effect of any food. The thermic effect refers to the amount of energy required to digest and utilize each food. Protein has the highest thermic effect - nearly 30 percent. Fats have the lowest thermic effect - only 3 percent. When you eat lean protein foods, 30 percent of the calories are burned off just to digest and absorb them. When you eat fatty foods, only 3 percent of the calories are burned off during digestion and absorption. See also: Tenacious Thermogenic Effect.
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