Recommended Maximum Percentage Of Body Fat For Young Women

Body fat percentage is a body measurement that directly calculates an individual's body composition without regard to that individual's height or weight. Exact body fat percentage is difficult to determine, but there are techniques to estimate it. Acceptable body fat ranges vary by sex and age. Women have a higher fat to muscle ratio than men. Having an estimated body fat above the recommended range might have adverse health effects.

Identification

Technically, body fat percentage is the total weight of a person's fat divided by that person's weight. There are two types of body fat, essential and storage. Essential body fat is the fat required and necessary to maintain reproductive function and support life. Women have a higher essential body fat than men mainly for childbearing function. Storage body fat is extraneous fat that accumulates in the adipose tissue. It includes fat that cushions internal organs. The maximum recommended body fat percentage includes both of these values.

Recommended Maximum Percentage

For women, the recommended essential body fat range is 8 percent to 12 percent, according to findings published in 2000 by the American Journal of Clinical Nutrition titled, "Healthy percentage body fat ranges: an approach for developing guidelines based on body mass index." However, both essential and storage body fat make up total body fat percentage. The American Council on Exercise (ACE) recommends a maximum body fat percentage for women (nonathletes) of 31 percent.

Age-Based Recommendations

As both men and women age, typically, lean muscle mass is replaced by body fat so older women generally have a higher percentage of body fat than younger women. The Navy, in conjunction with the National Institutes of Health (NIH) offers age-based recommendations for body fat percentage. For women aged 17 to 39, body fat percentage should not exceed 32 percent, and for women older than age 40, body fat percentage should not exceed 35 percent.

Methods and Accuracy

There are many methods for estimating body fat percentage, but many of these methods have a large margin of error (plus or minus 10 percent). The most accurate method for estimating body fat percentage is Dual energy X-ray absorptiometry (DXA or DEXA). DXA is used primarily to measure bone density. Two types of X-rays scan the body. One of the X-rays detects all tissues and another detects all tissues except fat. A computer can subtract the difference, measuring fat mass. Prior to DXA, body fat percentage was calculated using one of two formulas that estimated average body density (fat tissue has a lower density than muscles and bones). This method is reliable and carries an estimated error of 1 percent.

Significance

There is some controversy regarding how falling into a particular body fat percentage category affects health. According to NIH, excess body fat is associated with poor health outcomes, including an increase in blood pressure, an increased risk of developing diabetes, certain types of cancer and cardiovascular disease. In addition to health risks, excess body fat affects physical performance and is associated with a general lack of fitness and stamina. These conclusions are supported by major health and fitness associations, including the American College of Sports Medicine and the American Council on Exercise.