Navy Nutrition and Weight Control Self-Study Guide.

Obesity is defined as a condition of excess fatness. The National Institutes of Health NIH has determined that a 20 percent increase in body weight above desirable body weight desirable as defined by NIH substantially increases the risk for high blood pressure, heart disease, diabetes, elevated cholesterol and triglycerides. Obesity is also considered a risk factor for some kinds of cancer and is associated with joint diseases, gallstones, and respiratory problems. According to recent federal government statistics, 32 percent of white females, 48 percent of African-American females, 47 percent of Hispanic females, and 32 percent of men of all races were overweight or obese. Obesity has become an enormous public health problem. Health care costs related to overweight and sedentary lifestyle are now at over 100 billion a year. To summarize, increases in body weight of 20 percent or more above desirable body weight defines obesity and is a major health hazard. The Naval Health Research Center NHRC, San Diego, was tasked with evaluating techniques for estimating body fat. Since that time, the Navy added the heightweight tables as an initial screen, with body fat assessed by the NHRC circumference tape measure as a final check for those who fail the heightweight screen. Weight for height is a less precise indicator of fatness than percent fat estimated from circumference tape measure. Muscle weighs more than fat, so therefore a very muscular person may fail heightweight screening, yet may meet body fat standards. The 2-tiered system appears to work best for the Navy.