Pressure (symbol: p or P) is the force applied perpendicular to the surface of an object per unit area over which that force is distributed. Gauge pressure (also spelled gage pressure) is the pressure relative to the local atmospheric or ambient pressure. Various units are used to express pressure.
A BMI of 25 to 29.9 indicates a person is overweight. A person with a BMI of 30 or higher is considered obese. Like the weight-to-height table, BMI does not show the difference between excess fat and muscle. BMI, however, is closely associated with measures of body fat. It also predicts the development of health problems related to excess weight.
Because it's simple, Ahima said, adding that it's easy to weigh people and measure their height. For most people, BMI provides a reasonable measure of body fat, but is not accurate for athletes (who weigh more because of muscle) or older people who have lost height, he said.Other methods of measuring body fat also have their pros and cons. person's BMI is calculated as her weight in kilograms divided by her height in meters, squared. A BMI of 18.5 to 24.9 is considered normal, a BMI of 25 to 29.9 is overweight, and a BMI greater than 30 is obese..