You may not be overweight, but you could be overfat and vice versa.
Excess fat is a factor in high blood pressure, heart disease, diabetes, and cancer.
Excess fat stresses the cardiovascular system and reduces the body's ability to work efficiently. So, when assessing your ideal weight, it's the percentage of your body that is composed of fat, and not your weight in itself, that makes the difference. This percentage varies for men and for women. Measuring Body Fat Underwater weighing is the most accurate measurement of body fat, and is available at some fitness centers, hospitals, and clinics. Since fat is more buoyant than lean muscle, an over-fat person will actually weigh less underwater than a trimmer person.