New duo model stores personal data for two people and is calibrated for standard adult and child body types - people with moderately active or sedentary lifestyles. Features easy two button programming. Can be used by more than two persons by reprogramming the personal data. Available in Light Gray. Overweight means an excess of total body weight based on population averages for heights and body frame sizes. Athletes and very muscular people may be overweight, but that does not mean they are over fat. Obesity means an excess of body fat regardless of weight. Weight alone is not a clear indicator of good health because it does not distinguish between pounds that come from body fat and those that come from lean body mass or muscle. Carrying too much fat is a condition called obesity, and puts a person at risk for many serious medical conditions including heart disease, diabetes and even certain forms of cancer. Tanita's patented "foot pad" electrode design uses Bioelectrical Impedance Analysis (BIA) to determine body fat.