Internal organ fat (visceral fat) is fat that accumulates in the abdominal cavity and around, and partly within, internal organs. It normally accounts for about 10% of total body fat mass, but a large amount can accumulate even in people with normal weight. Excess internal organ fat is metabolically active and increases the risk of cardiovascular diseases, type 2 diabetes, and fatty liver, among others. The amount is reliably measured with a body composition measurement.