Definition: Body fat is a compound comprised of glycerol -- a substance formed in fatty acids -- and fatty acids which is required as a concentrated energy source for our muscles. Fat is a storage substance for the body's extra calories and it fills fat cells (adipose tissue) that help insulate the body. When the body has used up the calories from carbohydrates it begins to depend on the calories from fat.
Examples: Excess fat causes overweight and obesity.
