Ask the Personal Trainer Joni Hyde is a Certified Personal Trainer and owner of WorkoutsForWomen.com Q. Is it true that you can lose fat from your breasts? If so, how? -- Liz A. Most of the breast is made up of fat, especially the middle and lower parts. This fatty tissue is layered around milk glands and ducts, supporting fibers and a very small amount of muscle tissue. Because most of the breast is composed of fat, body weight plays a role in the shape and size of your breasts. Their size depends not on the muscles in them or the muscles behind them but on the amount of fat they contain. So if you lose weight your breasts will get smaller and if you gain weight your breasts will get larger. This is also why you cannot increase the size of your breasts with exercise. Other recently asked questions: • Should I exercise with a cold? • Can chromium picolate increase your metabolism? • Does your metabolism slow with age? • More questions WorkoutsForWomen.com provides home exercise programs for today's busy women, under the guidance of a certified personal trainer.