Whether you long for full, large breasts or are desperate to lose heavy breast tissue, weight loss will affect your breasts. The breasts are primarily composed of fat, and as you shed fat in the rest of your body, you'll also lose fat in your breasts. The amount of weight you lose in your breasts depends on a variety of factors, including the exercises you do and your starting breast size.
Breast Anatomy Basics
Although your breasts themselves don't contain any muscle, they rest on top of your pectoral muscles. Your breasts are built upon a thick layer of adipose tissue, and near the nipple are sections called lobules. These lobules contain the ducts that produce breast milk. When you lose weight, you'll lose adipose tissue, but the lobules won't go away, so even if you lose massive quantities of weight, you'll still have some breast tissue. The amount of breast tissue you'll have left is partially dependent on the natural size of your breast lobules.
Chest exercises such as pushups and pullups build muscle tissue. Although you'll burn a few calories with targeted exercise, you won't burn enough calories to shed significant quantities of fat. Consequently, strength training your chest may actually make your breasts look larger. The muscles under your breasts will grow, creating a fuller appearance. Similarly, muscles that strengthen your back and shoulders can help offset the posture effects of full breasts. While these exercises won't shrink your breasts, they will make you look less stooped, and can help your breasts look perkier. Try workouts such as squats, pullups, pushups and front planks.
Aerobic Exercise and Diet
Aerobic exercise and diet are the keys for losing fat throughout your body, including your breasts. Running, swimming and jumping rope can help you burn calories and, over time, you might notice a reduction in breast tissue. For the best results, though, you'll also have to keep an eye on your diet. No matter how much you exercise, if you eat more calories than you burn, you'll accumulate more fat in your breasts.
Effects of Weight Loss
When you rapidly lose a lot of weight, you might notice other changes in your breast tissue. According to a 2004 article published in "Seminars in Plastic Surgery," weight loss can fundamentally alter breast shape. Some women notice that their breast tissue looks saggy or their nipple shape and placement changes.