Your body uses protein to heal, and this includes damage to the skin, connective tissues, and muscles which help your breasts resist gravity.  The average adult should eat two to three portions of a protein-rich food per day. This can be meat, milk, fish, eggs, soy, beans, legumes, or nuts. Lean meats and low fat dairy products are good because they won't simultaneously increase your fat intake. Complex carbohydrates take longer to digest and provide you with energy for a longer period of time than simple sugars do.  Excellent sources of complex carbohydrates are beans, peas, lentils, peanuts, potatoes, corn, green peas, parsnips, and whole-grain breads. Simple sugars should be avoided and are found in candies, pastries, cake, soda, cookies, and table sugar. Carbohydrates should make up approximately half of the calories you consume each day. This will provide your body with the vitamins and minerals it needs to keep your breast tissues young and healthy looking.  Adults should consume four servings of fruit and five servings of vegetables each day. Tasty options for getting your servings of fruits include berries, cucumber, apples, grapes, cherries, papaya, bananas, and more. Vegetables include broccoli, beets, carrots, celery, lettuce, spinach, cauliflower and potatoes. If you think you are not getting what you need, vitamin and mineral supplements are widely available over-the-counter at drug and grocery stores. If you believe you have deficiencies, first talk to your doctor, and then if they recommend it, try adding particular supplements or multivitamins which contain lots of different vitamins and minerals. Most women will gain and lose weight from their breasts as well as other body areas. Such rapid changes can cause your skin to stretch as you gain weight faster than your body can handle. Similarly, when you lose weight too quickly, you can wind up with excess saggy skin.  If you plan to gain or lose weight, see a nutritionist so you can plan to do it slowly and steadily to prevent your skin from stretching. Avoid becoming overweight. As you do, your breasts will become larger increasing their weight and making them more likely to sag over time. Avoid yo-yo dieting. Major weight fluctuations — going from very heavy to much lighter and then back to your original weight — is another way your skin can stretch out. Try to lose weight by losing 1 to 2 lbs. per week (cutting about 500 calories from your daily calorie intake), and make lifestyle changes to keep the weight off. Fad diets may cause you to lose weight rapidly, but it rarely stays off. Not breastfeeding won’t prevent the sagging that comes with pregnancy. Your breasts sag as they get larger and heavier during pregnancy. This stretches the ligaments, leaving lasting sagging. This sagging will happen regardless of whether you breastfeed and breastfeeding will not make it worse.

Summary:
Keep your skin resilient by eating enough protein. Give yourself the energy to exercise regularly by eating complex carbohydrates. Keep your youth by eating lots of fresh fruit and vegetables. Avoid putting on and losing weight too quickly. Don’t be afraid to breastfeed your baby.