Breast cancer patients may suffer from malnutrition due to the progression of the disease or adverse reactions during treatment, and overweight due to overeating is one of the problems faced by breast cancer patients during their recovery. Patients with cancer are also at high risk for second primary cancers, cardiovascular disease, diabetes, and osteoporosis, so proper nutrition and a healthy lifestyle are especially important during the recovery period. Maintaining a healthy weight, adequate physical activity, and a healthy diet can reduce the risk of disease recurrence and increase the probability of disease-free survival. There is no evidence that a particular food group is associated with the recurrence or metastasis of breast cancer. (1) The American Cancer Society (ACS) primarily recommends a diet rich in fruits, vegetables, coarse grains, and soy products. The American College of Public Health recommends that adults drink at least 2.0 to 3.0 cups of vegetable juice and 1.5 to 2.0 cups of fruit juice per day. In some observational studies, breast cancer survivors with a high intake of vegetables and coarse grains have been shown to have a 43% reduction in overall mortality. Dietary supplements (e.g., multivitamins) are not recommended at this time. (2) Placenta and its products and health products of unknown composition need to be avoided. Exercise During the recovery period, choose an aerobic activity that is suitable for you and that you can maintain throughout your life. Regular exercise, at least 150 min of moderate intensity exercise per week and strength training twice a week, is recommended. Some recommended exercises are brisk walking, bicycling, swimming, tai chi, and aerobic dance. A balanced diet and aerobic exercise can strengthen the immune system, effectively reduce stress, improve sleep, relieve fatigue caused by cancer and its treatment, and increase the body’s resistance to disease.