The low menstrual flow due to weight loss is caused by incorrect weight loss methods: 1. Women who achieve weight loss through excessive dieting, due to insufficient dietary intake, resulting in a lack of various nutrients in the body, so that the ovaries lose the proper nutrient supply and premature aging, can not properly secrete estrogen and progesterone, resulting in low menstrual flow or even amenorrhea. 2. Women who have lost too much weight, resulting in a body shape that is too thin. The lack of subcutaneous fat can also cause a lack of estrogen levels in the body, leading to low menstrual flow. 3, some women take diet pills to achieve the purpose of weight loss, irregular weight loss drugs, or large doses of long-term use of weight loss drugs, may lead to endocrine dysfunction, resulting in reduced menstrual flow, amenorrhea and other adverse consequences. Once the low menstrual flow due to weight loss, should immediately change the bad diet and lifestyle habits, reasonable diet, moderate exercise, healthy weight loss.