Some women do not change their weight during menstruation, and some women may experience weight gain during menstruation, which is mainly caused by a combination of physiological and behavioral factors: 1, physiological factors: some women, during menstruation, the level of estrogen and progesterone in the body changes, metabolism slows down, resulting in water and sodium retention and edema, so the weight will increase during menstruation. The weight fluctuation during the physiological period will not be too obvious, usually around 0.5kg, and can be recovered after the period through self-regulation; 2. Behavioral factors: the hormone level is larger before and after the period, women can have mood swings, and some people will be relieved by consuming high-sugar food, if the activity decreases at this time, but the energy intake increases, there will be the possibility of weight gain. Some women also overeat and eat too much hard-to-digest food during their periods, which can also lead to weight gain. There is no need to worry about minor weight fluctuations, but if there is a significant change in weight, you should seek medical attention to see if there is any associated disease. It is also recommended to maintain regular rest and rest during menstruation, not to stay up too late, and to avoid eating too much cold food to ensure emotional and physiological stability during menstruation.