Does anyone know the cause of getting fat during lactation? How to lose weight safely and quickly during lactation? The baby grows up day by day, but I am getting fatter and fatter, which is really annoying. Because breast milk needs nutrition during lactation, mothers will eat nutritious things and eat too much, so they will get fatter and fatter during lactation. If the baby grows up day by day, you can lose weight and exercise every day after he is milked, so that you will gradually lose weight in the future.