The milk secreted in the first 3 days is called colostrum, which is yellowish in color and contains more proteins and minerals and is close to the plasma of the mother and fetus. As the time lengthens, the composition of the milk will gradually change, and the changes are adapted to the growth and development of the baby, and the changes in the amount and composition of the milk secretion are influenced by environmental and dietary factors. If you don’t have enough protein and vitamins in your diet, or if you don’t sleep well, or if you are in a bad mood, it will affect the quantity and quality of your milk secretion, and it will show up as white and thin to the naked eye, which means that the amount of protein in your milk is low and the amount of trace elements is not enough. Please don’t worry about gaining weight on weekdays, and exercise properly to ensure lactation, which can ensure the needs of baby’s growth and development.