Both foremilk and hindmilk are nutritious, just with slightly different compositions.
Foremilk is mostly used to refer to the milk secreted at the beginning of breastfeeding, which contains more protein, as well as water, inorganic salts, lipids, etc. The hindmilk is the milk secreted at the end of breastfeeding.
The hind milk is the milk secreted at the end of the lactation period, which also contains mainly protein, water, inorganic salts, etc., but the proportion of lipid-based nutrients is slightly increased.
Whether it is foremilk or hindmilk, it is an irreplaceable nutrient for infants, which can provide enough nutrition for their growth and development. If you have enough milk, you can often be full with only foremilk, and it is generally recommended that you can squeeze out some of the foremilk before eating milk to store it for later use. Therefore, as long as the conditions allow, try to prefer breastfeeding.
If there is insufficient milk production due to various reasons, you need to go to the hospital in time for treatment.