What you eat is converted in your body into usable substances (building blocks for cells, hormones, neurotransmitters, fuel) for your body.Your organs must be able to function properly in order to perform this task properly. The food must first be chopped into very small pieces (chewing, stomach, duodenum) and can then absorbed (small intestine). Then the small pieces can be converted into building blocks (liver).
However, it is very important that your body gets enough nutricious substances to make these building blocks. If you eat badly, your building blocks are also of poorer quality. If you do not get enough of the suitable substances, your body will use up its own substances. But those substances were actually needed elsewhere. In the long run, this will also have consequences for your body.