Starvation leads to death primarily through diaphragm muscle failure and subsequent drowning in one's own body fluids, caused by muscle loss and electrolyte imbalance.

“what happens your diaphragm is the last muscle that will be digested and there's a there's a momentum that starts now you have to realize that these guys that did this so they don't die of just acidosis there's the it's actually the diagram they're drowned in your own body fluids basically jeez it's brutal so because what happens is once your diaphragm can't work your lungs fill up with with fluids and you drowned in your own fluids and the diaphragm presumably stops working because of either the loss of muscle or the electrolyte imbalance yeah both the combination of both”