system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: How does starvation actually kill you? Would someone with more body fat survive longer than someone with lower body fat without food?
gpt
Someone with higher body fat *would* survive longer because once people run out of fuel from food, their bodies switch over to something called "ketosis" which is when your body can eat its own fat to survive (this is what the keto diet is). Of course they still would need to find a source of vitamins and minerals ~~and fiber~~ and electrolytes. Albeit they feel absolutely terrible *while* switching over, but once the switch is done they usually feel much better.

The food you eat is broken down into tiny little parts. These parts give the your cells energy to function. Some parts are made into electrolytes (or extracted from) that allow your neurons to communicate with each other. Proteins from food allow your body to heal itself and grow muscle. When you cut off food supply, you are taking away your body's ability to not only fuel its cells, but also proper nerve function and ability to heal.

When you die of starvation, it's usually because you've used up all the body fat and the body then starts to eat muscle instead, pulling nutrients from organs. It eats itself until the heart (usually) is no longer strong enough to pump blood to your brain.