system
Given the following post, respond as if you're commenting on Reddit:
human
Why do people die of starvation without using up all their bodies' fat reserves first?

I've read that the human body starts breaking down proteins for energy after some time during starvation even when there is still fat left that the body could have utilized to make energy. Why is that so?

Also, is it possible for a person to survive on just his fat reserves for a long period of time if he can't find anything to eat?
gpt
Your body requires more than just fat and protein to survive, and this long list includes your vitamins and minerals that keep your inner machinery working. Not enough vitamin C? Scurvy! No vitamin A in your diet? Keratomalacia!Lacking vitamin B12? Say hello to atrophic gastritis.

Again, you can't survive on just fat alone.