We all know that food is essential to our survival (and it also happens to taste great). But what actually happens to your body if you just stop eating? The latest episode of AsapSCIENCE explains the day-by-day process of starvation, including why you get so damned hangry, what really happens in 'starvation mode', and most importantly, all the ways you can die from hunger.
Don't worry if it's been a while between meals, because for the first 6 hours after eating, everything is pretty much status quo, and your body is busy breaking down glycogen - which stores energy - into glucose to be used as fuel by your cells. Around 25 percent of this glucose is used to power your brain alone, and the rest goes to powering muscle tissue and red blood cells.
But after around 6 hours, that glycogen beings to run out, and this is when the dreaded hanger kicks in. As most people know too well, being hangry is combination of being hungry and irrational angry, and it can result in you lashing out at the people you love the most. And it's all caused by your brain running out of the energy it needs to make good decisions.
It doesn't last forever though, because when your body realises it isn't getting anymore glycogen, it will enter ketosis, which means it begins to break down excess fat for energy. As the AsapSCIENCE boys explain, this is fine for your body, but the only problem is that your brain can't use these long-chain fatty acids, so it also switches modes and uses ketone molecules for energy instead of glucose. But this can only provide 75 percent of its energy requirements, so while your body is happily burning fat and fuelling the rest of your organs during ketosis, your cognitive function becomes impaired.
Still, ketosis isn't necessarily a bad thing, and it's a state that a lot of athletes, such as marathon runners, enter when they run out of glycogen supplies, and low-carb dieters often try to trigger ketosis in their body to assist weight loss. In small doses, like during intermittent fasting, ketosis can have benefits for our bodies.
But things get really dire after 72 hours, when your brain decides it needs more than just ketones to survive. This is when your body starts to break down its own proteins so that it can use their amino acids to form glucose. This means your body literally cannibalises itself and eats away at your muscle tissue just to stay alive.
If you don't eat at this point, the break-down of your body will continue, and death can occur as little as three weeks after you stop eating - if you don't get sick from a lack of immune system-essential vitamins and minerals first.
So how exactly do you die from hunger? We'll let the AsapSCIENCE boys explain that in the video above. And it's kind of impressive how long the human body can last with no nourishment at all.