Eli5 So we need calories to survive. If there are 100 calories in a spoon of oil, how come we can’t survive on oil for emergencies?

Question

Eli5 So we need calories to survive. If there are 100 calories in a spoon of oil, how come we can’t survive on oil for emergencies?

In: 3554

Answer 1

Your body also needs oxygen to survive, but you cannot breathe water (H2O). Its about your body’s ability to access that oxygen, or in your case the calories.

Calories are a measure of energy. Think of it more of a physics term than a biology one. If we burn a substance, it gives off heat. For most things it gives off more heat than we put into it. 100 calories worth of oil will give off the same amount of heat as 100 calories of biscuits*.

The problem is, your body doesn’t literally set fire to its fuel. It uses biological processes to break down the molecules into smaller parts, which also happens to give off energy.

*the unit commonly used for food is kilo calorie (kCal), which is actually 1,000 calories.