Why does digestion occur inside your body?

Answer 1

The digestion of food starts in the mouth where it is masticated. Saliva is added to form a bolus. This is the start of chemical digestion. Salivary Amylase breaks downs carbs. Food then goes down oesophagus ito stomach where digestion continues. The stomach muscles churn the food with hydrochloric acid and lubricates it with mucus. This then forms a substance called chyme. The hydrochloric acid deactivates salivary amylase and neutralises bacteria. There is a lot more to it but just remember that it starts in the mouth.

Answer 2

This is because the nutrients in your food cannot be absorbed by the body without digestion. They are too complex and too big to diffuse into your bloodstream by the small intestine. So you need to break down these nutrients into smaller and simpler substances through digestion, and the nutrients can then be absorbed into the bloodstream and be utilised. If digestion does not occur in your body, then you're eating for nothing as the nutrients cannot be absorbed.