What change food to a substance the body can use?

The process that changes food into a substance the body can use is called digestion.

Here's how it works:

1. Mechanical Digestion: This is the physical breakdown of food into smaller pieces. It starts in the mouth with chewing and continues in the stomach where muscles churn and mix the food.

2. Chemical Digestion: This is the process of breaking down large food molecules into smaller molecules that can be absorbed into the bloodstream. This involves enzymes, which are proteins that act as biological catalysts.

3. Absorption: Once the food is broken down, the nutrients are absorbed into the bloodstream through the small intestine.

4. Elimination: Any remaining undigested food waste is eliminated from the body through the large intestine as stool.

The digested substances the body can use are:

* Carbohydrates: Broken down into simple sugars like glucose, which provides energy for the body.

* Proteins: Broken down into amino acids, which are used to build and repair tissues, make enzymes, and produce hormones.

* Fats: Broken down into fatty acids and glycerol, which provide energy and help absorb vitamins.

* Vitamins and Minerals: These are essential nutrients that the body needs for various functions.

So, digestion is the crucial process that transforms food into a form the body can use for growth, energy, and repair.