Your cells and organs function to the best of their ability.
Your hair grows and your nails get stronger as well as your bones.
Your skin is usually less dry when you eat properly (and get enough water).
You have more energy.
Easier to sleep at night when you get the right nourishment and fuel i.e not super hungry or extremely full which can prohibit sleep.
Stronger physically and mentally.
More capable of doing things. Both work and fun stuff.
Better concentration and focus.
A happier body and better functioning body.