Because it stretches your muscles <span />
Wings. All day. Every day. Forever.
1,2,3 ,5
age and body growth will effect what the body needs.
The more active you are the more healthy proteins you will need to eat.
If you are having a baby the developing fetus will require some things meaning higher intake is key. Finally, If you have a iron deficiancy more iron is needed to keep you as healthy as possible.
