One of the most important rules when thinking about healthy eating is that, you should mind the food you eat, try eating natural food which has not been processed (examples include different types of twinkies, etc.). Natural food which involves eating meat, vegetables, fruit, rice, etc. is what should be strived towards.
It's also important to understand that you have to balance between eating what is good for you and also what you like to eat :)
The answer is d.vitamin B-12.
By contracting, muscles pull on bones and allow the body to move. Muscles can only contract. They cannot actively extend, though they can move or relax back into the non-contracted neutral position. Therefore, to move bones in opposite directions, pairs of muscles must work in opposition
