what is the meaning of calorie and under nutrition

Answer 1

http://en.wikipedia.org/wiki/Food_energy

http://www.merck.com/mmhe/sec12/ch153/ch153a.html

Answer 2

Since this is not my area of expertise, I searched Google under the key words "calorie" to get these possible sources:

http://en.wikipedia.org/wiki/Calorie
http://health.howstuffworks.com/calorie.htm
http://www.google.com/search?hl=en&client=safari&rls=en&q=calorie+needs&revid=66137386&sa=X&oi=revisions_inline&resnum=0&ct=broad-revision&cd=4

In the future, you can find the information you desire more quickly, if you use appropriate key words to do your own search.

I hope this helps. Thanks for asking.