Ja sam slicno cuo kao SSpin. Malo sam prosvrljao po netu i nasao sledece:
A person can live without food for quite some time, usually for many weeks. The body will use its fat and protein stores (muscles) to help it survive.
If a person has a lot of fat stores (is very heavy), they will live longer than a person who has very little fat (very thin), so how long a person can survive depends a lot of the person. Of course, if you go without food for a few weeks, you will be very weak since you have been using your own muscles for energy.
Water is a different story. A person will die within 3-4 days without water. The size of the person really doesn't make much difference.
Thanks for the interesting question.
Ohio State University
source: Nutrition in Perspective, Patricia Kreutler, 1980