Who would starve first a fat person or a skinny person?

All else equal*, a skinny person would probably starve first as the fat person has more energy already stored within his body than the skinny one, who must get more from food for equal energy expenditure.

*It is important to recognize that each person's body works differently and the result of any individual experiment would depend on age/ gender/ height/ race/ metabolism/ etc... However, if this were repeated many times then the fatter people would statistically last longer.