Assuming general good health. one man is obese, the other is muscular and lean-5-7% bf%. no access to food or water in a desert, who would die 1st? y?

Interesting question: The death for both would most likely be due to lack of water. If the obesity was due to water retention (a common cause) and if the body could use the accumulated water the obese person might survive longer. If it was fat rather than water the obese would live longer in regard to hunger since he could live on his fat. I believe that water would be the vital issue. It is purely theoretical.