Genetics may play a much larger part in it then most of you think. When I was young I could run and almost never stop. Only two or three of my close freinds were in better shape then me. My two best freinds both weighed close to 60 pounds less then me growing up. The one in the best shape took each of us on bike trips to mount rainier park. He took the skinney freind on the first trip and it took 9 hours. Despite protests, he insisted it would take us longer. We made it in less than 4 hours up and then turned around and rode back. Despite running the rest of my freinds in to the ground, I was always heavy than them. My family just has weight problems.

On the flip side, my wife's family has always been fairly thin. My kids can out eat me and are the skinniest kids around, while I still stuggle with weight.