I don't think anyone's saying that lifestyle choices (what we eat, how much we eat, how much we exercise) have no effect on weight.
Just, various lifestyle choices have different effects on people who have different types of genetic makeup. There are people who could do what you did and eat as you ate and not gain anything. There are people who could do what you did and eat as you ate and gain much more than you did.
It's controllable -- it's just that it takes much more effort for some people. And I don't just mean willpower-type effort, I mean slam-dunking-the-basketball-when-you're-5'6"-as-opposed-to-7'-effort.
For example:
Quote:they were burning as much as 24 percent fewer calories per square meter of their surface area than the calories consumed by those who were naturally thin.