I'll absolutely agree that its damn hard to do control what people are eating in experiments, but I disagree that exercise plays the role you say. You can eat

I'll absolutely agree that its damn hard to do control what people are eating in experiments, but I disagree that exercise plays the role you say. You can eat something in a single meal that will take SEVERAL HOURS on a treadmill to burn. It is incredibly easy for the number of calories you need to burn to pass the number of hours possible to exercise.