In our weight loss podcast, we mentioned how leptin and other hormones control metabolism, activity and dietary habits. I have attached the video that I talked about in the podcast so that you can see just how amazing the difference in activity is between the rats. This is what we call “spontaneous activity”; scientists have found that this phenomenon happens in humans as well. When they attach hardware that monitors movements, naturally thin people fidget, move, walk, stand and are just up and about a lot more than overweight and obese people. These findings are completely separate from exercise, thin people just appear to have a subconscious drive to move around more. This is a neat video, I hope you enjoy.
(Source: Howard Hugh Medical Institute, http://www.hhmi.org/biointeractive/obesity/mice_behavior.html)