Is this really so hard to figure out?
I have wondered this first hand since I was about 15 years old. Because I had to deal with being overweight for about 10 years of my childhood, all because I was on a seizure medication that had the little side-effect of weight-gain (75 pounds of weight gain).
And since they basically try to solve everything they can with a drug pill now, I have asked the same question about the obesity epidemic myself, again and again. If not, there has to be at least a big percentage of the obesity being caused by medication.