Not necessarily. The point is that given the current environment, some people become obese and others do not. The difference between the two groups may be partl

Not necessarily. The point is that given the current environment, some people become obese and others do not. The difference between the two groups may be partly due to genetics. And actually, we do talk about the genetic basis for opioid addiction. I recall one doctor suggesting that a small percentage of the population are born addicted to opioids from birth whereas most people will have greater difficulty developing opioid addiction.