Regardless, weight loss happens in the kitchen not in the gym. Studies show that compensatory eating from exercise, especially if you're overweight, can actually lead to weight gain. I.e., you should get your diet under control before you start fooling yourself into believing you can exercise yourself skinny. That will only lead to frustration. And that's over and above the real physical toll exercise can take on the joints and organs of the morbidly obese.

That's in an ideal world though. For some people, just walking a mile throughout a day qualifies as exercise because they are so sedentary. But if people are serious about getting healthier, they need to examine and change their diet regardless of how "addictive" food is. Many things are addictive. That doesn't mean that you shouldn't stop doing them or that their addictive nature excuses continued use.

If you're addicted to a harmful substance (and I think we can count junk food in that category), than, like any other addictive substance, you likely need counseling and, ultimately, you need to stop the addictive behavior.