From "Psychology Today":
"However, most addictive behavior is not related to either physical tolerance or exposure to cues. People compulsively use drugs, or gamble or shop, nearly always in reaction to being emotionally stressed, whether or not they have a physical addiction. Since these psychologically based addictions are not based on drug or brain effects, they can account for why people frequently switch addictive actions from one drug to a completely different kind of drug, or even to a non-drug behavior."
I am not surprised at this. For me, aerobic walking has taken on many of the benefits I used to gain from overeating: it is energizing, relieves stress, gives the body a "feel-good" state. And on which days do I find overeating hardest to control? on the days I don't exercise. So it seems that I have switched exercise for overeatimg. But since it ISN'T ruining my life, I'm OK with that..