Kicking an addictive substance from your system is very difficult, don't get me wrong. But a lot of eating habits are either about depression or poverty- not something that can be fixed by sheer will. People who are emotional eaters have a vast number of things to fix before you can get rid of the behavior of eating junk food. People who live in poor urban areas or on food stamps have little access to fresh produce and other healthy choices, and it is much cheaper to eat junk. Feeding a family of four a truly healthy meal costs several times as much as feeding them crappy processed Mac and Cheese from a box.
Unfortunately, the answer is no. Not that I myself have smoked, but I do know that nicotine is an addictive active ingredient in cigarettes. Because Nicotine is addictive, it may be extremely hard to stop smoking. Junk food on the other hand is food and there are no proven addictive ingredients in it.
I have never smoked, but I have seen people attempt to quit smoking. Most people fail at kicking the nicotine addiction. Equally, I have never tried to stop eating sugar, but I know plenty of people who have done that for a time. Those who stopped eating sugar ended up complaining much less about stopping than those trying to quit smoking.