It’s not just the nicotine that acts as a appetite suppressant; it’s mostly the menthol. You can get the same effect just consuming cough drops. They’re cheaper and won’t cause cancer.
Aren't cough drops mostly sugar? Seems that would be a hindrance. As far as cigarettes, I understand there is a small amount of menthol in non-menthol cigarettes but is that enough to have an effect? Finally, I think part of the suppressant part is the length of time needed to smoke, it gets your mind off the immediate desire to eat -- versus a cough drop which typically lasts 15-30 seconds.
It's not just the oral fixation and act of smoking. Cigarettes genuinely suppress appetite. As an added bonus, after you smoke for a while (not that long), your taste buds don't work very well and eating becomes less pleasurable.