As an experiment, a nutrition professor went on a junk food diet, eating mostly packaged snacks like Twinkies.  He kept track of his calories though, and in so doing, dropped 28 lbs in two months.  Even better, since he cut meat out of his diet, he burned off his cholesterol and bad fats!
Does he recommend the diet?  No.  But it certainly shows that counting calories, any calories, works.
Source: http://www.cnn.com/2010/HEALTH/11/08/twinkie.diet.professor/

Good for him... But how did he FEEL?  After 10 weeks I wonder if his stomach rebelled at the ingestion of what little vegetables he ate.

hmm....sounds like my kinda of diet SUGAR SUGAR SUGAR!!

I wonder if he is now having Twinkie withdrawal?

I don't know, but I am!  

There's a gentleman at work who has 3 to 5 pepsi's a day.  He tried to go cold turkey and had the shakes for week.  It drove him mad and he eventually succumbed to the sweet call of his siren elixir.