Temptation On A Diets?

Alright, so I want to lose some weight. But the problem is I have no backbone against temptations. I.E. I always get junk out of vending machine, drink soda, and eat fast food etc. Now in your opinion, what are the most effective ways of resisting these temptations in a diet? I really want to diet and I can't resist those types of things. Also, how does someone diet if they aren't really a fan of eating vegetables? Thanks :o)