My tip, which I recently gave to someone on Reddit, is to develop a "snobby taste". If you can only bring yourself to eat high end treats: whether that's Godiva chocolate or a truly fine wine, you can reach the stage where junkier stuff repels you. I can't eat cheap chocolate, even though I'm a chocaholic. (I can eat mid-range stuff like Lindt, but even that gets kind of sickly).
Not only is the higher end stuff richer and more sating: you can't, for example, drink a pint of fine, strong espresso in the same way you could slosh down a pint of weak, sugary, creamy, flavoured coffee, but it also costs a tonne more. Even if you can afford it, you tend to be more restrained (because dropping $100 on gourmet treats really makes you aware of what you're spending/eating).
Alongside this you're trying finer, better food with your regular eating. Cleaner food. Cooking from scratch more. Developing a taste for fresh food that makes you reject the canned stuff or processed stuff as kind of icky and fetid.