How would you like a diet where you get to eat more than you currently do?
Here's the thing, most diets fail because they go completely opposite of natural human psychology. To restrict yourself from something or to limit yourself, is not normal. But if you continuously include more foods and open yourself up to more variety then you naturally push bad or more inferior foods out of your diet. You start to crave the good things more and more, and slowly become repulsed by the bad things.
Start by picking one healthy food that intrigues you. Begin to eat it regularly. Because your body can only handle so much food your goal to eat more of this one healthy food will automatically push one or more bad foods out of your diet. This is a much more instinctive way of dieting. Think of it as diet by natural selection.