You won't eat junk food if there isn't any around. Remove the temptation by either putting it away and out of sight, or just not buying it in the first place. Having healthy food around you will make it easier for you to eat it.
If all you have in the house is junk food, it should be no surprise that you reach for it first when you are hungry. The healthier the foods you have available in your kitchen are, the more likely you are to choose them instead of sugar laden junk! Be sure to have plenty of healthy options available, such as veggies, fruits and nutritious snacks. If you do not have junk food in your cupboards you will be less likely to overinduldge. Eliminating these junk foods from your pantry and replacing them with healthy choices will help you stop making unhealthy choices.