Think twice!
A great help to stop making nonsense with your food is to think about what you are going to eat.
When you see a package of french fries at the supermarket, think: I shouldn't eat this! Therefore you don't buy it.
And so, you don't have it at home and consequently you do not eat it.
Instead, buy fruits. When you feel like having a little snack pick some nuts, blackberries or blueberries, or peel a tangerine.
Your health will thank you and your feeling of good alimentary behaviour will also be good for you.
It's just a matter of habits. Believe it.