I found to be successful in eating right there is one thing you must never do. RUN OUT OF FOOD.
If you don't have good food readily available to consume you are guaranteed to eat the wrong stuff. Most things that are bad for you take 90 seconds to heat in the microwave right?
To help combat this I try to always plan meals and prep food for the week of eating. This is usually done on Sunday but there have been week nights I've cooked a few items with no intention of eating them that night.
This is one of my favorite and simplest tricks. Buy your bulk fresh chicken breasts from the market. Clean them, trim visible fat from them and put them in individual zip lock baggies. Yep, one in each bag. Choose a variety of seasoning from the pantry. I like to mix it up and make several different flavored packets.
When it's time for a quick meal, grab a chicken breast bag, grill it up or bake it. I use this great little griller stone from Pampered Chef. In about 5 minutes you a delicious cooked chicken breast! Pair it with some steamed broccoli and fresh fruit and you have a meal.