When having trouble sticking to healthy eating, there are a few steps that have worked for other people.
1) Be sure you are eating enough. Overeating later on in the day may be a sign of not enough calories.
2) Increasing healthy fat intake with foods such as avocados, nuts, seeds, etc. Fat takes longer to digest in the body, meaning you feel fuller for longer. It is also satisfying to the taste buds and can reduce cravings for sugars.