You have to count calories. Over long time periods, a few hundred calories makes the difference, and they can slip in really easy.
I found quiting sugar made it easy to stay in the calorie budget. Read all the labels, and look for 5g or less per serving. The more sugar, the quicker you feel hungry again. You might be surprised how many non-threatening foods have 15g+ of sugar. Check that cereal label (also, a 'bowel' of cereal might be too much...).
You don't have to be hungry, or eat only veggies. If you cut out the empty calories, you can eat plenty of lean meat, all the green veggies you can handle, and some complex carbs. I made a one-time, permanent lifestyle change, and drifted down 120 pounds in 2 years, and stayed there. If you count the calories, the weight will come off. good luck.