If your problem on the weekends is eating a lot or eating unhealthy foods, one thing I do is keep a few frozen meals on hand so I can pop one in the microwave when I don't feel like cooking. Healthy Choice recently came out with an "All Natural" selection of frozen meals...they're made with whole grains, EVOO, no preservatives.....in other words, it's good wholesome food with no added crap
Most of them range between 200-300 calories, so I usually add a salad, extra veggies, lowfat cottage cheese, or some other side food to make it more filling (yet within a good calorie range for one meal). They're not as expensive as some other frozen meals (like Lean Cuisines) I can normally get them for $1.88 each.