Stay diligent during the weekdays.
Five days a week, put some serious work into your diet. Here are examples for breakfast, lunch, and dinner.
Breakfast, eat a bowl of oatmeal with low-fat milk with a few raisins or cranberries. You may also opt for a couple of eggs, a piece of fruit, or a piece of whole wheat toast with almond or peanut butter.
Lunch, include a lean protein like chicken or fish, with plenty of vegetables (or a salad) with beans or sprouts (a great fibre source), and an optional piece of fruit. If you need a drink other than water, go for unsweetened teas or juices.
Dinner, have a bowl of broth-based soup, a wrap or half a sandwich, brown rice or quinoa, and more fruits and vegetables (fresh, ideally).
Snacks, should be protein and calcium rich, like nuts, cheeses, or yoghurt.
Include exercise in your plan, too.
It is recommended to get 150 minutes per week of moderate exercise or 75 minutes per week of vigorous exercise. You can do it all at once or divide it up into 5-minute chunks or anything in between. A mixture of weight-training and cardio is best.
Sprinkle into your normal routine activities like fast walking or running, swimming, or cycling. Keep in mind that everyday activities, like walking the dog, vigorously cleaning the house, and gardening count, too.
On weekends, take it easier on yourself. You've put a lot of hard work into the week, and here is your reward. Don't gorge yourself, but do treat yourself to whatever you've been craving. And don't feel guilty about it, there's a lot of science to back up the idea of calorie cycling, or eating more one or two days a week.
Use Saturday night to be your go-out night, where you can finally hit up that restaurant you've been dying to go to. Getting the craving out will keep you from rampaging through the kitchen and eventually destroying all the progress you've made.