To the best you can try and cut out all sugar, junk-food and dessert.Replace your dessert with a low-fat yogurt or a fruit salad.
Do at least 30 mins of exercise each day.. Trust me it helps! if you are too busy to do 30 mins each day, try 3 times a week but increase the time and intensity to your workout
Crunches are something you can do at home to tighten your tummy. To improve your results running and crunches will more likely strip fat off your tummy.
Drink 2 glasses of water before each meal, you will get full faster and are less likely to pig out.