Here are 6 ways:
Smaller plates = Smaller portions
True enough, the smaller the plate you eat in, the small portions of food you eat. According to research, you can retrain your brain to feel full on less food. Begin by using smaller plates and bowls. This will force you to eat smaller portions but will still make you full. Over time you'll get used to eating in smaller portions and you'll feel less compelled to eat more.
Lower "SWEET" volume
If sugar is part of your daily intake, start by removing it in areas of your diet where you're less likely to notice. Target more on non sweet foods and after a while, your taste buds will become more sensitive to sugar making the foods you really want to avoid, a little less appealing.
Keep your hunger in check
Rate your hunger on a scale of zero to ten. Zero being starving and Ten being overstuffed. Then try to stay somewhere in the middle.
Work out
Exercise is really important, it can change the body's biochemistry and our metabolism. Also, time spent working out is time that you won't be eating.
and last but not the least... and I think the most important one...
Don't return to the "scene of the crime"
Addicts get into trouble when they go back to where they used to buy drugs. Similarly, when you return to the pattern that trip you up. So try to shake up you're routine. If McDonald's fries is your weakness, then stay away from McDonalds or better yet, stay away from those fast foods.
Tips from MSN Health and Fitness