What kind of person are you? Are you easily swayed by temptation? If so, be careful: know your weaknesses and plan ahead so you don't get caught in a bad situation.

For instance, if you have a weakness for desserts, don't go out to eat at the Cheesecake Factory where you'll be tempted to have a high calorie dessert.

Another good tip is to come prepared with your own solution. Say you've been invited to someone's home for a party. You know there are going to be fattening foods offered, especially those delicious -- but ridiculously unhealthy -- appetizers. You don't want to go off your diet, yet you don't want to be rude either. So bring your own healthy appetizer!

A variation of this is to bring your own healthy snacks when you and your friends go out. They can indulge and you can feel like you're participating, but when they dive into that huge container of popcorn or those loaded nachos, you can pull out your celery sticks or apple slices or low-fat crackers.