Here's what to do if you want to wear that slinky black dress, and stay sane:
1. Make sure that you're not being neurotic and overly body conscious.
Meditate. Try to catch yourself naked unawares in a full length mirror. Find out your ideal height-weight ratio. Get some amateur photos taken of yourself in casual clothes. Try to be detached and objective.
Overweight is sometimes a state of mind instead of body. What trauma or childhood inadequacy causes you to see yourself as fat and undesirable, when medically you're normal, or just a little full figured?
If you are definitely a fatty:
2. Meditate. Try to home in on reason you are overweight.
Is it genetic; are your family 'big-boned'? If not, what need are you trying to fill by stuffing yourself; are you anxious, insecure, do you have family or money or sexual troubles? If so deal with THEM and your need to eat will be easier to beat.
Eating is pleasurable; we get a rush of blood sugar which makes us temporarily feel good, and having a full stomach makes us feel sleepy and calmed down. Are you going for effect rather than nourishment?
3. Change your diet.
Eat simpler, less processed, less over-prepared and overcooked food.
Get back to basics. Substitute fruit for candies, wholemeal bread and boiled potatoes for potato chips, lean steak for burgers, water instead of fizzy drinks.
Eat a grape or a piece of orange instead of a candy; you get a better 'buzz', and it's healthier for you. Another benefit of eating whole, natural food is you fill up quickly, while eating less. The horror of junk food is that it's got loads of fats and sugars in it while not being physically substantial; you can eat ounces of fat in seconds.
Basically, if a chimp wouldn't eat it, you shouldn't eat it. Yes, I KNOW a chimp could probably get hooked on junk food. All right, try this; if an athlete preparing for a track meeting wouldn't eat it, you shouldn't.
Have three meals a day only. Have a proper breakfast; people tend to skip this and then have snacks later to keep themselves going. This is folly.
NO snacks in between; let your belly growl. You're going to train it to need less. It will protest, as it's used to being big, but it will adjust in time.
Stay away from people and places which remind you of your old treats. Try not to let on you're dieting; your 'friends' will try to get you off it, or tempt you for fun.
4. Take more exercise.
You can do light exercise, or better yet work it into your daily routine.