What have you done with the leftover desserts from yesterday's dinner? Did you parcel them out among your dinner guests? That't one way to protect your diet.

If you didn't, why don't you pop them into the freezer. Now.

Then come back and read some more strategies for cutting your gains between now and New Year's, that depressing period when the world mobilizes to sabotage your will power and deep-six your diet.

Whether or not you should be dieting at all, of course, is between you, your metabolism and your doctor, and the subject of future Healthtalks.

But if you're on a reducing regime, you're entitled to get through the holidays with a maximum of enjoyment, a miniumum of weight gain and, even more important, none of that destructive emotional complex of guilt, shame, self-disgust and eventual surrender -- the endless cycle.

It doesn't have to be that way.

You can face the holidays with a number of decisions.

The main thing is to make them consciously, thoughtfully and, most importantly, in advance . For example:

* You can decide to pig out for the next five weeks or so, with full knowledge that come January you will have five or so pounds to work off. If that is what you decide, so be it. You made your bed, so what if it collapses under your weight Jan. 2. If you decided on this option, you must know you can work it off lifting weights, running -- whatever your schtick . The important thing: It's what you decided to do. Remember, no guilt!

* You can torture yourself and stay home with your carrot sticks and TV. If you're going to be Mr., Mrs. or Ms. Perfection, healthier-than-thou and as pencil-thin as you like, you will probably be hungry, hostile and miserable. And probably alone. Fat lot of good being thin does you then.

* You can be sensible. (You knew I was leading up to something like this, didn't you?) You can almost have your pumpkin pie, plum pudding, eggnog and eat-drink-them too. Almost.

Put your diet on hold for the holiday. That doesn't mean going back to your old habits of shoveling it in willy-nilly, but it does mean that you can do enough tasting so you won't feel cheated. By and large, holiday food is more for tasting than for dining anyway.

You may not lose any weight for the next few weeks, but if you keep up with your regular exercise, plot each day, each social event in advance, and know, really know what you are eating, you'll be fine. Remember, it takes something like 3,500 extra calories to pile on a whole pound. Judiciously spread over five weeks, that's a heap of tasting. Going to a Party?

Decide before you go if it will be the eggnog or the butter cookies. Decide before you go that you will not have a second eggnog or more than two butter cookies-the amounts are up to you. The main thing is that you know what you are going to do before you do it.

If drinking gives that ever-starving inner self an excuse to take over, limit your alcoholic intake to a tablespoon of wine in a tall glass of club soda. You'll be amazed how good it is, how good you will feel and how long you can nurse it.

Talk a lot, Eat a little. Famous for Your Cookies?

Sure, they're marvelous, but don't bake them too soon. That virtous feeling you have about getting them done early is a fraud. You're doing it so YOU can eat them. You always bake more at the last minute, don't you? So this year, don't bake anything until the last minute.

And if raw cookie dough's your thing, set a bit aside before you get the rest into the oven and eat it after -- not during -- the preparation. Savor it. Enjoy it. Those spoonsful you used to pop never tasted so good and you probably ate twice as much as you thought you did. . . Other Strategies

Carol Shapiro, gestalt therapist and founder of Take It Off, a private weight-management program, she runs has -- with the help of clients and from long personal experience -- devised these suggestions, among others:

Parties : Pay attention to your feelings. Are you eating because you are exited? Scared? Shy? These are, she says, "normal feelings and rather common at parties. Let uourself feel whatever is there instead of stuffing it down with food."

(If you're uncomfortable, you can always leave.)

Family dinners : "They can be tricky. All the feelings of anger, jealousy, sadness, greed that we have grown up trying to push down can be seated with us around the table." So, she suggests:

* "Instead of having another piece of pie, say to yourself, 'I am jealous of my sister who is getting all the attention. . .'"

* If someone is urging "Eat, eat, eat," you can "play with the food on your plate. Mash things around. Cut them into little pieces. If you are angry, take it out on the food instead of taking it in."

Restaurants :

* Order two appetizers and a salad.

* Shred you bread. Roll it into little balls. Make it into crumbs.

* If you feel control slipping, imagine yourself "running from table to table eating everyone else's food."

* If you're bothered by your dinner partner's dessert, imagine it is made of cardboard.

It's all a matter of keeping your head -- your taste buds will benefit and your Calvins will still fit.

For information on free one-hour "Take It Off" introductory sessions in December, phone 338-8200 .

Other tips above are from the Georgetown University Diet Management Center: 625-3674 or 625-2064 .