As you move toward the platter of cookies in the coffee room, you know you're not about to fight temptation. Why bother dieting now, you ask yourself. You'll start after your birthday ... after your cold ... after your vacation ... or whatever your excuse is.

That's not a good sign, according to diet behavior expert Daniel S. Kirschenbaum.

This probably isn't the first holiday season you've put off your diet. But it can be the last, if you get serious now.

"It's a real mistake to put off a diet," said Kirschenbaum, a professor of psychiatry and behavioral sciences at Northwestern University Medical School in Evanston, Ill., and the author of "The 9 Truths about Weight Loss", (Henry Holt and Company, 2000). "Everything counts. Weight controllers have to get clear about this. You don't want to have a final blowout before you diet.

Why would you want to go on that last chocolate binge?

"It's so self-destructive," said Kirschenbaum, who has done considerable diet research as director of the Center for Behavioral Medicine and Sports Psychology in Chicago. "You can be very effective dieting for six days, then have a one day blowout and erase all your efforts on the seventh day."

Improving your attitude will enhance your chances of keeping weight off, he added. "You won't be successful if you think a diet is punitive. Don't beat yourself up. Some people get into a 'why me?' thing -- 'Why do I have to deal with this when other people don't?' Don't rebel against it."

Kirschenbaum suggests we learn to love the food that's safe. "You can have so much food that's wonderful, tastes good and is healthy," he explains. "Why get excited about grease?"

You may find that you're resistant to change, and that's natural, according to Kirschenbaum. "Change puts us outside our comfort zone ... but we have to take the plunge. Think of (your new food choices) not as a diet, but as a new way of life."

He suggests you begin by setting goals.

"In 200 studies of goal-setting, 93 percent of goal-setting led to performance improvement. Specific, well-defined goals do way better than vague goals.

Making a resolution takes about 20 seconds, he said. But making a specific plan takes more time, more commitment, and that's why it will work better. "Measurable and important goals can be met when you are specific," he said.

Your goal could start with a five-block walk every day. Then you might add the goal of switching from your mid-morning doughnut to an apple.

Kirschenbaum doesn't emphasize short-term diets. Instead, he urges his clients to get more exercise, keep diaries so they know what they're eating and switch to low-fat, low-calorie foods.

"Writing things down diffuses emotions. It's one of the keys," said Kirschenbaum. "Instead of saying, 'A doughnut is horrible', say that it has 12 grams of fat. Eating a doughnut isn't a tragedy, but it is a problem, and you have to work on what the problem is."

Often people blame themselves when they pig out, and Kirschenbaum says that's not useful.

"Lapses are inevitable. It's not about whether you're a good or bad human being. You can have (food) moments you're not proud of. It's OK," he said.

Use these tips from Kirschenbaum to improve your chances for success:

1. Make an immediate commitment to eating less and getting more exercise.

2. Make a promise to someone. You're more likely to stay on course if people expect you to.

3. Build on success. If you were able to get through the office party without overindulging, congratulate yourself, and keep working on your self-control.

4. Think of how bad you'd feel if you failed at your diet.

5. Be around others who are dieting. If you're with other people who are psyched up, there's a team effect.

6. Get support from your family and friends. Their optimism will help you develop your own.

And make it your goal to include more recipes like this zesty steak sandwich.

Flank Steak with Orange Salsa Wrap

1 (12-ounce) flank steak
1/2 teaspoon paprika
Juice of 1 lime
2 large navel oranges
1/3 cup minced red onion
1 jalapeno chile, cored, seeded and minced
1/4 cup minced cilantro
2 tablespoons orange marmalade
1/4 teaspoon salt
Dash of pepper
4 (7-inch) flour or corn tortillas

Rub the flank steak on both sides with paprika and lime juice.

Place in a shallow bowl and refrigerate one hour.

For salsa, peel oranges and cut into 1/2-inch chunks. Place in a bowl. Add ingredients through pepper.

Broil beef 4 to 5 inches from heat until medium-rare, about 4 minutes per side. Cut into thin diagonal slices.

To serve, arrange one-fourth of meat on each of 4 tortillas. Add salsa. Serves 4.

Each serving has: 305 calories; 11 grams of fat; 20 grams of protein; 26.5 grams of carbohydrate; 45 milligrams cholesterol; 305 milligrams sodium and 0.5 grams dietary fiber.