The period between Thanksgiving and the New Year should be marked as a Diet Danger Zone on calendars. It is filled with homemade cookies, an abundance of alcoholic beverages, candy, prime rib, fruitcake, and cheese.

No wonder the average American gains a pound or more every holiday season.

Many approach the holidays certain that they can avoid overeating. How much damage can a couple of parties do? The sad fact is you will gain weight unless you take action. And now is the time to act.

Prevent those inevitable extra calories from becoming excess pounds.

In an effort to help people help themselves before it is too late, Amy Moore, an assistant professor of nutrition and dietetics and Ethel Frese, an associate professor of physical therapy and athletic training, at Saint Louis University teamed up to offer some strategies for dealing with the threat of holiday food.

Stay Off the Holiday Weight Gain Express

Their two-pronged approach starts with getting some control over your holiday eating and uses exercise to help prevent those inevitable extra calories from becoming excess pounds. “Even the healthiest eaters need to exercise and the best exercisers need nutrition, ” says Moore. “Nutrition and exercise provide the one-two punch for holiday weight management.”

Be Choosy

During the holidays, we're all offered foods we don't see the rest of the year. Grandma's Christmas cookies will not be around in a month, so have them but pass up the brownies and sugar-sweetened soda that might otherwise tempt you. They're always available.

Unless you offset all those extra calories, you'll gain weight. It's that simple. The best first line of defense is to cut out other high-calorie foods that you normally eat so your overall calorie intake stays the same.

The sad fact is you will gain weight unless you take action. And now is the time to act.

Holiday parties mean platters and platters of food. Be selective, Moore advises. The order in which you see food influences what you eat. A study of people who went through a typical breakfast buffet found that simply by changing the order in which diners saw the food reduced the number of people who chose bacon from 54% to 5%!

Load up on low-calorie foods first like veggies (watch the dip), Moore advises. They're filling and can help prevent over-indulging on high-calorie foods.

Be Mindful

The holiday period is the season of mindless eating. It's easy to park yourself in front of a bowl of chips and finish them all as you watch a game on TV or engage in conversation at a party. Mindless eating can add pounds to your waistline.

As always, pay attention to what — and how much — you eat. Avoid the holiday food trap by making sure you put food on a plate, so you can see what and how much you have before you start eating. Savor every bite.

At gatherings, the St. Louis team suggests that once you've taken some food, step away from the table and mingle with the other guests. The holidays are supposed to be about family and fellowship. Food is just a bonus.

Plan Ahead

Some people approach parties and buffets like a military campaign. They skip meals so they can pack away even more tasty food than they would normally. Don't do that.

Planning is good. But don't skip meals so you can eat more later. In fact, eating a small snack to take the edge off your hunger before facing a table full of rich food is a good idea.

Bring something healthy along with you if you are heading to a potluck, so you're sure to have at least one healthy option. Fruits — pomegranates, clementines, blueberries — are colorful party foods that are tasty, nutritious and unlikely to spend a lifetime on the hips. The other guests will be happy that you brought something healthier, too.

Make Water Your New Best Friend

Alcohol is not your only beverage choice. Moore suggests alternating a glass of water with every alcoholic beverage to pace yourself as you celebrate and prevent a next day hang-over. Water is a good choice for non-drinkers as well, offering a no-cal substitute for sugar-sweetened drinks. That's also true for everyday eating: Instead of sweet tea or soda with a meal, choose water.

Alternate a glass of water with every alcoholic beverage to pace yourself as you celebrate and prevent a next day hang-over.

For people who are shy about walking around a party with an obviously non-alcoholic drink, club soda with a slice of lime fools them every time. Or consider creating a wine spritzer by adding sparkling water to your wine.

Because drinking water fills you up, it is a favorite dieter’s trick, Moore says. Water also does good things for your digestive system, skin, muscles and kidneys.

Beat Over-Indulgence: Expand Your Exercise Horizons

If you already have a moderate regular exercise regimen, you know how exercise can help keep the weight off. But even strenuous exercise program won't completely counter holiday bingeing. Frese warns that it takes about one full hour of intense exercise to burn off all the calories from a 350 calorie pastry. Clearly, exercising does not give you a license to feast at will. Be sure it remains a part of your holiday plans.

Park the car so you have to walk farther to do your shopping.

You will weigh less if you exercise. And perhaps more importantly, you'll feel healthier, more alert, less sluggish and happier in general.

You don't have to go to a gym to exercise. Just think of being active. Climbing stairs, cleaning the house, going for walks, even playing with the children or pets are all ways to be active that burn calories and help the blood circulate. Park the car so you have to walk farther to do your shopping; shovel snow.

Activate, Don't Hibernate

Many people have a tendency to be less active in the winter. Avoid this. Yes, curling up in front of a toasty fire is nice, but don't let cold or wet weather become an excuse not to get out. The key to being active outdoors in winter is to make sure you're dressed warmly. So bundle up and get out.

Even if you do gain weight, activity will help limit the damage. Come January, you may only have an extra pound or two that needs to be shed instead of four or five.

Even if you're not quite as active as you are in the warmer weather, there's still plenty to do; you just make more of a conscious effort to do it. Even running everyday errands and going out to visit others helps keep you active. 'Tis the season for skating and skiing.

If outdoor activities are a challenge, try an indoor approach. Take a yoga or swimming class. Join a basketball team. It will not only keep you active, it will make the winter less lonely.

Keep It Up and Don't Get Discouraged

The secret to success, Frese says, is to add a little bit of exercise every day. You may not feel noticeably healthier immediately but eventually you will. And if you do gain weight, being active will help limit the damage. Come January, you may only have an extra pound or two that needs to be shed instead of four or five.

Just a little self control and the will to stay active will help keep you in shape for when the New Year rolls around.

Amy Moore, PhD, MPH, RD, LD, and Ethel Maureen Frese, PT, DPT, MHS, CCS, are on the faculty of Saint Louis University's Doisy College of Health Sciences.