This Chocolate Marshmallow Fudge is surprisingly low in calories. (Laurie Skrivan/St. Louis Post-Dispatch/TNS)

The turkeys have been obliterated, the cookie tray ravaged … and the pies? Don’t even ask about the pies.

Now it’s time to diet.

But there are so many diets out there: the alkaline diet, the blood-type diet, the master cleanse, the cabbage soup diet, the HCG diet.

How do you know which one is right for you? For that matter, how do you know which one is actually harmful for you?

“If it sounds too good to be true, it usually is,” said Rabia Rahman, assistant professor of nutrition and dietetics at St. Louis University.

“If they’re asking for a lot of money (for items other than food products), don’t do it. If they say you can eat as much as you want and still lose weight? Bogus.”

And some diets that sound as if they are scientific are equally worthless and potentially dangerous, Rahman said. The people pushing diets may use scientific terms and jargon, but that does not necessarily mean the science behind them is sound.

The healthiest way to lose weight, and the only successful way to keep it off, is to strive for balance, variety and moderation, she said.

You should find a balance not only in the different types of food you eat but also a balance between the amount of calories you consume and the ones you work off through exercise and other activities. If you consume as much as you burn off, your weight will stay the same. If you can burn off more than you consume, you will lose weight.

Choosing a variety of foods is important because it is healthiest to eat from all of the food groups. It is a way to make sure you get all the protein, carbohydrates and fats you need to get through the day, she said.

And if you eat the same foods every day, you will end up missing out on necessary nutrients found in other foods.

Rahman added that eating in moderation means “there is really nothing that you should consider bad or off-limits completely. If you want to have dessert, have dessert, but have a small portion.”

One plan that does all of this, and that Rahman recommends, is Weight Watchers. According to St. Louis Weight Watchers Leader/Ambassador Ellen Abramson, the organization looks to help its customers both lose weight and, just as vitally, keep it off.

Weight Watchers works on a system of points. Every food is assigned a number of points — low numbers for foods that are low in calories, are lean proteins or are high in nutrients and fiber such as fruits and vegetables, and high numbers for foods that are high in calories, sugars and saturated fats.

Based on their height, weight, age and sex, clients are given a target number of points to hit each day, plus a few extra points each week as a cushion, Abramson said.

By following the point system, the clients eat healthful, properly portioned foods. But that doesn’t mean they go without their favorites.

“If it’s Christmas and your aunt makes the best pecan pie ever, you can have it. But you have to have less of everything else. It’s called mindful eating. If I’m going to have pecan pie, I maybe will not have mashed potatoes,” Abramson said.

To get into the dieting spirit, I prepared several dishes from Weight Watchers’ recipes. And they were good. Not just good for diet food, they were actually good. Even the fudge.

Yes, Weight Watchers has a recipe for Chocolate Marshmallow Fudge, and it’s actually relatively low in calories.

How can that be? Well, it uses fat-free evaporated milk instead of the regular kind, reduced-calorie margarine instead of real butter and melted marshmallows to give it body and flavor. Plus, the portions are small.

It is surprisingly excellent.

No less good was a Honey-Glazed Salmon With Wasabi. Salmon, of course, is beloved by dieters because it has a high amount of flavor while still being good for you (though salmon tends to be fattier than other fish).

This version uses a popular combination of Japanese seasonings, with a hint of honey for sweetness and a blast of wasabi paste for heat. It doesn’t take long to cook, but you will probably gobble it up faster than that.

Chocolate Marshmallow Fudge

Makes 36 servings

12⁄3 C granulated sugar

2 TBS reduced-calorie margarine

14 lg marshmallows, chopped

12 oz semisweet baking chocolate, chopped

2⁄3 C fat-free evaporated milk

Coat an 8-by-8-inch baking pan with nonstick spray.

Stir together sugar, evaporated milk and margarine. Bring to a boil in a saucepan, reduce heat to medium-low and cook 3 minutes, stirring constantly. Stir in chocolate and marshmallows. Remove from heat and stir until smooth.

Pour into prepared pan and refrigerate until firm, about 2 hours. Cut into 36 squares – 6 rows of 6 – and serve.

Per square: 96 calories; 3 g fat; 2 g saturated fat; no cholesterol; 1 g protein; 18 g carbohydrate; 17 g sugar; 1 g fiber; 7 mg sodium; 14 mg calcium.

— Recipe by Weight Watchers