That Christmas fruitcake is probably still nestled tightly in its tin, way in the back of the pantry on top of the one you got last year. And the one from the year before that.

But where did those holiday cookies go? And the big New Year’s Eve cheese tray? Remember that gallon of guacamole at the Super Bowl party? Whatever happened to that?

You know. Look down. They're not hard to find.

Winter weight gain is a real thing. For years, putting on pounds around the holidays and beyond was something strongly suspected but still largely unproven. But an oft-cited 2000 study in the New England Journal of Medicine, and others that have followed, suggest that winter weight gain is not just real. It’s lasting.

The NEJM paper found that people gained a little more than a half-kilogram — a smidgen more than a pound — over the holidays. A similar paper, published in the European Journal of Clinical Nutrition in 2013, put the weight gain around the holidays at about a pound and a half. That study, of about 150 people, noted a significant increase in body fat percentage and blood pressure, too.

So now we’re left with even tougher questions. Like, how do we stop this runaway gain? And how do we get rid of what’s there already?

Exercise, you guess?

Well, good luck with that.

The 2013 study, conducted by nutritionist Jamie Cooper and others, raised some alarms in showing that even regular exercisers were not protected from winter weight gain. Further, it suggests, as many of the studies do, that getting rid of that pound or two (or more!) is very, very difficult. In fact, that extra weight is something that many people carry all year, then compound it every holiday with more cookies and chips and ... well, you get it.

“People just don’t realize how quickly they can do a lot of damage,” Cooper, an assistant professor and associate chair in the Department of Nutritional Sciences at Texas Tech University, told MNN.

Take the simple sugar cookie, Cooper said. Let’s just say it’s 150 calories — meaning it will take a half-hour walk to burn it off. Have a couple of those, maybe a slice of that delicious fudge over there, a couple potato chips and soon, even a 24-hour workout won’t help.

“People think I’ll just exercise a little more ... they’re not able to exercise enough,” said Cooper, who has a PhD in nutritional sciences. “People have to be careful. They have to make good decisions on a daily basis.”

Those decisions start with eating right and, in the mantra of dietitians and nutritionists the world over, doing it in moderation. That’s never easy over the winter, with the holidays interfering and many people bundled up at home where all that food is lying around.

But that’s where it starts — being smart about what you eat and how much you eat.

“I think sometimes people get into this mindset that, ‘I already blew my diet, so I might as well keep going,’” Cooper said. “If you’re overindulging on Thanksgiving Day, then make sure you're not overindulging on the next seven days ... everything in moderation.”

Along those lines, here are some not-as-obvious keys to combating those wintertime pounds:

Don’t shop when you’re hungry

This may sound like simple conventional wisdom, but at least one study suggests it’s true. The research found that shoppers stock up on higher-calorie foods when they’re hungry. And when you’re house-bound because of the shorter days and colder weather, you don’t want to have a bunch of snack foods and desserts tempting you from the kitchen.

“It makes very logical sense that if you're going for a period without food, and you're wanting food, you're more likely to go for the food that's high-calorie," endocrinologist Tony Goldstone told Reuters in 2013.

“When you're really hungry, what are you thinking about? A nice chicken breast and steamed vegetables?” Cooper said. “No, you’re thinking, ‘Give me some brownies. Give me some sugar.

“The best advice I can give is stick to the perimeter of the store,” where all the fruits and vegetables are, Cooper said.

Soup it up

At least one study suggests that having some soup before a meal drastically reduces how much is eaten during a meal. Clearly, it’s better to lay off the cheesy stuff, the chili and the creamier soups, which can be high in calories themselves. Go for something like vegetable soup instead. And drinking a gallon of whatever kind of soup probably isn’t advisable.

But, according to the study published in Appetite in 2007, using soup as a “preload” led to a “significant reduction in test meal intake compared to consuming no soup …” The 73 subjects in the study reduced their “total intake energy” at lunch by a whopping 20 percent.

Remember, a lot of good fat is not good

“Even good fats or healthy fats have the same amount of calories that unhealthy fats do,” Cooper said. So the difference between a dip or two (a few calories) and a good handful or three (many, many calories) of that delicious guacamole, no matter how mono- and unsaturated fat-filled it is, can make a difference. A big, bad difference.

Yes, you still have to exercise

Even the best exercisers, as the 2013 study suggests, may not be able to do enough to offset a bad diet. But, according to Cooper, exercise is still important, and good exercisers definitely have a “leg up” on those who don’t. So — you’ve heard this before — watch what you eat (and drink, because booze is full of calories, too). And exercise. Always, of course, after your physician OKs it.

Related on MNN:

How to shed winter weight before winter is over
The eating began over the holidays — and it never really stopped. But don't freak out; you can stem the tide.