Winter weight gain isn’t just an urban myth. Research has shown most of us could gain around a pound (half a kilo) during the winter months. That may not sound like much, but over the course of a decade it can add up.

“There’s good evidence that people put on weight over the winter,” says dietitian Sian Porter. “The more overweight you are, the more you tend to put on. And the most worrying aspect of this seasonal weight gain is that the pounds tend to stay on. People don’t seem to lose the extra weight.”

The three main reasons that people put on weight in the winter are lack of physical activity, comfort eating and overindulging at Christmas.

Cold weather and shorter days make it harder to exercise outdoors, so it’s easy not to do any exercise over winter. If you’re not outside as much, there’s more time and temptation to reach into the kitchen cupboard for high-calorie sweet snacks, such as biscuits and cakes.

Then of course there are the festivities surrounding Christmas. “What used to be a couple of days of parties and overeating now seems, for some, to be six weeks of overdoing it,” says Porter.

So what’s the solution? Here are four simple ways to avoid winter weight gain.

1. Stock up your kitchen cupboards

Keep your store cupboard stocked with staples such as cans of tomatoes, spices, beans and pulses, dried wholewheat pasta, wholewheat cereals, noodles, couscous and dried fruit.

Keep some extra bread in the freezer if there’s space. That way, you’ll be able to create a quick and nutritious evening meal, such as a lentil or vegetable soup or stew, at short notice. You’ll save money and avoid the temptation to order a high-calorie takeaway.

Here are 10 healthy hot meals for winter.

2. Exercise more in winter

When the outside temperature drops, it’s easy to give up on outdoor exercise. In winter, we stop doing calorie-burning outdoor activities such as short walks and gardening. But reducing the amount of physical activity you do is one of the biggest contributors to winter weight gain.

Cold weather and shorter days don’t mean you have to abandon exercise completely. Instead, rearrange your schedule to fit in what you can. You don’t need formal exercise to burn calories.

A brisk walk can be revitalising after being indoors with the central heating on, and it’ll also help boost your circulation. Put on some warm clothes and jog around the neighbourhood, or start a snowball fight with the kids.

Most leisure centres have heated swimming pools and indoor tennis and badminton courts. If you’d rather stay at home, buy some dance or workout DVDs, and always walk up the stairs at work rather than using the lift. “These little things can make all the difference when it comes to avoiding that pound of weight gain over winter,” says Porter.

Get more tips for exercising in winter.

3. Watch out for high-calorie drinks

It’s important to consume hot drinks throughout winter because it will help you keep warm. But some hot drinks are high in calories.

Milky, syrupy coffee shop drinks and hot chocolate with whipped cream can add a lot of calories to your diet. A Starbucks medium caffe mocha, for instance, contains more than 360 calories.

Stick to regular coffee or tea, or ask for your drink to be “skinny” (made with skimmed milk). Also, limit your alcohol intake as much as possible.

4. Get your winter greens

Eating a wide variety of foods ensures you get a range of nutrients, including vitamins and minerals. Don’t get stuck eating the same food every day.

Look out for root vegetables, such as swedes, parsnips and turnips, and winter veggies such as cauliflower, Brussels sprouts, kale and artichokes. They’re filling as well as nutritious, so they will help you resist a second helping of trifle.

This recipe for a hearty vegetable soup is a great way to get more winter vegetables into your diet.