We all want to look gorgeous for the holidays—and we definitely don’t want to start the New Year with an extra roll of belly fat. Unfortunately, Mother Nature’s plans aren’t the same as ours. Biologically, we’re hard-wired to slow down, eat more, and gain weight when cold weather sets in.

For early humans living in icy caves and facing winter famines, this made survival easier. But these days, cocooning in a warm home in front of the TV with a bag of chips just makes us fat. All around the world, people tend to gain weight in cold weather—and the cozier our winters get, the worse the problem is. In fact, research shows that increases in “comfortable” winter temperatures thanks to indoor heating correlate strongly with increases in obesity.

Luckily, you can keep those extra pounds off by winter-proofing your body. This means taking action right now—in the fall—to keep your body from going into “hibernation” mode. Here are four power tips for keeping that winter weight from sneaking onto your waistline.

RESET YOUR INNER CLOCK. Shorter days and longer nights send your biological clock into a tailspin—and that makes you tired, fat, and even depressed. Optimize your circadian rhythms with melatonin, vitamin D, a daily dose of sunlight, and a light therapy box when the skies are cloudy.

GET COLD! It’s tempting to bundle up in layers of clothing so you never get chilled. However, don’t be afraid to shiver a little. Research shows that 15 minutes in the cold can rev up your metabolism as much as an hour of exercise—and that even turning your thermostat down from 74 to 68 degrees can make you burn fat faster.

ANTICIPATE YOUR APPETITE. It’s normal to be hungrier in the fall and winter. So don’t fight it; instead, prepare for it! Load your fridge and freezer with filling soups and ingredients for smoothies and green drinks, and get rid of the sugary, high-carb foods that pack on winter pounds.

GET IN THE “BROTHING” HABIT. Two or three times a week, substitute a mug of bone broth for a meal. It’s rich and satisfying, so you won’t feel hungry—and it’ll help you melt off extra fat.

Put these four simple winter-proofing strategies in place now, and you’ll be prepared when cold weather arrives. In fact, rather than gaining a few pounds over the holidays, you can actually wind up slimmer by January—and that’s an awesome way to ring in the New Year!

Keep thinking Big and living BOLD!