Winter Weight Gain: Why You Eat More in the Winter and How to Avoid It

December 4, 2011

by Cathe Friedrich

When the temperatures fall, does your appetite rise along with it? Many people eat more during the cold, winter months, which isn’t surprising since there’s less opportunity to get outside and be active. But that’s not the only explanation for why you’re more likely to crave carb-rich foods like brownies in the winter. Cold weather seems to alter appetite hormones like leptin that help to keep carb cravings at bay.

Why Cold Weather Stimulates Your Appetite

According to research carried out at the National Institute of Mental Health, those cold winter temperatures alter the way your body responds to leptin. Leptin is a hormone produced by fat cells that send satiety messages to the brain. This means it’s important for turning off the desire to snack and for curbing the desire to overeat. Ironically, people who are overweight or obese often have elevated leptin levels. This is because their leptin receptors aren’t as responsive to the leptin they produce, and it fails to turn off their appetite as it does in a normal person.

Based on these findings, it appears that the body processes leptin differently in the winter. This means it may not do its job of turning off the desire to eat as readily as it should. That’s bad news if you’re trying to avoid winter weight gain. Combine that with the fact that people are less active in the winter and indulge in a few holiday splurges, and it’s easy to see why many people gain during the months between November and March.

Beyond Leptin: Why You Eat More in the Winter

There’s another factor that contributes to increased appetite in the winter. Some people experience a drop in serotonin levels in the winter. Serotonin is a brain neurotransmitter that helps to regulate mood and appetite. People who are depressed and obese people often have lower levels of this mood and appetite-regulating brain chemical. When serotonin levels are low, it triggers cravings for high-carb foods. Cortisol levels are also higher in the winter than they are in the summer. Cortisol is a hormone that boosts abdominal fat storage, especially unhealthy visceral fat.

Is There a Way to Avoid Winter Weight Gain?

One solution is to make sure you’re getting at least seven hours of sleep a night. When you don’t get enough sleep, it lowers leptin levels, so you’re more likely to crave carbs. Getting adequate sleep also keeps cortisol levels from rising, a factor that can contribute to abdominal weight gain. High cortisol levels are also linked with leptin resistance. Cortisol and leptin are two hormones you want to keep in balance if you want to avoid weight gain.

According to Scott Isaacs, M.D., author of The Leptin Boost Diet, focus on getting adequate amounts of zinc in your diet since a deficiency in this mineral lowers leptin levels. Zinc is found in highest levels in meat products such as beef, pork, and some seafood. Vegetarian sources include wheat germ, fortified cereals, and nuts.

Don’t Shun the Sun

Since low serotonin levels are also linked with carb cravings, getting adequate sunlight is important. Some people experience a drop in their serotonin level in the winter because they experience seasonal affective disorder due to lack of exposure to light. This causes them to feel blue and to crave carby foods. Try to stay as active as possible during the winter. Sitting around too much can make the seasonal blues worse and lower serotonin levels. Make sure you have an indoor place to exercise or work out in your home on days where the weather doesn’t cooperate.

The Bottom Line?

During the winter, you may experience changes in appetite hormones and neurotransmitters that boost cravings for carbs. Stay on track by working out regularly, sleeping at least 7 hours a night, getting enough exposure to light and adding more zinc to your diet. It’ll feel good knowing you don’t have to whip yourself into shape come the spring. You’ll already be there.

References:

Obesity Research. 3: 477S-480S.
The Leptin Boost Diet: Unleash Your Fat-Controlling Hormones for Maximum Weight Loss by Scott Isaacs. Ulysses Press. 2006.