Every time winter rolls around, I notice a distinct change in my appetite: namely, that it increases. Not only that, but the type of food I crave also changes—from the light salads and refreshing juices of spring and summer to heartier, more carb-heavy meals: stews, casseroles, soups, you name it.
Which had me wondering: Why? From speaking to friends and family who say they experience a similar shift, I know I’m not alone in this, either. So I decided to reach out to experts to find out why we see such a sea change in our eating habits in the bleak stretch between fall and spring—and if it’s anything to be concerned about health-wise.
Why feeling hungrier in winter is so common
“We definitely see this trend of people having more appetite or going for heavier foods when things are colder,” Thanh Thanh Nguyen, MS, RDN, a registered dietitian at Mendinground Nutrition, tells SELF. Think creamy dishes or those heavy on dense, starchy vegetables, like mac and cheese or mashed potatoes. It’s even culturally ingrained to some extent, hence the “soup season” moniker. Put simply, “feeling hungrier during winter is normal,” Kathleen Moore, RDN, LD, a staff dietitian at the Ohio State University Wexner Medical Center, tells SELF.
More specifically, Moore explains, “reduced sunlight and lower temperatures influence appetite and mood” in ways both subtle and overt. Seasonal fluctuations in food choices and eating patterns can “vary from person to person” (and don’t affect everyone), Janice Dada, MPH, RDN, a registered dietitian and intuitive eating counselor, tells SELF. But they’re certainly widespread in light of the physiological effects of winter on the human body. Below, we’ll break down the main drivers.
Thermogenesis
To maintain your core body temperature of 98.6 degrees Fahrenheit, your body naturally has to work harder when it’s cold out. “Our metabolism will increase, and we’ll start utilizing a different type of body fat, called brown fat, as a fuel for keeping our bodies at the right internal temperature,” Dada says. One 2014 study published in the journal Diabetes found that the resting metabolic rate in healthy people with detectable levels of brown fat increased by 14% after cold exposure, though most estimates hover around five to 11%, according to Dada. (Brown fat, or “brown adipose tissue,” is notable for its unique ability to translate excess calories into heat.) In addition to digging into its brown adipose tissue stores, your body might shiver—the involuntary muscle contractions produce heat much like exercise does, as a 2014 study published in the journal Cell Metabolism showed. Whatever the mechanism(s), this metabolic boost means you burn way more calories than you would in more mild conditions, prompting the need to replenish them through eating, Moore says.
Thermic effect
Digestion can also increase your metabolic rate and produce heat, according to Nguyen. Fermentation (or the process by which microorganisms in your gut break down complex carbohydrates like fiber) churns out an estimated 60 calories of heat per hour—a significant amount. Taking this into account, “the hypothesis is that we want to eat more often [when it’s cold out] because that is a heat-generating activity that keeps us warmer,” Nguyen says. (Hence why cold plunges are often touted as a fat-torching health hack!)
Declining serotonin
Last but not least, the reduced sunlight available in winter can also mess with serotonin, a neurotransmitter nicknamed the “happy hormone” thanks to its role in regulating mood. Because serotonin is produced partially in response to sunlight exposure, shorter days can cause a drop in levels, according to Nguyen—a potential cause of seasonal affective disorder (SAD). In a 2014 study published in the journal European Neuropsychopharmacology, researchers reported that people with SAD had 5% more SERT, a protein that terminates serotonin signals, in the winter than in the summer. Besides modulating your emotions, serotonin also acts as a natural appetite suppressant, so a lack thereof can trigger overeating. (And if you’re dealing with full-blown SAD, you might find yourself turning to food to self-soothe on top of that.)
On the subject of changes in cravings, higher-carb items tend to address all the issues we described above—thermogenesis, thermic effect, and declining serotonin—so it makes sense we may be instinctively drawn to them in winter. First, carbs offer a rapid burst of energy, so they’re better positioned to fulfill that increased metabolic demand. Research even shows that when we’re hungrier, “our brain actually starts to prefer things that are going to kind of satisfy that need faster,” Dada says. (Fun fact: This is also why you crave carbs when you’re stressed or sleep-deprived!) Second, high-protein and high-carb dishes produce more heat during digestion, so they “create a bigger thermic effect than those that are high in fat,” Nguyen says. (Larger meals do this, too—another reason why your appetite might increase in the winter.) Third, carbs actually act on your brain to increase serotonin release and lift your mood, Moore says.
