It’s cold, I’m hungry | The Press

With the return of autumn and cold weather, do you want to eat more, and eat more fatty foods? And you know that almost inevitably you’ll put on a pound or two during the winter? You are not alone. Overview of scientific knowledge on the issue.

Energetic cost

One thing is clear: when you are cold, the body works to maintain its temperature, and this implies an increase in energy expenditure. This increase is explained by chills – involuntary muscle contractions – and by the activation of brown fat, an adipose tissue involved in the fight against the cold. A study published in 1981 gives an idea of ​​the magnitude of the energy expenditure associated with cool temperatures. Participants who had spent 30 hours in a room at 10 p.m. ^ohC had spent on average 7% more energy than those who had spent 30 hours at 28 ^ohC, with equal clothing and equal diet. Note that the energy expenditure associated with the cold varies from one individual to another.

food intake

“If we look at animal models, the increase in cold is very largely compensated by an increase in food intake, explains Kurt McInnis, doctoral student at the University of Ottawa. In general, as they burn more, they eat more to try to maintain their body weight. The mechanism behind this is increasingly understood: in rodents, explains Kurt McInnis, the cold causes a “cross-effect” in the brain, which activates not only the chills, but also the appetite. “Mammals are excellent at maintaining this homeostasis, this balance between energy intake and expenditure,” emphasizes Stéphanie Fulton, full professor in the nutrition department at the Université de Montréal.

Appetite

And in humans, does the cold make you hungry? Anecdotally, people report feeling hungry after doing an outdoor activity, “but that has never been studied scientifically,” notes Kurt McInnis, whose doctoral dissertation will “fill in this gap in the scientific literature. For eight weeks, for a period of 90 minutes every two days, about sixty participants will be exposed to the cold to see the effect that this exposure will have on their appetite, their food consumption and their weight. “In animal models, there is a tendency to overfeed. Will it be the same in humans? We’ll see,” says Kurt McInnis, who points out that the small size of rodents makes them very vulnerable to the cold.

Weight

People’s weight fluctuates throughout the year, and generally peaks during the winter, according to a few studies published in recent years. According to one of them, conducted in Massachusetts, participants consumed an average of 86 kilocalories more in the fall than in the spring and also tended to do less physical activity during the cold season. Their weight varied on average by half a kilo per year. “The variation in weight is not necessarily due to climatic conditions”, emphasizes Stéphanie Fulton, who specifies that human beings are particularly adept at protecting themselves from the cold, with their heated houses and insulated clothing. In winter, she says, not only do you exercise less, but you also tend to see fewer people — so, possibly, snack more.

habits

The eating habits acquired during childhood also have an impact on the choice of food, says Stéphanie Fulton. If our parents served us cheese fondue and roast beef when fall came around, maybe we’ll tend to crave those same foods as adults.

These habits, which are sometimes passed down to us from generation to generation, are not unrelated to agriculture and food availability, she says. Moreover, people will also eat what is offered in their immediate environment. And during the holidays, treats are especially available…

Evolution

Species have evolved to be able to cope with temperature variations. Before the advent of the industrial era, the hot season was that of abundance for humans, and the cold season, that of restrictions. Like other species, which fill up in anticipation of winter, can evolution explain our food cravings? That’s according to researchers at the University of Bristol, UK. According to them, people deal with “subconscious cravings” to overeat during this time of year to maintain their fat levels. “In our modern life, it’s something that is less involved,” however nuance Stéphanie Fulton.