We feel hungrier when it is cold than when it is warm and we gravitate toward high-calorie foods in colder weather and low-calorie foods in hot weather. These are common beliefs, but they leave out one important factor: emotions. We humans are emotional eaters. This is not to say that other animals do not also eat out of grief or boredom or a variety of emotional states, but we rather excel at it. Nothing wrong with that. We are a complex and extraordinary creature after all.
Then there is gender. Studies show that temperature affects men’s appetite more than women’s. This sounds rather like some sort of myth to us, though there might be some evolutionary reason behind such variations. Overall, humans seem to defy science in many ways.
Not all experts agree. Some report that extreme temperature, for instance the heat of summer and the cold in winter here in the Northeast, contribute to extreme changes in appetite. We tend to eat less in summer and more in winter. This sounds right at first glance, but then consider summer BBQs. Surely not a time when we eat less. However, while the volume of food we ingest in summer may be very similar to our winter intake, our summer selections tend to lead to a lower intake in calories. The reasons are obvious: fresh produce is everywhere.
Meanwhile, other experts suggest that it is not the weather itself that affects appetite so much as the length of days. Studies show that our appetite grows as the days get shorter, and vice versa. Thus the weather may not be the key here so much as the balance of daylight and night. A study from the University of Georgia found that we may consume as much as 200 more calories per day as the days get shorter in fall and throughout winter. Another study measured similar results merely by changing light exposure, without a change in temperature. Shorter days seem to increase appetite.
At the root of the issue is a matter of instinct, agree most scientists. It makes sense for a predator, which is what we are after all, to have increased appetite leading up to and during the colder months, for food may be scarce in those times and the body needs reserves. How this theory applies to tropical climates is not clear, but again leads many to attribute changes in appetite to the length of days rather than weather. Although if one lives smack in the middle, between the poles, the length of days and nights does not vary much, so the weather may be a greater factor after all in such places.
Part instinct, part environment might be a better explanation. When it comes to humans, environment is a multi-faceted factor. We have created occasions when, by now, we instinctively look forward to meals. BBQ parties in summer and holidays throughout the year provide unique and somewhat unnatural circumstances. Add to this the fact that we assign specific times of day to three specific meals. As far as we know, we are the only creature who has come up with scheduled occasions to partake of food. This throws off many of our natural inclinations.
In the end, weather does affect appetite no matter how we rationalize our cravings or lack thereof. It is a matter of instinct and one of memory also. The prowling cat may hunt ceaselessly on the eve of a thunderstorm, because it remembers that it got hungry in similar conditions at a previous time. Likewise, we crave food or indulging in large meals when stormy weather keeps us shut in, because we remember feeling “empty” on such days.
Clearly, the reasons for the weather-appetite correlation are more complex than we can fully explore in one article, and digging up information on this topic, along with the gray skies and heavy atmosphere this afternoon, has made us rather hungry. One final question comes to mind: We know that food gives us calories and calories keep us warm. Does cold food really cool us down?