Something special happens to us when we are exposed to cold. Considering we are all endothermic mammals, thermogenesis (the ability to produce our own heat internally) is built into us. We have two types of fat tissue in our body: white adipose tissue (WAT) and brown adipose tissue (BAT). When mammals are in a warm adapted state (i.e. summer), they tend to store more fat in WAT from the foods they eat because food is available in warm climates where they grow via photosynthesis and they need to store fat during the day to use as energy at night while they sleep in darkness without food. On the contrary, when mammals are in a cold adapted state (i.e. winter), they tend to convert WAT into BAT, and BAT is highly thermogenic. This means that calories from food are no longer stored as fat, but are liberated as heat to maintain core temperatures under freezing cold conditions. Given that food (carbohydrates) is also minimally available in winter months, the majority of those calories required for thermogenesis come from body fat stored in WAT during summer months and autumn when carbs were still available and consumed.
Interesting how our biology is designed to completely rewire itself under drastic changes to our environment huh? Have you ever seen a deer in the summer versus the winter? If you flip on the discovery channel, you will see that mammals are their leanest in the dead of the winter. Could it be that the lack of food availability, and the simultaneous increased caloric requirements for regulating the core temperature would be a mechanism to shed fat stores quickly to reduce metabolism (energy requirements) allowing life to cope with famine and thrive in the cold? Similarly, trees shed their fruits and leaves in the autumn in preparation for winter. Have you ever wondered why that occurs? When living things decrease their mass, they decrease their energy requirements and this helps them adapt to conditions less than ideal for life (i.e. winter). Ask yourself this: does it require more energy to heat a mansion or a shack? Now you know why it is advantageous to lose fat mass in response to the cold and evolution has built this into all living things using the laws of physics, because cold shrinks and condenses matter.
Now, how many humans do you know today that are truly cold adapted? I’m talking walking in the snow with minimal clothing on without shivering? Next to none. As humans, we are the only species capable of controlling our environment for comfort. That means we no longer have to face a true winter again. We can avoid the cold by using artificial heat in our homes and cars, and dress in heavy winter clothing should we have to go outside. But what if winter and the cold was designed to do something special for us? What if it was a way to “reverse” the damage and inflammation accumulated from a period of high activity such as summer? In long light cycles we eat more food (especially carbohydrates) because it is available to us. We exercise more because we need to explore our environment, fight and flee from predators. We sleep less because there is less darkness. We are exposed to stronger light stimulus and heat from the sun. All of these factors are potential stressors that have to be dealt with accordingly and we all know that stress needs to be balanced by rest and regeneration.
As I mentioned earlier, cold condenses matter. On the contrary, heat or light UNcondenses matter. This is a synonym for swelling. A synonym for swelling is also inflammation. In physics, this means that things get bigger. When living things increase their mass, they increase their metabolic rate which increases energy requirements, which subsequently increases the amount of food required to maintain their current state. Could this be why humans, unlike all other mammals are their fattest in the dead of winter? Is there a connection between the excessive use and reliance on artificial lighting and heat to get us through these dark, cold times and our increased desire for food during the holiday pig-out events? Foods (i.e. carbohydrates) that are not supposed to even be available to us because they do not grow in cold, dark environments due to a lack of photosynthesis? So does it make sense to postpone winter indefinitely? Or might Mother Nature be providing us with an environment to optimize regeneration? Could a lack of cold on our skin and excessive bright lights through our eyes 24/7 be blinding us from another pathway found in our brain to reverse chronic inflammation and restore optimal health and function? If so, how could a modern human tap into this pathway for wellness?