Science Journal

Are Fat People Warmer Than Thin People?

I have a lot of fat friends who do not wear any sweaters or jackets at all in a cold environment, which raised a question if their excessive fat acts like a heat generator to keep their body warm. So as usual, I consulted Google if my theory is correct.

Our brain and hormones are responsible for regulating our internal temperature, and warming our blood which is distributed all over the body making us feel warm. When our skin detected coldness, the thermoregulatory cells on our skin constricts our capillaries and blood vessels (this process is called vasoconstriction) to reduce the speed of the blood flow as little as 0.02 L/minute, to maintain the warmth of our body core temperature and prevent us from experiencing hypothermia, an excessive feeling of coldness. For fat people, they cannot detect the coldness because their body fat acts as an insulator to the cold. Even though their extremities are cold they could not feel the coldness because their internal temperature stays warm. Whereas, people with low body mass index (BMI) of course have less body fat so they feel the cold more quickly than fat people but have warmer extremities. Plus, they eat less food reducing their metabolism, which generates body heat.

I also learned that women are colder than men, not emotionally but their extremities. Women's body contained more fat that stores heat, thus their body core temperature is higher and their blood flow is programmed to go directly to the vital organs such as brain and heart than their hands and feet, making it colder. While men have more muscle mass that generates body heat so men are hotter than women. Being hot protects them from hypothermia. And I learned that small people lose more heat quickly because they have more surface area but less volume of their bodies. 

Anyway, my theory is close to the facts I researched but not as a heat generator but some sort of protection from coldness or maybe the reason why they do not wear any jacket or sweater is that none of these fit in.