The main purpose of brown fat is to keep the body warm when exposed to cold temperatures. This process of fat burning is what leads the body to a warmer self-regulated internal temperature. A high percentage of brown fat is common among babies as they lack the fully developed internal systems that older humans do, mainly the ability to shiver in order to keep warm. While this is great for babies, after a few years, the brown adipose tissue dissipates as the child is able to regulate it's body temperature more effectively. This means that adults lack the ability to use fat for heat energy as quickly and robustly as a baby does. Or does it?
Brown fat in adults
It was thought for a long time that brown fat was non-existent in adults but this has largely changed over the last several years. A study performed by The Wenner-Gren Institute1 shows that it is possible for adults to possess and utilize brown adipose tissue as a tool for generating body heat. In adults, they found deposits of brown fat to be present around the neck region, the spinal column, and the heart. This proves that brown fat is indeed present in adults. The next step is activating it.
Turning on the furnace
The same study took an adult male and injected him with a chemical that would allow scientists to see just how active the brown fat became when the individual was exposed to colder temperatures. The results were astounding: there was a significant increase in brown fat activity around the neck. Logic would then dictate that if we expose ourselves to cold temperatures, we should be able to burn additional body fat as the body initiates these brown fat deposits to stay warm. The location of brown fat is stationary, meaning if you attempt to activate brown fat in a fatty region, it will not result in your desired outcome so please do not go out and perform ab exercises in cold temperatures thinking it will reduce belly fat, it will not work.
This exposure to cold temperatures has mostly become non-existent for most adults in developed countries. We all have ample clothing and heating sources to maintain optimal external temperatures during all seasons of the year. We do appear to be fighting our physiology each cold season as the body has no need to burn any fat in order to stay warm. Brown fat takes needed energy from white fat in order to create heat and this is what may lead to weight loss.
Weight loss implications
The idea behind using brown fat for weight loss is simple: stay in the cold and let the brown fat burn white fat to keep the body warm. As with most things in life, nothing comes easy, especially weight loss. While the study shows it may be possible, more research much be done regarding the effects of brown fat usage and prolonged exposures to cold temperatures. There is no replacement for healthy eating and the execution of exercises to target the variety of muscles in our bodies.
1Unexpected evidence for active brown adipose tissue in adult humans: The Wenner-Gren Institute, The Arrhenius Laboratories, Stockholm University, Stockholm, Sweden -