Recent scientific research suggests that modern ambient living conditions may be an important factor in the worldwide obesity epidemic. One reason for this is related to brown adipose tissue (BAT). Brown fat tissue or BAT has the opposite function of white fat tissue; instead of storing fat, it burns it. BAT makes up 25% of the body mass of new-born infants, who need this fat type to maintain their body temperature. Hibernating animals also use BAT to maintain body temperature during long periods of exposure to cold. Only recently have researchers discovered the importance of BAT in adult humans. BAT uses a specialized protein called “UPC1” to generate heat by “uncoupling” thermogenesis (heat generation) from cellular respiration which results in the production of ATP. The body uses ATP for most of its energy needs. However, uncoupling causes cells to “lose” energy; the “lost” energy (meaning it doesn’t produce ATP) results in the cellular production of heat. This process of uncoupling burns up fat more rapidly than does using fat to produce ATP.
What does all of this have to do with modern ambient living conditions?
The first person to blame for the current obesity epidemic may well be Thomas Edison. The circadian hormone, melatonin regulates both the amount and activity of BAT; and melatonin production is regulated by exposure to light. During the winter season, when there is less daylight, the body increases melatonin production, increasing the amount and activity of BAT, burning greater amounts of fat, presumably to help stay warm during the cold winter months. With exposure to modern lighting humans produce less melatonin, and burn less fat, leading obesity. Why not just take supplemental melatonin? This may not be a bad idea; but it is unlikely to be an adequate substitute for darkness.
What about ambient temperature?
BAT activity is very responsive to changes in ambient temperature.
This fact has led researchers to suspect that another important factor in the current obesity epidemic is modern indoor heating. Very few people are presently subjected to seasonal cold conditions, since virtually all modern dwellings and workplaces have climate control which provides year-round, comfortable, warm temperatures.
So, to lose those extra pounds, turn down the thermostat, and turn off the lights.