Transforming Fat by Socialising
Engaging in a more socially and physically challenging environment alters the type of fat in your body from white, which is for storage, to brown, which is burnt to generate heat. This study, published in Cell Metabolism, was carried out in mice and showed that placing them in larger enclosures with lots of social interaction and other engaging items, like toys and hiding places, caused a dramatic change in fat composition.
These "enriched" mice were leaner but at the same time were eating more, so the change wasn't due to having less food. Even "running mice" which were two or three times more active than the enriched mice didn't show the same conversion to brown fat.
"Not only were the mice leaner" explains Professor Matthew During from Ohio State University Medical Centre, "you could also see the change in the fat composition. It had actually turned browner and this alerted us to what was going on."
The hormone leptin, which is produced by fat, was remarkably reduced in the enriched mice, and their total fat reduced by 50-70%. This fat reduction was more than double that which was seen in the "runner" mice. "The more brown fat you have the more resistant you are to obesity" explains Professor During. Previous work has shown that this conversion of fat can take place if the subjects are placed in cold environments for prolonged periods of time, but this new work implies another mechanism is also involved.
Complex social interaction is healthy for individuals. The mice were leaner and displayed other observable benefits such as a decreased risk of heart disease, cancer and overall increased longevity. Although pounding away in a gym will cause fat loss by challenging yourself on a physical level, the social interactions you have may be as important if not more in changing fat composition.
So fat, far from the passive organ it was previously thought to be, seems to respond to how social you are!