When we get overweight, a protein in our bodies tends to locks the excess fat, preventing it from being burned. Research shows that mice lacking the gene to produce this protein burn off excess weight faster.
Fat is stored in our bodies in two forms, white adipose and brown adipose tissue. The white fat is regular fat, and gives up energy whenever we need it. The brown fat, though, is burned only to keep us warm. Babies have a lot of it, because they’re more susceptible to the cold than adults. And it’s this brown adipose tissue that gets locked up by the protein, sLR11, say researchers from the University of Cambridge in the U.K.
Mice that lack the gene to produce sLR11 “were indeed more thermogenic and had increased energy expenditure, particularly following high fat diet feeding,” says the study.
The research suggests that the fat cells produce these proteins themselves, as a kind of self-preservation mechanism, meaning the more of this fat you lay down, the more the protein inhibits its use. The idea is that this fat is keeping itself from being wasted on regular energy production.
“Our discovery may help explain why overweight individuals find it incredibly hard to lose weight,” said study co-author Andrew Whittle. “Their stored fat is actively fighting against their efforts to burn it off at the molecular level,”
The team thinks that the burning-inhibiting protein is there to safeguard these important fat reserves when the rest of our metabolism undergoes a spike in activity–after eating a large meal, for example, or when we experience a short temperature drop.
This discovery could eventually lead to drugs that help weight loss by inhibiting the sLR11 protein in the body, allowing our bodies to burn more of the stored fat.
“We have found an important mechanism that could be targeted not just to help increase people’s ability to burn fat,” said project leader Professor Toni Vidal-Puig, “but also help people with conditions where saving energy is important such as anorexia.”