Clearly, modern eating habits and a sedentary lifestyle have contributed majorly to this rapid increase in obesity. But a new research states that evolution played a crucial part in enhanced formation of human fat.
According to the research published in the journal Genome Biology and Evolution, over a period of time our DNA packaging inside the fat cells have changed, which has cut down our ability to transform bad fat into good fat.
The co-author of the study, Devi Swain-Lenz, who is a postdoctoral associate in biology at Duke University in Durham, said, “We are the fat primates.”
To carry out the study, researchers Swain-Laiz and Greg Wray analysed and compared fat samples collected from humans, chimps along with other primates. The technique used was called ATAC-seq, which studied the packaging of fat cell DNA in different species.
The findings showed that human bodies have 14 to 31 per cent body fat, in comparison to other primates, who had less than 9 per cent body fat. Moreover, they revealed that the DNA regions in human bodies are condensed, which limit their access to the genes that are involved in the process of fat metabolism. While chimps and macaques had close to 780 DNA regions that were more accessible. The outcome showed that humans have a stunted capacity to change bad fat into good fat.
The researchers also explained that most fat in human body consist of calorie-storing white fat, which sits on our bellies and around the waistline. The other fat cells, beige and brown fat, are the ones that help burn calories. And the reason humans carry more fat is because of compressed DNA regions that block the transformation of white fat into brown or beige fat. Swain-Lenz shared, “It is still possible to activate the body’s limited brown fat by doing things like exposing people to cold temperatures, but we need to work for it.”
A study into the lives of early humans reveal that they needed some mechanism in their bodies to accumulate fat to shield vital organs, to stay warm, and to nurture their brains. However, the human brain almost tripled in size during evolution and now uses more energy than any region in the body.
While more study needs to be done on how our body’s ability to convert bad fat into good fat can be enhanced, imagine if scientists do crack this gene, we could eliminate obesity forever.