You may have heard of muscle memory, but did you know fat cells also appear to ‘remember’ past obesity?
A new study published in the journal Nature on November 18 reveals that fat cells tend to resist attempts at keeping weight off, indicating a sort of biological memory that drives the body to revert to past weight levels. According to the researchers, this may be one of the reasons behind the so-called yo-yo dieting effect, where individuals see their weight rebound after shedding pounds.
The researchers examined fat tissue from patients with obesity before and after they lost weight using bariatric surgery. The tissues were then assessed against the fat from individuals with a healthy weight and no history of obesity.
They found that fat was impacted at a cellular level, changing how the patients responded to food. Notably, this cellular level impact persisted for years after weight was lost. The fat cells in formerly obese individuals were found to grow quicker than the other group, absorbing nutrients at a faster pace.
As recently reported in The Dallas Express, nearly 260 million Americans are forecast to be overweight or obese by 2050. The World Health Organization says that childhood obesity ranks among the top public health challenges of the 21st century. Nationwide, Texas has the eighth-highest rate of childhood obesity.
“Our study indicates that one reason maintaining body weight after initial weight loss is difficult is that the fat cells remember their prior obese state and likely aim to return to this state,” said the senior author of the study, Professor Ferdinand von Meyenn of the Federal Institute of Technology in Zurich, per the Guardian.
“The memory seems to prepare cells to respond quicker, and maybe also in unhealthy ways, to sugars or fatty acids.”
The researchers say fat cells are likely only part of why many people rebound after losing weight. They suspect similar memories may also exist in brain cells that drive a person’s food consumption and energy expenditure.
“From an evolutionary perspective, this makes sense. Humans and other animals have adapted to defend their body weight rather than lose it, as food scarcity was historically a common challenge,” said one of the study’s authors, Dr. Laura Hinte.