Fat cells can ‘remember’ being overweight and make it harder to shed pounds

Weight-loss drugs have taken the world by storm, but recent studies have shown that even these miracle-workers have one fatal flaw: people often rebound to their original weight after taking them.

This includes people like Artemis Bayandor, 41, an Illinois-based flight attendant, who used Ozempic to shed 15 pounds. After ceasing the drug because of cost concerns, Bayanador gained the weight back, plus an additional 16 pounds. 

According to a new study, if you’re like Bayanador, and the numbers on your scale keep creeping back up after you lose weight, you may have biology to blame. 

Researchers from Switzerland found fat cells in the body have a ‘memory,’ one that tells them to keep growing, even after losing weight. 

The team used fat cells from people with obesity and people at a healthy weight to see if there were differences in their genes that could be controlling their weight gain.

They found people who were obese had permanent changes to their DNA that affected how their cells use and store energy, even after they lost weight. 

These genes made their metabolism less active, which makes it harder to process food without gaining weight. 

This could explain why some people struggle to keep weight off after going on a diet, the lead author of the study, professor Ferdinand Von Meyenn from ETH Zurich, said.  

Artemis Bayandor, 41, from Illinois, says she is now about 20lbs heavier than before she used Wegovy. She shed 15lbs while on the drug for six months, but quickly gained back all the weight and extra

Studies from Stanford suggest between 80 and 85 percent of people struggle to keep weight off after losing a significant amount

Prof Von Meyenn told Bloomberg: ‘This is not just a lack of willingness or a lack of willpower, there’s really a molecular mechanism which fights against this weight loss.’

Between 80 and 85 percent of people who lose a significant amount of weight later regain it, according to Stanford Medicine. Sometimes, this is because people return to old habits, but other times, the pounds pile back on, seemingly without cause.

This mystery is what motivated the Swiss researchers to look at genes, and their results were published in the journal Nature. 

Genes are the instructions that dictate every part of our biology, but they can be influenced by small chemical changes called epigenetic changes. 

Epigenetics is how behaviors and environment can cause changes to DNA. These changes are reversible, unlike genetic changes, which permanently alter DNA. 

They can be caused by things like exposure to air pollution, dietary choices in childhood, substance use and even trauma at a young age, according to Cleveland Clinic. 

Research has shown these epigenetic changes are linked to cancer, substance use disorders, dementia and aging. 

Prof Von Meyenn and his colleagues wanted to look at the epigenetics of people with weight fluctuations and see if it differed from those who sat at a consistent, lean weight. 

They took samples of fat tissue from 10 lean people and 13 people with obesity. 

They also took samples from mice that were overweight and compared it with samples from mice that were a healthy weight.  

They then studied the fat tissue from the people who had struggled with their weight and found they had consistent epigenetic changes to the parts of their genes which control energy. 

These changes suppressed metabolism, making it harder to keep weight off. 

This suggests that even after they lose weight, these cells ‘remember’ their older state, and are likely to spring back into their previous patterns. 

Prof Von Meyeenn told Bloomberg explained that this may happen because the cells got used to the patterns of processing food and storing fat that were necessary in an obese body. 

An older UK study found people who used Wegovy experienced rapid weight loss, dropping 18 percent of their weight over 68 weeks. They regained two-thirds of that weight, or 12 percent of their original body weight in the year after dropping the weekly injections

Just because someone loses weight, it doesn’t automatically mean those cells, which were programmed by their environment to act one way, will change, he said. 

So, if you’re able to avoid becoming obese in the first place, then your cells won’t be trained to return to that state, he suggested.  

Prof Von Meyeen said, ‘If you never have been obese, you will never be exposed to that memory and never have this problem of regaining weight.’

A recent study found the power of these epigenetic pulls to gain weight can outlast even the dramatic changes associated with using drugs that control appetite, like Ozempic or Wegovy. 

These drugs, known scientifically as GLP-1 receptor agonists, mimic signals in the body that tell your brain when you feel full and control the pace that food moves through your gastrointestinal tract. 

Researchers from  Northwestern University found that the majority of patients who had been taking one of these drugs to lose weight regained two-thirds of the weight they had lost. 

This is concerning given how many people that begin taking the drug opt to go off of it, the scientists said. 

Around 85 percent of people who take these kinds of medications stop using them within two years. In order to overcome the yo-yo, then, doctors suggest that a GLP-1 user needs to stay on the medication for life.