Many people struggle to keep their weight under control as they grow older. Now, new research at the Karolinska Institutet in Sweden has revealed why it is: The lipid cycle in adipose tissue decreases during aging and facilitates weight gain, even if we do not eat more or exercise less than before. The study is published in the journal Nature Medicine.
The scientists studied adipose cells in 54 men and women on average 13 years. During this time, all individuals, regardless of whether they gained or lost weight, experienced a decrease in lipid volume in adipose tissue, i.e., the rate at which lipids (or fat) in adipocytes were removed and stored. Those who did not compensate, consuming less calories, gained an average of 20% by weight, according to a study conducted in collaboration with researchers at Uppsala University in Sweden and the University of Lyon in France.
The researchers also examined lipid volume in 41 women undergoing surgery and how the rate of change in lipids affected their ability to maintain their weight four to seven years after surgery. The result showed that only those who had a low rate of pre-surgery managed to increase their lipid cycle and maintain their weight loss. The researchers believe that these people may have had more room to increase their lipid cycle than those who had already had high-level surgery.
"The results show for the first time that processes in our adipose tissue regulate changes in body weight during aging independently of other factors," says Peter Arner, professor of medicine at Huddinge at Karolinska Institutet and one of the main authors of the study. "This could open up new ways to treat obesity."
Previous studies have shown that one way to accelerate the cycle of lipids in adipose tissue is to exercise more. This new research supports this concept and further shows that the long-term outcome of weight loss surgery would be improved if combined with increased physical activity.
"Obesity-related diseases and obesity have become a global problem," says Kirsty Spalding, senior researcher at the Department of Cell and Molecular Biology at Karolinska Institutet and one of the study's lead authors. "Understanding the dynamics of lipids and regulating the size of fat in humans has never been more relevant."
Materials provided by Karolinska Institutes. Note: Content can be edited for style and length.