Why people gain weight as they get older

We’ve all heard of how hard it is to lose weight or to keep in shape as we get older, and many people have thought of this as an excuse…but science is now revealing why people have said this for so many years.

New research at Karolinska Institutet in Sweden has identified why people gain weight as they get older. Apparently, the lipid turnover in the fat tissue decreases during ageing and makes it easier to gain weight, even if we don’t eat more or exercise less than before. The study is published in the journal Nature Medicine.

After studying the fat cells in 54 men and women over 13 years, all subjects showed decreases in lipid turnover in the fat tissue, that is the rate at which fat in the fat cells is removed and stored, and the subject that didn’t compensate for that by eating less calories gained weight by an average of 20 percent.

“The results indicate for the first time that processes in our fat tissue regulate changes in body weight during ageing in a way that is independent of other factors,” says Peter Arner, professor at the Department of Medicine in Huddinge at Karolinska Institutet and one of the study’s main authors. “This could open up new ways to treat obesity.”

But there is hope because other research has shown that one way to speed up the lipid turnover in the fat tissue is to exercise more.

“Obesity and obesity-related diseases have become a global problem,” says Kirsty Spalding, senior researcher at the Department of Cell and Molecular Biology at Karolinska Institutet and another of the study’s main authors. “Understanding lipid dynamics and what regulates the size of the fat mass in humans has never been more relevant.”

Journal Reference for ‘Why people gain weight as they get older’:

1. P. Arner, S. Bernard, L. Appelsved, K.-Y. Fu, D. P. Andersson, M. Salehpour, A. Thorell, M. Rydén, K. L. Spalding. Adipose lipid turnover and long-term changes in body weight. Nature Medicine, 2019; 25 (9): 1385 DOI: 10.1038/s41591-019-0565-5