One of the universal struggles many patients face, especially as they age, is how to keep extra weight off and understanding why it’s easier to gain weight than lose it. Recent studies may shed new light on these concerns.
One recent study—from from the Karolinska Institutet at Uppsala University in Sweden and the the University of Lyon in France—suggest that the tendency to gain/maintain weight more easily as we age may be due to a decrease in our lipid turnover rate within fat tissue. The term “lipid” is often used synonymously with the word “fat,” but “lipids” are really a broader category for many other fatty acids such as carbs, proteins, vitamins, hormones, and minerals.
In terms of how lipids affect our weight, it all depends on the rate at which they’re stored or removed from our bodies—the slower our turnover rate, the longer these lipids remain in our bodies and then convert to fat cells.
In the study, 54 men and women were monitored for 13 years, and all displayed a decrease in their lipid turnover rate, regardless of whether they gained, lost, or maintained their weight during that time. The subjects who tried to eat fewer calories to make up for this decreased rate, ended up gaining an average of 20% more weight despite their efforts.
The researches also examined 41 women who had bariatric surgery to understand how their lipid turnover rate would help them maintain their weight loss post-surgery for up to 4 to 7 years. The researchers found that only two of these women, who had a higher than average lipid turnover rate pre-surgery, saw an increase in their turnover rate after surgery and were able to maintain their weight loss. The researchers ultimately felt that those individuals may have had more room to increase their turnover weight post-surgery due to their higher-than-average level prior.
Kristy Spalding, a senior researcher in the department of cell and molecular biology at Karolinska Insitutet, stated: “Obesity and obesity-related disease have become a global problem,” and one of the lead authors of the study has also said: “Understanding lipid dynamics and what regulates the size of the fat mass in humans has never been more relevant.” Both statements highlight the need for more research in this area.
What this may mean is that weight loss requires more than recommending that patients cut calories. Increased physical activity may be a big factor, especially as patients get older.
“Adipose lipid turnover and long term changes in body weight,” Peter Arner, Samuel Bernard, Lena Appelsved, Keng-Yeh Fu, Daniel Andersson, Mehran Salehpour, Anders Thorell, Mikael Rydén, Kirsty Spalding, Nature Medicine, September 9, 2019, doi: 10.1038/s41591-019-0565-5