Forget crash diets, weight loss pills and exercise fads — the key to weight loss could already be in our bodies, UC Berkeley researchers found.
The study, which was published in the journal Cell Metabolism on March 6, found that brown fat cells — once activated — can lead to muscle-like contractions and improved health.
UC Berkeley researcher and study co-author Kevin Tharp said in an email that re-energizing these cells will enhance the body’s consumption of glucose and fatty acids, ultimately reversing the effects of obesity.
“Activation of brown fat is an attractive new strategy for weight loss, as calories from our diet are converted into heat and thus burned away,” Andreas Stahl, study co-author and campus nutritional sciences and toxicology professor, said in an email.
Tharp said in an email that the team discovered that muscle-like contractions are required for brown fat to reach its maximal metabolic rate. Stahl added that signals from cold temperatures trigger a function within brown fat cells that are similar to the ones that cause contractions in muscles. These contractions are crucial for uncoupled respiration, the “hallmark of brown fat activity,” Stahl said in an email.
By discovering the similar functions between brown fat cells and muscles, the team was able to use drugs to “supercharge” the metabolic activity found in brown fat cells to increase the strength of muscle-like contractions.
According to Tharp, brown fat cells found in babies become dormant as children age because humans develop other “behavioral interventions,” such as shivering, for retaining warmth. As a result, all adults have varying levels of brown fat that have the potential to aid weight loss.
Individuals who were born and raised in colder climates tend to have a higher number of brown fat cells in their bodies as opposed to those who live in mild climates, according to Tharp. He added that people from Scandinavian countries tend to have higher levels of brown fat.
“These studies have not been reproduced in American populations, but the correlation between low BMI and high levels of brown fat is consistent,” Tharp said.
The team’s prior research, which focused on bioengineering brown fat cell tissue, served as the building blocks for this study. Tharp recalled how the team engineered synthetic brown fat implants, which helped define the mechanisms of brown fat. These implants resulted in weight loss in mice, but Tharp said there is more work to be done in order to increase weight loss in humans.
According to Stahl, the study was a multidisciplinary research effort, drawing experts from several departments across campus and showcasing UC Berkeley’s “fertile collaborative environment.” Tharp encouraged people who found the study interesting to help fund science and to support researchers and their work.
“We hope to find new treatment options for obesity-related disorders such as type-(2) diabetes and fatty liver disease, which affect millions of people worldwide,” Stahl said in an email.