Brown fat and obesity in humans

Humans have the most brown fat when they are babiesTrusted Source, which helps them stay warm. The amount of brown fat in the body lowersTrusted Source as we age.

Adults typically have small amounts of brown fat in/around the shoulders, neck, spinal cord, kidneys, and heart.

This is not the first study to look at activating brown fat to help decrease weight and protect against obesity.

A study published in August 2019 found that activating brown fat helps to improve metabolismTrusted Source, providing potential targets for obesity and diabetes treatments.

A review of existing research, published in March 2019, reported both cold exposure and exerciseTrusted Source may help trigger brown fat in the body.

And a study published in October 2023 discovered the exact nerve pathwaysTrusted Source needed to “turn on” brown fat.

Can adults increase their brown fat levels?

If “switching on” brown fat helps to protect against obesity, can adults do anything to add more to their bodies?

Kornfeld said there is currently no consensus on that:

“In animal models, it is very clear that this decline in brown fat amount and activity can be delayed by pharmacological and environmental approaches — cold exposure [and] certain forms of drugs. As these drugs have strong side effects, many researchers are looking for more safe ways to bring back brown fat activity — e.g. in obesity and older age — or prevent its loss during the course of life.”

In an effort to increase brown fat levels in adults, current studies are looking at “browningTrusted Source” white fat through exerciseTrusted Source or the use of certain drugs, such as thiazolidinedionesTrusted Source and glucagon-like peptide-1 receptor agonists (GLP-1 agonistsTrusted Source).

“Unfortunately, brown fat is made when you’re a fetus and as you age, you can’t really develop more brown fat,” Mir Ali, MD, bariatric surgeon and medical director of MemorialCare Surgical Weight Loss Center at Orange Coast Medical Center in Fountain Valley, CA told MNT after reviewing this study. “It’s hard to grow specifically brown fat.”

“But what you can do is stimulate the brown fat cells that are still there to grow and work more,” Ali continued. “People still have stores of brown fat like their shoulders and behind the neck between their shoulder blades. So putting ice to that area or cold water baths and things can help stimulate brown fat.”

Ali said it would be great to see in humans if there’s a way to measure the amount of brown fat someone has and figure out ways to stimulate that brown fat.

“But the take-home point for most people [is that] all these things can be helpful, but if people still are not choosing or making the right food choices, then nothing is very successful,” he added. “You still have to eat the right things to lose weight.”