The Skinny on Fat: Can Exposure to Cold Convert White Fat to Brown Fat?
For most of us, body fat has a bad reputation.
From the dimply cellulite that plagues women’s thighs to the beer bellies that can pop out in middle-age men, fat typically is something that we agonize over and try to exercise away. But for scientists, fat is fascinating.
A lot depends on the type of fat and the color of fat that is present in your body. Dr. Shehla Ebrahim and our experienced family physicians, explain how different types of fat, and the hormones they produce, can have a dramatic effect on weight loss.
“Brown fat. Brown fat has received a lot of buzz lately as it is a more efficient burner of calories.
- Studies have shown that lean people have more brown fat than overweight or obese people, and that when stimulated brown fat can burn calories.
- Scientists are currently investigating it as a potential obesity treatment if they can figure out a way to increase a person’s brown fat.
- Studies have also shown that brown fat is more active in people in Boston in colder months, and a more recent study has suggested that a moderate amount of exercise and the body’s natural reaction to cold—shivering—appear to be equivalently efficient at encouraging the transformation of white fat, which stores energy, into the dark brown fat, which gets processed as energy more readily.
- When we feel cold, brown fat is the first of our stored energy to activate and is used to keep us warm. In the event this activation alone is not enough, we begin contracting our muscles—shivering—in order to generate more warmth
Dr. Paul Lee, an endocrinologist from Garvin’s Institute of medical research, wanted to study the effects of shivering as compared with exercise by measuring the rise in a specific hormone called Irisin, which is produced by muscle, and the hormone FGF 21, which is produced by brown fat.
- In his study, he showed that after 10-15 minutes of exposure to cold both hormones were elevated to the same degree as they would after an hour of moderate activity.
- Dr. Lee also showed that in humans these hormones can aid in transforming white fat cells into brown fat cells in as little as six days.
If you have additional questions about white and brown fat and weight loss, or if you would like to schedule a complimentary consultation with our physicians, please contact us today.