Original title: basking in the sun or making people "eat all but fat"

Science and Technology Daily, Beijing, May 23 (Reporter Zhang Jiaxin) According to a new study published in the Journal of Investigative Dermatology on the 22nd, researchers at Seoul University Hospital in South Korea found that sun exposure may have the advantage of "eating without being fat". Their research shows that UV exposure can increase appetite and prevent weight gain. These findings may bring new hope for the prevention and treatment of obesity and metabolic disorders.

The sun contains ultraviolet rays, which can bring harmful effects such as sunburn, photoaging and skin cancer, but it is also related to the synthesis of vitamin D.

Previously, the team found that ultraviolet radiation on the skin will not directly reach the subcutaneous fat, but can regulate the metabolism of subcutaneous fat. The latest research shows that ultraviolet radiation limits the weight gain of obese mice.

Leptin is a natural anorexic agent secreted by adipose tissue. The researchers found that when continuously exposed to ultraviolet radiation, mice fed normal diet and high-fat diet showed reduced leptin and increased appetite, but their weight did not increase.

They found that UV exposure increased norepinephrine levels, reduced leptin levels, and induced subcutaneous fat browning, thereby increasing energy consumption. As appetite increases and energy intake increases, these energy will be converted into heat and burned before being stored in subcutaneous fat, thus preventing weight gain.