It may be that the sun doesn’t just give you vitamin D, but also helps slow weight gain and control metabolism. A recent study, published in the journal Diabetes, suggests that a compound secreted by your skin after exposure to sunlight, called nitric oxide, may curb weight gain.

Scientists in Edinburgh and Southampton, led by colleagues at the Telethon Kids Institute in Perth, Western Australia, found that exposing overfed mice to UV rays stifled their potential for obesity. Rubbing a cream containing nitric oxide onto their skin had the same effect. Additionally, these mice showed fewer warning signs of diabetes, such as abnormal glucose levels and resistance to insulin. Dr Martin Feelisch of Southampton University said in a press release that “These observations indicate that the amounts of nitric oxide released from the skin may have beneficial effects not only on heart and blood vessels but also on the way our body regulates metabolism.”

More research needs to be done to see if the release of nitric oxide has the same effect on weight gain in humans as in mice, but the study’s authors remain optimistic that the findings will prove beneficial, especially to children. Dr. Shelley Gorman of the Telethon Kids Institute, lead author of the study, said, "Our findings are important as they suggest that casual skin exposure to sunlight, together with plenty of exercise and a healthy diet, may help prevent the development of obesity in children."

According to the American Diabetes Association, 29 million Americans have type 2 diabetes, while 86 million more are at risk, many of them children. A major risk factor that contributes to the development of this disease is obesity. With moderate sun exposure, people may have the benefits not only of hampered weight gain, but of lowered blood pressure and more vitamin D, which studies have proven come from sun rays. Therefore, actual sunlight may be better than rubbing a cream of nitric oxide on your skin.

While skin cancer should still be recognized as a serious concern, some suggest that the benefits of sun exposure outweigh the risks. Reportedly, 9,700 Americans die from melanoma each year, whereas diabetes causes or contributes to the deaths of 234,051 Americans annually. Dr. Richard Weller, senior lecturer in dermatology at the University of Edinburgh, elaborates, “We know sun-seekers live longer than those who spend their lives in the shade. Studies such as this are helping us to understand how the sun can be good for us. We need to remember that skin cancer is not the only disease that can kill us and should perhaps balance our advice on sun exposure.”

Of course, people should still wear sunscreen and be moderate in their sunray intake.

Sun exposure has also been suggested to make people happier. Therefore, with these benefits in mind, Americans should go on more family outings in the sun and shake off the growing traditional lifestyle of TV, video games, and other reclusive activities to help curb obesity and the potential onset of type 2 diabetes.

To learn more about diabetes and sunlight:

Vitamin D: A Drop of Golden Sun
Sustain Your Energy, Stave Off Fatigue
What Vitamins Do Diabetics Need?