It is an unexpected effect of the sun’s rays. And even more so, because of its selective consequences. The sun stimulates hunger in men, not in women. This is because it stimulates the so-called “hunger hormone”. This is reported by scientists at Tel Aviv University.
“Sun exposure causes increased energy intake and metabolic profile in men. There is a difference compared to women.” So concludes a study published in the scientific journal Nature Metabolism.
Several nutritional studies on the influence of dietary intake according to the seasons of the year were reviewed. The work was done over three years on about 3000 individuals. How does caloric intake increase? It increases by about 300 calories per day in the summer, while in women it does not.
During the experiment the scientists asked men and women to go out in the sun wearing sleeveless shirts and shorts. What was the hypothesis held by the researchers? That the effect of the sun’s rays is relative to the amount of skin exposed.
They discovered what sun exposure causes in men. It releases the hormone ghrelin in the blood of men. However, this is not so in women. This hormone is known as the “hunger hormone”. The sun stimulates hunger in men, actually.
Also in mice
The same process was detected in mice. Males produced more ghrelin and ate more after being exposed to UVB rays. Females did not.
The differences may have to do with how testosterone and estrogen interact with UVB rays. These are harmful to the skin. However, they also added that avoiding the sun is not healthy. Ghrelin is anti-inflammatory.
Moderate sun exposure reduces cardiovascular disease. The study indicates that ghrelin may play a role in this. However, it also adds that further study of the phenomenon is needed.