The sun can affect summer hunger. Researchers have discovered that radiation leads to an increase in food intake – but only in men. The reason is hormones.
Should I empty the ice bag again? Or is it still not plump when grilling even after the fourth steak? You probably can’t do anything about it. It is well known that hormones have a great effect on the body. The same is true when it comes to summer food. Thanks to an experiment conducted on mice, a team of researchers accidentally discovered that men who spend a lot of time in the sun feel more hungry and therefore eat more.1 On the other hand, it “prevents” women from taking more of another hormone. This is behind her.
The sun feeds hunger in men
Research has already shown that sunlight stimulates vitamin D production, but it may also cause skin damage and increase the risk of skin cancer. A Spanish team of researchers, working with several institutions in Israel, with colleagues from Columbia University in the US and the Institute for Diabetes and Obesity in Germany, has found that sunlight can do something else: it makes men hungry. Originally, the researchers wanted to investigate how sunlight caused skin cancer in mice. However, they noticed that male mice seemed to feel hungry when exposed to ultraviolet light.
Also interesting: the dangerous game with fitness hormones
Data from 3000 people
As part of this, the research team examined data from a three-year Israeli health survey of 3,000 people throughout the year and found that men are significantly affected by solar radiation and its seasonal changes. The result is a 15% increase in energy consumption in the summer months. The scientists also found that daily UV-B exposure also increased food intake in male rats but not in female rats.
Also interesting: Do you feel hungrier when you exercise?
The sun activates the hormone in men
In order to clarify the question of why women’s eating habits haven’t changed, researchers closely examined the hunger hormone ghrelin. Ghrelin is produced by cells in the stomach, pancreas, small intestine, or brain and can activate neurons in the hypothalamus, which then respond by producing feelings of hunger. Ghrelin levels rise during periods of hunger and just before a meal. Tests on mice showed that levels of ghrelin were increased in male mice exposed to ultraviolet radiation. UV-B rays are more active than UV-A, but only penetrate the skin – UV-A rays penetrate the deeper layers of the skin. This hormone was also detected in the skin samples of men who were exposed to ultraviolet light in the laboratory.
Also interesting: What should I look for when it comes to UVA and UVB protection in sunscreen?
Estrogen suppresses the hunger hormone
Sunlight, or UV-B rays more precisely, causes the level of ghrelin to rise in the blood of men, and thus has an appetite-stimulating effect. However, estrogen prevents the level of ghrelin from rising. As a result, women who spend a lot of time in the sun do not feel as hungry as men. However, this does not automatically mean that men or male rats also gain weight. Specifically, the monthly data revealed that in addition to calories, energy expenditure was also higher in summer (March to September) than in winter (October to February). On the other hand, women’s energy intake remained stable.
Also interesting: anger due to hunger – researchers give an explanation for the phenomenon of “hunger”
The results show not only how differently women and men react to environmental stimuli, but also how gender depends on the reaction to ultraviolet radiation from the sun. The researchers explained that the absorption of sunlight through the skin has an important effect on energy balance, and the results of this study could lead to future treatment options for endocrine diseases.