A study published in the journal ‘Nature Metabolism’ showed that sunlight triggers a unique appetite-boosting hormone in men. A team of researchers from the Department of Human Genetics and Biochemistry, Sackler Faculty of Medicine at Tel Aviv University found that environmental cues, such as solar ultraviolet (UV) exposure triggered the hormonal changes.

The researchers found that exposure to solar rays had a more complex effect on male physiology and claimed that solar exposure induces food-seeking behavior, food intake, or both in men, but not in women. The team added that sex differences have a profound effect on health and behavior. The animal study conducted using a mice model showed that exposure to ultraviolet light led to increased food-seeking behavior, food intake, and weight gain, with a sexual dimorphism towards males. The team found that in both mice and human males, increased appetite was correlated with elevated levels of circulating ghrelin.

For the study, the researchers analyzed data from 3,000 participants as part of a national nutrition survey over three years and found that it was only men who increased their food intake during the summers and consumed an extra 300 calories every day. The urge to consume more food was caused by the increased levels of ghrelin. They explained that ghrelin was more likely to be released in the body due to DNA damage in skin cells from over-exposure to sunlight. 

(Source: https://www.indiatoday.in/science/story/sunlight-triggers-unique-hormone-that-makes-men-hungrier-study-finds-1978201-2022-07-21 )