Weather changes cause fat to shift within the body, thereby altering body shape at certain times of the year.
Researchers indicate that the fluctuation in testosterone levels has driven changes in body shape. This hormone, associated with muscle mass and aggression, varies seasonally in both men and women.
The most noticeable changes occur around the hips and waist. When testosterone levels rise, women tend to have less defined waists as fat shifts to the waist area. Conversely, men retain more fat around the abdomen when testosterone levels drop.
Scientists examined seasonal testosterone variations in saliva from 220 women and 127 men. They also measured the waist and hip circumferences of women throughout the seasons.
“We found that testosterone levels in both genders peak in the fall“, said Sari van Anders from Simon Fraser University in Canada, the lead researcher. “At the same time, the difference in waist and hip measurements for women is lowest in the fall, and fat accumulation in areas (such as abdominal fat) is also higher in the fall among women“.
Women also show high testosterone levels in summer, while men have their lowest hormone levels in spring.
The study demonstrates that women will have the most defined waists in winter and spring, while men will appear more masculine in spring.
The reasons behind these changes in body shape remain unclear to scientists. Van Anders suggests that these changes may simply be a byproduct of seasonal testosterone fluctuations, influenced by factors such as health, immune function, reproduction, and behavior.
M.T.
