The level of fat in our bodies is influenced by the month of conception, according to scientists.

The most extensive research on this topic has revealed that individuals conceived during the colder months store fat differently than those conceived in warmer months.

A team of scientists from the University of Tokyo, led by biomedical researcher Takeshi Yoneshiro, involved 356 healthy young male volunteers in their study. The researchers found that those conceived during the cold season exhibited higher activity levels of brown adipose tissue.

Brown adipose tissue is a type of fat that burns energy, retains heat, and helps regulate blood sugar levels.

Alongside the increased activity of brown fat, these participants also showed greater energy expenditure, a lower body mass index (BMI), and less fat accumulation around internal organs. All of this indicates good metabolic health, as reported by Science Alert.

It’s important to note that individuals with excess weight or obesity often show a lack of brown fat activity.

What Else Did the Scientists Discover?

To broaden the results to a larger population, the team examined a second cohort of 286 adult men and women. Ultimately, the researchers found “modest but significant links” between conception during the cold season and brown fat activity, as well as reductions in BMI, visceral fat area, and waist circumference.

The researchers believe that increased activity of brown adipose tissue (BAT) drives other metabolic processes.

The study results indicated that cold weather might influence the genetic expression of male sperm or female eggs, and these changes could be passed on to offspring during the meeting and fertilization of the two gametes.

According to the authors, this could represent a “complex adaptive response to cold” that is transmitted from generation to generation, providing descendants with a better chance of survival in cold climates.

The findings confirmed previous observations by other scientists who stated that the season in which a person is born can impact their health later in life.

The study results were published in the journal Nature Metabolism.