By Farid Farid in Sydney

Hitting the treadmill or going for a run on a chilly winter’s day is a race against genetic fate as much as it is about putting in the hard yards.

A study by Japanese researchers published on Tuesday in the latest issue of the peer-reviewed journal Nature Metabolism found that adults conceived during cold seasons exhibited a lower body mass index and lower visceral fat accumulation.

Visceral fat accumulation refers to the build-up of fat deep in the abdomen around organs – begrudgingly known as putting on weight.

The significant health hindrance is linked to increased risk of serious conditions such as heart disease and diabetes.

Naturally, the cure for it is a healthy diet and plenty of exercise to help shed those kilos.

The paper’s authors examined 683 healthy males and females in Japan, aged from three to 78, whose parents were exposed to cold temperatures in the northern hemisphere from mid-October to mid-April during the fertilisation and birth periods.

Those conceived in warmer weather were at greater risk of obesity, with only 66 per cent of the male cohort able to burn fat quicker compared to their winter counterparts, the researchers found.

“Meteorological analysis revealed that lower outdoor temperatures and greater fluctuations in daily temperatures during the fertilisation period are key determinants of brown adipose tissue (BAT) activity,” they said in their 32-page paper.

Brown adipose tissue (BAT), also known as brown fat, is a type of body fat that regulates a person’s body temperature in cold conditions, burning calories and storing energy.

The findings show that “metabolic fate and susceptibility of metabolic diseases” are pre-programmed by the genetic inheritance of cold exposure before fertilisation.

Although eating habits and exercise were key indicators of weight loss, the researchers said exposure to cold and warmth also played a part in understanding human physiology and genetic make-up.