The journal Obesity, found the instigator of menopausal women’s belly fat. You guessed it, testosterone.

Hormonal shifts were the underlying causal factors, per Rush University Medical Center’s researchers.

According to Imke Janssen, PhD, the study’s lead investigator, many factors were reviewed to find why there was a visceral fat increase in women. Result? Testosterone proved to be the clear winner.

More than added pounds. Visceral fat surrounds internal organs and, unlike subcutaneous fat located beneath the skin, it inflames the body, causing premature atherosclerosis and acute coronary syndrome.

A look at the study and findings.

• Approximately 360 women, ages 42- 60 in menopausal transition
• The racial split was about 50/50 black and caucasian
• Blood tests given/analyzed to determine testosterone and estradiol levels
• CT scans performed to measure the fat located in the abdominal cavity

Using statistical analysis, researches found that the amount of testosterone active in the body was the strongest predictor of visceral fat. Interestingly, neither age, race nor estradiol levels impacted the visceral fat amount.

Prior research findings. In 2008, Janssen also had a study published in the Archives of Internal Medicine that linked testosterone with metabolic syndrome, which happens during the menopausal transition.

The study looked at women over a 12-year span—six years before and after their final menstrual period. Janssen found the rise in the risk for heart disease correlated with the increase in testosterone activity.

While conventional thinking was that estrogen protected premenopausal women from an increase in heart disease, Janssen’s study showed otherwise.

Increased active testosterone leads to visceral fat, which in turn increases the risk of cardiovascular disease.