We already know that body fat accumulates differently in men and women. For men, it’s mostly in the belly region and for women, it’s the thigh and hips region. There are many studies being done on male and female rodents, which have mechanisms similar to humans.
The primary focus of these studies is to see if body fat has different effects on health depending on gender. One such study led by Djurdjica Coss, an associate professor of biomedical sciences in the UCR School of Medicine sees how body fat can have an impact on health depending on your gender. The study has some interesting findings.
Methodology and results
Previous studies have tried to explain why women tend to be leaner when young but get fatter as they get older. The estrogen in females in premenopausal phases acts as a protective barrier against fat accumulation. This explanation led to a highly popular opinion that the ovaries (the source of a form of estrogen) are highly important in keeping women lean.
Therefore, Coss decided to test this claim by removing the ovaries from the female rodents. The male and now ovariectomized female rodents were given similar high-fat diets and the results were compared. The results were interesting as Coss summarized by saying: “We found that the mice proceed to gain weight when fed a high-fat diet, suggesting that ovarian hormones are indeed protective against weight gain.”
Indeed, the results seem to point to the same conclusion as previous studies had come to. However, there’s a twist. Coss explained that it seems there are other factors at play apart from the ovaries that help in keeping the weight off. Coss explains:
“But we found, too, that these female mice exhibit neither neuroinflammation, nor changes in reproductive hormones, suggesting that they are protected by factors other than ovarian estrogen. This is a novel finding.”
Although the study was done on male and female rodents, it is still significant for humans. Coss explains that mice also develop insulin insensitivity and type 2 diabetes with high body fat levels, just like humans. Therefore, with fat having similar effects on mice, the results of the study are highly applicable to humans as well. Moreover, she also said:
“Obese men have lower testosterone levels, contributing to low libido, low energy, and reduced muscle strength,” explains Coss. “We see this in mice, too; obese male mice showed nearly 50 percent decreases in testosterone and sperm number.”
“Obese women have difficulty with their menstrual cycles,” she adds. “They don’t ovulate. Obese female mice show the same, contributing to decreased fertility.”
One major takeaway
As Coss had explained, there are other factors that work together with the ovaries to protect women from fat accumulation. Thus, women are more protected from being overweight, which is something that can be further looked into.
The results of the research back up the claims as the male subjects had higher levels of visceral fat. Men usually have an “apple-shaped” body due to the fat accumulating in the belly. However, females have more fat deposits around the hips which lead to a “pear-shaped” body. The study helps in explaining why this may be the case as the belly is able to store much larger fat reserves, which is why males tend to have higher visceral fat.
Visceral fat is highly dangerous as this type of fat is the one that can affect your internal organs. It also recruits immune cells from blood circulation, so overall it’s not good for the body to have high levels of visceral fat. The big takeaway from this research was also the fact that it opened up more ideas for future research.
The non-ovarian reasons for obesity protection in women can be investigated in future studies, and it wouldn’t have been possible without the study led by Djurdjica Coss.