Why might obesity affect men and women differently? Scientists looked inside fat tissues

You must have come across a lot of people who have the same weight but still look a lot different. One of them may look more obese than the other. It is because two people can weigh the same and carry different amounts of fat around their organs. People with different lifestyle, diet and genetics have different ways to cope with their fat.

If you are measuring your weight in a bathroom scale, then it will only give you the body mass but you won’t find out where you body exactly stores fat. You need to understand the body mass index to know how your body stores fat and how it uses it. Researchers at the University of California, Riverside, wanted to understand the second part. To exactly analyse it, scientists examined immune cells in mouse fat and found that the same type of white blood cell showed different patterns of activity in males and females, according to a report by Newsweek.



The cells they researched are known as eosinophils. These cells have a huge role to play when body catches allergies and also when a body gets prone to any parasitic worms. The study, published in the November issue of PNAS Nexus, suggests they could also help explain why fat tissue becomes more inflamed under some conditions.

How did eosinophils differ in male and female mice?

The team looked at which genes were active in individual eosinophils. Six distinct groups emerged. Some had patterns linked to keeping fat tissue stable. Others had patterns linked to inflammation. Female mice had a greater share of the first kind. The groups linked to inflammation were more prominent in males.

UC Riverside reported that those inflammatory groups tended to become more common in male mice fed a high-fat diet. For study co-author Meera Nair and her colleagues, the difference helps explain why a simple cell count tells only part of the story. Two samples can contain the same kind of white blood cell, yet the cells may be doing different jobs.

The team also found clues about how eosinophils might communicate with macrophages, another kind of immune cell found in fat. Gene activity helped the researchers predict some of those exchanges. The study didn’t establish what each signal does.

What could the findings mean for obesity in men and obesity in women?

If we take a look at how human store the fat then there is a difference between genders. According to the studies based on humans, most men tend to carry more fat deep in the tissues in the abdomen. Howeverm women do not target abdomen first, their bodies choose skin tissue around hips and thighs to store fat. The pattern can shift around menopause. Fat which is stored deep into the tissues of the abdomen which mostly surrounds the internal organs is also called as visceral fat. Higher levels are linked to a greater risk of heart disease and type 2 diabetes.


The mouse study raises a separate question: do immune cells in human fat respond differently, too? Researchers would need to identify comparable groups in people. They would then need to find out whether those cells contribute to inflammation or change in response to it. The study didn’t show that eosinophils explain where people store fat. It also didn’t test whether changing these cells would help treat obesity.

FAQs

What is visceral fat?

It’s fat stored deep in the abdomen, around internal organs. It differs from the fat you can pinch beneath the skin.

Is obesity more common in women than in men?

It depends on the population. A U.S. national survey from August 2021 to August 2023 found no significant difference in overall adult obesity prevalence between men and women.