A major 2025 review titled 'Sex and Gender Differences in Obesity' highlights that men and women store fat differently due to both hormones and genetics. Men are more likely to accumulate visceral fat, the kind that surrounds internal organs, while women typically store subcutaneous fat around the hips and thighs. This distinction isn't just visual; it has serious health implications.

According to a meta-analysis published in Nutrition Reviews (2025), visceral fat is more metabolically active and strongly linked to conditions like type 2 diabetes and heart disease. This helps explain why men often face metabolic complications earlier, even at similar body weights.

Why It Happens


Hormones are a key driver behind these differences. The 2025 review notes that estrogen encourages fat storage in the lower body and supports healthier fat distribution in women. In contrast, testosterone in men promotes lean muscle mass and a higher resting metabolic rate. However, this balance can shift over time. For instance, after menopause, declining estrogen levels can lead women to store more abdominal fat, bringing their risk profile closer to men.


Earlier foundational research, such as 'Sex Differences in Adipose Tissue Function,' further supports this idea, showing that fat tissue behaves differently at a biological level in men and women. Men's visceral fat tends to be more inflammatory and metabolically active, increasing disease risk. When it comes to weight loss, differences show up here too. Studies, including clinical trials reviewed in obesity research, suggest that men often lose weight faster, especially in the initial stages of dieting. This is largely because they have more lean muscle mass, which burns more calories at rest.

What About Outcomes?


But faster weight loss doesn't necessarily mean better outcomes. Women may experience more gradual changes, but improvements in markers like insulin sensitivity and cholesterol can be just as significant over time. Health risks tied to obesity also vary. Research on visceral fat and metabolic disease indicates that while both sexes are affected, men are generally at higher risk for cardiovascular disease earlier in life. Women, on the other hand, may face increased risks related to hormonal shifts, certain cancers, and mental health impacts linked to obesity.


All of this is pushing experts toward a more tailored approach. The 2025 review emphasises that obesity treatment may need to move beyond a one-size-fits-all model. Diet, exercise, and even medical interventions could be more effective if they account for sex-specific biology. The takeaway is simple: obesity isn't a uniform condition. As research continues to evolve, it's becoming clear that understanding these biological differences isn't just academic, it could be key to better, more personalised health outcomes.