A new study from researchers at Sweden’s Karolinska Institutet has revealed that women process stored fat more efficiently than men through a mechanism called lipolysis. This discovery may offer a biological explanation for why women are generally less prone to developing metabolic complications such as type 2 diabetes, despite carrying a higher percentage of body fat.

Lipolysis is the metabolic process through which triglycerides—fats stored in the body’s adipose tissue—are broken down into glycerol and free fatty acids, which serve as vital sources of energy during fasting or physical activity. According to Professor Peter Arner, one of the lead researchers, efficient lipolysis plays a key role in maintaining energy balance and preventing metabolic disorders related to overweight and obesity.

The research specifically examined how lipolysis is activated by catecholamines—hormones that surge during stress or exercise. While women’s fat cells were found to be less sensitive to these hormones, once lipolysis was initiated, it occurred more rapidly in women’s cells than in men’s. This paradoxical response could be a crucial factor in their lower susceptibility to metabolic diseases.

To conduct the study, Arner and Dr. Daniel P. Andersson of the Karolinska University Hospital Huddinge collected abdominal subcutaneous fat cells from adult men and women. These cells were then exposed to various levels of catecholamines to assess how much glycerol—a marker of fat breakdown—was released. The results showed that although women’s cells required higher hormone levels to kick-start lipolysis, they ultimately outperformed men’s cells once the process was activated.

“These findings provide a deeper understanding of sex-based differences in fat metabolism,” said Arner. “In the long term, they could help inform the development of new treatments to reduce the risk of type 2 diabetes in men with obesity.”

The researchers believe this insight could eventually lead to targeted therapies aimed at improving metabolic health outcomes based on biological sex differences.