Waist Size Beats BMI in Predicting Men’s Cancer Risk | Image Source: pharmacydaily.com.au
STOCKHOLM, Sweden, 23 March 2025 – An innovative study at Lund University shakes decades of health assessment practices by revealing that the circumference of human size can provide a better indicator of cancer risk than the widely used body mass index (BMI). The research, which covers nearly 340,000 people for nearly 40 years, sheds new light on the link between abdominal fat and cancer development, particularly in men. Published in the Journal of the National Cancer Institute, the results of the study were also highlighted at the European Obesity Congress (ECO) 2025 in Malaga, Spain.
According to Dr. Ming Sun and his colleagues, who led the research, while BMI has long been considered a reliable marker of obesity and its health risks, it does not distinguish between types of fat and their distribution. Circumference in size (WC), on the other hand, seems to provide a more accurate reflection of visceral fat, the type of fat that involves internal organs and is more metabolically active, playing a more important role in inflammation, insulin resistance and other metabolic disturbances.
Why size counts more than BMI for men
In the study, male participants with a height increase of 11 cm had a higher risk of developing obesity-related cancers compared to a 19% increase associated with a corresponding BMI increase. It’s not just a numerical difference: it’s a change in how we could start measuring cancer risk by moving forward. According to the study, even when BMI was reported, the circumference of the size remained an important predictor of cancer, which means that abdominal fat itself plays a critical and independent role.
As the researchers explain, “BMI is a measure of body size but does not provide information on fat distribution, whereas the circumference of size is a more closely related substitute for abdominal adiposity.” This distinction is important. Unlike subcutaneous fat, which is just below the skin, visceral fat surrounds the organs and has been linked to worse results in everything, from diabetes to cardiovascular disease, and now cancer.
For men, the implications are even more direct. Visceral fat is more common in the distribution of male fat, while women tend to accumulate more subcutaneous fat. This physiological distinction may explain why toilets exceed BMI as a predictor in men, but not as convincing in women.
What are you doing? Does that mean for women?
The study did not find the same predictive power in women. In women, the circumference of size and BMI showed similar links to cancer risk, with a 12 cm increase in size or 4.3 kg/m2 of BMI associated with a higher risk of 13%. This parity suggests that WCs do not offer a significant additional predictive value for women relative to BMI only.
Why the Gender Gap? An explanation lies in the distribution of fat. According to the researchers, “a plausible explanation is that men are more likely to store visceral fat, while women generally accumulate more subcutaneous and peripheral fat.” Simply put, men are more prone to belly fat, while women store it more under the skin, and it is that belly fat is the most harmful when it comes to cancer risk.
The authors also suggest that future studies consider incorporating hip circumference into risk models, particularly for women. “The combination of hip size and circumference can give a better estimate of visceral fat than the circumference of the waist alone,” they said. This combined measure could better reflect body composition and health risks, particularly among women.
What cancers are related to obesity?
Obesity is not only about aesthetics or lifestyle, it is linked to some of the most deadly diseases that exist. As noted in this study, cancers considered related to obesity were evaluated by the International Centre for Cancer Research (IARC). These include:
- Esophageal adenocarcinoma
- Gastric cardia cancer
- Colon and rectal cancer
- Liver and intrahepatic bile duct cancers
- Gallbladder and pancreatic cancer
- Postmenopausal breast cancer
- Endometrial and ovarian cancers
- Renal cell carcinoma
- Meningioma
- Thyroid cancer
- Multiple myeloma
The list is sober. According to the study data, 18 185 individuals in the sample group developed one of these cancers for a follow-up period of 14 years. This is clear: identifying more accurate predictors for cancer risk in obese people is not only academic – it could save lives.
Q: Why is size circumference more informative than BMI?
A: The circumference of the size captures the distribution of fat, especially the organs surrounding visceral fat, which the BMI does not do. This type of fat is more metabolically active and is related to the higher risk of cancer.
Q: How does the type of fat differ between men and women?
A: Men tend to store viscerally fat (around internal organs), which is more dangerous. Women usually store subcutaneous fats (under the skin), which are less likely to cause cancer.
Q: Should we stop using BMI completely?
A: Not necessarily. BMI still provides a large and easy measure of body mass, and is correlated with health risks. But the study suggests that it should not be the only metric, especially in men, where size can tell a more detailed story.
Q: How does lifestyle change size?
A: Diet, exercise and sleep all influences abdominal fat. Reducing added sugars, avoiding excess alcohol, managing stress and staying active can help cut the size and potentially reduce the risk of cancer.
Q: Is this change in clinical environments adopted?
A: Not too much. However, this study and others like him are conducting discussions in the health community on how obesity and its associated risks are measured and managed.
Impacts on Public Health and Future Research
The impact of this research goes beyond the clinic. Obesity is the second most preventable cause of cancer in the UK after smoking and costs nearly 11 billion pounds per year at the National Health Service (NHS). According to the authors, adapting cancer prevention efforts by circumference of size, especially among men, could improve outcomes and reduce costs.
However, researchers note that measuring toilets may be more difficult than calculating BMI. There is more room for error, especially when it is called self. To take this into account, the study adjusted for measurement inaccuracies and standardized scores to allow comparisons between apples and applications. It is this level of rigour that reinforces its conclusion: the circumference of size is a better indicator of the risk of obesity-related cancer in men.
They also call for further research on the interaction of fat distribution and hormonal or metabolic differences between the sexes. ”The divergence in how the circumference of size and BMI is related to the risk of cancer between men and women underscores the complexity of the impact of adiposity on cancer development,” concluded the authors. The most precise tools, such as body analyses or fat mass indices, can eventually replace both BMI and WC. But by then, a ribbon around the waist could be our best bet.
According to 𝐌𝐞𝐝𝐢𝐜𝐚𝐥 𝐗𝐩𝐫𝐞𝐬𝐬 and 𝐓𝐡𝐞 𝐓𝐞𝐥𝐞𝐠𝐫𝐚𝐩𝐡 , this study brings us closer to personalized health strategies that explain sex, body composition and lifestyle, rather than being dependent on a single measure. With cancers associated with increasing obesity, this nuance could not come at a more crucial time.
Researchers stress the need for a broader approach. “Comprehensive research that incorporates more accurate adiposity measures, as well as comprehensive data on possible confounding factors, could further clarify the relationship between the distribution of body fat and the risk of cancer,” they said.
