Waist circumference predicts cancer risk in men better than BMI.
For years, body mass index (BMI) has been used as the go-to measurement for assessing weight-related health risks. However, new findings suggest that waist size may actually be a better indicator of cancer risk in men. Researchers in Sweden examined decades of health data and found that excess fat around the abdomen played a bigger role in the development of certain cancers than BMI alone. This discovery could change how health professionals assess obesity-related cancer risks, particularly for men.
The study looked at health records from over 300,000 people in Sweden, spanning nearly 40 years. It compared BMI and waist size to determine which measurement better predicted obesity-related cancers. Researchers tracked cases of cancers known to be linked to obesity, including those affecting the digestive system, liver, pancreas, kidneys, and reproductive organs. They also factored in lifestyle variables like smoking, age, and socioeconomic background to ensure accuracy.
The results showed that for men, a larger waistline increased the likelihood of developing these cancers more than a higher BMI. A waist circumference increase of around 11 cm was associated with a 25% higher cancer risk, while a comparable increase in BMI correlated with a 19% increase. Even after adjusting for BMI, waist size remained a strong risk factor, highlighting the specific dangers of excess abdominal fat. For women, the risk increase was similar whether measured by BMI or wait size, suggesting a different fat distribution pattern.
One reason why waist circumference may be a better predictor than BMI is that it more accurately reflects the distribution of visceral fat. This type of fat, stored deep within the abdomen around organs, is known to disrupt hormones, increase inflammation, and contribute to metabolic disorders—all factors that can promote cancer development. BMI, on the other hand, only considers overall body weight without distinguishing between fat and muscle or fat location. As a result, two people with the same BMI may have very different levels of health risk depending on where their fat is stored.
Men and women store fat differently, which could explain why waist circumference is a stronger cancer predictor for men. Men tend to carry more fat in the abdominal area, whereas women often store fat in the hips and thighs. This difference is influenced by hormones, particularly estrogen, which plays a role in fat distribution. Women also have a higher proportion of subcutaneous fat, which is less harmful than visceral fat. Because of these variations, using WC alongside BMI may provide a more complete picture of health risks.
The findings suggest that measuring waist size should become a standard practice for assessing obesity-related cancer risk, especially for men. Current guidelines primarily focus on BMI, which may not fully capture the dangers of excess belly fat. Health professionals could improve early detection and prevention strategies by incorporating waist circumference into routine check-ups. Lifestyle changes such as diet modifications, increased physical activity, and targeted weight loss strategies could help reduce waist size and lower cancer risk.
Future research may explore additional markers, such as hip circumference, to refine risk assessments, particularly for women. Further studies could also examine the biological mechanisms that link visceral fat to cancer development. In the meantime, individuals looking to lower their risk should pay attention to their waist size in addition to maintaining a healthy BMI. Making small, sustainable changes in diet and exercise could have a significant impact on long-term health outcomes.
Sources:
Waist circumference identified as a stronger cancer risk marker in men
Body mass index across adulthood, weight gain and cancer risk: a population-based cohort study
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