Waist circumference is a subject more commonly discussed in female health context, but research has made it clear that it is an equally meaningful metric of male health. It is well-known that excessively large waists generally mean poor health management, an unhealthy lifestyle, or unfortunate genetics, which predispose men (and women) to a number of diseases and lower their life expectancy.
The size of the belly gives clues about one's lifestyle and diet, cardiovascular health and other things. Abdominal fat is a type of visceral fat that affects the organs, such as the intestines, pancreas and liver. The amount of it matters because this type of fat also produces inflammatory substances, which increase the risk of atherosclerosis and are believed to promote other health problems. Hence, waist circumference has been used as one more data point in the evaluation of health risks: the larger the waist, the stronger the risk of heart problems, stroke, and some forms of cancer. Research has found an association between waist size and prostate cancer in men.
In a meta-analysis published on The Lancet in 2009, researchers from the University of Oxford looked at 57 studies and concluded that people with larger waists are nearly two times more likely to die 3 to 10 years ahead of time. People whose weight is threefold more than the ideal for their height have their lifespan shortened by at least three years.
Another survey, involving more than 350,000 people, revealed that a 5-centimeter increase in waist size leads to a 17% higher risk of death in men. In short, the health risks of obesity are comparable to those of smoking.
Prostate cancer is one of the most prevalent in men, especially among those with larger waists. Men with waists measuring 94 cm or more are 13% more likely to suffer from a more aggressive type of prostate cancer. The survey carried out by the University of Oxford involved more than 140,000 men in eight European countries with a follow-up of 14 years. Tracking BMI and waist circumference metrics, researchers estimated that the risk of prostate cancer increases by 18% for every 4" of additional waist size.
A study done at the Mayo Clinic in the US concluded that the risk of cardiovascular disease is much higher among people with large waists but normal BMI.
Obesity is a risk factor for dementia, but the exact mechanism of such an association has remained elusive. Research carried out by the Kaiser Permanente healthcare provider in the U.S. — involving 6,500 people and spanning almost 30 years of data — revealed that a large waist was the most statistically relevant factor in such association.
Waist size has been found to be so meaningful about people's health that specialists and scientists are increasingly proposing the replacement of the BMI (body mass index) measure with the WHtR (waist-to-height-ratio). The latter has been found to correlate significantly better with health problems than BMI. WHtR is calculated by dividing the waist circumference by height: the higher the value is than the healthy cutoff (0.5), the higher the health risks. A value of 0.5360 in males puts them at a significantly increased risk of cardiovascular diseases.