The body mass index (BMI) is the ratio of your weight in kilos to the square of your height in meters and can be used to determine if you’re at a healthy weight, overweight or obese. But two new studies from England suggest that doctors should set aside BMI and focus on their patients’ waist circumference when assessing health risks. One study, published online June 5, 2012, in the journal PLoS Medicine, found that the larger your waist circumference, the higher your risk of type 2 diabetes. The second study, published in the March 2012 issue of Obesity Reviews, suggested that keeping waist circumference to less than half your height can increase life expectancy. This study evaluated the health of 300,000 people and found that waist to height ratio was more predictive of high blood pressure, diabetes, heart attacks and strokes than BMI. In addition to the two British studies, in 2010 American Cancer Society researchers reported that the larger your waist - regardless of your weight - the greater your risk of dying from cancer, heart disease and respiratory disease. To accurately determine your waist circumference measure mid-way between your lowest rib and the top of the pelvic bone at your hip.
My take? We’ve known for some time that a waist circumference of 35 inches or more for women and 40 inches or more for men is a risk factor for metabolic syndrome, a collection of health concerns that when taken together dramatically increases the risk of heart disease, stroke and diabetes. In addition to waist circumference, other indications of metabolic syndrome include fasting blood glucose at least 100 mg/dL, serum triglycerides at least 150 mg/dL, blood pressure at least 135/85mmHg and HDL ("good") cholesterol lower than 40 mg/dL for men or below 50 mg/dL for women.