Body Mass Index (BMI), a ratio of weight to height, may be an industry proxy for whether someone is at a healthy weight. Those who are overweight or obese are considered unhealthy. But a recent study by Janet Tomiyama et al published in the International Journal of Obesity found that millions of people are being erroneously labelled unhealthy based on their BMI.
The scientists analyzed the link between BMI and several health markers, including blood pressure and glucose, cholesterol and triglyceride levels, using data from the most recent National Health and Nutrition Examination Survey.
The study found that close to half of Americans who are considered “overweight” by virtue of their BMIs (47.4 per cent, or 34.4 million people) are healthy, as are 19.8 million who are considered “obese” and 2 million who are considered “very obese.” Conversely, more than 30 per cent of those in the normal BMI range, about 20.7 million people, are actually unhealthy by other measures.
In reviewing previous studies, Tomiyama also found that there was no clear connection between weight loss and health improvements related to hypertension, diabetes and levels of cholesterol and blood glucose.
The point is that people should focus on eating a healthy diet and exercising regularly, rather than obsessing about their weight. One’s weight is not necessarily an important indicator of their health.
Dr. Zachary Levine is an assistant professor in the faculty of medicine at McGill University Health Centre and medical correspondent for AM740 (a ZoomerMedia property).
A version of this article appeared in the March 2017 issue with the headline, “Weighing In,” p. 26.