Less than 20 percent of people know how to correctly calculate their body mass index (BMI), the Bureau of Health Promotion said, and it advised the public to improve their understanding of such matters to avoid health problems related to being overweight.
The results of the Healthy Weight Management Plan Survey carried out by the bureau showed that of those people whose weight is considered to be within a healthy BMI range, just under half of respondents considered themselves to either be overweight or underweight, with 31.6 percent believing themselves to be overweight and 12.5 percent thinking they are underweight.
In addition, 39 percent of those who are considered underweight according to the BMI scale believe they are of normal weight, while 3.9 percent think of themselves as being overweight.
Meanwhile, 21.3 percent of those considered overweight or obese on the BMI scale saw themselves as being of normal weight.
The bureau said the results of the survey indicated that a majority of people misjudge their weight, with the poll also finding that only 17.6 percent of those surveyed actually know how to accurately calculate their BMI.
Calculating BMI is a useful and simple way to determine weight categories that can act as indicators of health problems, the bureau said, adding that people with higher BMI are at greater risk of developing certain conditions and experience higher early mortality rates than people with lower BMI.
According to the bureau, to correctly calculate BMI, the following formula should be used: Weight (kg) / [height (m)]2 (weight in kilograms divided by the square of a persons’ height in meters).
The standard range for Taiwanese adults is between 18.5 and 24, the bureau said, meaning those with a BMI less than 18.5 are considered underweight, while those considered overweight would have a BMI of between 24 and 27, while obese people would record a BMI equal to or greater than 27.
The Healthy Weight Management Plan Survey was conducted by the bureau from December last year through February, and was based on telephone interviews with a nationally representative random sample of 22,920 adults.