Study Shows That People Are Likely to Underestimate Their BMI and Body Size

A study titled Perception of Body Size and Body Dissatisfaction in Adults has found that people could miscalculate their Body Mass Index (BMI) due to humiliation and increasing occurrence of obesity. The researchers published this study in the Scientific Reports.

The researchers estimated that about 17% of people with a healthy BMI reported having an underweight BMI. Moreover, they found that two-thirds of adults could calculate their BMI accurately while the others could not.

How researchers conducted the study 

The team gathered 740 volunteers from Poland with an average age of 36. In addition, more than 60% of them were female. The researchers calculated the adults’ BMI from 2010 to 2011 and compared it to estimates that the participants gave on their BMI and body size.

The team found that about 21% of the volunteers had a BMI below 18.5kg/m2, which meant they were underweight. More than 320 had a healthy BMI between 18.5kg.m2 and 24.9kg/m2. Another 221 volunteers were overweight and had a BMI between 25kg/m2 and 29kg/m2. The rest of the respondents were obese with a BMI over 30kg/m2.

In their study, the researchers described body image as a multidimensional construct encompassing negative and positive self-perceptions. This included thoughts, behaviors, and feelings about our bodies. They also found that people who previously or currently suffered from anorexia nervosa and bulimia nervosa had incorrect assessments of their bodies.

Many participants underestimated their body size and BMI

When the team evaluated the BMI the volunteers had estimated, they found that 63.5% of them had a correct estimate. Only 49.5% estimated their body size correctly.

Other participants misestimated their BMI. For instance, 17% with healthy BMI thought they were underweight. Another 14% who were overweight estimated they were healthy. About 41% of the obese respondents also thought they were overwrought.

More of the participants gave the wrong estimates for their body size. For instance, about 39% of those who had healthy body sizes believed they were underweight. Another 35% who thought they were healthy were overweight, while 40% of the obese thought they were overweight.

The researchers also realized that the male participants were more likely to underestimate their body size and BMI. However, they were also more likely to be comfortable with their bodies.