Do the obese know they are obese?

To determine whether adults accurately perceived their weight status category and could report how much they would need to weigh in order to be classified as underweight, normal weight, overweight, or obese.

Height and weight were measured on 104 White and African American men and women 45 to 64 years of age living in North Carolina. Body mass index (BMI) was calculated for each participant, and participants were classified as underweight (< 18.5), normal weight (> or = 18.5 to < 25.0), overweight (> or = 25.0 to < 30.0), or obese (> or = 30.0). Participants self-reported their weight status category and how much they would have to weigh to be classified in each weight status category.

Only 22.2% of obese women and 6.7% of obese men correctly classified themselves as obese (weighted kappa: 0.45 in women and 0.31 in men). On average, normal weight women and men were reasonably accurate in their assessment of how much they would need to weigh to be classified as obese; however, obese women and men overestimated the amount. Normal weight women thought they would be obese with a BMI of 28.9 kg/m2, while obese women thought they would be obese with a BMI of 38.2 kg/m2. The estimates were 30.2 kg/m2 and 34.5 kg/m2 for normal weight and obese men, respectively.

The sample size was small and was not selected to be representative of North Carolina residents.

Obese adults' inability to correctly classify themselves as obese may result in ignoring health messages about obesity and lack of motivation to reduce weight.