adults in the age range of 35 to 55, and the bias towards greater underreporting among women than men tends to disappear with older age. More importantly, it is possible to adjust self-reported BMI scores, based on a few, easily gathered demographic characteristics (gender, age, race/ethnicity, marital and pregnancy status, and household income), and thus to obtain a closer approximation to the measured BMI. Of these, age and gender as well as pregnancy status appear to contribute most towards adjusting BMI scores. This is not surprising, as older persons tend to over-report height, probably because they recall their taller selves of yesterday [3], and younger women in particular tend to under-report weight, probably due to a social desirability response [4]. That pregnant women under-report their weight, but not their height, should also not be surprising. While the remaining systematic biases are consistent with those reported in the literature [15,16], overall estimates of the population prevalence of overweight and obesity are nonetheless improved substantially by using the adjusted measures.
