excellent comment ○○ - about validity of self report BMI
this is a 'perfect' posting - it responds to my question, goes to the literature, finds out the answer specifically, and posts that [new] information ... this adds to the pool of discussion beyond what is exactly in the readings
My responding here is just to point out the characteristics of a very good posting - and many of you are doing this sometimes in this module - its very good adult education / online learning practice [too much work to do all the time, but occasionally it really helps the discussion move along]
There is a systematic review about the validity of self reported height and weight. Usually, weight is underestimated and height is overestimated. This trend varies between genders and studies (1).
In addition, in last module, I suggested that there was an age effect on this validity (2). Moreover, this trend varies for the region. For instance, in the Scotland, the people are likely to be under-reporting of height as well as weight, which resulted in BMI estimates with low error (3).
Therefore, it is essential to consider these differences when the self-reported methods are used in the surveillance at the population level.
Reference 1. Kuczmarski MF, Kuczmarski RJ, Najjar M. Effects of age on validity of self-reported height, weight, and body mass index: findings from the Third National Health and Nutrition Examination Survey, 1988-1994. J Am Diet Assoc. 2001;101(1):28-34; quiz 35-6. 2. Gorber SC, Tremblay M, Moher D, Gorber B. A comparison of direct vs. self-report measures for assessing height, weight and body mass index: a systematic review. Obes Rev. 2007;8(4):307-26. 3. Bolton-Smith C, Woodward M, Tunstall-Pedoe H, Morrison C. Accuracy of the estimated prevalence of obesity from self reported height and weight in an adult Scottish population. J Epidemiol Community Health. 2000;54(2):143-8.