Obesity incidence underestimated and threshold overestimated
Posted by Dave Bath on 2010-09-01
A study of US population weights, adjusted for birth cohorts, suggests weights ballooned decades earlier than generally accepted, so diagnostic indicators need to be tightened, many now labelled "normal" are actually overweight, and stronger action against the obesity epidemic is needed.
The flawed indicators are used here in Oz as well as the US.
Because the baseline for population obesity was set from studies in the late 1950s, the common wisdom is that the 1980s was when the obesity epidemic kicked in.
The new paper, by looking not just at the weights of the population as a whole, but by age range, shows a significant rise in obesity between the two world wars, which fits in with the rise of radio and cars, just like later rises fit in with the introduction of television.
If populations were already overweight by the time baseline studies were done, then thresholds for obesity need to be lowered.
It’s like defining "normal" CO2 levels from a baseline of 1950 rather than before the industrial evolution – things would seem better than they are, and government action even more woefully inadequate.
Reference charts are supposed to reflect what is "normal" within the
In this case, however, they do not do so, insofar as they incorporate BMI values obtained at a time when the transition to post-industrial weights was already under way, i.e., at a time when obesity was already more widespread than in historical times. That was an arbitrary choice.
The current standards are thereby misleading as they suggest that the weights obtained in the midst of the obesity pandemic were actually normal ones.
Yes… "obesity pandemic" is the phrase, not epidemic.
This study shows a more obvious smoking gun of electronic passtimes (radio, as well as TV and internet), with the accusations strengthened with studies of other nations, using the subtler analysis of this paper.
I note the paper includes references to intake weights of West Point cadets, which, while a population biased for better fitness than the general population, could be adapted for countries where the introduction of western diets, and even fast food, predated any major population-wide studies, because military book-keeping is introduced pretty early in a nations history (which is why we know so much about the health and longevity of Roman soldiers!).
So… more action needed by governments if the health budget is to get under any control…
…and time for me to tone up a bit.
- "The evolution of BMI values of US adults: 1882-1986", (Vox 2010-08-31) Marek Brabec (Statistician for the National Institute of Public Health) and John Komlos (Professor Emeritus of Economics, Ludwig-Maximilians University)