The evolution of BMI values of US adults: 1882-1986

Vox: The evolution of BMI values of US adults: 1882-1986

Conclusion

The lifestyle changes of the 20th century affected the four groups under study somewhat differently. Identifying the deep causes of the long-run trends is outside of the scope of this study, but the “creeping” nature of the epidemic, as well as its persistence, does suggest that its roots are embedded deep in the social fabric and are nourished by a network of disparate slowly changing sources as the 20^th-century US population responded to a vast array of irresistible and impersonal socio-economic and technological forces.

The most obviously persistent among these were:

• the major labour-saving technological changes of the 20th century,
• the industrial processing of food and with it the spread of fast-food eateries (To illustrate the spread of fast food culture, consider that White Castle, the first drive-in restaurant, was founded in 1921. McDonald started operation in the late 1940s, Kentucky Fried Chicken in 1952, Burger King in 1954, Pizza Hut in 1958, Taco Bell in 1962, and Subway in 1962.),
• the associated culture of consumption,
• the rise of an automobile-based way of life,
• the introduction of radio and television broadcasting,
• the increasing participation of women in the work force, and
• the IT revolution.

These elements – taken together – virtually defined American society in the 20^th century (Chou et al. 2008, Cutler et al. 2003, Hamermesh 2010, Lakdawalla and Philipson 2009, Offer 2006, Philipson and Posner 2003, Popkin, 2004).

Noteworthy in this regard is that the timing of the first accelerating phase after World War I among whites coincided with the spread of radios and automobiles, while the timing of the second accelerating phase of the 1950s cohorts among both blacks and whites coincided perfectly with the spread of television viewing and the spread of fast food consumption.

The fact that the obesity epidemic started earlier than hitherto thought also implies that the current weight and BMI standards published by the Centre for Disease Control are inaccurate, i.e., not ideal for gauging the true extent of the obesity epidemic especially among children and youth. Reference charts are supposed to reflect what is “normal” within the society. 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. As a consequence, many overweight and obese children and youth are misled into believing that their weight is normal – when it is not. The US should strive to adopt standards such as those in the Netherlands, where policymakers are less content to stand by and watch an obesity epidemic spread unabated.