Public health researchers reported discouraging findings on Monday: The rate of obesity among U.S. children remains stubbornly high and has actually increased among the youngest children ages 2-5. According to data collected by the National Health and Nutrition Examination Survey (NHANES), administered by the Centers for Disease Control and Prevention (CDC), 35 percent of U.S. children ages 2-19 are overweight and 26 percent are obese, putting them at risk of a wide range of chronic health conditions including cardiovascular disease and type II diabetes. The obesity rate among some minority populations is even higher; more than one-in-three African American and Hispanic children are obese according to these latest estimates.
Not only is the absolute rate of obesity among U.S. children shockingly high, but these findings counter the suggestion of research based upon the last NHANES cycle in 2013-14 that obesity rates were leveling off or even declining following a four-decade period of steady increases. The childhood obesity rate has tripled since the 1970s according to the CDC.
These recent findings are particularly discouraging given heightened public awareness and the efforts of public health institutions to counter what is now considered to be one of the greatest public health threats facing the nation. The authors of this most recent NHANES study write “The obesity epidemic is becoming endemic” and go on to argue that public health institutions from government agencies to individual clinicians must redouble their efforts in fighting this scourge.
The causes of the obesity epidemic are frequently linked to decades-long increases in caloric consumption and sugar consumption, in particular. Cities and some countries are taking action to reduce the consumption of sugar-sweetened beverages through taxes, advertising regulations, and, as I wrote about recently, labeling laws. But research is also increasingly focused on the hypothesis that chemical exposures are contributing to the obesity epidemic by affecting the number and size of fat cells, changing metabolism, and altering the body’s control of appetite and satiety. These so-called obesogens include phthalates, bisphenol A, perfluoroalkyl substances (PFASs), flame retardants, pesticides, and many other chemicals widely used in commerce today.
Earlier this month, researchers reported that higher baseline plasma PFAS concentrations are associated with greater weight regain following dieting. PFASs are extensively used in many industrial and consumer products, including food packaging, paper and textile coatings, and non-stick cookware. Women enrolled in the study lost an average of 6.4 kg while dieting and then regained about half of that weight over the next 18 months. But women with the highest PFAS levels regained 2 kg more weight on average than women with the lowest PFAS levels. The researchers suggest that a possible mechanism through which this chemical exposure might work is by slowing the body’s resting metabolic rate.
Here at Praedicat we are monitoring the development of scientific research addressing more than a dozen chemical substances (or Litagion® agents) which scientists hypothesize could increase the incidence of obesity and its sequelae. The ubiquity of exposure to many of these chemical substances, along with myriad personal factors, make it all but impossible to know today which, if any, caused any one individual to become obese (or prevented them from losing weight once they gained it), but as scientists come to understand the specific biochemical mechanisms that govern weight gain and loss they are likely to narrow the range of possibilities allowing for more targeted public health strategies and, perhaps, litigation strategies as society seeks to compensate those who suffer the consequences of this lifelong disease.
Despite previous reports that obesity in children and adolescents has remained stable or decreased in recent years, we found no evidence of a decline in obesity prevalence at any age. In contrast, we report a significant increase in severe obesity among children aged 2 to 5 years since the 2013–2014 cycle, a trend that continued upward for many subgroups.