No, our kids aren't getting skinny: Column

Late last month, a New York Times headline announced: "Obesity Rate for Young Children Plummets 43% in a Decade." The story, pegged to a study by researchers at the Centers for Disease Control and Prevention, heralded the drop among children aged 2 to 5 years old a sign of exciting progress in our national battle against obesity.

In the same newspaper, food columnist Mark Bittman called the toddler obesity plunge a "tribute to the improved Special Supplemental Nutrition Program for Women, Infants and Children (WIC), which encourages the consumption of fruits and vegetables; to improved nutrition guidelines; to a slight reduction in the marketing of junk to children; and probably to the encouragement of breast-feeding."

But in fact, this spectacular drop is likely an artifact of the data sample, for which 2- to 5-year-olds are a small portion. Indeed, rates of obesity among this group have gone up and down several times within the past decade. The real story is less spectacular but clearer: Rates of obesity for Americans of all ages—which increased during the 1980s and 1990s — have plateaued since 2000.

The question is why, and the answer is that we have no idea.

There is no shortage of hypotheses. Some point to fluctuating levels of caloric intake, but this has been difficult to demonstrate. Indeed, one study found that that children and adolescents in 1988-1994 consumed the same amount of calories as their counterparts had in the 1970s. Another line of research posits that the weight gain of the 1980s and 1990s was largely an adaptive response to toxins in our water, air, and clothing. Our bodies may have created fat deposits to store these toxins away from vital organs. In this scenario, weight gain may not be — in itself — a bad thing. Some research suggests that a small but significant part of the weight gain can be attributed to smoking cessation, clearly a development we do not wish to reverse.

More interesting theories underscore the importance of broad societal trends, like growing levels of inequality. Some researchers point to evidence that obesity rates rose highest in those nations with the greatest levels of inequality and with the stingiest welfare states, as well as among the poorest members of all societies. They reason that economic inequality and insecurity produce high levels of stress, raising levels of cortisol, which, in turn, leads to weight gain.

But the poor and socially disadvantaged also have unequal access to information, fruits and vegetables, and safe opportunities to exercise, as well as greater exposure to toxins. There is also evidence that weight-based discrimination leads to downward mobility — that being fat makes you poor, rather than the other way around.

What's frustrating about not being able to isolate precisely why our weight skyrocketed and then stabilized is that it becomes difficult to rely on the right public policy measures to further the trend. Many of the policy interventions we credit for creating our current obesity plateau were developed a decade or more after it started. And even public health interventions designed to help people lose weight have been shown to produce no weight loss, even when they were successful in changing diet and exercise behaviors.

This is not to say that policy efforts — such as improving access to fruits and vegetables in low-income neighborhoods or building more bike paths and parks — are not laudable. These changes, as well as larger efforts to alleviate economic insecurity, are likely to improve our overall quality of life and perhaps even health outcomes, even if they do not lead us to lose weight.

And maybe that is OK. There is growing evidence that people benefit from physical activity and improved diet even in the absence of weight loss. For instance, several studies have shown that physically fit "obese" individuals have a lower incidence of heart disease and mortality from all causes than do sedentary people of "normal" weight. Similarly, a clinical trial published in the New England Journal of Medicine showed that adopting a Mediterranean diet reduced cardiovascular risk without inducing weight loss. And economic security has consistently been shown to positively affect health and longevity, which is — after all — what all this is about.

Or isn't it?

Abigail C. Saguy is associate professor and vice chair of the UCLA sociology department and the author of What's Wrong with Fat? (Oxford University Press, 2013). She wrote this forZocalo Public Square.

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