A Century and a Lifetime of Disparities in Obesity

“The arc of the moral universe is long, but it bends toward justice,” said Martin Luther King Jr. in 1968. We can point to ways this is true. But if you dig into health disparities, this claim might be harder to support. A new study in the Proceedings of the National Academy of Sciences (PNAS) offers a bracing reminder. Yang Clair Yang and colleagues offer us a unique view of disparities in obesity from birth cohorts spanning a century. In fact, disparities in obesity between Black and White persons are growing wider in more recent birth cohorts. The authors explain:

“Black and Hispanic excesses in BMI compared with Whites were present early in life and persisted at all ages, and, in the case of Black–White disparities, were of larger magnitude for more recent cohorts.”

BMI Across Lifetimes and Generations

Yang’s study is remarkably comprehensive. Researchers integrated data from four big NIH cohort studies. So they provide a view of BMI across the lifetimes of multiple generations. They analyzed cohorts born as early as 1905.

This rich analysis provides many insights. One thing is especially clear – obesity is becoming a problem much earlier in life. For people born in the early 1950s, average BMI stayed below 30 until they reached their 60s. With successive cohorts, average BMI became higher earlier in life. Among people born in the early 1980s, average BMI surpassed 30 in their 30s.

In short, younger generations are living with more obesity earlier in life. This is especially true for racial and ethnic minorities.

Disparities Beyond Socioeconomic Inequality

Yang et al found that social and economic inequality does not fully explain racial and ethnic disparities in obesity. They suggest that the burden of discrimination may be playing a role, as well as differences in access to community assets that promote health.

Furthermore, they find that adolescence and early adulthood are critical times for the development of obesity and the emergence of disparities. In light of more recent data from the COVID-19 pandemic, this is a great concern. The increase in youth obesity has been greatest in Black and Hispanic families.

Knowledge is power. This study describes the problem of increasing obesity and increasing disparities across multiple generations in greater detail than ever before. It points to critical points in life for intervention. Thus, we have more insight than ever to guide us in bending this curve toward less disparity and better health for all.

Click here for the study and here for further perspective.

Twentieth Century, painting by C. R. W. Nevinson / WikiArt

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April 24, 2021