Obesity rate among emerging adults significantly increased from 1976 to 2018

The obesity rate among emerging adults — who researchers defined as individuals aged 18 to 25 years — increased more than 26 percentage points over a 42-year span, National Health and Nutrition Examination Survey data show.

The data also revealed that adults’ BMI rose more than 4 kg/m² during the same period.

Most obesity analyses have not specifically analyzed prevalence among those aged 18 to 25 years, thus reducing “opportunities for developmentally informed intervention and treatment,” Alejandra Ellison-Barnes, MD, MPH, an assistant professor at Johns Hopkins University School of Medicine, and colleagues wrote in JAMA.

To fill this data gap, the researchers examined data on 8,015 nonpregnant adults who completed an NHANES from 1976 to 2018. The analysis included 3,965 women; 2,386 individuals who met the threshold for household poverty and 3,037 non-Hispanic Black individuals.

“Given the changes in how the NHANES assessed race and ethnicity over time, we were limited to the aforementioned groups,” Ellison-Barnes and colleagues wrote.

The researchers reported that the prevalence of obesity among emerging adults increased from 6.2% (95% CI, 4.9-7.9) in 1976 to 1980 to 32.7% (95% CI, 24.7-41.8, P for trend = .007) in 2017 to 2018. During the same timeframe, the number of emerging adults whose weight would put them in the “normal” BMI category dropped from 68.7% (95% CI, 66.3-70.9) to 37.5% (95% CI, 29.5-46.4; P for trend = .005), whereas the mean BMI increased from 23.1 kg/m² (95% CI, 22.9-23.4) to 27.7 kg/m² (95% CI, 26.2-29.1; P for trend = .006).

Sensitivity analyses that were restricted to the continuous NHANES cycles (1999-2018) yielded similar results, according to Ellison-Barnes and colleagues.

“Emerging adulthood may be a key period for preventing and treating obesity given that habits formed during this period often persist through the remainder of the life course,” Ellison-Barnes and colleagues wrote. “There is an urgent need for research on risk factors contributing to obesity during this developmental stage to inform the design of interventions as well as policies aimed at prevention.”

References:

Ellison-Barnes A, et al. JAMA. 2021;326(20):2073-2074.

Healthy People 2030. National Health and Nutrition Examination Survey (NHANES). https://health.gov/healthypeople/objectives-and-data/data-sources-and-methods/data-sources/national-health-and-nutrition-examination-survey-nhanes. Accessed Nov. 19, 2021.