Socioeconomic disparities in obesity prevalence among adolescents in the US have widened over the past 2 decades, according to a cross-sectional study using data from the National Health and Nutrition Examination Survey (NHANES).
From 1999 to 2018, the prevalence of obesity increased overall, but especially among adolescents from low-income households, with a 6.4% greater change (95% CI 1.5-11.4) in difference over the study period versus teens in higher-income households, reported Kosuke Inoue, MD, PhD, of Kyoto University in Japan, and colleagues.
Similarly, adolescents from households with lower levels of education also saw a greater increase in obesity prevalence, with a 4.2% greater change (95% CI -0.8 to 9.3) by the end of the study, the authors noted in JAMA Pediatrics†
The difference in obesity prevalence by income and education increased by an average of 1.5% (95% CI 0.4-2.6) and 1.1% (95% CI 0.0-2.3) every 4 years, respectively.
“Obesity during adolescence can have immediate health consequences and long-term outcomes in adulthood,” Inoue and team wrote. “Accordingly, the larger obesity prevalence among adolescents from lower-socioeconomic-status households may exacerbate socioeconomic disparities in chronic diseases into adulthood.”
A previous study using NHANES data on more than 16,000 individuals from 1999 to 2008 also showed that children and adolescents from low-income families had higher prevalences of obesity, central obesity, sedentary behavior, and tobacco exposure.
Maintaining a healthy weight and diet is challenging for all ages, but it is especially challenging for adolescents, Lauri Wright, PhD, co-director of the Doctorate in Clinical Nutrition program at the University of North Florida in Jacksonville, told MedPage Today†
“As screen time increases from social media, physical activity declines and it is harder to maintain a healthy weight,” added Wright, who was not involved in the study. “It is important to encourage regular physical activity and decreased screen time. This is also an age where peers begin to have greater influence over food selection.”
One way to encourage healthy eating among teens is to have healthy foods on hand that are easy to grab, such as sliced veggies and fruits in the fridge, she suggested. In addition, research has shown that families that share at least one meal together each day have healthier weights and better nutritional intake.
As far as the socioeconomic disparities observed in the study, “we repeatedly see strategies utilized by low-income families to ‘put food on the table’ are high calorie/poor nutrient density,” she noted. “It is essential that we increase access to healthy and affordable foods. More and more food pantries are now offering fresh fruits and vegetables, low-fat dairy, and lean meat options. SNAP benefits can often be doubled at farmer’s markets.”
For this study, Inoue and colleagues analyzed data on 21,296 adolescents ages 10 to 19. Mean age was 14.5 years, and 49% were female.
Adolescents from low-socioeconomic households were more likely to be Black (21.7%), have obesity (22.8%), and have an unmarried parent (45.5%).
Obesity was defined as an age- and sex-specific body mass index (BMI) greater than or equal to the 95th percentile, based on the 2000 CDC growth charts.
To stratify households by income, the authors used a cutoff of 138% of the federal poverty level, with lower-income households defined as those at or below this level. To stratify by education level, they considered whether or not the head of the household had graduated from college.
Inoue and team used various statistical models, including ordinary least-squares regressions, to examine linear trends in socioeconomic differences in obesity prevalence by 4-year cycles. The analyzes adjusted for variables including race and ethnicity, height, and marital status of the head of household.
Limitations to the study included potential unmeasured confounding and potential misclassifications due to self-reported socioeconomic status indicators.
“Future studies should assess strategies to reduce socioeconomic disparities in obesity among US adolescents and evaluate their long-term health consequences,” Inoue and colleagues concluded.
The study was supported by the Japan Society for the Promotion of Science.
The authors reported no conflicts of interest.
Wright reported no conflicts of interest.