Abstract
BACKGROUND: Severe obesity (body mass index [BMI] of 40 kg/m(2) or higher) poses significant health risks. It reflects a multifaceted interplay of genetic, behavioral, and environmental factors, contributing to rising rates of metabolic diseases and reduced quality of life. This study aimed to examine the prevalence and risk factors of severe obesity among adults in the United States. METHODS: We analyzed data from the National Health and Nutrition Examination Survey (NHANES), a complex, multistage, cross-sectional survey, designed to collect health and nutritional data from a representative sample of the civilian noninstitutionalized U.S. POPULATION: A total of 6729 respondents from the 2017 to March 2020 cycle of NHANES were included in the analysis. Descriptive statistics were used to summarize the characteristics of the sample. Multivariable logistic regression models were utilized to study risk factors for severe obesity. All analyses accounted for the complex survey design of the NHANES. RESULTS: The weighted prevalence of severe obesity among adults was 9.4%, with a higher rate found in females, 11.9%, compared to males, 6.2%. Binary logistic regression analysis revealed that males had 39% lower odds of severe obesity compared to females (odds ratio [OR]: 0.61, 95% confidence interval [CI]: 0.32-1.14), though this was not statistically significant. Participants aged 31-40 years were more than twice as likely to have severe obesity compared to those aged 20-30 years (OR: 2.73, 95% CI: 1.07-6.96). Non-Hispanic Asians had significantly lower odds of severe obesity than Mexican Americans (OR: 0.06, 95% CI: 0.01-0.27). Arthritis nearly doubled the odds of severe obesity (OR: 1.94, 95% CI: 1.17-3.22), and high blood pressure showed the strongest relationship, increasing odds more than fourfold (OR: 4.42, 95% CI: 3.30-5.91). Marital status, health insurance, and income level showed no significant associations with severe obesity. These findings highlight the complex interplay of factors influencing severe obesity. CONCLUSION: In conclusion, the study highlights a significant prevalence of severe obesity among adults in the United States, particularly among females, individuals aged 31-40 years, and those with specific comorbid conditions such as high blood pressure and arthritis. Non-Hispanic Asians exhibited notably lower odds of severe obesity compared to other racial/ethnic groups, underscoring potential protective factors. The findings emphasize the multifactorial nature of severe obesity, driven by demographic, behavioral, and health-related factors, and underline the importance of tailored interventions to address this public health challenge.