The Life's Essential 8 (LE8) is a novel indicator of cardiovascular health proposed by the American Heart Association. While numerous studies have demonstrated its guiding value in chronic diseases, research on its role in lung function remains limited. This study utilized data from the National Health and Nutrition Examination Surveys (NHANES 2007-2012), which included comprehensive measurements of lung function, diet, physical activity, nicotine exposure, sleep patterns, body mass index (BMI), blood glucose, blood pressure, blood lipids, and relevant covariates. We calculated lung function Z-score and LE8 scores, employing multiple linear regression, multivariable logistic regression, and restricted cubic spline models to evaluate their correlations. In this study of 10,400 participants (mean age 44 years
48.75% male), participants were classified into threeforcedexpiratory volume in one second (FEV1) Z-score groups: Z1 (normal lung function, n = 9,600), Z2 (mild impairment, n = 618), and Z3 (moderate to severe impairment, n = 182). Significant differences in demographic characteristics and health parameters were observed among the groups. Notably, variations in the Healthy Eating Index 2015 (HEI-2015), physical activity, nicotine exposure, and sleep patterns were identified within the LE8 health behavior domain. Higher LE8 scores were found to be positively associated with lung function, even after adjusting for demographic and health factors. Further analysis revealed positive correlations between lung function and favorable dietary habits, higher physical activity levels, reduced nicotine exposure, and improved sleep quality. Conversely, BMI, blood lipids, blood glucose, and blood pressure exhibited variable effects. Subgroup and sensitivity analyses consistently supported findings, confirming a positive correlation between LE8 and lung function. Our study highlights significant associations between LE8 scores and lung function, demonstrating that higher LE8 scores, which reflect better cardiovascular health behaviors, are positively correlated with improved lung function.