Temporary Employment Is Associated with Poor Dietary Quality in Middle-Aged Workers in Korea: A Nationwide Study Based on the Korean Healthy Eating Index, 2013-2021

Temporary employment is associated with an elevated risk of cardiovascular diseases and mortality. This study explored the association between temporary employment and dietary quality in middle-aged workers. This cross-sectional study included a nationwide sample of middle-aged Korean workers (n = 6467). Employment type was categorized into regular, fixed-term, and daily employment, based on labor contract duration. Dietary quality was assessed using the Korean Health Eating Index (KHEI), which ranges from 0 to 100, with higher scores indicating superior dietary quality. Linear regression was used to estimate beta coefficients (β) and 95% confidence intervals (CI). The survey-weighted proportion of regular, fixed-term, and daily employment was 79.0%, 14.2%, and 6.8%, respectively. Fixed-term and daily employment were associated with a reduced KHEI compared with regular employment (β [95% CI]: -1.07 [-2.11, -0.04] for fixed-term and -2.46 [-3.89, -1.03] for daily employment). In sex-stratified analysis, the association between temporary employment and dietary quality was more pronounced in men (β [95% CI]: -1.69 [-3.71, 0.33] for fixed-term and -2.60 [-4.63, -0.53] for daily employment than in women. In conclusion, this study suggests that temporary employment is a social determinant of dietary quality in middle-aged workers.