Abstract
Determining the ideal ratio of macronutrients for increasing life expectancy remains a high priority in nutrition research. We aim to investigate the association between carbohydrate, fat, and protein intake and all-cause mortality in Koreans. This cohort study investigated 42,192 participants from the Korea National Health and Nutrition Examination Survey (KNHANES) linked with causes of death data (2007-2015). Hazard ratios (HRs) were calculated using the multivariable Cox proportional regression model after adjusting for confounders. We documented 2110 deaths during the follow-up period. Time to exceed 1% of the all-cause mortality rate was longest in participants with 50-60% carbohydrate, 30-40% fat, and 20-30% protein intake. Adjusted hazard ratio (HR) with 95% confidence intervals (CIs) was 1.313 (1.031-1.672, p = 0.0272) for <50% carbohydrate intake, 1.322 (1.116-1.567, p = 0.0013) for ≥60% carbohydrate intake, 1.439 (1.018-2.035, p = 0.0394) for <30% fat intake, and 3.255 (1.767-5.997, p = 0.0002) for ≥40% fat intake. There was no significant association between protein intake proportion and all-cause mortality. We found a U-shaped association between all-cause mortality and carbohydrate intake as well as fat intake, with minimal risk observed at 50-60% carbohydrate and 30-40% fat intake. Our findings suggest current Korean dietary guidelines should be revised to prolong life expectancy.