Background: Data on the long-term association between low- carbohydrate diets and mortality are sparse.

ratio [HR] comparing extreme deciles, 1.12 [95% CI, 1.01 to 1.24]; P for trend 0.136). The animal low-carbohydrate score was associated with higher all-cause mortality (pooled HR comparing extreme deciles, 1.23 [CI, 1.11 to 1.37]; P for trend 0.051), cardiovascular mortality (corresponding HR, 1.14 [CI, 1.01 to 1.29]; P for trend 0.029), and cancer mortality (corresponding HR, 1.28 [CI, 1.02 to 1.60]; P for trend 0.089). In contrast, a higher vegetable low-carbohydrate score was associated with lower allcause mortality (HR, 0.80 [CI, 0.75 to 0.85]; P for trend 0.001) and cardiovascular mortality (HR, 0.77 [CI, 0.68 to 0.87]; P for trend 0.001). Limitations: Diet and lifestyle characteristics were assessed with some degree of error. Sensitivity analyses indicated that results were probably not substantively affected by residual confounding or an unmeasured confounder. Participants were not a representative sample of the U.S. population. Conclusion: A low-carbohydrate diet based on animal sources was associated with higher all-cause mortality in both men and women, whereas a vegetable-based low-carbohydrate diet was associated with lower all-cause and cardiovascular disease mortality rates. Primary Funding Source: National Institutes of Health.