A worsening diet over the course of 12 years was associated with an increased mortality of 6% to 12%, the researchers found.  Those who stayed consistently on a healthy diet starting at baseline had a 9% to 14% lower risk for death than those who stayed consistently on a poor diet.

Source: Change in Diet Can Lower Mortality Risk

Source: Association of Changes in Diet Quality with Total and Cause-Specific Mortality — NEJM