Findings demonstrate that a sustained dietary change could confer substantial health gains for individuals of all ages both for optimized and feasible changes. The earlier the dietary changes are started in life, the larger the gains would be. This study offers the Food4HealthyLife calculator, an online tool that could be beneficial for clinicians, policy makers, and laypeople to understand the health effect of dietary choices.

• Interpreting as well as utilizing the revelations of nutritional research can be difficult for clinicians, policy makers, and even researchers.

• Researchers have created a decision support model that predicts how dietary choices impact life expectancy (LE).

• Their modeling methodology using meta-analyses, data from the Global Burden of Disease study and life table methodology demonstrated that LE gains for prolonged changes from typical Western to optimizing diets could translate into more than a decade for young adults.

• Intake of more legumes, whole grains and nuts, and less red and processed meat would result in the largest gains.

• LE gains for the older population would be smaller but substantial.

• Even the feasibility approach diet (a midpoint between an optimal and a typical Western diet) indicates increased LE by 7% or more for both genders across age groups.

• The online Food4HealthyLife calculator (https://food4healthylife.org/) allows the instant estimation of the impact on LE of a range of dietary alterations.