BackgroundPoor diet is a leading risk factor for cardiometabolic disease (CMD) in the United States, but its economic costs are unknown. We sought to estimate the cost associated with suboptimal diet in the US.Methods and findingsA validated microsimulation model (Cardiovascular Disease Policy Model for Risk, Events, Detection, Interventions, Costs, and Trends [CVD PREDICT]) was used to estimate annual cardiovascular disease (fatal and nonfatal myocardial infarction, angina, and stroke) and type 2 diabetes costs associated with suboptimal intake of 10 food groups (fruits, vegetables, nuts/seeds, whole grains, unprocessed red meats, processed meats, sugar-sweetened beverages, polyunsaturated fats, seafood omega-3 fats, sodium). A representative US population sample of individuals aged 35–85 years was created using weighted sampling from National Health And Nutrition Examination Surveys (NHANES) 2009–2012 cycles. Estimates were stratified by cost type (acute, chronic, drug), sex, age, race, education, BMI, and health insurance. Annual diet-related CMD costs were $301/person (95% CI $287–$316). This translates to $50.4 billion in CMD costs (18.2% of total) for the whole population, of which 84.3% are attributed to acute care ($42.6 billion). The largest annual per capita costs are attributed to low consumption of nuts/seeds ($81; 95% CI $74–$86) and seafood omega-3 fats ($76; 95% CI $70–$83), and the lowest are attributed to high consumption of red meat ($3; 95% CI $2.8–$3.5) and polyunsaturated fats ($20; 95% CI $19–$22). Individual costs are highest for men ($380), those aged ≥65 years ($408), blacks ($320), the less educated ($392), and those with Medicare ($481) or dual-eligible ($536) insurance coverage. A limitation of our study is that dietary intake data were assessed from 24-hour dietary recall, which may not fully capture a diet over a person's life span and is subject to measurement errors.ConclusionsSuboptimal diet of 10 dietary factors accounts for 18.2% of all ischemic heart disease, stroke, and type 2 diabetes costs in the US, highlighting that timely implementation of diet policies could address these health and economic burdens.