Background: Although diet beverages are typically consumed to promote weight control, positive associations with increased cardiometabolic risk have been reported. Objective: The objective was to examine the joint and independent association between dietary pattern and diet beverage consumption with 20-y cardiometabolic risk. Design: We analyzed a prospective 20-y cohort of young adults from the Coronary Artery Risk Development in Young Adults (CARDIA) Study. With the use of cluster analysis, we identified 2 baseline (year 0) dietary patterns [Prudent (higher intakes of fruit, whole grains, milk, and nuts and seeds; n = 1778) and Western (higher intakes of fast food, meat and poultry, pizza, and snacks; n = 2383)] and examined the interaction with diet beverage consumption (Consumers compared with Nonconsumers) by using proportional hazards regression models. Results: Among Consumers, 66% were classified as having a Prudent diet. In fully adjusted models, being a Nonconsumer with a Prudent diet was independently associated with a lower risk of the metabolic syndrome through year 20. Lower risk in the Prudent than in the Western dietary pattern was maintained after stratification by diet beverage consumption: Prudent Nonconsumers had the lowest risk of high waist circumference (HR: 0.78; 95% CI: 0.62, 0.97), high triglycerides (HR: 0.72; 95% CI: 0.56, 0.93), and the metabolic syndrome (HR: 0.64; 95% CI: 0.50, 0.82) compared with Western Consumers. Conclusions: Our results suggest that both overall dietary pattern and diet beverage consumption are important, to various degrees, for different metabolic outcomes. This covariation and interaction may partially explain differences in the relation between diet beverage consumption and cardiometabolic health observed in previous studies.