Although away-from-home eating is adversely associated with weight, other comorbidities have not been examined; therefore, we sought to determine the associations of fast food (e.g. Wendy's, McDonalds) and restaurant (sit-down style) consumption (times per week) with weight and multiple metabolic outcomes, including homeostatic model assessment insulin resistance (HOMA-IR), waist circumference, and plasma triglycerides (TG), LDL cholesterol, and HDL cholesterol (HDL-C). We used 3 waves of data (exam y 7, 10, and 20) from the Coronary Artery Risk Development in Young Adults Study, a prospective cohort study of black and white young adults [aged 25-42 y in 1992-93, n = 3643 (men, 1659; women, 1984)]. Individuals in the highest (vs. lowest) quartile of baseline (defined as the mean of y 7 and 10) fast food consumption had higher y 20 weight [adjusted mean (95% CI): 5.6 kg (CI, 2.1, 9.2); P = 0.002], HOMA-IR [0.9 (CI, 0.4, 1.3); P < 0.001], waist circumference [5.3 cm (CI, 2.8, 7.9); P < 0.000], TG concentrations [0.25 mmol/L (CI, 0.10, 0.40), 22.7 mg/dL (CI, 9.1, 36.3); P = 0.001], and lower HDL-C concentrations [-0.014 mmol/L (CI, -0.215, -0.067), 5.4 mg/dL (CI, -8.3, -2.6); P < 0.000]. Baseline restaurant consumption was unrelated to y 20 outcomes. Adjusted change in weekly restaurant (P < 0.05) and fast food intake (P < 0.001) was associated with 13-y changes in body weight [0.09 kg (CI, 0.02, 0.17) and 0.15 kg (CI, 0.06, 0.24), respectively] and waist circumference [0.08 cm (CI, 0.02, 0.14) and 0.12 cm (CI, 0.04, 0.20), respectively]. Fast food consumption may be an important target for the prevention of adverse metabolic health outcomes.