Excessive weight gain in a subset of intensively treated Diabetes Control and Complications Trial (DCCT) subjects was associated with higher waist to hip ratio; higher triglyceride (TG), low-density lipoprotein (LDL) cholesterol, and apolipoprotein B (ApoB) in the presence of small-dense LDL; and decreased high-density lipoprotein 2 cholesterol (HDL2-C), suggesting that weight gain in these subjects resulted in higher intraabdominal fat (IAF), and an atherosclerotic dyslipidemia mediated through hepatic lipase activity (HL). Objectives were to investigate relationships between IAF, HL, and dyslipidemia and to relate IAF to previous body mass index change during the DCCT. Sixty-one subjects were studied approximately 4 yr after DCCT closeout. IAF was positively related to HL (P < 0.001). IAF positively correlated with logTG (P < 0.001) and ApoB (P < 0.001), and negatively with LDL relative flotation rate (P < 0.001) and logHDL2-C (P = 0.001). HL accounted for most of the relationship between IAF with logHDL2-C and LDL relative flotation rate, and none of the relationship between IAF and logTG or ApoB. DCCT-related body mass index change accounted for a significant portion of logIAF variance measured 4 yr later (P < 0.001). Elevated IAF in subjects with type 1 diabetes was related to an atherosclerotic dyslipidemia similar to that seen in individuals without diabetes who have metabolic syndrome. DCCT-related weight gain positively correlated with subsequent IAF.