© 2014 The Obesity Society. Objective: Examine whether there are independent influences of a greater degree of adiposity and longer duration of obesity on cardiac structure and function. Methods: Participants of CARDIA were 18-30 years when they underwent a baseline examination in 1985-86. Seven follow-up examinations were conducted every 2-5 years. Results: Among 2,547 participants who underwent an echocardiogram at the year 25 examination and were not obese at baseline, 34.4 and 35.5% were overall (BMI ≥ 30 kg m-2) and abdominally obese (waist circumference: men: >102 cm; women: >88 cm) at year 25, respectively. A greater degree of overall and abdominal adiposity at year 25 were each associated with a greater left ventricular (LV) mass (P < 0.001), LV volume (P < 0.001), LV mass-to-volume ratio (P < 0.001), left atrial dimension (P < 0.001), and ejection fraction (P < 0.05) after adjustment for duration of obesity and other risk factors. In contrast, a longer duration of overall obesity was associated with a greater LV mass (P = 0.003) and a trend for a lower ejection fraction (P = 0.07). Conclusions: A greater degree of adiposity is strongly associated with concentric LV remodeling in midlife, while the cumulative effects of a longer duration of overall obesity during young adulthood contribute to concentric remodeling predominantly by increasing LV mass.