Introduction: Traditional risk factors are poor predictors of cardiovascular events in younger adults. Considering the long silent evolution of atherosclerosis beginning in younger adulthood before the appearance of clinical events at a more advanced age, a simple tool to predict early atherosclerosis in young adults would be desirable to guide primordial prevention. An altered cardiometabolic profile is associated with increased cardiovascular disease in older adults independent from traditional risk factors, but the value of this profile in an otherwise healthy young adult population is unknown. Hypothesis: Cardiometabolic risk markers would be associated with early atherosclerosis in young adults despite the absence of traditional risk factors. Methods: Healthy young adults (18-35 years) devoid of cardiovascular risk factors (diabetes, smoking, hypertension, dyslipidemia) and obesity were prospectively enrolled. Anthropometric measurements, ECG, lipid profile, fasting blood glucose, blood pressure and high-resolution carotid artery MRI were realized. Results: Although the 240 participants (25.8 years, SEM=0.29, 48% women) were at low risk for atherosclerosis, we identified atherosclerosis in 72.6% of men and 64.7% of women (p=0.19). Males had greater atherosclerosis burden vs. females (carotid wall volume [CWV]: 1817 mm3/48mm, SEM=29.7 vs. 1579 mm3/48mm, SEM=21.2; p<0.0001). By multivariate analysis, atherosclerosis burden was associated with fasting blood glucose (p=0.01), BMI (p=0.01), and waist circumference (p<0.001), the latter having the strongest correlation with atherosclerosis burden (r=0.41, p<0.0001). ROC analyses established cutoffs for waist circumference identifying greater atherosclerosis burden in apparently healthy young adults. Conclusion: A simple low-cost office-based tool, waist circumference measurement improves prediction of early atherosclerosis in otherwise apparently healthy young adults.