Abstract Body (Do not enter title and authors here): Background: Guidelines recommend that pediatricians screen for cardiometabolic (CM) risk factors at certain thresholds of body mass index (BMI) percentile, with lipid screening after BMI exceeds the 85th%ile for age and sex, and glucose metabolism screening after BMI exceeds the 95%ile. We hypothesize that for Hispanic children, BMI may be an insufficiently sensitive harbinger of CM risk factors. Here we describe the CM profile of children and adolescents from an ethnically homogenous cohort of Mexican Americans with a high risk for CM disease and investigate whether some CM characteristics appear prior to usual BMI thresholds. Methods: We assessed children enrolled in the Cameron County Hispanic Cohort, one of the largest and most comprehensive prospective cohorts of Mexican Americans, with participants recruited from randomly selected households living on the Texas-Mexico border and followed every 2 to 5 years since 2014. Using data from the first visit, we describe the prevalence of individual CM risk factors and their clustering based on age, sex, family history, and obesity category. Results: Of 450 participants under 18 years old, the combined prevalence of overweight and obesity was 48.9%, with median age 12 years (range 8 to 17), 49% male, and 97.7% self-identifying as Hispanic/Latino, and no differences observed in demographic factors across weight status categories. Individual CM risk factors, including high triglycerides, low HDL-C level, abdominal obesity, insulin resistance (IR), or elevated BP, alone or in combination, were present in 59.8% of the sample. IR, the most prevalent risk factor, was present in 40.4% of the children, specifically in 76.0% of obese children, and 39.7% and 19.0% of overweight and normal/underweight children. Clustering of any 3 CM risk factors was more likely to occur with increasing weight status categories and occurred in 1.9% of normal weight, 13.7% of overweight, and 42.3% of obese children. Conclusion: In this cohort, abnormal glucose metabolism and dyslipidemia are present well before BMI percentiles exceed usual thresholds. We observed alarmingly high rates of insulin resistance among children who did not meet BMI criteria for obesity, in 40% of overweight and 19% of normal weight children. Reliance on the BMI as a trigger to screen for CM risk factors may be disadvantageous to some high-risk groups, including Mexican Americans.