Anthropometric percentiles for Peruvian adults: population reference curves for body mass index, waist circumference, and waist-to-height ratio

Introduction: Current anthropometric cut-off points for defining overweight, obesity, and abdominal obesity are based on predominantly Caucasian populations, raising questions about their applicability in ethnically and geographically diverse populations such as the Peruvian population. The lack of population-specific references limits the appropriate assessment of anthropometric distributions and cardiometabolic risk in Peruvian adults. Objective: To develop body mass index (BMI), waist circumference (WC), and waist-to-height ratio (WHtR) percentile curves specific for the Peruvian adult population, stratified by age and sex. Methods: Analytical cross-sectional study based on data from the Demographic and Family Health Survey (DHS) 2015 to 2023. From an initial sample of 385,247 adults aged 20–97 years, 164,513 participants with complete anthropometric measurements and plausible values were included in the final analysis. Percentiles (P5, P10, P25, P50, P75, P85, P90, P95, P97) were calculated using the LMS (Lambda-Mu-Sigma) method for BMI, WC, and WHtR by five-year age groups and sex. Results: The final sample included 164,513 participants (48.52% women, 51.48% men) with a mean (±standard deviation, SD) age of 44.38 ± 16.72 years. Mean BMI was 27.77 ± 4.80 kg/m². The prevalence of overweight was 42.16% and obesity 28.09% according to BMI criteria. Abdominal obesity varied dramatically according to the criterion used: 44.75% (ATP III) versus 68.31% (IDF) for WC, highlighting the problem of universal cut-off points. Sex-specific percentiles showed distinctive age patterns with increases until middle age followed by gradual decline. Altitude differences were clinically significant: 2.5–3.0 kg/m² for BMI, 4–6 cm for WC, and 0.04–0.06 units for WHtR between sea level versus high altitude (≥3000 m). Conclusions: Age- and sex-specific anthropometric percentiles reveal distinctive age patterns that differ substantially from international cut-off points. Classical criteria for abdominal obesity (ATP III, IDF) and WHtR (≥0.5) systematically overestimate prevalence in the Peruvian population, with discrepancies reaching differences of up to 23.5 percentage points between criteria. Altitude differences are clinically significant, suggesting specific physiological adaptations in Andean populations.