Critical overview of current anthropometric methods in comparison with a new index to make early detection of overweight in Spanish university students: the normalized weight-adjusted index.

BACKGROUND: overweight and obesity have been increasing, and university students are an important target for prevention programs. Previous studies have reported differences in the diagnosis between different anthropometric methods, so some students can be misclassified depending on the method used.

OBJECTIVE: to evaluate the efficacy of different anthropometric methods to detect those university students in a probable status of overweight, including a comparison with a new proposed method, the normalized weight-adjusted index (NWAI).

METHODS: different anthropometric methods (waist circumference, waist-hip ratio, waist-height ratio, body mass index, conicity index, bioimpedance and Brozek, Siri and Heath-Carter equations) were calculated for 505 university students. By k-means cluster analysis, students with higher values according to variables involved in overweight were identified. Parameters of accuracy were calculated by operating characteristic curves.

RESULTS: NWAI showed significant correlations with the most used methods. Prevalence of students with body fat excess varied from 5.9% to 48.4% for women and from 8.5% to 49.0% for men depending of the method employed, being demonstrated a great variability between the different methodologies. Body mass index for women and waist circumference for men resulted to be the most accurate methods to detect a probable situation of excess of body fat or cardiovascular risk associated. NWAI resulted also a good alternative for overweight classification.

CONCLUSIONS: differences between anthropometric methods for overweight and cardiovascular disease risk classification were confirmed. Classical cut-off point may misdiagnose overweight or health risk in Spanish university students depending of the method employed.