The relationship between body mass index and educational level in young Portuguese males: 1995 and 1999 cohorts.

INTRODUCTION: Over the last decades, a progressive increase in height and weight has been observed throughout Europe. Increase in weight has been more marked however, with a resulting increase in overweight and obesity prevalence. RESULTS published have analyzed the relationship between body mass index (BMI) and educational level. Most studies indicate an inverse relationship between BMI and educational level in developed countries. OBJECTIVE: This study's main objective was to evaluate the relationship between BMI and educational level (years of schooling) in young Portuguese males in 1995 and 1999. METHODS: Transverse study of data (BMI and years of schooling) from the military inspection records of virtually the entire Portuguese male population with an average age of 20 years, examined in 1995 and 1999, totaling 81 363 and 71 254, respectively. Four classes of BMI (<20, 20-24.9, 25-29.9 and > or =30 kg/m2) and four schooling levels (<5, 5-9, 10-12, and >12 years) were considered. We applied the chi2 test for associations between BMI and educational level and the odds ratio to quantify categorical variables. The significance level was 5%. RESULTS: In 1995, 15.2% were overweight (BMI> or =25 years), increasing to 20.8% in 1999. The percentage of obesity (BMI> or =30 years) was 1.4% in 1995 and 2.2% in 1999. The percentage of overweight and obesity increased directly in line with the increase in educational level, both in 1995 and 1999. In 1995, the percentage of subjects with obesity according to years of schooling was as follows: <5 years--1.4%; 5-9 years--1.4%; 10-12 years--1.5% and >12 years--1.7%. In 1999, the results were as follows: <5 years--1.4%; 5-9 years--2.2%; 10-12 years--2.8% and >12 years--3.2%. CONCLUSIONS: We can conclude that the prevalence of overweight and obesity in young male Portuguese increased in the last decade and that, unlike most developed countries, the higher the level of education, the greater the percentage of overweight and obesity, both in 1995 and 1999.