Prevalence of overweight and obesity in 7-9-year-old Portuguese children: trends in body mass index from 1970-2002.

The aim of this study was to assess the prevalence of overweight and obesity in Portuguese children age 7-9 years and to analyze trends in body mass index (BMI) from 1970-2002. Data were collected from October 2002 to June 2003 in a random sample of Portuguese children. Height and weight were measured and BMI (Kg/m(2)) was calculated. The International Obesity TaskForce (IOTF) cutoffs to define overweight and obesity were used. In the total sample we found 20.3% of overweight children and 11.3% of obese children. These results indicate a prevalence of overweight/obesity of 31.5%. Girls presented higher percentages of overweight than boys except at age 7.5. Girls also showed a higher percentages of obesity than boys except at age 9. From 1970 to 1992 and 1992 to 2002, height, weight, and BMI increased at different velocities: weight increased faster than height, and, consequently, BMI increased more in the last period than in the first one, leading to an increase in obesity values. Compared to published data by IOTF on other European countries, who applied the same methods to define overweight and obesity, Portuguese children showed the second-highest mean values in overweight/obesity. Italy showed the highest values (36%). The present study shows a very high prevalence of overweight/obesity (31.5%) in Portuguese children compared to other European countries. Portugal followed the trend of other Mediterranean countries like Spain (30%), Greece (31%), and Italy (36%). These high values require a national intervention program to control childhood obesity.