Inverse but independent trends in obesity and fitness levels among Greek children: a time-series analysis from 1997 to 2007.

OBJECTIVE We examined secular trends in physical fitness and BMI status in 8- to 9-year-old Greek children during an 11-year period (1997-2007). METHODS Population data derived from a yearly health survey performed in over 85% of Greek schools. Anthropometric measurements and physical fitness tests from 651,582 children were analyzed. The gender- and age-specific BMI cut-off points by the International Obesity Task Force were used to define overweight/obesity. RESULTS Aerobic performance decreased by 4.9% (p < 0.001) for boys and 4.4% (p < 0.001) for girls between 1997 and 2007 while obesity increased by approximately 50% in both genders (p < 0.001). Time-series analyses revealed that the increasing trends in obesity were independent of the reduction in fitness levels. An increase from 21% in 1997 to 48.2% in 2007 was observed in the prevalence of the low quartile of aerobic performance for girls (p < 0.001) and from 25.7% in 1997 to 38.7% in 2007 (p < 0.001) for boys. Approximately 80% and 85% of obese boys and girls, respectively, failed to pass the low quartile of all aerobic tests in 2007. CONCLUSIONS Inverse but independent trends in obesity and fitness levels were observed among Greek children during an 11-year period (1997-2007), a fact that predisposes our children to serious health risks as they grow older.