Prevalence of childhood overweight in Northwestern Spain:: a comparative study of two periods with a ten year interval

OBJECTIVE: To determine the prevalence of overweight children and its modifications over a period of 10y and whether changes in overweight prevalence is similar in the inland and coastal areas in our country. DESIGN: Cross-sectional study in two stages, the initial survey being in 1985 and the second in 1995. SUBJECTS: 1131 children (827 and 304 from coastal and inland areas respectively) in the initial survey, and 903 children (695 and 208 from coastal and inland areas) in the second survey, of both sexes, aged from 6 to 15 y were selected by a random process from the total school population in the Province of Pontevedra, North-western Spain. MEASUREMENTS: Overweight was defined in terms of body mass index (BMI), using Spanish standards. Children having BMI at or above the 85th percentile were classed as overweight and at or above the 95th percentile as very overweight. RESULTS: Overall prevalence of overweight and very overweight were significantly higher in the second survey than in the first, 18.1% vs 11.7%, P < 0.05 for overweight prevalence and 6.8% vs 2.7%, P < 0.05 for very overweight prevalence respectively. When we compared modifications in overweight prevalence over the period 10 y between the inland and coastal areas of our country, increase prevalence was observed in the inland area 9.8% vs 19.7%, P < 0.05 for initial and secondary surveys respectively, whereas in the coastal area overweight prevalence remains stable, 20.2% vs 17.6%, P > 0.05. CONCLUSION: An increased prevalence of overweight children of both sexes in over a period of 10y was observed, however, this increase was particularly caused by an increased prevalence in the inland area whereas in coastal area it remained stable. We speculate that differences in overweight prevalence between both areas might be due to differences in physical activity associated with different degrees in technological development between inland and coastal areas.