Trends in excess weight and thinness among Spanish schoolchildren in the period 1992-2004: the Cuenca study.

BACKGROUND In developed countries, there is abundant information on the epidemic of childhood obesity, but only a few studies on trends in the dual burden of body weight (overweight and thinness). OBJECTIVE To examine trends in overweight and thinness among 9-10-year-old Spanish children in the last decade. METHODS Data were taken from cross-sectional studies on schoolchildren in Cuenca (Spain), conducted in 1992, 1996, 1998 and 2004 with similar methods. Weight and height were measured by trained personnel with standardized procedures. Overweight (including obesity) and thinness were defined according with the International Obesity Taskforce BMI cut-offs. RESULTS The overall prevalence of overweight increased from 24.4% in 1992 to 30.9% in 2004 (P = 0.07), rising from 21.2% in 1992 to 32.0% in 2004 (P = 0.03) among boys and from 27.7% to 29.8% (P = 0.67) among girls. The overall prevalence of thinness was 2.7% in 1992 and 9.2% in 2004 (P < 0.001); in the same period, thinness prevalence rose from 1.9% to 9.0% (P = 0.10) among boys and from 3.7% to 9.5% (P < 0.01) among girls. CONCLUSIONS The dual burden of body weight has increased among children in Cuenca in the last decade. Population-based policies addressing childhood obesity, which is the most frequent problem, should not increase the risk of thinness.