Childhood obesity

By Dr. Davide Sganzerla

Childhood obesity is a problem of considerable social importance. The phenomenon, which affects one child in four in Italy, is the result of a positive energy balance continued over time; in practice, more calories are introduced than are consumed.

Insights

Definition of childhood obesityCauses of childhood obesityConsiderations of childhood obesityChildhood obesity in ItalyChildhood obesity in Europe and the WorldChildhood obesity: solutions Prevention of childhood obesityChildhood obesity: prevention

The definition of overweight and childhood obesity is more complex than the adult, whose ideal weight is calculated based on the BMI (Body Mass Index or Body Mass Index), which is equal to the weight in Kg divided by the height in meters high squared. (Confalone, 2002).

Despite having low error of observation, low measurement error, good reliability and validity, BMI cannot be a sensitive measure of obesity in very tall and low people, and in people who have unusual compositions of lean mass and fat mass. (Sardina, 1999). However, a competent committee, convened in the International Obesity Task Force in 1999, determined that - although the BMI was not an ideal measure - it was still the most valid of all the formulas that calculate adiposity in an individual, and therefore could be used to define overweight and obesity in children and adolescents. (Bellizzi, 1999).

Based on these conclusions, the WHO (World Health Organization), to define a child as overweight and obese, uses the "points" of BMI made by a Cole study in 2000 and developed using different global data. For this reason, they represent an international reference that can be used to compare the different world populations.

The Italian Ministry of Health defines as obese a child whose weight exceeds the ideal one by 20%, and overweight if it exceeds 10-20%; alternatively, it defines it as its BMI is greater than expected. The weight growth of the child is calculated by referring to the percentile tables, graphs that combine the percentage values of weight and height of children, divided by sex and age. (Confalone, 2002).

According to recent studies, carried out in 2000 by the NCHS (National Center for Statistics for US Health), growth is normal if it is around the 50th percentile, while the more the average value is exceeded the more the risk of obesity increases; therefore, from the 85th to the 95th percentile the child is defined as overweight while from the 95th percentile he is defined as obese. (Kuczmarski, 2000).