Prevalence of obesity and related factors in schoolchildren aged 3 to 4 years

To describe the prevalence of obesity and analyse possible differences in it according to sociodemographic characteristics, diet, physical activity, screen use and family perception of the weight and dietary habits of schoolchildren aged 3 to 4 years in Barcelona.

We conducted a cross-sectional study in a representative sample of schools selected based on the socioeconomic status (SES) of the corresponding neighbourhood and school ownership. We selected 101 schools in Barcelona and recruited pupils aged 3 to 4 years during the 2016-17 academic year (n = 2936 children). Anthropometric measurements were taken in each participant. Family members completed a questionnaire on eating habits, physical activity, sleeping hours, screen use and the family's perception of the child's weight and diet. The primary variable was the body mass index (BMI) for age and sex, subsequently categorised as normal weight, overweight or obese.

Approximately 7.0% of girls and 7.1% of boys aged 3 to 4 years presented obesity. The prevalence of obesity (8.3%) was higher in neighbourhoods of lower SES compared to those of higher SES (5.2%; p = .004). Parents of children with obesity reported that the child had some excess weight or excess weight in 46.9% of cases, 3.9% indicated the child's weight was appropriate and 0.9% that the child was a little underweight or underweight (p < .001).

The prevalence of obesity in children aged 3 to 4 years is high. There are social and geographical inequalities, and obesity was more prevalent in areas of lower SES. A large percentage of the families of children with obesity do not consider that the child's weight is excessive.