Prevalence of overweight and obesity and associated lifestyle, socio-demographic and environmental factors among children in the age of 4 - 13 years in the city of Zwolle.

In the period 1980-1997 the prevalence of overweight and obesity among children
clearly increased (HiraSing et al., 2001). Recent figures by TNO 'kwaliteit van
leven' and VUmc (March, 2006) confirmed this development (van den Hurk, 2006).
This is worrisome because especially obesity in children is associated with
increased cardiovascualr risk, diabetes mellitus type 2 and psychosocial
problems. In addition overweight in childhood predicts overweight in adulthood.
Moreover, adults who were obese children have an increased risk on morbidity
and mortality independent of their adult weight.
Overweight is considered as one of the largest Public Health problems.
Therefore early prevention starting at a young age is very important.

The objective is to study the trends and the prevalence of overweight and
obesity among children in the age of 4 - 13 years in the city of Zwolle.
Moreover, sociodemographic, lifestyle and environmental factors associated with
overweight and obesity will be studied.
The results of ChecKid will contribute to the examination of the effect of a
Community Based Intervention which is momentarily in development in a couple of
neighbourhoods in Zwolle. In addition this research gives an insight in eat-
move- and (in)activity behaviour and its determinants of children in Zwolle.
These results can be related to BMI and waist circumference, because body
height, weight and waist circumference are measured in al children. Moreover
clustering of (un)healthy behaviour and associations between individual
behaviour, physical and social environment will be looked at so that
interventions can be implemented more efficiently.

All primary schools in Zwolle will be invited to participate in the ChecKid
study by means of a letter and a telephone call. When a school gives
permission, all parents and children will be invited to participate by means of
a letter. With this letter, an informed consent is enclosed.
In ChecKid 2006, 80% of 46 schools gave permission for participation. The
remaining schools refused mostly because of logistic reasons. Fifty-six percent
of the parents handed in a written informed consent. The participation is
expected to be about the same for ChecKid 2009.
The study consists of measuring body height, weight and waist circumference by
trained students of Hogeschool Windesheim, using protocols for all
measurements. Besides these anthropometrical measurements, the parents of all
participating children and the children in class 6, 7 and 8 are asked to fill
out a questionnaire. The parental questionnaire contains questions about
sociodemographic characteristics of parents and child, children*s lifestyle
factors (nutrional- and physical activity behaviour) and physical environment.
These questionnaires will be taken home from school by the children. The
children*s questionnaires will be filled out in class, during school hours and
contains questions on nutrional- and physical activity behaviour. The study
will only be performed in those kids whose parents have allowed them to
participate by signing an informed consent form. When a child is at the age of
12 or older, a written informed consent is needed from them as well.

Length, weight and waist circumference of all participating children is
measured at one moment. In addition parents of all participating children are
asked to fill in a questionnaire and all children of 9-12 years are also asked
to fill in a questionnaire. To fill in a questionnaire takes about 30 min.
there is no risk for the participants.