The prevalence of obesity and overweight is rising worldwide, in the Netherlands, and in Rotterdam, also in children and adolescents. This public health problem is more prevalent in lower socio-economic groups and ethnic minority groups that constitute a major proportion of the Rotterdam population. A positive energy balance causes weight gain, i.e. energy intake (diet) exceeds energy output (physical activity). Long-term successful treatment of obesity is rare and more emphasis should be given to prevention of unnecessary weight gain. Children and adolescents are probably the most important target group for prevention of overweight since overweight is often initiated early in life. For successful prevention a combination of changes in both energy balance behaviours, i.e. diet and physical activity, seems most promising. These two behavioural categories are further associated with other major burdens of disease such as cardiovascular disease, different cancers, diabetes. In order to promote changes in energy balance behaviours it is necessary to have insight into the behavioural determinants. Most research into health behaviour determinants has used cross-sectional designs and has focused on personal, mostly cognitive, factors. It has, however, been proposed that for many health behaviours, and especially for energy-balance behaviours, environmental factors may be more important than personal determinants. More specifically, so-called obesogenic environmental factors, such as excess availability of tasty, low priced, high calorie foods and low and decreasing opportunities and necessity for physical activity, are expected to be important determinants of energy balance behaviours. Such social and physical environmental factors may be more important than cognitive factors in explaining energy balance behaviours especially in children and adolescents since they often have less autonomy and behaviour control than adults. However, recent reviews of the literature show
· Conflicting or lack of evidence on the importance of environmental factors as determinants of energy-balance behaviours, most so for dietary behaviours,
· Lack of strong research designs in studies on potential environmental determinants
· Lack of studies that allow comparison of the importance and interrelationships of potential environmental and personal determinants of energy balance behaviours
The present study proposes to use a longitudinal design to study personal and environmental determinants of energy-balance behaviours. This study will:
1. Identify environmental and personal determinants of behaviours that are associated with overweight and obesity in youth in order to inform intervention development tailored to these determinants, in order to contribute to prevention of overweight and obesity
2. Assess the contribution of these determinants to the higher prevalence of obesity-inducing behaviours, and overweight and obesity, in disadvantaged groups
3. Provide recommendations for obesity prevention interventions tailored to environmental and personal determinants of relevant behaviours in adolescents, for the general adolescent population and for disadvantaged groups.
4. Contribute to health behaviour theory development by providing insight into the relative importance and inter-relationships between determinants at the individual and environmental level for different health-related behaviours
The proposed study builds on the ENDORSE (ENvironmental Determinants of Obesity in Rotterdam StudEnts) which is an ongoing cross-sectional CEPHIR study. The present application proposes a longitudinal follow-up phase to ENDORSE to ensure analyses of prediction instead of mere association.