Energy balance-related behaviours associated with overweight and obesity in preschool children

A systematic review just published online in the journal Obesity Reviews aimed to systematically identify dietary, physical activity and sedentary behaviours in preschool children (4-6 years of age) that are prospectively related to overweight or obesity later in childhood. Dr. Saskia te Velde is first author of this paper. Prospective studies published between 1990 and 2010 were selected from electronic data bases of scientific publications and 23 papers reporting on 15 different study samples could be included in the review. Strong evidence was found for an inverse association between total physical activity and overweight, i.e. the more the kids were physically active, the less likely they were overweight. Moderately strong evidence was found for a positive association between television viewing and overweight, thus the more they engaged in TV watching, the more likely they were to be overweight. In the reviewed studies dietary intake was assessed is so many different ways that insufficient evidence was found for an association between dietary intake or specific dietary behaviours and overweight. These results suggest that interventions aiming to prevent overweight among preschool children should focus on promotion of total physical activity and limitation of screen time and that further research is needed to establish whether and which dietary behaviours are important for obesity prevention in this age group. However, we also concluded and recommended that despite the lack of evidence for dietary behaviours from the present review, future interventions may already target specific dietary behaviours that are highly prevalent and for which there a clear rationale as well as preliminary evidence that these behaviours are associated with overweight.

A second paper in that same special issue of Obesity Reviews with Dr. Maartje van Stralen as first author reported on secondary analyses of different studies conducted across Europe on weight status and risk behaviors for overweight and obesity in pre-scholers. This study aimed to gain insight in the prevalence of overweight in European preschoolers (4–7 years), to identify energy balance-related behaviours associated with overweight/obesity; and to explore children at risk for overweight and obesity. Secondary analyses of six European data sets were conducted according to standardized protocols. Based on objectively measured height and weight, prevalence of overweight and obesity across the countries ranged from 8% to 30% and 1% to 13%, respectively, with highest rates in Southern European countries (i.e. Spain and Greece). Kids who spend more time in sedentary activities were more likley to be overweight/obese. We concluded that future obesity prevention interventions in preschoolers should target screen time giving specific attention to children from parents who are themselves overweight/obese and from lower socioeconomic positions.