A systematic review of the evidence: The effects of portion size manipulation with children and portion education/training interventions on dietary intake with adults

Background: Evidence shows that 3-5-year-old children undergo important physical and behavioral changes that include being affected by the amount of food they are served, with larger portions of food served resulting in greater dietary intake. This may be a key finding as researchers continue to identify effective treatments for the growing number of preschool children who are overweight or obese. Knowledge of the effects of varying portion sizes on young children's dietary intake is important; however, because parents of young children control the manner in which children are fed, educating parents regarding the estimation of portion sizes is an approach worth exploring as a way to affect the trajectory of their young child's weight gain. Aims: The purposes of this systematic review were to determine (1) findings regarding the effect of varying portion sizes with young children and (2) the evidence regarding the effects of educating adults to estimate portion sizes. Evidence from this review may guide clinical practice and future research efforts. Methods: A comprehensive literature search was conducted with multiple databases using MeSH Headings and keywords. This search strategy was supplemented by ancestry searches of all relevant articles. Two independent, trained pediatric practitioners determined quality of the studies using established criteria. Results: Nine studies met the inclusion criteria as portion-manipulation interventions or portion-education/training interventions and were appraised. Evidence showed the positive effect of portion sizes on the energy intake of children. In addition, the ability of adults to accurately estimate portion size improved following education/training. Conclusions: Although many studies have focused on a variety of portion-related interventions, the influence of portion education with parents of young children has not been well researched. More research is needed to understand the effect of parent-focused, portion-education interventions that encourage appropriate energy intake and healthy weight attainment in young children.