Curvilinear Associations between Weight Status and Diet Variety in Children Referred for Eating Problems
Author(s): Helen M. Hendy, Marsha B. Novick, Keith E Williams and Laura J. Seiverling
Background: Past research has found positive linear associations between weight status and the variety of grains, proteins, and snack
foods accepted by children and adults, but with negative linear associations for vegetables. To date, the literature has only examined linear
associations between these variables. With their broad range of body mass index (BMI) z-scores in comparison to same-aged peers, children
referred to clinics for the treatment of eating problems provide a unique opportunity to examine both linear and curvilinear associations
between children’s BMI z-scores and the number of foods accepted. Methods: Participants included 587 children with various problems with eating, such as poor weight gain, selective eating, and/or overweight
with autism spectrum disorder, other special needs, and no special needs. Clinic staff measured children’s height and weight to calculate BMI
z-scores and parents completed surveys to report children’s acceptance of 77 common foods from six food groups. Results: ANCOVAs found greater diet variety accepted by children who were older, female, without special needs, and with higher BMI
z-scores. Hierarchical multiple regression revealed the expected positive linear associations, but also J-shaped curvilinear associations
between BMI z-scores and diet variety for fruits, vegetables, proteins, grains, and dairy foods with upswings in diet variety for both
underweight children (BMI z-scores < -2.00) and especially for children with severe obesity (BMI z-scores > +2.00).
Conclusion: These results suggest that only encouraging children to eat a variety of foods will not be a successful weight management
strategy. The willingness of underweight children to eat a variety of foods may also help promote weight gain through offering a variety of
foods at meals and snacks to decrease satiation and increase intake.