Parent healthful eating attitudes and motivation are prospectively associated with dietary quality among youth with type 1 diabetes.

A family-based behavioral nutrition intervention grounded in Social Cognitive and Self-Determination Theories showed an increased intake of whole plant foods. This study examined 1) whether the intervention changed parent diet-related attitudes/beliefs, 2) whether these attitudes/beliefs were associated with youth diet quality, and 3) the moderating roles of youth age and parent nutritional knowledge. Youth with type 1 diabetes and their parents (n = 136, mean ± SD youth age = 12.6 ± 2.8 years) participated in an 18-month trial targeting intake of whole plant foods. Parents reported attitudes/beliefs (self-efficacy, outcome expectations, perceived barriers, autonomous and controlled motivation) for providing healthy food to their families, and type 1 diabetes-specific nutrition knowledge at 6, 12, and 18 months. Whole Plant Food Density (WPFD; cup or ounce equivalents per 1000 kcal of whole grains, fruit, vegetables, legumes, nuts and seeds) was calculated from 3-day youth food records. Linear mixed models estimated the intervention effect on parent attitudes/beliefs, associations of parent attitudes/beliefs with youth WPFD and the moderating roles of parent nutrition knowledge and youth age. There was no effect of the intervention on parent attitudes/beliefs. Across groups, higher parent self-efficacy and autonomous motivation were positively associated with youth WPF. Parent perceived barriers and negative outcome expectations were inversely associated with youth WPFD, especially when parents had higher nutrition knowledge. Youth age did not modify any associations. Parent diet-related attitudes/beliefs were associated with youth diet quality, highlighting the importance of parent psychosocial factors across this age range. Despite a positive effect on youth diet, the intervention did not affect parent attitudes/beliefs, suggesting it worked through a different mechanism.