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.