Effect of a web-based nutrition intervention among families to increase regular-fat and low-fat dairy products: a randomized controlled trial.

OBJECTIVES

This study evaluated the effect of a family- and web-based nutrition intervention, "Dairyathlon," promoting regular- or low-fat dairy consumption on dairy and calcium intakes, diet quality, and weight outcomes.

METHOD: Fifty-seven families, 108 parents and 109 children participated in an 8-week web-based nutrition intervention. They were randomly assigned to either Control, Low-fat dairy, or Regular-fat dairy group. All groups received education based on the 2019 Canada's Food Guide. Intervention groups were asked to include four daily servings of dairy (milk, cheese, and two yogurt servings). Three assessments were completed at baseline (T0), postintervention (T1), and 4-6 months follow-up (T2) for dietary intake via three 24-hour web-based dietary recalls and anthropometric.

RESULTS

In parents, a significant effect of the intervention was observed, indicating differential changes over time across groups. Post hoc analyses showed that both intervention groups increased dairy consumption and calcium intake at T1. Specifically, Low-fat group increased dairy intake from 2.1 ± 0.2 to 3.1 ± 0.3 servings/day (P = 0.03) and calcium intake (P = 0.04), while dairy intake in Regular-fat group increased from 2.3 ± 0.2 to 3.5 ± 0.3 servings/day (P = 0.006) and calcium intake (P = 0.02). Only dairy consumption remained elevated at follow-up in the Low-fat group, which was significantly higher than in the Control group (2.7 ± 0.2 versus 1.6 ± 0.2 servings/day, P = 0.04). A significant interaction was also observed for diet quality; C-HEI was significantly higher at follow-up compared to baseline among parents in the Low-fat group. No significant changes were observed in children.

CONCLUSION

Dairy and calcium intake improved among parents in the intervention groups during the program's active phase; however, sustained effects were limited. A significant effect at follow-up was observed only for the low-fat dairy intake group among parents. Web-based, family-centered approaches may facilitate targeted dietary changes, but additional strategies are necessary to achieve lasting, clinically meaningful impacts.

TRIAL REGISTRATION NUMBER: ClinicalTrials.gov [Full-fat Dairy Products, Body Weight Control and Metabolic Health]; [NCT05417347]; [https://clinicaltrials.gov/study/NCT05417347?titles=NCT05417347&rank=1].