The myth and reality of familial resemblance in dietary intake: a systematic review and meta-analysis on the resemblance of dietary intake among parent and offspring.

Background: There is a strong societal belief that parents are role models for their child's dietary behaviours in early life that may persist throughout the life course. Evidence has shown inconclusive dietary resemblance in parent-child (PC) pairs. This systematic review and meta-analysis aimed to examine dietary resemblance between parent and children. Methods: We systematically searched for studies on PC dietary resemblance, via six electronic databases (PubMed, Ovid MEDLINE, Embase, APA PsycNet, CINAHL, and Web of Science) and other grey sources of literature between 1980 and 2020. We performed quality effect meta-analysis model on transformed correlation coefficients (z) to examine the resemblance in dietary intakes including nutrient intakes, food group intakes and whole diet. Finally, the Fisher's transformed coefficient (z) was used for meta-regression analysis to identify potential moderators. Heterogeneity and inconsistency were examined using the Q and I2 statistic. The study is registered on PROSPERO, CRD42019150741. Findings: A total of 61 studies met the inclusion criteria for systematic review, 45 were included in the meta-analysis. Pooled analyses showed weak to moderate PC dietary intake associations for energy: (r: 0.19; 95% CI: 0.16, 0.22), fat (% energy): (r: 0.23; 95% CI: 0.16, 0.29), protein (% energy): (r: 0.24; 95% CI: 0.20, 0.27), carbohydrate (% energy): (r: 0.24; 95% CI: 0.19, 0.29), fruits and vegetable (g/d): (r: 0.28; 95% CI: 0.25, 0.32), confectionary food (g/d): (r: 0.20; 95% CI: 0.17, 0.23), and whole diet (r: 0.35; 95% CI: 0.28, 0.42). Dietary intakes associations by study characteristics, including population, study year, dietary assessment method, person reporting dietary intake, quality of the study, and study design were highly variable, but associations were similar between PC pairs. Interpretation: The resemblance among parent-child pairs was weak to moderate for most aspects of dietary intakes. These findings challenge the social myth that parental dietary intake behaviour shapes their child's dietary intake. Funding: None.