Supporting strategies for enhancing vegetable liking in the early years of life: an umbrella review of systematic reviews

BACKGROUND: Many children worldwide do not eat recommended amounts of vegetables. Disliking vegetables is a key factor associated with low intake. OBJECTIVE: This umbrella review synthesized systematic reviews to determine the effectiveness of sensory and behavioral strategies to facilitate liking of vegetables (primary outcome) in young children up to 5 y of age, as key predictors of vegetable intake (secondary outcome). METHODS: Nine databases were searched up to May 2019 (updated in September 2020). Two reviewers independently conducted study screening and selection, data extraction, and assessment of methodological quality using AMSTAR 2 (A MeaSurement Tool to Assess systematic Reviews). Eleven reviews (n = 1 rated strong quality, n = 4 moderate quality, n = 6 low/critically low quality) examining 85 primary studies met the review criteria: systematic reviews and meta-analyses of primary studies (any quantitative design) that examined sensory or behavioral strategies on vegetable liking or intake (outcomes reported separately for children ≤5 y). Strategy effectiveness was synthesized into 3 categories based on evidence strength: 1) promising (large and consistent body of moderate quality evidence), 2) emerging (small to moderate body of mixed consistency and quality evidence), and 3) limited (small body of limited consistency and quality evidence). RESULTS: Promising evidence was identified for repeated exposure to a single or a variety of vegetables. Emerging evidence was identified for several strategies that increase familiarity with vegetable flavors (e.g., via exposure in utero and through breast milk, and a "vegetable first" approach to complementary feeding) and/or willingness to try vegetables (e.g., via parental role modeling, nonfood rewards, and vegetable-based story books). CONCLUSIONS: Current evidence supports incorporation of tailored advice into guideline documents for parents and carers to repeatedly expose their children to a variety of vegetables to increase vegetable intake. Ongoing robust research on strategies to facilitate children's liking of vegetables is warranted to strengthen the evidence base underpinning advice for parents and health professionals.