Impact of Plant-Based Diets on Children’s Growth, Nutritional Biomarkers, and Health Outcomes and Risks: A Systematic Review

CONTEXT: Plant-based diets are becoming increasingly popular among families for health, environmental, and ethical reasons. However, concerns persist about their adequacy for children who have unique nutritional needs during critical growth and developmental stages. OBJECTIVE: This systematic review examines the impact of restricting animal-sourced foods in children aged 6 months to 11 years, focusing on growth metrics, nutritional biomarkers, and health outcomes. DATA SOURCES: A comprehensive search was conducted in PubMed, Web of Science, Embase, Scopus, and CINAHL Plus (October 2024). DATA EXTRACTION: From 2721 records and 8 manually added articles, 31 articles met the inclusion criteria. Two reviewers independently screened the studies, with disagreements resolved upon discussion with 2 additional reviewers. DATA ANALYSIS: Restrictive plant-based diets during complementary feeding (6-24 months) were linked with nutrient deficiencies, growth deficits, and developmental delays. Among toddlers and preschoolers (24-60 months), vegan and macrobiotic diets were associated with moderate height and weight deficits, whereas lacto-ovo vegetarian diets were associated with normal growth. Vegan preschoolers showed distinct metabolic profiles, including lower cholesterol and higher adiponectin-to-leptin ratios. In prepubertal children (6-11 years), vegan diets supported adequate growth but were often accompanied by iron and B12 deficiencies. Despite similar bone mineral density, vegetarian children had higher bone turnover markers. Across ages, vegan diets were associated with lower fat mass and favorable cardiovascular risk markers. Balanced plant-based diets with essential micronutrient supplementation reduced nutritional concerns. CONCLUSIONS: Well-planned plant-based diets can support healthy growth in children, but strict avoidance of animal-sourced foods during critical periods may cause deficiencies in iron, vitamins A, D, B12, and docosahexaenoic acid (DHA), affecting overall and bone growth, immune function, and cognitive development. Impacts vary by developmental stage, dietary pattern, supplementation, and cultural context, emphasizing the need for individualized planning and monitoring. SYSTEMATIC REVIEW REGISTRATION: PROSPERO registration No. CRD42024568306.