Optimizing early life nutrition: An EPA-UNEPSA overview for general pediatricians on essential nutrients and feeding practices during the first 1000 days

Background The first 1,000 days of life, spanning from conception to two years of age, constitute a critical period for growth, neurodevelopment, immune maturation, and metabolic programming. Nutritional exposures during this developmental window have lasting effects on cognitive function, physical health, and disease susceptibility throughout life. Given the rapid evolution of nutritional evidence and variability among international recommendations, general pediatricians require practical, evidence-based guidance to optimize infant and early childhood nutrition. Methods This EPA-UNEPSA overview integrates current evidence from peer-reviewed literature, international clinical guidelines, and expert consensus regarding nutritional requirements and feeding practices during the first 1,000 days. A structured search of PubMed/MEDLINE, Scopus, and Web of Science (2000–February 2026) was complemented by recommendations from major international organizations, including the World Health Organization, UNICEF, the American Academy of Pediatrics, and the European Society for Pediatric Gastroenterology, Hepatology and Nutrition. Emphasis was placed on high-quality evidence addressing nutrient requirements, feeding strategies, neurodevelopment, and long-term health outcomes. Results This review summarizes current recommendations on breastfeeding, complementary feeding, early allergen introduction, probiotic use, and appropriate supplementation, together with the physiological roles, dietary sources, and clinical significance of essential macro- and micronutrients during early life. Particular attention is given to nutrients critical for brain development. The review also highlights the importance of nutrient timing, bioavailability, nutrient interactions, and individualized nutritional assessment. Evidence indicates that deficiencies during sensitive developmental periods may result in serious impairments in neurodevelopment, growth, immune competence, and long-term metabolic health, whereas inappropriate supplementation may also adversely affect outcomes. Conclusions Optimal nutrition during the first 1,000 days represents one of the most effective strategies for promoting lifelong health and human development. By translating current scientific evidence and international recommendations into practical clinical guidance, this EPA-UNEPSA overview provides general pediatricians with a comprehensive framework to support evidence-based nutritional counseling, prevent nutrient deficiencies, optimize neurodevelopment, and improve long-term health outcomes.