NUTRITION DURING THE FIRST ONE THOUSAND DAYS AND THE RISK OF OBESITY

Abstract

The first 1,000 days of life represent a critical developmental window during which nutritional exposures may influence growth trajectories, body composition, and health throughout the life course. This narrative review aimed to analyze the relationship between nutrition during the first 1,000 days and the risk of obesity, considering maternal and child nutritional exposures, different developmental periods, and the isolated or concomitant occurrence of risk factors and their outcomes. Sixteen longitudinal studies published between 2009 and 2025 were analyzed. maternal and/or child nutritional exposures were assessed in 68.75% of the studies, including maternal dietary patterns, consumption of ultra-processed foods, breastfeeding, and complementary feeding. Greater adherence to healthy dietary patterns during pregnancy was associated with a lower risk of overweight and obesity in childhood, whereas higher maternal consumption of ultra-processed foods was associated with a greater risk of overweight in offspring. Higher maternal carbohydrate intake was associated with increased methylation of the RXRA gene in umbilical cord DNA, which was related to greater fat mass and body fat percentage in children. The coexistence of multiple unfavorable factors was associated with a greater risk of overweight and adiposity. In one cohort, the predicted probability of overweight/obesity ranged from 9.4% under favorable conditions to 63.6% under unfavorable conditions. Additionally, rapid weight gain during infancy was associated with subsequent changes in body composition. These findings suggest that nutrition during the first 1,000 days is associated with growth and adiposity outcomes and epigenetic alterations related to body composition; however, further mechanistic studies are needed.