LAUSR

Leptin contributes to the control of food intake and energy balance. However, its association with appetitive behaviors during childhood is not well understood. We aimed to investigate the association between leptin, assessed at birth and at 7 years of age (y), and appetitive behaviors assessed at 7 and 10 y. Children from a Portuguese cohort with assessment of leptin levels at birth from umbilical cord blood (n = 645) and at 7 y from venous blood samples (n = 587), were included. The Children's Eating Behavior Questionnaire assessed appetitive behaviors at 7 and 10 y. Weight and height were measured at 7 and 10 y to derive BMI z-scores (BMIz). Generalized linear models were adjusted for maternal age, education, pre-pregnancy BMI, smoking during pregnancy, child physical activity and BMIz, and interactions terms for child sex and child BMIz. At 7 y, 116 boys and 118 girls were classified as having overweight/obesity, and these children had higher leptin levels. Higher leptin at 7 y was significantly associated with lower scores on Satiety Responsiveness, Food Fussiness and Slowness in Eating, and higher scores on Food Responsiveness, Enjoyment of Food and Emotional Overeating at 7 y. Significant interaction effects between child sex and leptin were found for appetite at 7 y such that higher leptin was associated with higher Food Responsiveness (p < 0.001) and lower Slowness in Eating (p < 0.001) to a greater extent among boys. Umbilical cord blood leptin was not associated with appetitive behaviors at 7 or 10 y. Our results show that leptin levels are positively associated with food approach and negatively with food avoidant behaviors. Associations tended to be stronger among boys, were more consistent in cross-sectional analyses (at 7 y), and were dependent on child weight. Our findings support a role for leptin in affecting appetite, with potential consequences for current weight status and future weight gain.