Appetitive behaviors and body composition in school-age years: Bi-directional analyses in a population-based birth...

Cross-sectional studies have consistently associated appetitive behaviors with child body mass index. However, few prospective studies have investigated the association between appetite and other measures of body composition and its directionality. We aimed to investigate the bi-directional relationship between appetitive behaviors and body composition in school-aged children. Data from 3668 children of the Generation XXI birth cohort were analyzed. Appetitive behaviors were assessed at 7 and 10 years through the Children's Eating Behavior Questionnaire. Higher fat mass and fat-free mass were measured through tetrapolar bioelectric impedance and waist-to-weight and waist-to-height ratios were calculated. Fat and fat-free mass indexes, waist-to-weight and waist-to-height age- and sex-specific z-scores were then calculated. Cross-lagged analyses were performed (body composition at 7 to appetitive behaviors at 10 and the reverse) to measure the magnitude and direction of associations. Fat mass and waist-to-height ratio at 7y predicted greater food approach behaviors at 10y (Enjoyment of Food, Food Responsiveness, Desire to Drink and Emotional Overeating), but not waist-to-weight, which seems to be consequence of child's avid appetite (e.g. Enjoyment of Food at 7y: β_standardized = 0.085, 95%CI = 0.041; 0.128, p < 0.001). Child scores on food avoidant behaviors, such as Satiety Responsiveness (β_standardized = -0.073, 95%CI = -0.110;-0.034, p < 0.001) and Slowness in Eating (β_standardized = -0.080, 95% CI = -0.120;-0.041, p < 0.001) at 7y predicted lower fat-free mass at 10. Appetitive behaviors may not solely predict weight status, but the path of association between body composition and later appetitive behavior may also be true, especially for food approaching behaviors and adipose tissue. Interventions aiming to prevent excess weight should focus on appetitive behaviors. Moreover, in children with higher adiposity, other pathways also seem to regulate appetite and need to be considered in interventions.