Addition of Supplementary Foods and Infant Growth (2 to 24 Months)
Betty Ruth Carruth, PhD, RD, Jean D Skinner, PhD, RD, Kelly S. Houck, MS, and James D. Moran III, PhD
Nutrition Department (B.R.C., J.D.S., K.S.H.), Child and Family Studies Department (J.D.M.), College of Human Ecology, University of Tennessee, Knoxville, Tennessee [bcarruth@utk.edu]
Objective: To determine the effect of adding supplementary foods on infant growth 2 to 8 and 12 to 24 months.
Methods: Length (cm/month) and weight (kg/month) of white infants (n=94) were measured five to nine times from 2 to 24 months of age. Mothers reported birth weights, infants’ ages at first introduction of supplementary food, illnesses and information sources about infant feeding. Simple linear regression equations were used to compute slopes for each child (unit changes in length and in weight by age). Stepwise linear regression was used to determine the effect on weight and length slopes by the introduction of supplementary foods (e.g., an infant’s age when cereal, fruit, juice, vegetables and a meat cluster were first added) to the diet. Breast feeding (months duration or ever fed), illness scores and gender were covariates in the regression models.
Results: A significant model (F=10.09, p=.002) for weight gain (2 to 8 months) showed that gender explained 10% of the variance; for length slope, the model was non-significant and gender explained 3% of the variance. Females had a slower weight gain compared to that of males. None of the covariates or supplementary foods were retained in the models. Weight prior to 12 months was the best predictor (p=.0001, 54% of the variance) of weight gain 12 to 24 months.
Conclusions: Unit changes in weight or length for an infant’s age were not statistically associated with the timing of when supplementary foods were first added to the diet 2 to 8 or 12 to 24 months. Weight prior to 12 months was a significant predictor of weight gain 12 to 24 months.