Examining Childhood Obesity From Infancy: The Relationship Between Tummy Time, Infant BMI-z, Weight Gain, and Motor Development—An Exploratory Study

This exploratory study investigated the infant time spent in tummy time (TT) in relation to body mass index z score (BMI-z), weight gain, and motor development in infants from birth to 4 months. Mothers and their infants were telephone surveyed at 2 and 4 months. Mother demographics; TT; feeding practices; and infant length, and height, and development were collected each time. Results from Cochran–Mantel–Haenszel and single logistic regression showed a significant association between development, level of BMI-z, and time spent in TT at 2 months of age (p < .0001). The threshold model showed there was a decline in BMI-z at 4 months as daily time in TT increases past the threshold value of approximately 12 minutes per day. Mother education and TT at 2 months were significant predictors of BMI-z at 4 months. Study outcomes suggest that infant positioning and time in TT promote infant motor development and may moderate rapid infant weight gain.