Objective: Rapid infant weight gain has been shown to predict later obesity risk; however, it is unclear which factors influence infant diet and weight gain. The objective of this study was to determine whether different feeding patterns and energy intakes that are provided to infants affect body weight and BMI later in childhood.
Methods: This representative birth cohort study was conducted in the United Kingdom. Energy intake at age 4 months was estimated from 1-day unweighed dietary records in 881 infants and related to their childhood weight gain and BMI.
Results: Among formula- or mixed-fed infants (N = 582), energy intake was higher in first-born infants (mean +/- SE: 2730 +/- 29.4 kJ/day; n = 263) than in subsequent-born infants (2620.8 +/- 25.2 kJ/day; n = 296). Energy intake at 4 months was also higher in infants who were given solid foods earlier (1-2 months: 2805.6 +/- 50.4 kJ/day, n = 89; 2-3 months: 2658.6 +/- 25.2 kJ/day, n = 339; 4+ months: 2587.2 +/- 46.2 kJ/day, n = 111). Higher energy intake at 4 months predicted greater weight gain between birth to age 1, 2, or 3 years and larger body weight and BMI at ages 1 to 5 years. No significant associations were seen in breastfed infants (N = 299).
Conclusions: Among formula- or mixed-fed infants, dietary energy intake at age 4 months predicted postnatal weight gain and childhood obesity risk. Both prenatal and postnatal factors may influence infant energy intake and postnatal weight gain.