Maternal obesity can result in unfavorable (epigenetic) pre- and postnatal programming of important genes of the offspring. Infants of overweight mothers have faster weight gain during the fetal period (i.e. higher birth weight) and infancy.
Several epidemiological studies and systematic reviews confirmed the relationship between rapid weight gain 0-12 mo and childhood- as well as adult obesity. Our longitudinal data indicate a strong correlation between weight gain during the first year and BMI at 5 years (R=0.46; p<0.0001).
Weight gain and BMI at 12 mo is associated with protein concentration in breast milk (5). Infants fed traditional high protein formulas have higher weight than breastfed infants at least until 24 months. Three randomized clinical trials indicate that infants receiving new whey-based low protein formulas (1.7g/100kcal) have lower weight gain during the first 12 months than infants receiving isocaloric higher protein formulas (2.4g/100kcal; p 0.05).
Several factors might contribute to the global childhood obesity pandemic. High protein intake during infancy is not the only risk factor but can be easily corrected by promoting breastfeeding >6 mo or if breastfeeding is too short for the use of low protein formula at least until 12 months.