Impact of complementary feeding on obesity risk

Purpose of reviewTo discuss recent evidence on the influence of complementary feeding (CF) timing, content and feeding methods on childhood obesity risk.Recent findingsThe evidence-base is limited by heterogeneity, risk of bias and the predominance of observational studies. The content of the diet and feeding practices are more influential than timing for obesity risk. There is limited evidence that CF introduction before 4 months may be associated with increased risk. Intake of animal protein, particularly dairy protein, may contribute to rapid weight gain; protein from infant/follow-on formula shows the most robust association with later obesity risk. Evidence linking sugar intake to obesity risk is limited, but intake should be as low as possible given there is no nutritional requirement. Responsive feeding (RF) practices may promote appropriate infant growth and reduce risk. The effect of baby-led weaning (BLW) is inconclusive.Recent evidence supports current recommendations to avoid high protein intakes, especially from infant/follow-on formula, for infants in high income countries; and to promote RF practices for all infants. Studies in low- and middle-income countries are required to define optimal CF practices given increasing rates of child obesity alongside double-burden malnutrition.