Abstract
The complementary feeding period, when solids and liquids other than breast milk and formula are added to the infant diet, is an important development window shaping infant growth and weight gain, metabolic development, and lifelong eating practices. Yet, relatively little is known about how the timing and types of foods offered to infants at this stage may shape their growth and subsequent risk of developing obesity. This narrative review describes the existing literature on complementary feeding practices, discusses potential biological and behavioral pathways linking complementary feeding practices to the development of obesity, and offers potential avenues for intervention. While further research is needed to more fully understand optimal complementary feeding practices, existing evidence supports the importance of healthful early feeding practices in the physiological and behavioral regulation of growth and metabolism and the need for early intervention to prevent the development of obesity.