ABSTRACT
Infancy is the period of the life cycle with the highest growth rate, and thus meeting energy and nutrient needs is critical to ensure optimal development. Infants have comparatively high needs for most nutrients relative to body size. Mature human milk remains relatively stable in composition during lactation, although longitudinal declines occur in protein content and some micronutrients. When human milk is not available, an alternative human milk substitute should be recommended. Complementary feeding, the inclusion of other foods and liquids besides human milk or infant formula, generally starts around 6 months of age and continues to 24 months of age. Consumption of meat also increases protein intake, for which caution has been raised with regard to potential accelerated weight gain and risk of obesity later in life. In Westernized settings, complementary foods have been introduced one food and one food group at a time with the rationale that allergies/intolerance can be readily identified.
