Your child's physical growth during the second year, although considerable, is less rapid than during the first year. In the second year, toddlers gain an average of 3 lb (1.4 kg) to 5 lb (2.3 kg) and grow an average of 3 in. (7.6 cm) to 5 in. (12.7 cm). Normal and expected physical growth requires adequate nutrients and a nurturing environment.
As toddlers start to walk and become more active, they develop leaner and more muscular arms and legs and lose fat around the face and tummy. They also lose some of their baby look.
In the second year, the molars usually begin to come in. These large and flat teeth may cause your toddler pain before and while they are erupting through the gum tissue. This may cause irritability, disrupt sleep patterns, and change your toddler's behavior. For more information about tooth eruption, see the topic Teething.