Growth is, along with learning, the essential determinant of health and wellbeing in a child. In year 1, it is all about the food, milk initially and then the introduction of solids when appropriate.
In the years thereafter nutrition remains vital, but the growth hormone, IGF-1 and thyroid, as well as good health become integral parts of growth. Monitoring height and weight are essential to ensure appropriate growth (not too big or too small!).
As a rule of thumb:
Girls height = (dad’s height -13cm) + mom’s height / 2
Boys height = (Mom’s height + 13cm) + dad’s height / 2