K.C.
The way to tell if they are about to have a growth spurt is to check their weight. They always eat more and gain weight (getting what my friends and I jokingly called a 'buddha belly') right before a growth spurt. After the growth spurt, they will eat less than usual for a few days before resuming a normal eating pattern and their weight will again balance out too. Sometimes it disrupts their sleeping patterns as well, they will sleep less right before (they are full of energy), but more during and just after a spurt (growing takes energy)....at least that was my experience with it with my kids. Good luck to ya! :)