Laws related to Berachos
We learned previously that if one eats an entire meal of an item that is considered pas haba’ah b’kisnin, the brachos recited would be Hamotzi and Birkas Hamazon. Is the amount of pas haba’ah b’kisnin that would mandate Hamotzi the same for everyone?
No. To require the bracha of Hamotzi one must eat an amount, “she’acheirim kov’im alav” that other people normally eat for a main meal (Shulchan Aruch O.C. 168:6). The Biur Halacha (ibid) writes that “other people” refers to people of similar physical properties. Rav Belsky, zt”l explains that this refers to people of the same age and build. While an adult might need to eat two or three slices of pizza in order to say Hamotzi, a child might only need to eat one slice if that is a typical main-meal for a child that age.