Hi,
The Eucharist is food. Food is to be eaten. Chewing is part of the digestive process which culminates with the activity of the very strong acid in the stomach. Consuming the Eucharist is the consuming the the body and blood of Christ IN THE FORM OF BREAD AND WINE. We are not consuming the body of Christ in the form of flesh and bones.
So certainly, we are to chew the host.
Fr. Vincent Serpa, O.P.