There is a Duo exercise:
Yo como pollo.
I eat chicken.
There is no definite article in front of pollo.
Then there is this exercise:
Yo no toco la carne.
There is a definite article in front of carne.
The construction is almost identical. I cannot believe both are grammatically correct. Why does one use the definite article and the other not. What is the grammatical rule that applies?