Should mean I don't get food. Surely no food would be bukan makanan???
bukan makanan = not food; itu bukan apel = that is not an apple. Tidak is used with verbs and adjectives; hence, tidak mendapat = did not receive/get ...
Bukan = no ... usually to answer a question. Itu apel? (Is that an apel). Bukan (No).
Why can't I say "Saya tidak menerima makanan"?