The phrase "comer con tino" is used in the Spanish language to convey the idea of eating with discretion, in a careful and thoughtful manner. It's not a very common expression, but it is used more in written contexts or in formal speech.
Comer con tino es fundamental para mantener una dieta balanceada.
English: Eating with discretion is essential to maintain a balanced diet.
En la reunión, todos comieron con tino, sin excederse en las porciones.
English: At the gathering, everyone ate with discretion, without overindulging.
"Comer con tino" is not part of a widely known idiomatic expression in Spanish. It is more straightforward in its meaning and typically used as described above.