Questions & Answers about Quizás la nutrición no es fácil, pero es importante.
Why do we use pero here instead of sino, even though the first part of the sentence is negative?
We use sino (but rather / instead) only when the second part of the sentence corrects or replaces the negative first part. Here, being "important" doesn't replace or cancel out being "not easy"—both things are true at the same time. Because we are just adding a contrasting idea rather than correcting one, we must use pero.
Could I use sino que in this sentence if I changed the wording?
You would use sino que only if you were completely replacing the first conjugated verb with a new conjugated verb. For example: No es fácil, sino que es imposible (It's not easy, but rather it is impossible). Since "being important" doesn't correct "not being easy", pero is the only right choice for the current meaning.
Why does quizás take the indicative verb es here instead of the subjunctive sea?
While quizás (perhaps) often triggers the subjunctive to express doubt, you use the indicative when you feel highly certain about the statement or want to state it as a fact. Here, the speaker is acknowledging a widely accepted reality: nutrition simply isn't easy.
Why do we say la nutrición instead of just nutrición?