Mi amiga va a visitar a la nutricionista porque quiere aprender a cocinar más sano.

In Spanish, when you talk about a near future using ir (to go) + another verb, you almost always need a:

• ir a + infinitive = to be going to do something
  
  • Mi amiga va a visitar… = My friend is going to visit…

Without a, va visitar is incorrect.
So the pattern is:

• voy a comer, vas a estudiar, vamos a viajar, etc.

Because in Spanish, when the direct object is a specific person, you usually use the personal “a”:

• Visita a su mamá.
• Voy a ver a mi profesor.
• Mi amiga va a visitar a la nutricionista.

If you’re visiting a place or a thing, there is no personal a:

• Voy a visitar el museo.
• Quiero visitar la ciudad.

Here, la nutricionista is a person, so we add a: visitar a la nutricionista.

Both are grammatically correct, but they mean slightly different things:

• va a visitar a la nutricionista
  → the nutritionist, someone both speaker and listener probably know or have already mentioned (a specific nutritionist).

• va a visitar a una nutricionista
  → a nutritionist, not a specific one in the conversation, just some nutritionist.

The sentence with la suggests it’s “her (usual / known) nutritionist” or “the one we already know about.”

No. In Spanish you normally need an article (like el / la / un / una) in front of countable nouns:

• a la nutricionista
• a una nutricionista

You don’t say a nutricionista by itself.

The main common exception is with professions after ser:

• Ella es nutricionista. (She is a nutritionist.)
  No article there.

But in your sentence the nutritionist is an object of the verb visitar, so you do need the article: a la nutricionista.

Nutricionista is widely understood across the Spanish-speaking world.

In some Latin American countries, especially Mexico, people also say:

• nutriólogo (masculine)
• nutrióloga (feminine)

All of these are fine:

• la nutricionista
• la nutrióloga

Your sentence is completely natural with nutricionista, and it works everywhere.

Spanish often drops subject pronouns (yo, tú, él, ella, etc.) when the subject is clear from context and the verb ending:

• Mi amiga va a visitar… porque quiere…

We already know the subject is mi amiga, and quiere (3rd person singular) matches ella, so adding ella is not necessary.

You could say:

• …porque ella quiere aprender…

That would be correct, but it usually sounds more emphatic, like stressing that she (and not someone else) wants to learn.

In this sentence, quiere refers to mi amiga.

Reason: Spanish assumes the subject of the second verb is the same as the subject of the first verb, unless there is a clear change.

• Mi amiga va a visitar a la nutricionista porque quiere aprender…

So the default reading is:

• Mi amiga goes to visit the nutritionist because she (mi amiga) wants to learn.

If you wanted to say that the nutritionist wants to learn, you’d need to make that very explicit, e.g.:

• Mi amiga va a visitar a la nutricionista, que quiere aprender a cocinar más sano.
  (“the nutritionist, who wants to learn…”)

With aprender (to learn), Spanish normally uses:

• aprender a + infinitive

Examples:

• Quiero aprender a bailar. – I want to learn to dance.
• Está aprendiendo a conducir. – He is learning to drive.

So your sentence follows this rule:

• quiere aprender a cocinar – she wants to learn to cook

Without a (aprender cocinar) is generally incorrect or at least non-standard in most varieties of Spanish.

The a here is simply part of the fixed pattern:

• aprender a + infinitive

It’s not the same a as in va a visitar, but it works similarly: it links the conjugated verb to the infinitive.

So you have two different structures in the same sentence:

• va a visitar → ir a + infinitive
• aprender a cocinar → aprender a + infinitive

Literally, sano/sana is an adjective that agrees in gender and number:

• comida sana – healthy food (feminine singular)
• hábitos sanos – healthy habits (masculine plural)

But in everyday Spanish, adjectives like sano, rico, etc. are often used in an adverbial way after verbs like comer, cocinar, vivir:

• Comer sano. – To eat healthy.
• Cocinar más sano. – To cook healthier.
• Vivir sano. – To live healthily.

In that use, sano doesn’t agree with any noun; it’s acting more like an adverb (“healthily”), and the form that appears is usually the masculine singular.

So cocinar más sano is idiomatic and very natural.

You could, but they’re less colloquial:

• cocinar más saludable
  – Grammatically a bit odd by itself because saludable is an adjective.
  You’d more commonly see:

  • comida más saludable (healthier food)
  • de una forma más saludable (in a healthier way)

• cocinar más sanamente
  – Correct (it uses the adverb sanamente = “healthily”), but it sounds more formal or “textbooky”.

In everyday speech, especially in Latin America, cocinar más sano is the most natural-sounding option.

Spanish has four forms:

• por qué – used in (direct or indirect) questions:

  • ¿Por qué vas? – Why are you going?
  • No sé por qué vas. – I don’t know why you are going.

• porque – “because” (to give a reason):

  • Voy porque tengo una cita. – I’m going because I have an appointment.

• porqué – a noun meaning “reason” (less common):

  • el porqué de la decisión – the reason for the decision

• por que – rare combination of por

  • que in some special structures.

In your sentence, we are giving a reason:

• …va a visitar a la nutricionista porque quiere aprender…
  → “…because she wants to learn…”

So the correct form is porque, one word, no accent.

Va a visitar is the periphrastic future: ir a + infinitive.

• Mi amiga va a visitar a la nutricionista…
  = My friend is going to visit the nutritionist…

Visitará is the simple future:

• Mi amiga visitará a la nutricionista…

In modern spoken Spanish:

• ir a + infinitive is more common and more “everyday,” especially for the near or planned future.
• simple future (visitará) can sound a bit more formal or less immediate, and it’s often used for predictions, promises, or more distant / less certain future.

Both are correct here; the difference is mostly nuance and style.

Yes, but it changes the meaning slightly:

• va a visitar a la nutricionista
  – She is going to visit the nutritionist (focus on the visit itself).

• va a ir a la nutricionista
  – She is going to go to the nutritionist (focus on the act of going; very common way to say “go to the nutritionist / doctor”).

Both are natural in Latin American Spanish.
Often, for doctors and professionals, you’ll hear:

• Voy a ir al médico.
• Tengo que ir al dentista.
• Va a ir a la nutricionista.