Haber-related question

Question

In the test question, How would you say "I have eaten only fruit for a week."?, the answer was Desde hace una semana solo como fruta.But I chose Desde hace una semana solo he comido fruta. Why isn't that one correct, given the "have eaten?"

Accepted Answer

Hola William
The lesson is about not using generally the present perfect tense (like in English, I have eaten..., using haber) when we talk about things that we have done since/for a certain time:

No fumo desde hace un año.
I haven't smoked for a year.
No veo a Luis desde el 2020.
I haven't seen Luis since 2020.

Our tendency is to use the present instead, not the present perfect with haber.
I hope this clarified it.
Saludos

Answer

Google translate prefers the present perfect to the present. It translates the suggested answer as "For a week I only eat fruit" and suggests an accent on the sólo.

Spanish speakers must use the present perfect some time

Answer

Hola Marc
The use of the present tense (not the present perfect) is the most natural way to express this type of sentence with desde / desde hace. That doesn't mean that you may find the present perfect now and then. As for google translate, bear in mind that google may give you a literal translation sometimes as it is probably doing in this case. 
Solo both as an adverb and an adjective doesn't take the orthographic accent (that's the rule since 2010 by RAE) - only recently the academy has made this rule a bit flexible and says now that if it is an adverb and the person who writes it thinks there might be ambiguity (i.e. the word may get interpreted as both an adverb and adjective as it's not clear by the context), then you can use the orthographic accent IF it is acting as an adverb.  In this specific sentence, in my opinion, it's clear that it refers to the adverb ("only", not "alone") and there's no room for ambiguity because of its position in the sentence so there is no justification for the accent. 
Saludos cordiales