past perfect or past perfect progressive

[SFinCH]

Hello, I'm new to this website and am glad that I found it! I am teaching a prep course for Cambridge First Certificate and have the following problem:

This was part of a class exercise to determine if the tense were past perfect or past present progressive.

The beginning of the text is: Last month actress Stella Glass gave birth to her second child - yet now she is back on screen and looks more attractive than ever. Many people have wondered about her secret and how she has got back her near perfet figure so quickly...

The text then goes on and you are supposed to pick past perfect or past perfect progressive in several sentences of the rest of the text. This one has me stumped!


"To lose weight I have had five portions of fresh fruit and vegetables every day and I have been eating popcorn as it's low in calories.

"To lose weight I have been having five portions of fresh fruit and vegetables every day and I have been eating popcorn as it's low in calories."

Why can the first part of this sentence be both past perfect and past perfect progressive while the second part is only past perfect progressive?

Thank you so much in advance for your advice.

[5jj]

Some course books and basic grammars unhelpfully imply that only one form is correct in any particular utterance. This is rubbish. Very often there is more than one possible tense/aspect.; the choice depends on what is, often unconsciously, going through the speaker's mind at the moment of speaking.

Both progressive and non-progressive forms could be used in both halves of that sentence.