keep? a healthy diet

[lokasseyve]

Hi,
Is it correct to say "People should keep a healthy diet"?

I think keep can be used here. But my dictionary(Longman contemporary) says keep a diet is a common error. Is that true?

Thank you so much.

 

[intentando todo]

It is understood. You could say maintain a healthy diet.

 

[Copyright]

Google results:

keep a healthy diet – 71
maintain a healthy diet – 307
follow a healthy diet – 304

I wouldn't use keep myself.

 

[lokasseyve]

Then I'll use maintain.
Thank you so much, intentando todo and Copyr.

 

[natkretep]

However, if you put 'should stick to a healthy diet' on Google, you get 332,000 results!

Edit
I should add that Google does funny things, and my results might not be comparable to Copyright's (post 3). If you go to the last page, Google shows 363 results:

In order to show you the most relevant results, we have omitted some entries very similar to the 363 already displayed.

The comparable number is 363.