+0
" Though more debt than is admitted to may have been squirrelled away off the national balance sheet , our fears on the economy have proved exaggerated . "

Why not , " More debt than is admitted might have been hidden from the balance sheet..."

will my structure be correct ? If not , why ?
Comments  
your version is far more technically correct- I don't see any proper usages in the original!Emotion: stick out tongue
but you might need to know what the inferrence was, vis-a-vis "off the national balance sheet".
To me, this implies much more than your "from the balance sheet"
I'm rather worried about the grammatical structure of my sentence . I need to know
in which situation I should add a " to " after " admitted " .
Students: Are you brave enough to let our tutors analyse your pronunciation?
I would offer an alternative answer here, N19.

Your 2nd sentence doesn't have quite the same meaning as #1. I would change it to this:

1. Though more debt than is admitted to may have been hidden from the national balance sheet, our fears on the economy have proved exaggerated.

Even then, 'hidden from' isn't quite the same as 'squirrelled away off': the latter has a sense of 'hidden from the balance sheet and dispersed in one or more places'. It gives a more active impression.

MrP
I need to know in which situation I should add a " to " after " admitted "

I think when you admit something you agree that it's true. When you admit to something you confess it as wrong.

CJ
I have eaten more than i am admitted .

I have eaten more than I am admitted to .

Which sentence would be the correct one above ?

I think , both sentences should be right because the first one states a fact and the second one states a wrong thing .
Site Hint: Check out our list of pronunciation videos.
I'd use "to be allowed" here.
As CalifJim says, "admit" has the meaning of "agree that sth is true", I don't think it fits in your examples...

Or there's another possibility:
"I admitted to having eaten more than I am allowed to"
Mister didactic sez, don't end sentences with infinickys