hi..i had the same doubt and clarified it while applying the loan with my bank manager. Firstly my living expenses were approved based on the estimate provided by my college for hostel and boarding expenses.So at first i gave a declaration letter that i wont be staying at the hostel provided by my college, instead i will be sharing accommodation with my friends and so not to release funds in the favor of college.
After getting the loan approved, my suggestion is to ask the bank to release funds as and when required, it will save on the interest. For this the bank manager asked me to give a letter initially stating the amount required for the initial month for my living expenses. And for the subsequent needs, i should authorize my "??" to approach the bank on my behalf and give a letter stating the amount needed, which would then be deposited in my account.
Then again rules may change from bank to bank, or the manager may not be so patient to take up this extra work. So make sure you talk with your manager and clear all your doubts.Hope it helps