A little late to the punch, but it is canonically a strict fast, no water either. However, spiritual fathers may allow condecensions to weakness, work, or even not allow something due to prelest (though this is overdone, you never see the saints trying to enforce spiritual mediocrity). Most priests honestly don't care about every bit of food put in or not put in your mouth. It is wise before any fast to get a blessing from the spiritual father to do this or that. If not, or you forget, do what you need to do and next time you confess let your spiritual father know what you did and why.
