No, just no.
Factoid:
You have to eat to live. When Christ fed the 4000 he didn't say "You're all full now, yum" he actually made some food.
Did monks and stuff fast for 40 days during lent in olden days ?
Yeah, they did - but they cheated and it still caused them issues in their lower digestive tracts.
They drank. (Not food so - so still fasting - technically anyway)
Triple bock and Assyrian ale is basically liquid bread BUT It also keeps you half in the bag all the time and completely goofs up your large intestine and stomach. You need to eat to keep thing healthy in there. And then there's the whole vitamin thing
Can you pull this off for 40 days ? Ok,
120 days? maybe but scurvy and rickets are going to become an issue. (Not to mentions the effects of long term alcohol abuse)
Years and years - no. You wouldn't have any connective tissue left and internal organs would be mush.