I have ALS. I can only drink Boost. Does anybody know how many Boost I need to drink a day to stay alive?

That would be a question for your Dr. What do they say?

Bluesman, has a dietician been provided to you for help with determining how much Boost to drink? If not, ask the doctor who's providing care for the ALS to script for a dietician to come, at least once, to help you along with whatever your doctor might advise.

My father's Senior Center provided Ensure at a good price, lower than if purchased in a store. That might be an option if you need to conserve funds.

You need about 1700 to 2200 calories each day, but you may also have runny stools. You still talk to a dietician to see what elements are missing