How long can you survive on beer alone?

> surely it must be damaging to the kidneys.

Alcohol is processed in the liver, not the kidneys, and excessive chronic drinking does have long term effects.

The way you phrased the myth isn't true for the entire population of England, for example. But it is somewhat true - depending on how one interprets what you wrote, and depending on geographical location and time period.

For example, it is true that everyone drank beer almost every day regardless of whether or not they had access to clean water - but not beer as we think of it today; it was probably less than 3% ABV, and had lots of varied additives that are now extremely rare in commercial beers (counting all breweries small and large.)

In places where clean water was easily available, beer was consumed for its calories (people worked all day) as well as quenching your thirst, and for its taste - but also because it wasn't cold. Your body spends lots of energy warming up cold water. Safe drinking water was often cold, because it came from underground wells or moving sources like what we'd call aqueducts.

Even infants were fed beer. You can look up the poem "Beer" by Charles Calverley, which contains the famous line "Guinness, Allsop, Bass! Names that should be on every infants tongue." He lived between 1800-1900.

I was intrigued by this question ever since I read Angela's ashes by Frank McCourt.

Seems like his father survived on porter alone (although obviously this is told though a child's eyes).

Beer seems to contain around 1% protein which isn't much. Carbs should be plenty though.