As seen in the movie,
The Beatles are given "uppers" pills so they can keep performing when they're getting tired. Also, as seen in the shot after John accepts the pills for the first time, The Beatles are performing "Long Tall Sally" like crazed maniacs with eyes bulging and sweating profusely. The reason for this is that the uppers were actually prescription-strength "speed" pills. According to all of The Beatles in various interviews (most prominently in the "Beatles Anthology" film and book), the band was forced to perform up to eight hours a night, far and away more than a band can possibly play given the normal fatigue that sets in from singing and playing. Whenever they grew tired, the bartenders or the waitresses would often give them (and other performers) uppers to keep them going. Because of this, and their horrible living conditions in the Kaiserkeller Club's back room, The Beatles were often sweaty, smelly, pale and shockingly thin (speed pills back then doubled as diet pills) because they rarely bathed, hardly ever washed their clothes or, more importantly, ate healthy meals. However, after
Stuart Sutcliffe began dating
Astrid Kirchherr, she would feed the band and wash their clothes and allow them access to her bathroom for bathing. All of The Beatles have said that Astrid, more or less, kept them alive and healthy.
