This is from memory, had an argument with someone about this years ago.

Standard-strength lager is around 200 calories/pint on average. Mainly chemicals, not that great at all.
Cider is around 220 a pint, but arguably the best for you, being vaguely more natural than anything else.
Guinness is 230-odd, and can make you piss out of your arse.
Bitter on average, is around 180 a pint.

And we worked it out (at the time) a vodka/diet works out about 3 to a pint of premium-strength lager(!) if you're easy on the coke.