I have a 30 min/10km each-way ride to work which I do five days a week without fail. That's about it for regular exercise these days because arthritis in my right foot means I've had to quit running (boo). Never been anywhere near a gym in my life, and consequently have no muscles above my waist

Eat relatively healthily without really paying much attention to calories, but having done so in the past reckon I'm on about 1800. Probably drink too much. Net result of all that means I'm usually around 72-74kg.