Rides for overweight unfit people?

Are there any? I suppose critical mass is about the closest as the pace would obviously be slow (although it's a demo and not really a ride as such I guess) but it would be nice to be able to go out on a ride where one doesn't need to worry about keeping up or conking out halfway there.

Look, just face it fatty, cycling is not for you. There's TV, the internet and masturbation (or all 3 combined) for your sort. Why embarrass yourself and others by launching a flabalanche in ill-chosen 'shorts' and a jersey that with your figure looks more like a lady's sports bra?
If you insist on leaving the house (and, frankly, that's your first mistake right there) then you could order a taxi. Chances are the driver is an even bigger wobble-bottom than you are and you can strike up a friendship.
It may not be 'politically correct' to 'tell it as it is' these days but facts have to be faced: your future lies beneath the welcoming folds of a Kaftan, not astride a bicycle.