Late to the party as usual but echoing "most" of whats been said I have been on a strict diet (WW, it works) now for about a year and a half and have shed 85lbs, which is 6 stone in old money, no idea what it is in kilos, what's a kilo? Some french rubbish inflicted on the UK.
I have found the bikes handle a lot better now the big blob on top of it is less of a big fat blob and also found that my old BMW R1100S doesnt actually need to be resprung, it just needed less fat on it
Can't run because of arthritis everywhere but I can swim and swimming is the key, it's great exercise and you are supported while you do it, less impact on your old joints. I go 3 or 4 times a week and walk on the days I dont swim. Nice bonus is my arthritis isn't as bad now I am not carrying all that weight around.
Not stopped, still got another 2 or 3 stone to go, onwards and downwards