It seems to me that most people don't lose much weight from cycling, because it makes you so hungry. So, you can ride as much as you want, but back off if anything starts to hurt, and eat more if you get too thin or weak. To me, the "ideal" is the place where I feel great, where nothing hurts, and it's fun to get on bike. Usually, if I ride too much, I feel fatigued, and if I ride too little, I get moody.
'02 Eddy Merckx Fuga, Selle An Atomica
'85 Eddy Merckx Professional, Selle An Atomica
'10 Soma Double Cross DC, Selle An Atomica
Slacker on wheels.