I think it's just a matter of duration. I think three hours is about the duration where you start to see some weight loss, and it's a whole lot easier to ride three hours than it is to run three hours. I definitely dropped a couple of pounds when I started running the longer distances.

As far as The Hunger, though , IME that's all about recovery nutrition. When I come back from anything strenuous the last thing I want to do is eat, but if I force myself to eat those 2-300 calories within the first half hour - just like all the authorities tell you to do - then I won't get the insatiable eat-everything-in-sight that happens when my muscles are really depleted.

But yeah - form. Strengthen your hips - there are lots of resources online for hip exercises for runners. Keep your stride short and your cadence high. Those three things will make running a lot safer.