I've been running for 20 months now - and I haven't really lost any weight (but nor have I put any on - just the normal fluctuations). But something is definitely happening. Today we had a meeting at work where I met up with colleagues I haven't seen for at least 10 months. Two of them told me I was looking younger and asked what my secret was. This was on two separate occasions, completely independent of each other. One of them took up running about 4 years ago and I remember listening to him telling us about his morning runs - I was green with envy at the time. Now I do it myself.
This journey is so worth it. You don't have to be fast (I'm not) just get out there regularly. The exercise fends off diabetes and high blood pressure, it redistributes your weight, helps you sleep better, improves mood - and it makes you younger - obviously!