I'm a former runner (+/- 65 miles a week), but an ankle injury forced me to do something else. I learned that dedicated cardio actually can deplete muscle....which is not the goal. A well designed weight training program will work your heart plenty, and increase lean muscle, which burns fat. I managed to drop 20 more pounds after I stopped running (after being stuck at 60 lbs for a year of the excessive cardio), without the beating on my body that running provided. Every now and then, just for fun, I run just to do it, and learned early on that the lungs and heart are still there for me to easily run 4 or 5 miles without any issue. I'm no muscle head - nothing especially heavy, but I incorporate quite a bit of super sets and circuits in most of my workouts.
As for nutrition, I eat, and eat a lot. Depending on the time of year and the goal at the time (size and strength v lean and light), I eat 4, 5, and at times 6 FULL meals a day. Clean, lean meat (2-3 pounds a day), clean carbs at all but my last meal, not as many veggies as I'd like, virtually no sodium or sugar, and lots of water. No supplements, shakes, or bars. Just food. I fuel the fire about every 4 hours.
What do I do to get in shape? Lift weights. What do I do for cardio? Lift weights, faster.