Your cardiovascular health will improve, but it's very easy to not lose weight when running is something that burns less Calories than many people think.
Ehh, 5 miles (at the average pace of 10min/mile) burns 776 calories for 200lbs. That's an entire large McDonald's Double Quarter Pounder meal with calories to spare.
The funny part that comes after is that the human body is built for pure efficiency, and tries to offset burned calories by subconciously moving less throughout the rest of the day.
So in total, you won't actually have burned an extra 776
My training plan varies between 3 and 6 miles a day, which I do at a ten minute mile. I am definitely potato shaped. I'm not the fastest, but I do it day after day.
theres different kinds of fit and shape is just one of them.