Running 2x a day

First is this just your cardio day or are you training for a race. Second if you are starting to pick up running again I wouldn't recommend doing more than 10-12 miles in your first week or you will increase your chances of shin splints. Third if you ran a slow two miles your body should be able to handle another slow run later in the day.

If two miles is a lot for you, running 2 miles, twice a day isn't a hood idea. But if you can run 4 miles a day, running 2 in the morning and 2 in the afternoon is actually easier on your body. Probably not much at that distance. But some marathon training uses this method for when people get to the long runs. Instead of 15 miles, maybe 8 in the morning and 8 at night. Now you have 16 miles and it's probably better from an injury perspective.

Elite marathon runners do two runs a day. Average joe getting his cardio in should not run two times a day.

Just an average joe trying to lose belly fat. Btw, I usually run more like 3 - 4 miles in the morning. 2 is pretty easy. I would consider myself skinny fat.