Is this unhealthy for me to lose belly fat?

I am not fat but I have a flabby stomach I want to get rid of and turn into muscle. I am 5’9 and weigh 170 lbs. I was wondering if what I eat is unhealthy. This is what I eat for the day usually

- 2 doughnuts in the morning, lots of water and arizona ice tea, a 12 Inch subway for lunch/dinner

and everyday I exercise for an hour. Is this unhealthy eating or could I eat this same way and lose my belly fat and gain my muscle?