How can I lose my small belly while maintaining muscle mass?

I'm only about 20 years old, and have a similar problem, though I have gotten rid of a great deal of my belly. I'm assuming that you eat a fair amount of protein if you already have some muscle mass, so continue doing that. What I did was cut back on carbohydrates/sugars and increased my vegetable intake. Sugars, which are a form of carbohydrates are one of the main reasons for the formation of fat, as it a storage form of carbohydrates. Your body stores up this energy in case you are lost and cannot find any food. Carbs are not bad for you, just don't eat them unless you are going to do something active. You can also try eating healthier fats such as ones found in nuts. Aerobic activity on top of this will lose your belly but it WILL NOT lose muscle mass as long as you continue to work out and eat protein.

So:

Cut back on carbs (potatoes, pasta, rice) unless you ran a marathon or something.

Eat more vegetables

Eat nuts (small servings)

Aerobic activity such as running or sports (5-6 days a week)

Continue as normal

You do not have to do all of this obviously. I got off track of my diet at college, but now by doing this I lost 3 pounds off my belly in the first week (200-195 pounds), and am currently 191 a week later, with the same amount of muscle mass and am starting to see my pectoral muscles. It is really simple. Let me know if you have any questions.

Try to jog at a good speed, not just drag your feet. And a few foods to stay away from: pop tarts, ice cream, limit bread, and fast food. I gained 20 pounds in 2-3 months from ice cream. So definitely none of that. Good luck