Be in a Caloric Deficit
If you have a slow metabolism and want to lose belly fat, the first priority is to eat fewer calories, Dr. Lofton told POPSUGAR. You want to be in a slight caloric deficit, which means consuming fewer calories than you burn. "Weight loss always comes down to energy balance," Dr. Lowden explained. Dr. Lofton recommended cutting about 250 calories a day to start. Here's exactly how to get into a caloric deficit, if you've never done it before.
Decreasing your food intake slightly has two positive effects. For one thing, you'll start to lose fat. Maybe not necessarily from your belly; now is a good time to remember that you can't spot-reduce fat, but by reducing your body fat as a whole, you'll start seeing results around your belly. And when you lower your body fat percentage, you'll also start to boost your metabolism, Dr. Lofton said.