The best way to lose belly fat is to reduce your total calorie intake and increase your exercise. Reducing your intake and increasing your exercise will help you lose weight all over and that includes your belly.
Some research suggests that green tea intake can slightly boost belly fat loss along with exercise. Keep in mind, the most important part of that statement is “along with exercise”. No food will replace exercise as the best way to lose belly fat. Also of note, bottled green tea contains very little of catechin, the chemical that was found to be helpful. So if you’re going to use green tea, it’s better to be brewed from a tea bag or loose leaf green tea.