Your body will adapt to your level of activity and food consumption. This adaptation will change as you age. Someone who eats and exercises a lot may be the same weight as someone else (same sex, height, age) who eats and exercises less. But the more active person will probably have a lower body fat percentage. If that percentage is low enough, they will appear fit and lean, perhaps "ripped".
If you want to reduce your belly fat then you have to increase your activity and/or reduce your consumption. Your body will adjust to your new level of activity and consumption. At some point your body will have made its adjustment. If this new state is unsatisfactory (you've "plateaued") then you have to make further adjustments to your activity/consumption (increase/decrease). Once your body has adjusted to your satisfaction, you then need to either keep up your present level of activity/consumption or make very small adjustments to see how your body responds.
If you want to lose weight you need to use more energy than you consume (more activity and/or less food). It's far better to consume less AND exercise more so that you lose mostly body fat, otherwise you may lose too much muscle as well (which can lead to being "skinny fat": lower weight but same or higher body fat percentage). You can't choose where to lose your fat (unless you elect surgical methods); your arms and legs will "lean out" before the last of your belly fat can disappear.
As for reducing your calorie intake, you can take one or more of a few tacks: Smaller portions of everything, same portions but of lower calorie versions, or cut out something that's caloric but nutritionally inert. Very recently, I completely cut soda from my diet. I was consuming as much as 1,000 calories of it daily (already down 6 pounds in 2 weeks, but I'm exercising more as well). That shit is really insidious. Beer isn't any better. If you drink beer, stick to the high quality stuff that's consumed in small portions (because that shit costs money). Beer bellies are caused by the commercial swill that's intended for high consumption. People drink it to get drunk; some people require several servings to get wasted. By the time they get there, they've consumed 500 calories or more. Then they drink more.
