What you need to do is get that tape measure out, and start measuring that gut. Then you start working out and you start eating properly till that gut gets down close to it was when you were in your 20's. Then you'll find out what your weight should be.
You can't get rid of it with exercise alone. You can do the most vigorous exercise and only burn up 300 calories in an hour. If you've got fat on your body, the exercise firms and tones the muscles. But when you use that tape measure, what makes it bigger? It's the fat!
Scales lie! You lose thirty pounds of muscle and you gain thirty pounds of fat and you weigh the same, right? Take that tape measure out. That won't lie. Your waistline is your lifeline. It should be the same as it was when you were a young person.