30 Minutes of Cardio per day
That's the bottom line. Join a gym, get on a cario machine, and sweat lightly for 30 minutes a few times a week. Jogging also works, and swimming is better still. Don't try to do more at first, because then it becomes an ordeal and you'll find an excuse to avoid it. That's it. Plain and simple. After a few months, at your next physical, your yearly blood tests will improve so much that your doc will think that your results got mixed up with someone else's.
I once worked at a location that had a gym downstairs. I did my cardio, took a shower, had a quick bagel and coffee and tore throught the rest of the day.
Think you don't have time? During WWII, the main Soviet general, Zhukov, didn't have time to sleep, so he a had a daily regimen of jogging 1 Kilometer. I don't care who you are - your boss isn't tougher than Stalin and your problem isn't worse than Hitler.