One thing that really helped me with breaking the soda habit was seltzer/sparkling water (it's called different things in different places; just don't fall for the "sparkling water beverages," since they're just diet soda hiding behind another name). Turns out it was the bubbles that I missed about soda, more than the sweetness. So switching to unsweetened seltzer (it comes in a ton of flavors now, or you can buy a carbonation rig and make your own, like I did) was a huge help.
I also second the recommendation of stretching/warming up to prevent shin splints. When you're busy working on the computer all day, sometimes it can be a challenge just to get up and move around, much less take the time to stretch first. But it really helps!
Good luck in your health improvement efforts!