Good question. All soda's make the body acid, and the body then has to neutralize the excess acid we eat and drink. When the body cannot do that, the excess is stored in fat cells. So instead of burning more fat, which would release more acid into the system, the body burns muscle instead. Most carbonated sodas have a PH of around 2.5, and your goal is to keep your PH somewhere between 7.1 and 7.5. You have to eat a lot of greens and celery etc. to off set that 12 oz can of 2.5 PH, especially if you eat fast food a lot and always get a refill on your way out of the fast food place. Think about it. Ask for a bottled water instead.
You thought you were being carb smart by drinking diet soda and it turns out that diet soda makes you fatter than regular soda. This is a tough one for me, but I am making baby steps and teaching myself that good quality water is what God intended for us to drink. Replace soda's of all kinds with water, and you will have taken a giant step towards correcting your body's PH which in turn will help control and possibly cure one of the root causes of your diabetes in the first place.
Does that make sense? It does to me. Remember I am NOT a doctor or a scientist. I am just a guy who has Type II diabetes and am looking for a cure. I am doing my homework and making changes in my lifestyle.
DON'T take my word for it. Here is a website with more detail into the evils of drinking carbonated soft drinks:
Link to Dangers Of Drinking Soda
Psalm 107:20 "He sent forth his word and healed them; he rescued them from the grave"