I'm going to make a confession here, and I am prepared for the fallout
I drink atleast 5 cans of diet drpepper a day. I have done so since I was about 18. I have PCOS and my weight has been up and down ALOT since then, and I can tell you that how many calories and carbs I have a day is what affects my weight. There are no calories or carbs in DDP, so I have it whenever I want.
Yes, it has sodium in it. About 65 mgs. Considering that at my calorie target of 1300 that I can have around 1600 mgs of sodium a day, my 5 cans is still only about a 5th of my allotted sodium intake. If I watch the sodium in some of the other things I consume, it can still be WELL within a healthy range.
Does it make me retain water? Sure. So do carbs. So does my injury. It's not like I am going to keep retaining more and more until half my body weight is water retention. I am always retaining water, and I would still even if I never drank another diet soda.
The only thing I think is unhealthy about diet soda is the chemicals-who knows what those do, along with all of the other chemicals and preservatives in SO many other foods we eat-and the acidity for my dental health.
I figure it like this..unless you are eating strict and clean, LOTS of the things we eat and drink contain things we should probably not be ingesting. Diet soda falls into that category. But for fat loss, it has absolutely no effect.
I think the studies that have shown that people who drink diet sodas tend to be heavier is because people tend to use them as an excuse to eat higher in calories (using the logic that they "saved" calories by not getting a regular coke). Ever seen the lady who orders a double quarter pounder meal, super sized with a diet coke? It isn't the diet coke that makes her overweight.
Drinking a diet soda is more healthy than drinking a regular one. High fructose corn syrup is MUCH worse for you than artificial sweeteners.