I've done a lot of reading across the forum to address the issue of diet soda consumption and didn't feel I could find a good summary. There seem to be a few different categories by which people indicate they should be avoided with passion. I'm not here to say I believe we should be bathing in the diet drinks, but I am curious if they shouldn't be viewed as "restricted" instead of banned.
One argument is about the sweetener. I am not here to argue with whether or not Splenda, Stevia, Aspartame, etc. are good or bad. I've read many posts today saying how evil aspartame is, with many observational associations, for example possibly relating to migraines and possibly triggering insulin surges in some people. Again, I'm not saying one sweetener is evil, though it seems most favor Stevia. I read an article listed on the 3FC site today which showed there wasn't an association between an insulin spike and aspartame, though I think the study could be criticized for small sample size. In short, it seems the sweetener choice should be a personal one, as some people are *very* concerned about a natural approach, while others seem less troubled by it. So, if the main reason to ban vs restrict diet sodas is based on sweetener, I do not believe the argument holds water IMHO. Again, it's a personal decision if you want the product or not, but my alternative IP program will allow rare aspartame as a restricted item. Another article I read on the 3FC today mentioned an association between diet soda and metabolic syndrome. Unfortunately, it was an observational study based on self-reporting. As such, it should not be viewed as proving causality and should *only* be used for hypothesis generating. What is needed is a true study designed in a randomized, blinded fashion. Unfortunately, that will never happen, so we are left with observational data and a need the general rule of moderation.
Another argument is about the damning affects of carbonation. I find it hard to believe that 1 or 2 diet sodas will have enough impact on the body's acid/base homeostasis. I am away from my main computer, so I am not able to delve into this enough. The essential components of acid/base homeostasis in the body involves the lungs rapid ability, which blow off excess carbon dioxide (a method of removing bicarbonate), and the kidneys powerful (though slower) buffer system. So, I welcome real data to say why someone having one or two diet sodas can possibly overwhelm the healthy body's acid/base homeostasis. Yes, I've read that brown soda has more phosphoric acid. Again, it seems to be another acid/base issue that the lungs and kidneys of the average healthy adult should be able to address without difficulty. I'd love to see real science about how the very low level of phosphate in the average soda (~40-60mg vs body's daily need of 700mg -- Livestrong website numbers) could be harmful. So, for my IP alternative, I'll be considering diet soda a "restricted" item (EVERYTHING in moderation!).
One side note. If the body is heavily relying on the lungs to blow of extra carbon dioxide for acid/base homeostasis, the very morbidly obese need to know of something called obesity hypoventillation. In short, the rib cage cannot expand enough due to massive weight pulling down on the ribs, limiting the body's ability to take in and expel a full breath. So, be sure to be mobile and not a couch potato, ensuring full, deep breaths and prevent feeling short of breath due to obesity hypoventillation.
Diet soda cause cravings for me and many other posters. I really don't know if it will slow your losses, but for me it will- 1) cause me to eat carbs or 2) cause me to at very least crave carbs. I eliminated my cravings and had no desire to go back to any soda after only 1 week OP.
A diet pop will save me from a cheat. When I feel very deprived or left out of everyone else's indulgences, I have let myself have a pop. Probably 4 times in 17 weeks. Much better than the 1-2 cans a day I used to consume.
I appreciate your information...I always am interested in deeper exploration of "studies show...insert random fact here". Soda for me, however is my "gateway drug" into junk food. My clinic has ok'd "ice" which is carbonated and flavored with stevia. I have tried it and think it's pretty gross...my opinion.
The amount of empty calories I have consumed over the years in Coke makes me shudder.
I was a heavy diet pop (we rarely call it soda in Canada ) drinker before starting IP. 2 cans a day most days. I completely cut it out cold turkey since going OP, but there are times when I wonder what the harm of having one would be. I personally am not upset by aspartame or other chemicals (you can't really be too concerned with chemicals and eat packets of food every day, IMO) but my fear is that I'd be that one person who would have one and it would throw me out of ketosis.
I will see if I can find some information that I might have saved somewhere in my many IP files. What I do know is my sister was a Diet Pepsi addict until she got cancer and now she refuses to touch the stuff. That's a good enough reason for me.
I appreciate the science behind many things and often want to know the "why" behind the "what" too. And I deeply appreciate all your research to understand more about soda consumption.
That being said, I think it would be easy to pull apart just about every facet of IP and find reasons why one food or another could or should be allowed once in awhile, sometimes, more often than not, on an as needed basis, etc.
I see so much evidence that the plan works as it is written (including my own 50 lb loss that I could not lose on many other eating plans) that I am willing to accept that IP has done enough research to build an eating plan that works well for MANY. And sometimes second guessing or analyzing the "why" just isn't worth it. I accept IP's reasoning that the diet is alkaline in nature and is disrupted by the acidic nature of carbonated soda, especially those with phosphoric acid which is not a good compliment to IP.
Soda (diet for me) will be there when I am done, if I even want one, so for now I stay away from things with phosphoric acid to maximize my results.
Thank you JLUS (Laurie) I agree... there will always be a 'reason' to change the protocol to fit your lifestyle, but that is the original problem with why weight is gained - choosing little things that don't seem to matter. Pop, diet or otherwise, adds nothing nutritious to a healthy diet - so why use it?
Liana
For us, the reason for diet soda is that it would provide a small treat without a substantial downside. We each need treats and rewards. For some, I imagine feeding into oral pleasure leads to real eating problems, so I can see that triggering a slippery slope. So, for them, perhaps pure abstinence is necessary. But I can say I've lost substantial weight and had plenty of diet soda, with the weight staying off over years. It's like alcohol, in that small servings clearly have benefit, but taken to excess can cause real harm. One could argue that the data favoring the health benefits of low-dose alcohol are more clearly demonstrated, at least in terms of the heart, and I would not disagree.
For us, the reason for diet soda is that it would provide a small treat without a substantial downside. We each need treats and rewards. For some, I imagine feeding into oral pleasure leads to real eating problems, so I can see that triggering a slippery slope. So, for them, perhaps pure abstinence is necessary. But I can say I've lost substantial weight and had plenty of diet soda, with the weight staying off over years. It's like alcohol, in that small servings clearly have benefit, but taken to excess can cause real harm. One could argue that the data favoring the health benefits of low-dose alcohol are more clearly demonstrated, at least in terms of the heart, and I would not disagree.
Treats for many are enjoyable... So we make treats from packets (cakes, cookies, muffins, brownies, "milk shakes", etc.) while still following IP. Also IP built in the restricted for those looking for a sweet or salty treat.
Not clear by your comment about drinking diet soda over years... There is nothing wrong with drinking diet soda per se... We are ONLY discussing it while ON IP, right? And yes, some do have it and are fine. Others use products that avoid the phosphoric acid but still have the fizz factor.
However, part of IP is not just about losing weight. A very important part of the journey is learning to make wiser eating decisions, including exercising the resistance muscle to make us as strong and successful as possible in maintenance. Being okay NOT having something we want or crave or have convinced ourselves we "need" teaches us to master our cravings over food. So it just might be that sticking to the eating plan AS DESIGNED has benefits that extend far beyond having or not having a specific food!
My point about diet soda over time is that it seems inappropriately maligned on the IP diet, with some posters saying they are being kicked out for seltzer water (or threats of being kicked out). If the discussion centers around abstaining from soda as a target to enforce discipline, I will not argue, as some struggle with weight out of problems with discipline. An analogy may be how recruits in the military are drilled on discipline for even seemingly minor issues, as it builds strength in appropriate decision making. I will strongly argue against any biological harm from the pH of carbonated beverages or the minimal presence of phosphoric acid, as they just don't make sense (assuming moderation of intake and a healthy set of lungs and kidneys, of course). I resist following a program without understanding why decisions are being made. The discussions about diet, carbonated beverages are full of pseudo-science and anecdotes, with altogether too little real science. Again, it's a personal decision to not drink them in order to stay on plan, but it's important to keep educated about biology and understand the avoidance seems to be more about discipline and not health.
I was a huge diet Coke drinker for the last 15 years. Drinking close to 2 liters a day. In the summer if 2011 I stopped drinking it. I didn't do it intentionally just did. Anyway I lost about 15 lbs and I attribute it in part to quitting the diet Coke. Now that I don't drink it I can hardly get one down and can't figure out how I ever drank so much soda. Anyway, just my experience. I think there are studies that show diet soda causes weight gain in some people. There is Diet Coke made with splenda that I have had a couple times. It is different and I could never have more than a couple sips but there if I just need something to break up the water.
I quit drinking diet Pepsi because someone told me they quit and they were not hungry any more. I quit for 4 months and gained 15 pounds. It is a treat for me and if I don't drink it I eat something. It also did not curb my hunger.
Diet soda truly evil?!
) drinker before starting IP. 2 cans a day most days. I completely cut it out cold turkey since going OP, but there are times when I wonder what the harm of having one would be. I personally am not upset by aspartame or other chemicals (you can't really be too concerned with chemicals and eat packets of food every day, IMO) but my fear is that I'd be that one person who would have one and it would throw me out of ketosis. 
