Diet Soda's effect on weight loss

[MSgherzi]

I'm curious as to why you shouldn't take in any "flavored waters" during P90X. Regular soda I can understand because of the sugar, carbs, and calories, but why diet soda? I know that the artificial sweeteners can be bad for your health, but I'm talking about strictly fat loss. From all of the research I did, I could never find any conclusive evidence that pointed to artificial sweeteners and/or diet sodas negatively effecting a fat loss program.

[dhoyt86]

Check out this link, http://www.thefitclubnetwork.com/2009/11/how-diet-soda-makes-you-fat/

Gives some really good information that will address your question far better than I can. Spoiler alert: it's all about the acidity level of diet soda or any other soft drink. Have you read the ingredients on the labels? I don't think you would ordinarily put that stuff in your body if it was just sitting out on a table or something, but since it's mixed up in a pretty can, we throw it back without realizing what we are doing. Pretty crazy stuff really.

[Dave]

Thanks David - Yep it is the acidity issue. That's a sneaky one that doesn't get much publicity, but it really happens.

Dave

[JimNAZ]

I was a Diet Coke (aholic)! Always disregarded that acidy burning in my stomach just to get that fix. I have not had a diet soda since the day before I started working out (1/11/10). Have not missed it, do not want it, and just thinking about it makes my stomach turn. :eek:

[MSgherzi]

Wow, what an eye opener! Thanks!

Have any of you tried Litmus Strips?

[MSgherzi]

One problem I have though is that they say in the video that regular water is actually acidic. I don't understand this, because water helps the liver function correctly and if we're supposed to be drinking water during P90X and during just living, how can it have an adverse affect on the metabolism when helping the liver function more efficiently actually helps the metabolism?

[Dave]

Double check that Matt. Water is pretty much neutral on the pH scale, typically sitting right at 7. When it gets processed somehow the pH can change, and you can make it more alkaline by adding a lemon. Otherwise it is neutral. They show a distilled water in the video that they put on the acidic side of the pH scale, but if it is acidic, it would only be slightly so.

[FitRunner]

One problem I have though is that they say in the video that regular water is actually acidic. I don't understand this, because water helps the liver function correctly and if we're supposed to be drinking water during P90X and during just living, how can it have an adverse affect on the metabolism when helping the liver function more efficiently actually helps the metabolism?

There's a few different things here. One is whether the water also contains other things, like minerals (i. e. metal ions), and the other is that the pH of a solution may not indicate the effect on the stomach, like with lemon juice.

Distilled water (i. e. very nearly only molecules of H2O) is like Dave said mildly acidic, due to carbon dioxide dissolving into it from air. H2CO3, carboxylic acid, is a weak acid that has an equilibrium with CO2. So when you start out with pure water, that equilibrium is all on the CO2 "side" of the equation, and some CO2 dissolves into the water to make carboxylic anions, which are acidic. This is an example of Le Chatelier's principle from general chemistry, if you remember that. However, the real-life effect on pH is minuscule - if you look carefully, all the waters are clustered tightly around pH 7.

Water with other things dissolved in it (other than CO2 of course) may also have its pH slightly affected by them, depending on what it is. Metal cations in water solutions have what are called hydration spheres - water molecules crowd around the cation, and sometimes the metal ions and the water molecules directly react. The metal cation can pull a hydrogen off a water molecule, giving you a hydroxyl anion (OH-). Hydroxyl ions are what makes something basic (alkaline). So, metals can act as acids in water solutions, ripping off an H+ from water to make OH-! Some metals do this pretty spectacularly, mostly transition metals, but the metals commonly found in drinking waters mostly float around, and so they're not very basic at all, like the video shows.

I know nothing about how the pH of the stomach changes when you add things to it, though, but the video already tells you digestion can flip things around in surprising ways.

I might have gotten overly technical here, so if anyone has any questions please do ask!

Teresa