The Not So Definitive Guide to Diet Soda
Before I begin, I want to make something clear: this is not your standard definitive guide to whatever. I’d like to be able to issue a proclamation regarding diet soda that stands the test of time immemorial, but I cannot. Research is still in its infancy, and exactly what diet soda does to those who drink it – if anything – is incredibly confusing. The one thing I can say with any certainty is that, while it’s unfair to say it will kill you or give your unborn child prenatal tumors or make you impossibly obese, you’re probably better off without diet soda. It tastes weird, the list of unpronounceable ingredients is too long for my comfort level, and I’ve seen one too many unsuccessful dieters that seem to live on the stuff.
There are two things to consider when making any conclusions about diet soda’s place in a healthy diet. Do the ingredients used in diet soda pose a threat to your short-term or long-term (or that of your offspring’s) health? Is it a kind of sugary methadone, impeding healthy eating by making it harder to kick the desire for sweet things in your mouth because, well, you’re constantly putting things in your mouth that mimic sugar? Let’s dig in.
First, the ingredients. What goes into a can of your average diet soda?
Carbonated water, some sort of food coloring, and preservatives like potassium benzoate are all innocuous enough. Nothing to worry about there. You won’t see Mercola issuing dire warnings about Caramel Color No. 76 anytime soon. It’s the other stuff that interests (or worries) us: artificial sweeteners and (to a lesser extent) phosphoric acid. Let’s take a look at the two major sweeteners in popular use, aspartame and sucralose. Are they dangerous?
Aspartame gets a bad rap. High dose rat studies implicate it as a carcinogen, but in exceedingly large amounts. A can of diet soda a day probably won’t give you cancer. Would I avoid it as a pregnant mother? Yes. Would I be wary of drinking several cans a day? Yes. The basic takeaway is that while the clinical evidence of immediate danger upon normal ingestion of aspartame is lacking, inconclusive, or unclear, the vast amount of anecdotal evidence from people linking aspartame to headaches, migraines, panic attacks, and other maladies gives me great pause. I mean, the stuff tastes horrible, and that’s enough for me, but some people appear to have real health issues with aspartame. Not everyone, obviously, but some do. If aspartame appears to give you trouble, don’t let PubMed convince you that it’s harmless. It may very well be safe in the amounts we typically consume in the majority of people, but you can’t ignore your own experiences.
Also known as Splenda, sucralose is a popular sweetener that’s often called “natural” because it’s the product of selective sucrose chlorination. It’s 3.3 times sweeter than aspartame and 600 times sweeter than sucrose. It seems to have less of a disgusting aftertaste than aspartame (it’s all foul to me, though). Like aspartame, most of the studies reporting negative effects used insanely high doses of sucralose. I’m talking doses in the area of thousands of Splenda packets a day for months on end. I’m no fan, but I don’t think normal consumption of the stuff will kill you. There was a study that found normal doses (between 1.1 and 11.1 mg/kg per day; recommended maximum daily dosage is 5 mg/kg) of sucralose negatively impacted the gut flora in rats and lead to weight gain, although a later review called the study’s results into question. I’ll pass, but thanks, expert panel. There’s also the fact that sucralose is usually combined with something called acesulfame-K (potassium), another sweetener that many researchers think needs more toxicity tests. My take? Studies showing negative effects may be overstated or misguided, but why take the risk for that weird chemical aftertaste? Just avoid the stuff to be on the safe side.
And then there’s phosphoric acid. Here’s how the story supposedly goes: phosphoric acid, which soda makers use in place of pricier citric acid, leaches calcium from your bones and reduces bone mineral density. Is it true? Well, it’s become pretty clear that foods containing dietary phosphorus – like meat, dairy, and other “evil” foods – strengthen bones, rather than leach from them. But phosphorus isn’t exactly the same as phosphoric acid, which epidemiological studies have connected with loss of bone mineral density and osteoporosis. One in particular found that only colas (both diet and regular) were strongly associated with loss of bone mineral density. What do colas have that other diet sodas largely do not? Caffeine plus phosphoric acid. A more recent controlled trial found that only fizzy drinks containing caffeine resulted in increased calcium excretion; phosphoric acid content exerted no effect, either alone or in concert with caffeine. I don’t think we can implicate phosphoric acid just yet.
Okay, but remember: we’ve got to be careful when analyzing a food’s worth by singling out one of its constituent parts for good or for bad (although diet soda is by all definitions not food, it is a consumable whose stated purpose is to help dieters lose weight by avoiding sugar). Let’s judge diet soda on that. It may be technically safe to consume, but does it do its “job”? Does it help us lose weight by replacing our sugar intake with non-caloric sweetener intake and reducing cravings?
By most accounts, no. If you look at the literature, diet soda has repeatedly been shown to correlate with weight gain and increased incidence of metabolic syndrome:
One study found evidence of a linear dose-response; the more diet soda people drank, the more likely they were to be overweight or obese. As Sharon Fowler, the author of the study, puts it, “for each diet soft drink our participants drank per day, they were 65 percent more likely to become overweight during the next seven to eight years, and 41 percent more likely to become obese.”
Another study, which I covered a couple years ago, analyzed the diets of more than 9,500 men and women between the ages of 45 and 64 and found that drinking diet soda was associated with a 34% higher risk of developing metabolic syndrome – the perfect storm of high triglycerides, belly fat, insulin resistance, and obesity that’s so popular nowadays. This was an even stronger association than the one between the “high-meat, high-fat” Western diet and metabolic syndrome.
Authors of both studies speculate that diet soda drinking just extends the life of sugar cravings, rather than eliminating it. In this scenario, diet soda doesn’t regulate the desire for sugar; it increases it, and diet soda drinkers are simply replacing those empty calories with real sugar. This makes sense, and I think it’s part of it, but a couple other studies suggest that something else is going on entirely independent of caloric intake:
The dietary habits and weights of a homogenous group of middle aged women were tracked for a year. Regardless of initial weight status and inexplicable by “food consumption patterns,” users of diet soda were more likely than nonusers to gain weight. They didn’t eat markedly different from non-soda drinkers and yet they got fatter. It continues…
A more recent study broke rats up into two groups. The first received ad libitum oral doses of water sweetened with the maximum Acceptable Daily Intake (ADI) of saccharin, aspartame, cyclamate, and acesulfame-K (the same formulae used in commercial sweeteners), while the second group received plain water. Both were given ad libitum access to standard rat chow (which usually resembles the SAD: a disgusting mix of vegetable oils and sucrose). While caloric intake did not change between groups, the rats given non-caloric sweeteners experienced greater increases in bodyweight. The rats apparently weren’t driven to eat more because of confused satiety signals, and yet they still gained more weight. What gives?
Are diet soda drinkers eating more actual sweets to make up for the missing calories? Are their satiety signal hormones being altered by some chemical additive? Or is something in the diet soda actually causing weight gain independent of caloric intake?
We simply don’t know. We do know, however, that our bodies respond to everything they encounter. You lift a weight, you send a message to your body (build more muscle, make bones denser, establish neural pathways for movement!). You put food in your mouth, that elicits a response, even before the food hits your gut, as with the carbohydrate mouth rinse that increases athletic performance. It may be that introducing artificial sweeteners directly to your gut (bypassing the tongue) doesn’t affect subjective satiety or satiety hormones, but that’s not how we drink diet sodas. We taste them. With our tongues. And there is a decent amount of (mixed) evidence that certain artificial sweeteners in certain situations in certain individuals can actually elicit hormonal responses from taste alone, leading to hunger that isn’t really there and perhaps even insulin to handle dietary glucose that was never actually eaten. The details of any effect artificial sweeteners have on our hunger hormones are still being teased out, and the subject demands a dedicated post sometime in the future – so stay tuned for that.
In the end, diet sodas contain potentially harmful chemical additives and phosphoric acid that may or may not leach minerals. The majority of people who drink them to lose weight are unsuccessful, and most epidemiological evidence and some clinical evidence has linked diet soda intake to increased obesity, even irrespective of caloric intake. It may be that tasting sweet stuff without a corresponding caloric dose is throwing off our satiety signals and messing with our normal hormonal response to food, or perhaps relying on fake sugar just makes it harder to give up the real stuff.
Of course, whether they have a place in your diet is up to you. Maybe you’ll buck the trend and lose more weight and experience greater relief from sugar cravings with diet soda. Maybe you have one every few days and no more. If you’re a dedicated diet soda addict, maybe experiment with slowly eliminating it from your diet. Drink a bit less than usual and see how you feel. Try to save your 80/20 allowance for something a bit more fun, like maybe a high quality full-fat ice cream or a hunk of super dark chocolate (which actually has some nutritional merit, like good dairy fat). I’m gonna say that ideally you ditch them altogether, mostly because they seem to reinforce bad habits in most people and because the long term effects aren’t fully known.
Whatever you do, don’t start a diet soda habit after reading this post!
Comments? Concerns? Give me your diet soda stories. I want to hear about the aspartame headaches, the effect Splenda has on your satiety, and anything you can think of. Don’t hold back!
Grab The Primal Blueprint Cookbook Today and Receive Free S&H and a Free Primal Blueprint Poster
Posted By: Mark Sisson
Bruce,
I’ve done a very similar post to this one on my blog. I totally agree with you. Research is still inconclusive at best but the ingredients are definitely unhealthy and well the soda companies are just spending billions to market their so-called diet product claiming that its safe for consumption.
I’m still more of a pure coke fan than a diet fan by a mile. But after doing a bit of reading on diet sodas, I’ll stay away from it for a long time.
I’m surprised no one has mentioned LaCroix drinks yet… carbonated water with very small amount of natural fruit flavoring. No calories, caffine or sugar. Takes great and gives you that nice refreshing bubbly sensation
I do not allow anything with HFCS or artificial sugar in my pantry. I limit artificial ingredients and added sugar as much as possible. I wish I could be more selective when it comes to making everything myself, using organic fruits and veggies and grassfed beef; but I am on a very limited grocery budget. I cut out what I can. It disgusts me to see what most people I know eat and feed their children.
This is something I wrestle with. I do drink diet soda everyday and have for years. Some days it’s a little, and some days it’s a lot.
I went almost primal in mid 2010. I say almost b/c I do eat beans often (wife is from South America & eats it a every meal). I lost 52 pounds in 4 months. So diet soda didn’t stop me from losing fat, but I am concerned about the unnaturalness (is that a word?) of it.
I’m totally on the fence about it…
When I was using diet sodas and Splenda in my tea along with a low carb diet, I lost weight, but the recurring bladder infections (puzzled at least two doctors–they had no suggestions)and blood in my urine were not acceptable side effects. Both went away when I stopped using (artificial sweeteners).
Also, I have twice used Aspartame in an experiment on ants: I mixed a packet of Aspartame into a solution of lots of sugar in water and put it in a margarine container on the kitchen floor by the door the ants were coming in under. Within a day a I had no more ants and also discovered many spider mites dead on the container. This was enough to convince me to stay away from all artificial sweeteners.
I started drinking diet soda (Tab back then) when I was 11. I quit during two preegnancies and nursing and would then resume. I would sometimes drink as much as 6 cans a day (diet Coke), but I usually try to keep it to 2. I try and substitute bubbly water when I think I am consuming too much soda. I have never seen an impact on my weight either way but I do tend to feel better if I try to drink more water than soda. But I turn 49 this summer, am at a normal weight for my height and am pretty fit.
I live in Arizona and literally drink a gallon of water daily. In the evenings I usually have 1 can of diet soda or the clear flavored waters that have aspartame. I think that is a safe amount and I have no guilt.
Another reason to quit diet soda: no more acid reflux. For some reason I was being an idiot and never made the connection between 3 Diet Dr. Peppers a day and my terrible acid reflux. Then I quit soda when I started going paleo and I feel better than ever.
Before going primal, I used to drink a LOT of fruit juice, especially carbonated apple juice. I thought giving up those drinks would be very difficult for me, but I was surprised that it turned out to be easy.
However, like other readers, I love carbonated water. I highly recommend the “sodastream” device that lets you carbonate your own water. It’s very convenient, inexpensive, and I like that I reuse the same bottles over and over again. (I used to have a recycling bin full of glass bottles every week. Now I only have to put out the recycling bins once every few weeks.)
Another bullshit concept about diet drinks. If you are diabetic, diet drinks and sweetners are the way to go since sugar is bad for you.
I use aspertane all the time and my blood sugar wouild be sky high with any sugar product and corn sweetners are the worse.
ww ruland,
Really? Your comment makes it sounds like soda and diet soda are the only choices on the planet as far as beverages go. How about you don’t drink either of them. Sugar is bad and so is artificial sweeteners. Try some water.
Hi Mark, et al. I’m a new convert to the Primal lifestyle and have been amazed at how it’s already having so many positive effects!! I saw a posted question about Zevia “diet soda” naturally sweetened with Stevia and I didn’t see anyone answer…? It’s been my go-to since giving up Diet Coke 2 years ago. I have probably 2 per day on avearge. I also love Vitamin water Zero sweetened with Stevia too. Am I giving up one vice for another or are these ones primal enough for modern day?
8-12 cans every day for 25 years (pepsi max), getting fatter annually and no hope of quitting. I know the drinks make me thirsty – no other obvious adverse reactions but I would love to give up.
I don’t buy any of this stuff…if it really tasted so bad why would so many people love and drink diet coke??
There is no evidence that only dieters use diet soda.
I have a can or two of diet coke a day, and don’t plan to apologize for it. I usually drink it with a big portion of ice so it’s diluted. It provides the same hydration as water – why wouldn’t it? The main ingredient in soda, diet or not, is water.
Honey, molasses, or whatever else WILL cause an insulin response in the body and does contain calories. I’ll stick to my diet drink any day…
Sodas are highly acidic, regardless of sweetener. phionbalance.com has best test strips and pH (acidic versus alkaline) info. drfuhrman.com is also a tremendous resource for “food as medicine”. His acronym GOMBS for greens, onions, mushrooms, beans/berries and seeds/nuts inspires my recent soup efforts (plus garlic, peppers, celery, carrots, whatever veggies available). Amy’s low sodium veggie lentil is a great starter. Enjoy soup and websites. pH into the alkaline zone and Fuhrman’s micronutrients and phytochemicals emphasis is a likely formula for a healthy and long life!
Aside from the chemicals, its worth noting that these soda drinks ROT YOUR TEETH faster than anything I know. I was warned about it by a dentist when I was a teenager and to this day am grateful for his advice! The acids in diet sodas are just as damaging as the sugars in sweetened sodas apparently. Fruit juices are also up there as teeth rotters, not as bad as soda drinks, but woth noting that the alkaline content of your saliva can deal with most natural foods but the acid wash of a fruit juice or worse – a soda drink – is not so good for your gnashers.
I found this blog very interesting.
A year ago, I moved, and we had a second fridge that I stocked with diet soda. Before moving, I probably drank a couple of cans per week. After moving, I started drinking it like crazy – - 3 cans per day was not uncommon.
Oddly, I gained 12 lbs in a year WHILE training for a marathon.
I don’t know if I really slacked on my eating habits, but I don’t think I changed THAT much. I feel as though maybe the diet soda had something to do with the weight gain.
I stopped cold turkey and had 3 days of migraines (even though not all the diet soda was caffeinated). I’m moving toward a low carb lifestyle (just found your site and am perusing it with enthusiasm).
I feel better, but I am not losing weight quickly. However, I have hope that maybe I can at least drop the 12 lbs I gained over the course of the year . . .
I waited tables for years and drank Coke from the fountain during my entire shift. I remember one day it just hit me that, almost without exception, the people who ordered full sugar soft drinks were obese or very young. People who drank diet soda never looked healthy (overweight or otherwise unhealthy looking). The people who were noticeably attractive and fit looking drank water or unsweetened tea. I figured that was enough of a study for me. Quit then. For about a year I would drink a soda or diet soda occasionally. Now the thought of it is completely unappealing. Eliminate don’t limit!
I’ll be one to buck the trend, so to speak, and go “pro-diet soda” – but first let me explain why.
I was a HUGE regular soda drinker and it’s caused me to be skinny fat for a long time. I’m am/was a sugar addict in general, until recently I decided to cut it out as much as possible and follow a more primal diet. Since soda was such a big habit, I know from past experience I couldn’t just cut it out completely, because then I’d feel too deprived, and revert back to bad eat habits across the board. It’s as much a mental thing as it is a physical thing. So diet soda is the one thing I allow myself daily for now (cut out all refined carbs, sweets, and other junk). I literally drink over a liter day, but I’ve been dedicated with the gym and the rest of my eating habits. In just about 6 weeks, I’ve dropped 12 lbs (from 172 to 160) and have a noticeable decrease in belly fat (though not totally gone). As I mentioned, I am skinny fat, so I’m not visibly overweight…so 12 lbs is A LOT for me. I still think another 10 is in order to get lean, but I feel like I’m on my way…and if I get there, it will be the first time since I was like 10 years old that i’ll have a truly flat stomach (im in my 30′s now). I know other people experience other side effects like stomach aches and such, but maybe just because I’ve been a big soda drinker since I was a kid, it doesn’t bother me?
I realize diet soda in all odds is bad for you with all the chemicals, but this is helping me transition to avoid sweet drinks. Compared to my previous diet (loaded with sugar and processed food), this is an improvement. Im slowly starting to swap seltzer and water in as substitutes…so for every one glass of diet soda I have, I make the next glass water or seltzer to try and dwindle down the numbers (I drink a lot of liquid throughout the day). I eventually want to phase it out completely, but I know myself, and know that cold turkey doesn’t work for me long term.
Everyone is different, and like Mark said – if you aren’t drinking it already, I don’t recommend starting! Soda is my cigarettes…I was hooked at a young age and I’ve been trying to escape for years.
Also – my main point was to show that in my case, diet soda doesn’t appear to be what makes you fat. I’m drinking it in quite large quantities (I honestly drank close to 2 liters today), and if you added up the calories I’d be consuming if it was regular soda, I’d be GAINING weight instead of losing it. I’m convinced that those studies that show people gaining weight is because the rest of their diet is crap, and they are victims of the “Big Mac with a diet coke” syndrome.
Again – not advocating it as being healthy, but i don’t think it causes obesity either.
So I bought some cordial called ‘The Naturdal Cordial Company’ apple raspberry flavour, when I was trying to be healthy, before I discovered Primal.. And I haven’t touched it since. My husband however, has been going through the few sugary things we have left in the house he has recently finished the bottle of normal cordial and then yesterday he had a strawberry milk made from some milkshake syrup which I’m sure must be packed with sugar. (a big drink of milk usually makes him sick so he steers clear) He can’t seem to kick sugar! I just picked up my bottle of ‘healthy’ cordial and went straight to the amount of carbs and sugar listed.. Carbs 2.2 per 100g, Sugar 1.2 per 100 grams, Erythritol 1.0 per 100g.. It’s sweetened with stevia!
So that’s good right? I mean I can safely have (and feed my husband) a nice sweet drink of cordial without feeling guilty or ruining my eating? It’s basically just fruitness, water and a bit of stevia..??
I was a big Coke Zero fan, especially the vanilla variety. Then I watched ‘Sweet Misery’ (available on the net on vimeo, I think) … I don’t drink it any more. The aspartame business is nasty from the process of getting it approved to the massive list of side-effects. I actually feel guilty for giving my 7yo daughter a sip occasionally …
So I’ve been reading everyone’s comments on the soda issue, have noticed several people mention Soda Stream, which we own and use (a lot!). One of my friends was saying that anything carbonated with CO2 had carbonic acid in it and would cause loss of bone mass and tooth enamel degeneration. I can’t find anything in the MDA archives (maybe I’m just not trying the right search criteria) regarding this.
So-we’re really new to PB. Very happy so far-I got my husband and son to agree to try this and today is our one week anniversary. We’ve lost 18 pounds as family! (Hubby-11, me 5 and our son, not really overweight yet with a little pot belly, 2.)
We’re eating delicious home cooked meals, saving a ton on restaurant bills. So-does anyone know if my friend is right? I would hate to be trying so hard to be healthy and unknowingly doing something that could sabotage our health down the road. My son hates (yay!) anything fizzy, drank maybe one glass of juice every couple weeks, so his fluid intake has remained the same- milk and water. I was never a really big soda drinker, my fav remains iced tea with lots of lemon and some sweet-n-low. I haven’t had that, switched to Truvia for both ice tea and coffee. Haven’t noticed any sugar cravings associated with that, though I’m guessing the erythritol portion is probably a sugar alcohol. We do drink plain water, but the fizzy stuff (plain or with lemon) is very nice with meals.
So-soda water OK or not? Any comments/knowledge would be greatly appreciated by a couple of newbies. Thanks.
I just wonder if there is an insulin response or not??????
I’ve been trying to adapt to this diet by slowly switching over for the past week now, but really enjoy a dt dew in the morning or at lunch. Despite the other possible health affects, I would really love to continue doing so if it doesn’t affect insulin.
The migraine response to aspartame seems to be genetic. My mother-in-law, wife and daughter all suffer migraines when they consume aspartame and only when they consume aspartame. Those of us with Y chromosomes do not seem to be afflicted with these symptoms, but statistically, women are more prone to migraines in general (my doctor has a poster about migraine vs. cluster headaches). As I am well above my ideal weight, I’m going to begin elimination of soda (and energy drinks) from my routine, but it’s going to be a long road, as my office trash can is full of energy drink cans and I have a 32oz fountain drink on my desk at the moment.
If I give up diet coke and substitute with water, I’m inclined to try sparkling water. Are there salt issues with that?
While on the path to learning how to take care of my mind, spirit and body I have learned that I need to start trusting my intuition and I have this intuition that drinking Diet Coke is somehow messing with me in a way that prevents me from reaching my body fat goals. I’m a data driven guy though and finding the data that definitively validates my intuition is next to impossible. The only option I can see left is to stop the Diet Coke all together and see what happens
Even with carbohydrate intake of < 25 g per day, the addition of one diet soda per day COMPLETELY stalled what had been very steady weight loss and started me on the path to eating badly again.
I also did some self-experimentation to discover it is a major trigger for migraine and anxiety attacks. It's not the caffeine alone, b/c coffee does not have the same effect.
I do love soda, though, so I make it a weekly treat. I have one soda made with real cane sugar on the weekend. And I walk the mile to the healthy grocery store to buy it, and back, so the exercise burns a lot of the sugar.
In the summer here in Mississippi it is very hot. I make sun every couple days – steeped outside in an old 3 qt Ball mason jar pail for about 3 hours. I use a mix of green, black, and peppermint tea. The peppermint makes it even more refreshing.
I "sweeten" with just enough honey to not make it sweet, but just cut the bitterness. Add lemon, and it's incredibly cooling on a summer day.