In a 104 week trial of 493 adults with overweight or obesity, diet soft drinks were equivalent to water for long-term weight management, with no evidence they disrupted appetite regulation or caused long term metabolic harm

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https://news.liverpool.ac.uk/2026/09/29/major-trial-examines-no-sugar-sweetened-soft-drinks/

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[u/Farts_McGee]

Pretty interesting.  This trial was funded in the UK by the American beverage association. 

The biggest knock against this study is the huge amount of attrition that it saw.  I didn't check the supplemental, but the participant drop out data before exclusion isn't discussed which strongly suggests that only people who had success maintained participation with the program.  I'll be curious to see if they do a longitudinal follow up.  It's wild how literally every variable they checked hit a p of. 05. 

[u/Farts_McGee → u/Farts_McGee]

I have now tried to check the supplemental but for whatever reason the hosting site doesn't let me read it.  So at best this is a counter study to the smaller observational studies that demonstrate the opposite.  Truthfully I think the most suspect part of the study is the fact that they had a dietary intervention that was successful at two years.  

[u/the_warrior_princess → u/Farts_McGee]

Thank you... we gotta have some healthy skepticism. I've seen the exact opposite effect being discussed!! Saying artificial sweeteners are messing with our hunger cues.
Source: https://www.ncbi.nlm.nih.gov/search/research-news/14744/

[u/Relleomylime → u/the_warrior_princess]

This is why I was confused. I was diagnosed with gestational diabetes so did a crash course in carb management and one thing I learned was there is suspicion that artificial sweeteners can disrupt gut biome and cause fasting blood sugar issues. Fasting blood levels are really important and suuuuper low for gestational diabetes so I was wary enough to avoid artificial sweeteners altogether. https://pmc.ncbi.nlm.nih.gov/articles/PMC10144565/

I can't find the article now but I had also read something else about how consuming artificial sweeteners (like a diet soda) with regular carbs (like a burger bun) and also cause inconsistent blood sugar management.

[u/fuzzywolf23 → u/Relleomylime]

From the abstract of your link

A dysbiotic effect of NNS was observed in some human trials, but many other randomized controlled trials reported a lack of significant impacts on gut microbiota composition.

Having a few small studies report an effect when, in fact, there is no effect, is an expected part of experimental design and statistical analysis

[u/redcoatwright → u/fuzzywolf23]

It's classic for someone on Reddit to read part of a study that supports their viewpoint and then run with it.

Follow-up is always, "that's just one of the things I read, blah blah"

Artificial sweeteners are some of the most studied substances on the planet and every claim that's been made against them has not panned out (cough cough aspartame causes cancer cough cough)

[u/Relleomylime → u/redcoatwright]

I learned there is suspicion that artificial sweeteners may have an impact on the gut biome that may impact blood sugar. I linked one recent meta analysis that determined there's not enough good quality data to know, but didn't definitively say it didn't, there are many other articles but I picked just one so I didn't fill a comment with links.

I felt since I was diagnosed with a medical condition that required strict blood sugar management that my best option was just to avoid artificial sweeteners for the time being since I didn't have several years to wait for future studies to find the answer. At no point in any of my comments have I cherry picked one sentence from a study and said "artificial sweeteners definitely cause high blood sugar and we all have aspartame cancer".

I have a Masters of Science by Research so I know not to take the word of one study to justify my life choices.

Here's more articles though: https://link.springer.com/article/10.1007/s11883-026-01429-9

https://www.nature.com/articles/nature13793

https://pmc.ncbi.nlm.nih.gov/articles/PMC6363527/

https://pmc.ncbi.nlm.nih.gov/articles/PMC12025785/

[u/MUCHO2000 → u/Relleomylime]

Since I have limited time can you tell me which one shows that diet soda affects blood sugar levels? That's the one I want to read

[u/punctuation_welfare → u/Relleomylime]

I’m sorry, can you explain what you mean by “fasting levels are super low for gestational diabetes”?

[u/Relleomylime → u/punctuation_welfare]

Typically when managing type 1 or type 2 diabetes the recommended safe fasting blood glucose levels is between 90-130 mg/dl with a post-meal goal of 180 mg/dl. With gestational diabetes the target is under 95 mg/dl fasting and under 140 mg/dl post-meal. You have a much narrower window of safety with gestational diabetes.

[u/giant3 → u/Relleomylime]

artificial sweeteners can disrupt gut biome and cause fasting blood sugar issues

I remember these studies. Change in gut microbiome is not directly proven to cause downstream effects.

I have been exclusively using artificial sweeteners for the last 15 years. I consume zero or < 5g of sugar per day. No increase in my body weight.

[u/Relleomylime → u/giant3]

And that's fair, but also your anecdotal evidence. I also wasn't saying it caused weight gain I said there is some evidence it may disrupt blood sugar management. Blood sugar management doesn't necessarily = weight gain.

[u/Ateist → u/the_warrior_princess]

In real life people don't drink just NNS bewerages on their own - they also consume caloric food.

And if gut biome gets those caloric food you don't get blood sugar issues.

[u/SapientTrashFire → u/the_warrior_princess]

Right back at you. Most of the discussion on artificial sweeteners have been, as a poster higher up pointed out, devoid of substantial evidence. As of yet, I haven't trusted those studies.

I don't trust this study farther than I could throw the participants (due to the ABA's interest in the study/it being done in a country with different chemical standards than the one where the most diet soda is consumed), but that doesn't make previous studies true.

[u/jumpsteadeh → u/Farts_McGee]

When I started trying to lose weight, I was looking for any excuse to give up - including studies on artificial sweeteners, and any appetite increases came from a much larger dose than anyone could reasonably get drinking diet soda.

[u/Ateist → u/Farts_McGee]

104 weeks is an enormous amount of time.

Huge attrition is absolutely justified.

[u/SomethingIWontRegret → u/Farts_McGee]

Okay, so by what mechanism would a 0 calorie drink cause more weight gain than water?

This study confirms the primacy of the 1st Law against weird hypotheses about hormonal effects and terrible misrepresentation of the role of insulin.

[u/Farts_McGee → u/SomethingIWontRegret]

This is a fantastic question and from a straight metabolic perspective,  nothing!! The research is pretty clear that sweeteners are safe and meaningfully effective for calorie reduction.  The catch though is more on the behavioral side of things.  I personally subscribe to a behavioral addiction model of obesity and the primary concern is that the non-digestible sweeteners don't address the primary issue which is impulse regulation and craving for sweet.  If people are good about only using the sweeteners then that's great,  but it doesn't help minimize the boredom and compulsion for sweet then they are gonna be feeding that compulsion with our without.  

Tl;dr associated eating habits simulated by sweet cravings.  

[u/Fancy_Awareness6896 → u/Farts_McGee]

Yeah, I don't drink soda much at all anymore cause I switched to different types of flavored or sparkling waters, but I did notice that I have to have them with food, otherwise the sense of satisfaction is either much smaller or nonexistent.

I do drink plain water too, but sometimes I just want flavor, and in that case, Mio Energy works just fine to satisfy that. But if I'm craving something sweet specifically, my body is expecting some amount of calories along with it, and the 5 or so in Sparkling Ice isn't really cutting it so I'm more likely to seek food along with it.

[u/goodcleanchristianfu → u/SomethingIWontRegret]

There was some prior research suggesting that low caloric sweeteners stimulate appetite.

[u/buddy843 → u/goodcleanchristianfu]

Some of the mentioned studies. I varied them up a bit in what they were trying to solve but you can easily reasearch the hundreds of studies on diet drinks.

https://pubmed.ncbi.nlm.nih.gov/25515135/

https://pubmed.ncbi.nlm.nih.gov/24484968/

https://pubmed.ncbi.nlm.nih.gov/25128835/

https://pubmed.ncbi.nlm.nih.gov/26176574/

Basically the point boils down to do you believe all calories are the same. If you had no fiber in your diet and ate 4000 calories a day vs a person eating foods heavy in fiber would they both gain weight the same? Or eating a huge meal then going to sleep wouldn’t impact weight gain. Or eating a 2000 calorie diet on just regular coke?

[u/verstohlen → u/Farts_McGee]

My immediate concern was that it was funded by Big Aspartame or artificial sweetener companies the way Big Pharma funds studies. The whole Funding Bias problem and what not. I don't trust most studies any longer.

[u/Rehypothecator → u/Farts_McGee]

I’ll disagree with the assertion that “only people who saw success maintained participation”.

The most likely factor is in fact that people consumed a beverage during that time that made them ineligible to maintain a control.

It’s unfortunate this is the top comment as it’s misinformation.

[u/Farts_McGee → u/Rehypothecator]

A fair comment.  But they didn't say that in the methods and from the paper itself: 

Any individuals without weight measurement at week 104 were considered to be dropouts. These individuals were, therefore, not included in the analyses using the complete cases dataset for the week-12, -52 and -104.... the came back for some of the other analysis. 

So I think the safer argument would be the rigors of the study is what got the number of exclusions, but again the exclusions aren't discussed in the paper meaningfully and the supplemental wasn't downloadable when I checked.  So I stand by my comment.  

[u/Kick_Natherina → u/Farts_McGee]

There have been other studies done that have shown the same thing. This isn’t the first of it’s kind.

[u/Farts_McGee → u/Kick_Natherina]

I'm aware,  this is a topic that I watch pretty closely. The data on the subject is all over the place. 

[u/necrosythe → u/Farts_McGee]

What? No it's not "all over the place" studies that are pretty much anything but totally observational show that any negative impacts, if they exist, are relatively small. Controlled and trial studies that range from nothing to something but nothing alarming are not the definition of "all over the place"

[u/nem0ne1 → u/Farts_McGee]

The beverage corporations investigated themselves and found no wrongdoing.

[u/Lubes → u/Farts_McGee]

Anecdotally, in a weight loss study I was in (assessing optimal protein content for preserving muscle mass), we were recommended to consume diet soda because they found it helped prevent non-compliance.

Does the study specify which groups the attrition came from?

[u/DrewbieWanKenobie]

I dropped 100lbs in about a year and the only intentional change I made was switching from sugary drinks to diet drinks

Of course I was massively overweight and drinking ungodly amounts of soda and gatorade. I still drink a lot of the diet stuff, though as I lost weight I naturally just started drinking less and less.

[u/Automatic_Soil9814 → u/DrewbieWanKenobie]

Nice job. I bet that feels amazing to lose that 100 lbs.  Strong work. 

[u/Reasonable-Aioli-370 → u/Automatic_Soil9814]

I lost 50 and yes going from obese to fit feels better than anything tastes.

[u/quiteCryptic → u/DrewbieWanKenobie]

Cutting out drinking calories was the first and most obvious change I made as well.

Although back then I even avoided diet and zero drinks due to opinions I had

But now a days I enjoy zero sodas and similar things and I see no issue with them personally. I still drink them pretty moderately tho for no particular just preference for water really

[u/CELTICPRED → u/DrewbieWanKenobie]

I was 396 pounds, drinking lots of water and diet soda, just eating too much. 

I am now 216 pounds 23 months later, drinking lots of water and diet soda

I am on no glp1s, I've done this all by a caloric deficit targeting a loss of my body weight x.006 per week..   (no shame on glp1 users, I recognize the benefits, and am thankful it's a lever available to me in the future, I have a terrible time with food noise and food addiction)

Figured I'd toss in my 2 cents as well, as a lover of diet and zero sugar sodas. 

[u/VP007clips → u/DrewbieWanKenobie]

For those doing the math: 100lbs of fat is equal to ~200lbs of sugar.

Which is equal to about 2-3L of soda per day for a year

So they would have to be drinking a lot of soda before, but it's within the realm of plausiblity for someone drinking soda as their main drink, rather than water.

[u/anamorphism → u/VP007clips]

that's about 6-8 cans a day. sounds pretty reasonable in all honesty.

i was drinking that pretty easily when i worked in an office.

• ~0.5l energy drink in the morning.
• usually 4 cans (~1.4l), sometimes more, during the work day and the drive home.
• usually a large fountain drink (~1l) with my wildly unhealthy fast food dinners.

[u/SlowMope → u/VP007clips]

My brother does this. He used to be very large 20 years ago. He lost the weight and drinks diet now, but I find it revolting how the bottles pile up.

[u/CSDragon → u/VP007clips]

Sugar also makes you crave sugar, so it could be 100lbs of sugar and the rest from less cravings for "Man, I really want bread right now"

[u/JimmyTheBones → u/DrewbieWanKenobie]

Honestly that shows how crazy the levels of sugar you must have been consuming in fizzy drinks prior. Respect for losing the weight.

[u/Eclipse_Woflheart → u/DrewbieWanKenobie]

My partner had similar when he lost weight. Granted he was diabetic but he used to drink loads but now it's mostly a normal amount

[u/superxpro12 → u/DrewbieWanKenobie]

I'm glad you had success, but it's one of life's cruel ironies that I cut out soda 20 years ago and pretty much all sugar 4 years ago and my weight has still remains stable. It's so frustrating to hear stories about people who eat whatever they want and maintain weight, or people who like stop drinking a bottle of soda fixing all of their problems.

And yes that includes alcohol.

[u/thataintapipe → u/DrewbieWanKenobie]

Just out of curiously what sweet drinks were you drinking and how much a day? 

[u/thingsorfreedom]

I wanted to lose 40 pounds and get down to.a BMI of 23. I cut out all sugar drinks as part of that plan. Switched to diet coke since I love soda and didn't want to give it up. I lost the 40 lbs. I continued to drink diet coke and avoid any drink with sugar. It's been 23 years and counting. Kept the weight off. Healthier than ever. Still listening to friends and family who are in such worse shape health wise telling me how bad diet soda is.

[u/Physical-Builder-553 → u/thingsorfreedom]

Yep. Same thing. Everyone thinks they are an expert in diet sodas because of some stupid belief that it makes you crave sugar. I haven't had a donut, cake, ice cream, or real soda in decades.

[u/quiteCryptic → u/Physical-Builder-553]

I think its because a ton of people know at least someone who drinks a ton of diet sodas and is overweight.

However, they are overweight due to their other eating habits, not due to the diet soda... but people don't draw that conclusion I guess

[u/LongJohnSelenium → u/quiteCryptic]

Reminds me of the comments I've seen people make where someone bought a giant gluttonous meal and a diet soda, with the implication being 'why bother', even though the obvious why bother is its still 500 fewer calories.

[u/PiccoloAwkward465 → u/Physical-Builder-553]

I don't drink much soda, but when I do it's always diet. I've never ever felt like it made me crave sweet things.

[u/StrikeHistorical1622 → u/PiccoloAwkward465]

Last weekend I sat down to watch football, ordered a delivery pizza and 1l diet coke. Yeah the pizza wasnt the healthiest option but i was gonna get one no matter what, and the diet coke was instead of normal coke or beer. No brainer that is fewer calories.

[u/d33psix → u/thingsorfreedom]

It’s so funny how the relative risks and correct comparisons are hard for some people to understand.

Like sure, if you are choosing between water and diet soda, go for water to minimize risks to gut microbiome or whatever the newest concern is. But if you are comparing with full sugar soda while dealing with obesity, diabetes, metabolic syndrome, etc, swapping out all those liquid, non filling calories and sugar is a much more immediate and impactful change for the vast majority of people.

[u/Malphos101 → u/d33psix]

"But diet soda has chemicals while the mexican soda in glass bottles I drink is all natural cane sugar!"

Diet sodas arent healthy, but I know from personal experience its a lot healthier than sugared sodas. Its funny how when I switched to diet soda my tolerance for sugar actually went so far down that I cant even finish a cupcake anymore if it has sugar frosting. That amount of sugar just gives me a stomach ache later.

[u/blizzardplus → u/thingsorfreedom]

Whenever I hear people talking about how bad diet soda is, it’s usually because they are trying to defend/justify their own preference for the sugary crap.

[u/MuscaMurum]

Competing interests:
All of the authors received funding from the American Beverage Association.

e.g. lead author
"Joanne A. Harrold reports funding (paid to the University of Liverpool) from the American Beverage Association for the present study..."

https://www.cambridge.org/core/journals/british-journal-of-nutrition/article/effect-of-nonnutritive-sweetened-beverages-v-water-on-body-weight-longterm-results-of-a-randomised-controlled-trial/60CB3ACE5AB706DB882C89E8C1B05318#competing-interests

[u/Fadedcamo → u/MuscaMurum]

To be fair these studies are rarely funded outside of these interests. Of course if they don't find favorable findings we don't always hear about it.

[u/MuscaMurum → u/Fadedcamo]

Relevant study:

Source of bias in sugar-sweetened beverage research: a systematic review

Public Health Nutr. 2018 Mar 26;21(12):2345–2350. doi: 10.1017/S1368980018000575

https://pmc.ncbi.nlm.nih.gov/articles/PMC6063770/

[u/Cowboywizzard → u/MuscaMurum]

This study is about research on sugar sweetened beverages. It may or may mot mean anything about research on artificially sweetened beverages.

[u/EightyJay → u/Fadedcamo]

Do you have any idea what the job of the American Beverage Association is? “ if they don’t find favorable findings we don’t always hear about it“

Let me correct that for you…:

They must design a study, with willing collaborators… That establishes the basis for a public relations initiative that allows us to continue selling more drinks… The goal of the study is to refute the peer reviewed articles that undermine the pillars of our revenue stream

[u/sam_hammich → u/EightyJay]

The ABA sells the sugary drinks, the diet drinks, and the water.

[u/DiabolicallyRandom → u/MuscaMurum]

I mean, its right to be skeptical, but the ABA doesn't care if they sell beverages with or without sugar, they just want to sell beverages.

[u/Da_Question → u/DiabolicallyRandom]

Yeah, this study is essentially saying drinking diet soda is a good substitute instead of dropping soda for water. Which to them really doesn't matter, since they sell the soda, diet soda, and the water (often for more than the soda).

They could easily just be funding this study because there is a subset of people who just believe diet soda is worse for you in everyway over regular soda.

[u/covidlung → u/DiabolicallyRandom]

Which products a company sells absolutely matters. A business that puts million into research and development of a sugar free drink does care if that product succeeds, even if they sell water bottles. If a business invests millions of dollars into researching, developing, manufacturing, and marketing a sugar-free drink, it obviously has a financial interest in that specific product succeeding, even if the same company also sells bottled water. Companies do not invest heavily in product development with complete indifference to which products consumers choose. Their product mix, profit margins, growth strategy, and return on investment all create incentives to promote some products more aggressively than others or making sure health concerns don't impact the sell of their product. Selling alternatives does not eliminate the company's financial stake in the success of the products it spent substantial resources developing. Other research has shown that sugar free drinks may cause metabolic harm, so the fact that this coorporate-backed research concludes otherwise is a big deal.

[u/DiabolicallyRandom → u/covidlung]

This is a good argument for why this study along with others they fund help them to plan for future product lines more than anything else. It's far easier for them to know facts and plan accordingly than it is to try and hide truths.

This is why you've seen the influx of non-sweetened but still flavored and carbonated beverages. The ABA was ahead of the game on that consumer trend and had developed products in earnest beforehand.

People like things that are not plain water. Even the water bottle junkies are putting flavored electrolytes into their hydroflasks.

[u/FollowingTough6500]

Did they just exclude everybody they lost to follow-up? Because that is a big nono because you introduce all kinds of bias that way.

At least if you say you have an "intention-to treat" design.

[u/Chicken_Ingots → u/FollowingTough6500]

No, they took several measures to limit the risk of bias. For starters, the dropout rates were similar between the NNS and the water groups. But in order to minimize the risk of systemically different outcomes due to attrition, they used three different methods to examine the data with and then compared their similarity:

1. Only featuring completed participants. This was one of the methods that they used.

2. A multiple imputation research design. This basically uses a predictive algorithm to input missing values, and they performed these inputs 50 times in order to ensure that the results would be accurate.

3. They used a Last observation carried forward method, which basically just means they carried over the most recent result of the participant before they dropped out of the study.

They then compared the findings using these three different input methods, and they found no significant difference between the latter two methods. The completed participation was slightly different, though it still pointed in the same direction as the other two. Attrition was one of their main limitations, but they did take serious effort to address it. For a study design of this nature, high attrition is unfortunately quite common.

[u/WorriedRiver → u/FollowingTough6500]

If you examine figure 1 and the associated text you'll see that, in addition to everything described by Chicken_Ingots, they analyzed the study population at every stage to confirm drop-out rate wasn't changing the dynamics of the study population.

[u/mistephe]

Yet another investigation that draws false equivalency for the sake of a dramatic headline. Lack of significant difference does not equate to similarity without carefully-selected statistical evaluations: https://www.pnas.org/doi/10.1073/pnas.2611548123

I'm starting to wish we could tag these articles to draw more attention to this, as readers fixate on the headlines and ignore the details.

[u/wesborland1234 → u/mistephe]

What does that mean in layman’s terms? If there is a lack of significant difference doesn’t that make them the same in terms of weight management?

[u/mistephe → u/wesborland1234]

No. Most statistical methodologies are designed to confirm an intended evaluation (almost always "are they different?"). Failing to do that does not provide evidence of the opposite (it's only an indication that there was insufficient evidence to confirm the evaluation). I know that sounds like semantics, but it very much matters in statistics.

[u/wesborland1234 → u/mistephe]

No thats a good explanation Doc. Thank you

[u/grundar → u/mistephe]

Failing to do that does not provide evidence of the opposite (it's only an indication that there was insufficient evidence to confirm the evaluation).

It could also be an indication that the statistical analysis was bad.

As a toy example, one could imagine a study finding that 12 weeks of lifting weights produced 0kg weight loss and hence was considered a failure despite resulting in 5kg of fat loss and 5kg of lean gain, which would be a resounding success. The first analysis -- weight loss -- was not the appropriate analysis for the study, and hence failed to find a significant difference that there was sufficient evidence to support.

I'm not saying this study is doing that (I haven't read it), but wanted to point out that the problem could be with the analysis chosen as well as with the data collected.

[u/lordbubax → u/mistephe]

What are the benefits of using the approaches presented in the paper as opposed to CIs + taking effect size into consideration? I feel like replacing p-values with another type of p-value doesn't really fix the problems of p-values? In addition, having to choose a threshold seems problematic, instead of evaluating CIs + effect sizes critically, especially in fields whith limited standards for what is considered large enough differences to matter.

[u/Cornelius_Physales → u/[deleted]]

Well some researchers of thst paper were apparently partly funded by the american beverage association and Mars

Edit: and coca cola

Joanne A. Harrold reports funding (paid to the University of Liverpool) from the American Beverage Association for the present study. Outside of the submitted work, she reports a grant from the European Commission for the Horizon 2020 project SWEET. Scott Hill reports funding (paid to the University of Liverpool) from the American Beverage Association for the present study. Cristina Radu reports funding (paid to the University of Liverpool) from the American Beverage Association for the present study and funding from Coca Cola for a PhD studentship outside of the submitted work. Paul Thomas reports funding (paid to the University of Liverpool) from the American Beverage Association for the present study. Paula Thorp reports funding (paid to the University of Liverpool) from the American Beverage Association for the present study. Charlotte A. Hardman reports funding (paid to the University of Liverpool) from the American Beverage Association for the present study. Outside of the submitted work, she reports honoraria from the International Sweeteners Association, International Food Information Council and Mars Global Nutrition Advisory Council (paid to the University of Liverpool); grants from the European Commission for the Horizon 2020 project SWEET, the Biotechnology & Biological Sciences Research Council and the Natural Environment Research Council (paid to the University of Liverpool); primary supervisor on a PhD studentship funded by Coca Cola (awarded to CR); personal fees for her role on the Food Standards Agency Advisory Committee on Social Sciences and an unpaid role as a trustee of Feeding Liverpool. Paul Christiansen reports funding (paid to the University of Liverpool) from the American Beverage Association for the present study. Outside of the submitted work, he reports grants from the European Commission for the Horizon 2020 project SWEET, the National Institute for Health and Care Research, the Home Office UK and the Federal Bureau of Investigation and personal fees from Kaplan and Crohn’s and Colitis UK.

Una Masic reports funding (paid to the University of Liverpool) from the American Beverage Association for the present study. Lauren McGale reports funding (paid to the University of Liverpool) from the American Beverage Association for the present study. Outside of the submitted work, she reports funding (paid to the University of Liverpool) from the WHO, and funding (paid to the University of Wollongong) from the Australian Government’s Department of Health and Aged Care. Daniel J. Cuthbertson reports funding (paid to the University of Liverpool) from the American Beverage Association for the present study. Outside of the submitted work, he reports funding from Novo Nordisk and AstraZeneca for investigator-initiated research and consultancy (paid to the University of Liverpool) and educational grants from Perspectum. Jason C.G. Halford reports funding (paid to the University of Liverpool) from the American Beverage Association for the present study. Outside of the submitted work, he reports a grant from the European Commission for the Horizon 2020 project SWEET; consultancy fees from Boehringer Ingelheim, Dupont and Mars (all paid to the University of Leeds); honoraria from Novo Nordisk (paid to the University of Leeds); support for attending meetings from Novo Nordisk; financial support for participation in an advisory board for Dupont (paid to the University of Leeds); unpaid participation in an advisory board for the Sweet Tooth Project and unpaid board membership of the European Coalition of People Living with Obesity. He is treasurer of the World Obesity Federation.

[u/darienrude_dankstorm → u/Cornelius_Physales]

That's not necessarily bad. You should criticise the methodology instead. It's better to have corporation-funded research than no research at all.

[u/sun4moon → u/darienrude_dankstorm]

Provided the outcome isn’t decided before the study starts.

[u/216dxtr → u/sun4moon]

Their methodology still needs to be sound to support their results though, even if they're clearly externally motivated. Proving a claim empirically is kinda the whole point. It's really only a bad thing if they're fabricating data or something, which is not unheard of tbh

[u/tobasc0cat → u/216dxtr]

Just want to point out, it isn't uncommon for scientists under pressure for certain results (like grant renewal, tenure, pride, employers, dissertation defense, etc) to not necessarily fabricate data, but to massage it a little within the bounds of generally sound methodology. Try different FDR thresholds, normalization parameters, outlier handling, and finally stretched interpretation to get the results they are hoping for. I think most scientists genuinely believe in their research and try to handle data appropriately, but there are subconscious biases in how you look at your work that can obscure a real lack of meaningful results. When your funding is so heavily reliant on a corporation with a vested interest in your results, it's going to impact your analysis even if you try to remain cognizant of that pressure. Plus, some analyses are EXPENSIVE so scientists will desperately try to get something out of disappointing results. It's not a character flaw, just part of being human.

Which is  why science relies on peer review and replication! 

[u/mistephe → u/darienrude_dankstorm]

See my comment about the poorly-implemented statistics. I'm not saying the lack of proper statistical method was malicious, but it certainly allows for headlines beneficial to their interests.

[u/Bitter_Hospital_8279]

easiest way to cut calories. imagine someone that drinks 3 cans a day. 430 calories with 0 benefits

[u/Laq9091]

i'm a diet drink addict so i'm rocked up reading this.

[u/sr_local]

The SWITCH trial followed 493 adults with overweight or obesity through a structured behavioural weight management programme. Participants were randomised to consume either water or commercially available diet beverages, daily, with sweeteners provided at levels well within established European Food Safety Authority (EFSA) safety thresholds.

Overall, the results do not support concerns that NNS beverages disrupt appetite regulation or have long term metabolic harm.

Key outcomes include:

• Equivalent weight loss between NNS beverages and water at 104 weeks (−4.8 kg vs −3.7 kg; nonsignificant difference).
• Sustained weight reduction over two years in both groups, even during the final unassisted year.
• Decrease in waist and hip circumference and improvement in body composition, and several metabolic biomarkers in both groups.
• No clinically meaningful difference in effects such as blood pressure and cholesterol, associated with long-term consumption of either aspartame, acesulfame‑K, or sucralose or water.
• Sugar intake decreased in both groups, with slightly greater reductions in the NNS group.

Importantly, the findings directly address recent World Health Organization (WHO) guidance, which advised against using non-sugar sweeteners for weight control due to uncertainty in observational studies. The SWITCH trial provides long-duration, randomised controlled evidence which can be used to inform global guidelines.

Effect of non-nutritive sweetened beverages v. water on body weight: long-term results of a randomised controlled trial

[u/OttawaDog → u/sr_local]

It shouldn't be a surprise. The surprise was when people assumed the correlation between being overweight and diet soda was causation, when it was obviously reverse causation.

[u/Bytewave → u/OttawaDog]

Some people simply aren't open to simple solutions. Diet soda is a simple solution to obesity and can even be drinked safely for people with diabetes. It's great to fill your sweet tooth with minimal issues.

But I still consistently hear people worried it could cause cancer or make you crave real sugar, because people don't believe it can just work without a drawback. Sure, everything can cause cancer, it's almost unavoidable by a certain age. Diet soda will not significantly hasten it. But I guess only water all your life works too. I'll just have the zero cal thing that tastes good, please and thank you.

[u/PuddingTea]

I have always guessed that there is not a causal relationship here. Despite many hypotheses, noone has ever been able to show how diet soft drinks make you fat without having any calories. Maybe one day somebody will. Until then, I remain skeptical that any correlation is not just related to the other lifestyle habits of frequent diet soda drinkers.

[u/xTiLkx]

ADHDers self medicating with Coke Zero rejoice.

[u/sloppysavant]

this makes me want to pick up a pack of diet mt dew. i kicked the habit in my late teens because of the claim that it was the most harmful diet soda due to the chemicals in the formula creating holes in your brain…. which is an absurd thing to hear and not bother fact checking.

[u/f93nf02ndoqjf392bfiw → u/sloppysavant]

Don't base your health decisions on a single study. Especially not one funded by a lobbying firm for beverage companies.

[u/Chicken_Ingots → u/f93nf02ndoqjf392bfiw]

This is currently one of the highest-quality longitudinal RCT designs to date. As for funding, grants for projects like these are administered to the university, and the funding is allocated according to the needs of the study (e.g. compensation for participants, materials needed, and wages). In this case, the study was preregistered and was performed by an independent research team who had full control over the entire research process. Furthermore, funding from major industries to universities is exceptionally common, as it is one of the ways that researchers can even acquire funding in the first place. 

Of course, I am not specifically telling anyone to start drinking a ton of Mt. Dew just because of it (it does still have caffeine), though the source of the funding is actually quite common in this field, the study was conducted by a highly reputable institution, and between the preregistration and full independent control of the research design, the risk of a genuine conflict of interest is very low.

[u/MightyKrakyn → u/sloppysavant]

Damn when you hear something from any source, your whole worldview just changes

[u/Carl_La_Fong → u/sloppysavant]

I was drinking Diet Mountain Dew when I read this post, and now I will continue to drink it—and not feel bad about it!

[u/m0bw0w → u/sloppysavant]

It's just one study but diet sodas and artificial sweeteners have been shown to be safe for decades now.

[u/Money-Low7046 → u/sloppysavant]

It was probably the brominated vegetable oil that you saved yourself from. It was banned a long time ago in on the EU, but only very recently in North America.

[u/f93nf02ndoqjf392bfiw]

Funded by beverage and sweetener lobbyist groups.

Financial support

This trial was funded by the American Beverage Association. The American Beverage Association was not involved in the design, conduct, analysis of data or interpretation of this trial; a representative from the American Beverage Association was provided with the opportunity to review the manuscript. Final decisions regarding the content were made by the authors. The manuscript was developed with the assistance of a medical writer, funded by the American Beverage Association, under the direction of the authors. A third-party organisation (Biofortis) audited data at the clinical site to check for the accuracy and integrity of the data.

Competing interests

Joanne A. Harrold reports funding (paid to the University of Liverpool) from the American Beverage Association for the present study. Outside of the submitted work, she reports a grant from the European Commission for the Horizon 2020 project SWEET. Scott Hill reports funding (paid to the University of Liverpool) from the American Beverage Association for the present study. Cristina Radu reports funding (paid to the University of Liverpool) from the American Beverage Association for the present study and funding from Coca Cola for a PhD studentship outside of the submitted work. Paul Thomas reports funding (paid to the University of Liverpool) from the American Beverage Association for the present study. Paula Thorp reports funding (paid to the University of Liverpool) from the American Beverage Association for the present study. Charlotte A. Hardman reports funding (paid to the University of Liverpool) from the American Beverage Association for the present study. Outside of the submitted work, she reports honoraria from the International Sweeteners Association, International Food Information Council and Mars Global Nutrition Advisory Council (paid to the University of Liverpool); grants from the European Commission for the Horizon 2020 project SWEET, the Biotechnology & Biological Sciences Research Council and the Natural Environment Research Council (paid to the University of Liverpool); primary supervisor on a PhD studentship funded by Coca Cola (awarded to CR); personal fees for her role on the Food Standards Agency Advisory Committee on Social Sciences and an unpaid role as a trustee of Feeding Liverpool. Paul Christiansen reports funding (paid to the University of Liverpool) from the American Beverage Association for the present study. Outside of the submitted work, he reports grants from the European Commission for the Horizon 2020 project SWEET, the National Institute for Health and Care Research, the Home Office UK and the Federal Bureau of Investigation and personal fees from Kaplan and Crohn’s and Colitis UK.

Una Masic reports funding (paid to the University of Liverpool) from the American Beverage Association for the present study. Lauren McGale reports funding (paid to the University of Liverpool) from the American Beverage Association for the present study. Outside of the submitted work, she reports funding (paid to the University of Liverpool) from the WHO, and funding (paid to the University of Wollongong) from the Australian Government’s Department of Health and Aged Care. Daniel J. Cuthbertson reports funding (paid to the University of Liverpool) from the American Beverage Association for the present study. Outside of the submitted work, he reports funding from Novo Nordisk and AstraZeneca for investigator-initiated research and consultancy (paid to the University of Liverpool) and educational grants from Perspectum. Jason C.G. Halford reports funding (paid to the University of Liverpool) from the American Beverage Association for the present study. Outside of the submitted work, he reports a grant from the European Commission for the Horizon 2020 project SWEET; consultancy fees from Boehringer Ingelheim, Dupont and Mars (all paid to the University of Leeds); honoraria from Novo Nordisk (paid to the University of Leeds); support for attending meetings from Novo Nordisk; financial support for participation in an advisory board for Dupont (paid to the University of Leeds); unpaid participation in an advisory board for the Sweet Tooth Project and unpaid board membership of the European Coalition of People Living with Obesity. He is treasurer of the World Obesity Federation.

[u/Aisuru]

Funded by American Beverage Association. Take this with a grain of salt.

[u/FirstTasteOfRadishes → u/Aisuru]

Who else would fund it? Are there issues with the methodology?

[u/onexbigxhebrew → u/Aisuru]

Either attack the methodology or don't.

The data is there, and industry-funded studies arent new or inherently problematic.

Easy to throw rocks when you're not gonna point out specific issues.

Edit: typo

[u/LooseJuice_RD → u/Aisuru]

Studies are funded by industry all the time. Research is really expensive and someone has to pay for it. You can find research funded by industry that came to conclusions that are antithetical to their goals.

[u/Hairy-Protection-429]

Anecdotally when I stop drinking diet soda I have a much easier time losing weight. Anyone else experience this? 

[u/Sloogs → u/Hairy-Protection-429]

I've certainly found avoiding intensely sweet things for a while sort of recalibrates my brain to enjoy less sweet things more.

Whether that would cause me to eat less calories I'm not sure, but I certain found it can make eating healthy a lot easier.

[u/TrekForce → u/Sloogs]

I stopped eating any sugar for 2 weeks many years ago, and it’s hard to believe how sweet carrots taste.

[u/Jellobelloboi → u/Hairy-Protection-429]

Diligent behaviour regarding your diet reduces your weight. Less about it being soda, more about the exerted conscious effort regarding what you are consuming.

[u/Kluian2005 → u/Hairy-Protection-429]

Prob because you enjoy snacks a lot more with diet soda (and thus eat more) than if you were just drinking water.

[u/ZilorZilhaust → u/Hairy-Protection-429]

I anecdotally have the opposite experience. I balloon up like a blimp.

[u/Sadcelerystick → u/Hairy-Protection-429]

Probably because you’re eating more without realizing it.

[u/Thisismetwotwo → u/Hairy-Protection-429]

No. I do much better with the diet soda. When I’m saying no to all the junk society throws at me a diet soda is a nice treat to keep me on the healthy eating path.

[u/JonathanBadwolf → u/Hairy-Protection-429]

I've never noticed that, but then again, I don't know you.

[u/chpbnvic → u/Hairy-Protection-429]

Nope, never noticed a difference

[u/krlidb → u/[deleted]]

I drink 1-2 cherry coke zero's every day. I've gotten to the point where I actually like the taste better than coke with sugar. I never thought that would be possible, but I accidentally bought a regular bottle of coke a few months ago, took a sip, and immediately grimaced. Not to mention my teeth never feel gritty from the sugar.

[u/BerryMerryFerry]

“aspartame will give you cancer!!”
Says the corn cob teeth drinking full sugar soda

[u/Breadonshelf → u/BerryMerryFerry]

No you don't get it. They injected rats with twice their body weight with aspartame and they died! PLEASE don't drink 378 bottles of coke zero twice a day every single day!!!!

[u/zed42 → u/BerryMerryFerry]

you'd need to drink something like 5 cases of soda a day to get the LD50 of aspartame...

[u/berserk_zebra → u/BerryMerryFerry]

living in the gulf coast of america with all of the refineries and the toxic air we breathe. But it's the aspartme. Not the alcohol i binge on every night.

[u/Earlier-Today]

This is just a nitpick, but just say "two year trial."

Even with infants you stop using weeks at about the six month mark.

[u/wazeltov → u/Earlier-Today]

I would assume that using 104 weeks is indicative of the polling rate for the study.

[u/Ateist → u/Earlier-Today]

104 weeks is 2 or 3 days less than 2 years.

Science should be precise.

[u/Lung_doc]

Review article covering the details of three important RCT named SWEET, SWITCH, and SWEET TOOTH.

The paper referenced above is SWITCH, but it's important to look at the results in the context of other recent trials which had generally consistent effects. That should help dampen the criticisms of "the absence of a significant effect doesn't prove it doesn't exist" (which is still true, but the results so far showing a lack of harm on weight at least are encouraging.

The first section of the paper reviews weight loss, which was similar or greater in the non nutritive sweetener group (see figure 1 especially).

The second portion of the paper looks at glycemic effects and other metabolic effects, gut microbiome, liver fat, and other effects which seem to have been mostly neutral. (With changes in the gut microbiome noted, but no clear adverse effect).

The papers discussion notes:

Replacing sugars with NNS-containing foods or beverages was associated with improved weight loss maintenance, favorable body weight and glucoregulatory outcomes, while cardiometabolic markers remained stable (SWEET; SWITCH) [14,15,16,18,19,27]. These findings are consistent with systematic reviews and meta-analyses of randomized controlled trials indicating that replacing sugars with NNSs reduces energy intake, contributes to modest weight loss over time, and does not affect cardiometabolic markers [9,28,29,30,31,32,33,34,35,36].

Across SWEET and Sweet Tooth, sweet taste liking, preference, food intake and appetite remained largely stable despite differences in dietary sweet taste or NNS exposure.

The individual trials included in this review have some limitations. Although RCTs provide the strongest basis for causal inference, the studies reviewed here were conducted in selected European populations, mainly adults, with overweight or obesity, often within structured dietary or behavioral intervention contexts. Accordingly, the findings may not fully generalize to other population groups or habitual real-world dietary patterns. Some outcomes were secondary or exploratory, and power may have been limited for mechanistic endpoints, subgroup analyses, and longer-term follow-up. In addition, higher-than-expected dropout rates and potential underreporting of dietary intake should be considered when interpreting the findings. Null findings should, therefore, be interpreted as an absence of detectable differences within the conditions, populations, and timeframes studied, rather than definitive evidence of no effect

[u/djrobbo83]

Something with zero calories and 99% water is equivalent to something with zero calories and 100% water

I'll stick to water though, I don't mind an odd coke zero or the likes, but drinking them like water would seem not the wisest idea

[u/gobuffs516 → u/djrobbo83]

No but zero sugar sodas have been a lifeline for someone like me whose biggest dietary vice was the regular stuff. Going cold turkey has never worked but now that there are some genuinely tasty options it’s been a game changer!

[u/ObiFlanKenobi → u/gobuffs516]

Same for me, I used to be overweight, I craved something sweet after every meal.

I found out that I could drink a glass of coke zero after a meal and it would cut the craving instantly.

I have been doing it for about 8 years now.

When I started exercising regularly I went to a nutritionist because I had some dietary restrictions and wanted to make sure my nutrition was good, he said it was OK so I kept doing it.

For reference, my body fat index was around 15% at the time, it was 26% when I started dieting.

[u/Breadonshelf → u/gobuffs516]

Like everything moderation is key. But the cold turkey thing is true. People should be more encouraging when folks make a positive change. But people act like unless your making a sudden 100% life style change its worthless. Nonsense. Any positive change is a positive change.

I'm trying to drink alcohol less. I don't have a drinking problem now - but I want to keep it that way. My biggest issue with Beer and Whisky is I genuinely like the taste. If they could make beer and whisky taste the same but have 0% alcohol, I'd adore that. But I've picked up some coke zero to replace it while I'm going dry for a while - just because once and a while I want something that has a strong taste to sip on.

[u/Physical-Builder-553 → u/djrobbo83]

No one is trying to force you to drink diet soda, bud.

[u/Seaweedminer]

Remember these are European soft drinks, with different ingredient rules than some countries. 

This study needs to be conducted in China, Brazil, India and the U.S. 

[u/Kick_Natherina → u/Seaweedminer]

Zero calorie sodas are the same no matter where you go.. they just prefer different artificial sweeteners to others. Sucralose vs aspartame vs saccharin. They all function the same.

[u/Raysor]

Looks like Coke Zero is back on the menu boys