
Carbonated beverages induce increased food consumption in rats - vmarsy
https://www.ncbi.nlm.nih.gov/pubmed/28228348
======
mmastrac
Hrm, no carbonated water in the study [1]?

> The study involved groups of male rats who were all fed a standard diet, but
> given one of four different drinks:

> tap water

> regular degassed (flat) soda

> regular carbonated soda

> diet carbonated soda

EDIT: I found an offhand lower-quality reference [2] that suggests they did
test carbonated water:

> Subsequent tests on human volunteers found that those who drank sparkling
> water at breakfast had ghrelin levels six times higher than those who had
> still water.

[1] The only details I could find were at
[http://www.westerntelegraph.co.uk/families/print/Can_fizzy_w...](http://www.westerntelegraph.co.uk/families/print/Can_fizzy_water_make_you_fat__.nhschoices.1/)

[2] [http://www.telegraph.co.uk/news/2017/05/15/fizzy-water-
could...](http://www.telegraph.co.uk/news/2017/05/15/fizzy-water-could-cause-
obesity-encouraging-eat/)

~~~
kelnage
FYI, the paper says:

> Rats of each group were supplemented with different beverages: (i) tap
> water, (ii) regular degassed CB (DgCB), (iii) regular CB (RCB) and (iv) diet
> CB (DCB)

Where CB is carbonated beverages.

~~~
cryptonector
That doesn't answer the question though. It's a reasonable inference that "CB"
here means "carbonated beverage", and it's reasonable to further infer that
these are _sweetened_ carbonated drinks (otherwise why include diet CB?).

The paper is $35. In terms of advice to the public (which maybe it isn't!)
it'd be nice if it unequivocally and explicitly covered carbonated water. I
drink a lot of carbonated water. It's a recent habit. Thus I'm personally
curious.

~~~
cpncrunch
They tested carbonated water vs tap water for the human subjects, and Gherlin
was about 0.32 for CW compared to 0.5 for tap water (fig 3 in the full paper).

>The paper is $35

It's on sci hub.

~~~
3131s
Why can I never actually get sci hub to work? I've even downloaded the data
dumps but never figured out how to use their search. Is there a keyword
search? All of my searches return "no articles found".

~~~
ce4
Searching​ by DOI will give you results. for this paper it is:

    
    
         10.1016/j.orcp.2017.02.001

------
bognition
I'm not buying it without a comparison of water to carbonated water.

Its long been understood that soda w/o carbonation isn't palatable because its
too sweet and animals stop consuming it. However, when carbonation is present
it masks the sweetness which result in increased consumption.

So I think they're probably measuring a secondary effect here.

~~~
dahauns
_soda w /o carbonation_

Soda without soda? :)

As a non-native speaker, this continually fascinates me...

~~~
overcast
Soda, is just short for soda pop, which is the sweetened, carbonated water
beverage. So soda without the carbonation is just sweetened water. Flat soda
is a fairly common term to describe soda that has lots its carbonation.

~~~
dahauns
Yeah, I know. But everywhere else in the world, "Soda" is just the name for
(Natrium-)carbonate...

------
mysterypie
Whenever there's a study that says X causes Y, there should be a rule that
says you have to say _by how much_. That's a super-important piece of
information. The abstract should state it!

If a study says that drinking grapefruit juice shortens your lifespan by a
year, then I'll cut out grapefruit juice. If it shortens it by a few hours on
average, then even if the study is 100% accurate, it's too small to care
about.

Especially in news articles, we tolerate this imprecision with health-related
findings but not in other areas. You don't see the news reporting that
"avalanche kills some skiers". They'll at least tell you "avalanche kills 1
skier and second skier still missing" (unfortunate) or "avalanche kills as
many as 350 skiers" (major tragedy).

~~~
nonbel
The problem is that those estimates are conditional on what variables they put
into their statistical model, so they are really usually rather meaningless
(not that the mere direction is any more reliable, this can switch too). Maybe
you can say:

"A specific carbonated beverage (batch 1234 from supplier X) provided ad lib
via a standard rodent water bottle with sipper tube increased weight gain by
10% over the course of 3 months (as they aged 3-6 months) of male sprague
dawley rats bred by Harlan USA in 2015, raised two to a cage, fed Z brand rat
chow ad lib (10 % fat content), kept on a 12 hr reversed day/night cycle at
18-23 C with relative humidity maintained between 40-60%. Over the course of
the study, the rats were removed from the cage only three times a week: for 10
seconds of weighing in the afternoons MWF."

------
banashark
Whenever these `weight gain linked to soda` studies come up, I'm always
confused.

I've been told I'm in fantastic shape (>90% in all
[http://strengthlevel.com/](http://strengthlevel.com/) measurements and under
10% body fat) at the moment, and I used to consume a lot of diet soda every
day. At it's worst, I consumed >1 liter a day.

For me it was a caffeine source (since I dislike the taste of coffee and never
saw the benefit in acquiring the taste) that helped me focus when I needed to
get work done (I did a lot of tweaking around with amounts to make sure it was
a marked difference and not just a placebo effect for me) and acted as an
appetite suppressant so that I could manage my caloric intake without getting
distracted by hunger frequently throughout the day.

I constantly looked at aspartame/stevia/etc research to see what damage I
would be doing to myself. While I couldn't really find much in the way of
negative health effects (excluding weight gain, which I never noticed a
problem with), I ultimately cut off my consumption because of a semi-
irrational fear that either information was hidden by soda-corp et al, or that
just because of how these chemicals work that there might be bad effects that
just haven't been put under rigorous study yet.

As a side note, my metabolism is actually slower than average and I need to
eat on average ~10% calories less than any macronutrient calculator says to
stay in the shape (low bf + strong) that I enjoy being in.

~~~
SyneRyder
While I'm in nowhere near as good shape as you, I have similar 'anecdata'
findings.

I spent the last few months this year testing this, partly because I was
curious about the Tim Ferriss claim that Diet Coke causes you to gain weight.
(I actually wanted to test if I could lose weight just from walking & no diet
changes.) Even with my two cans of Coke Zero a day, plus sparkling water with
ice and a frappuccino most days, I've been losing weight for 4 months. (20.5%
bf down to 16.5%.) I did add exercise, but only walking - I increased my steps
up to 16000 steps a day for a while, but I'm back to sub-10000/day now.
(Pebble Health has been awesome on my Pebble Time Steel.)

Whatever effect carbonated beverages have, at least in my experience, it's
easily countered by exercise. Maybe that's not true for everyone, but it seems
it's something you can easily test on yourself for a month or two to make your
own conclusions.

~~~
dicroce
The study says that carbonation makes you more hungry, but you don't
necessarily have to respond to that hunger.

------
Etheryte
Very, very interesting, mainly because most of the time, the weight gain from
carbonated drinks is said to be linked with the amount of sugar. This study,
however, suggests that the mere fact that the beverage is carbonated has
noticeable correlation with weight gain.

Would love to find a link to the paper itself, not just the abstract.

~~~
bognition
[https://news.ycombinator.com/item?id=14352942](https://news.ycombinator.com/item?id=14352942)

------
mratzloff
Since I'd have to pay $36 to access the article, I guess I'll just never know
if the methods back up the headline. Oh well. A La Croix sounds good about
now.

~~~
kefka
[https://ipfs.io/ipfs/QmWiFX7bmU365CJPAddsjho4vKVsexi3u8eBE7s...](https://ipfs.io/ipfs/QmWiFX7bmU365CJPAddsjho4vKVsexi3u8eBE7sRYrALyJ)

~~~
mtw
How did you get this link?

I used the Unpaywall chrome extension and it wasn't able to show me an unpaid
version.

~~~
kefka
Library Genesis: [http://gen.lib.rus.ec/](http://gen.lib.rus.ec/) Sci-Hub
[https://scihub.org/](https://scihub.org/)

Also helps if you work for a university that pays these rape-quality fees to
access what should be public knowledge.

------
MichailP
Is this true? I once heard that carbonated water is bad for liver, but never
found facts to support this (until this paper). Can someone more knowledgeable
please comment? People may be destroying their liver and thinking they are
doing something good for their health by drinking mineral (carbonated)
water...

~~~
tdicola
People have been drinking carbonated water for over a hundred years now (maybe
even two hundred years actually). If there was a strong link between
carbonation and damage to your body we would have seen it by now.

~~~
rsync
"People have been drinking carbonated water for over a hundred years now
(maybe even two hundred years actually)."

There are naturally carbonated springs all over the world. I used to drink
from one in Guffey, Colorado when I was a kid - it tasted like a glass of
water with two alka-seltzer tablets in it. I think Soda Springs, Colorado is
named for one.

Perrier comes from one[1].

People have been drinking carbonated water for more than 100-200 years.

[1]
[https://en.wikipedia.org/wiki/Perrier](https://en.wikipedia.org/wiki/Perrier)

------
runeks
Studies like these are way too simplistic to conclude anything regarding
obesity, in my opinion.

An increase in ghrelin levels was measured, but what about all other other
hormone levels that were possibly affected as well? The body is a complex
system of thousands of equilibria; if an increase in e.g. testosterone levels
(which makes the body burn off fat) was also an effect, this may well offset
the effect of increased food consumption -- or even overpower it, causing a
weight decline as opposed to a gain.

------
sov
It's actually pretty interesting that at ~55 weeks, RCB, DCB and DgCB are in
very close proximity to one another, then, suddenly, the non-carbonated
beverages (DgCB, water) take a huge drop over the next month, with a bit of a
stutter on the DCB and a continuous rise on the CB. I wonder if the
significance they see in this study is due to an exogenous reaction with the
extra CO2 (eg, an environmental factor).

------
drcross
Its not a great abstract because it doesn't quote increase percentages.
Ghrelin is the hormone that make you hungry.

~~~
abandonliberty
Occam's Razor says: p is low but magnitude of effect very small.

------
mrfusion
Does the study suggest any mechanisms of action?

I'm wondering if there's an insulin response to a carbonated drink?

~~~
mattkrause
As the (real) title says, they think it is linked to ghrelin, a neuropeptide
associated with hunger. Drinking something carbonated causes more ghrelin
release (or less suppression of ghrelin released, actually) than drinking a
still beverage. More circulating ghrelin leads to more hunger, which leads to
more eating, which leads to weight gain.

The mechanism that allows CO2 to act on ghrelin isn't really clear. They
suggest that the bubbles push on the stomach wall, which in turn increases
ghrelin release. The whole ghrelin pathway isn't known, but I thought pressure
on the stomach walls would _suppress_ , rather than _induce_ ghrelin.

There are a few other odd things too. For the rat experiment, they show weight
gain curves (weight vs. time) for four groups: rats drinking a) water b) sugar
soda c) degassed sugar soda d) diet soda. As you might expect, rats drinking
water end up weighing the least, rats drinking (sugar) soda weigh the most.
However, the rats drinking the degassed (sugar) soda weigh significantly less
than those receiving diet carbonated soda. They take this as support for their
theory, but it seems odd that this effect would totally dominate the actual
calories in the sugary soda. Similarly, the carbonated (sugar) soda vs.
carbonated (diet) soda groups also aren't different.

~~~
WorldMaker
This is pure conjecture, as I don't have the links on hand and quick searches
don't turn them up, but I saw a study also on HN at one point theorizing that
there are pathways for CO2 sequestration as fats/fatty acids in many animal
species. (In the terms of the paper that I think I recall, an hypothesis was
the increasing levels of atmospheric CO2 due to climate change/industrial
outgassing/car exhaust were potentially implicated in the cross-species
overweight/obesity epidemic of most species living in human cities.)

I wonder if a follow up study into this surprising ghrelin reaction that
increased CO2 pressure in the stomach induces it rather than suppresses it may
implicate just that sort of carbon sequestration process?

------
cheath
Does this mean that Sparkling Water makes you fat?

~~~
Etheryte
In addition to testing rats, the study[1] compared five categories of drinks
in humans: water, regular carbonated beverage (think soda), diet carbonated
beverage (think diet soda), carbonated water and degassed regular carbonated
beverage. They measured the release of ghrelin[2], the hormone which
essentially tells your body you're hungry.

According to their results, both regular carbonated beverages, diet carbonated
beverages and carbonated water resulted in noticeably increased amount of
gherlin released (see [1] for the specifics).

So shortly put, it seems sparkling water makes you hungrier. That doesn't
necessarily mean it will make you fat, giving in to the feeling of hunger is
always up to you, but feeling more hungry sure as hell will make it likely
that you will put on more weight.

[1] [https://sci-hub.cc/10.1016/j.orcp.2017.02.001](https://sci-
hub.cc/10.1016/j.orcp.2017.02.001)

[2]
[https://en.wikipedia.org/wiki/Ghrelin](https://en.wikipedia.org/wiki/Ghrelin)

~~~
tomohawk
As far as I can tell, the paper does not include carbonated water as one of
the options. It says:

"All rats were provided with standard diet Teklad Global 18% protein (2018SC
from Harlan Laboratories). Rats of each group were supplemented with different
beverages: (i) tap water, (ii) regular degassed CB (DgCB), (iii) regular CB
(RCB) and (iv) diet CB (DCB)"

~~~
jjnoakes
Read page 6:

"To extrapolate the study on humans, ghrelin levels were measured in male
subjects after drinking any of the aforementioned beverages, in addition to CW
(no caloric content, no sugar)."

~~~
tomohawk
OK, so they didn't do the rat study where they only changed the carbonation
(still vs carbonated water), but later it appears they did this for the human
subjects and measured the hormone level. It would be interesting to see a
study with only that one variable changed to see actual weight gain in animal
and human populations.

Anecdotal, but I changed from carbonated soft drinks to carbonated water and
noted a marked difference.

~~~
saurik
For this model, this hormone is only an indirect effect on weight (through
hunger); however, there is also a direct effect that is pretty strong: you are
no longer drinking a ton of sugar, which has a noticeable number of calories
in and of itself. They aren't saying the weight gain is equivalent, only the
hormone release.

------
maxpert
I don't get it... first it was fats, burgers and pizzas. Then a study came out
claiming it's sugar. Now carbonated beverages! What do they want me to do? Eat
grass and drink water?

~~~
aibottle
Nonono there is so much wrong here.

Sample size: 20 people. (Okay what? Are you even trying guys? Releasing
something about the the human metabolism with a sample size of 20? Shame on
you!) Concluding a weight gain because Ghrelin levels are raised? What? Do you
even science? Ghrelin in the first place only tells your brain to look for
more food because it signals an empty stomach.

Studies on Nutrition don't get me started...

~~~
anigbrowl
Oh please. It's hard to attract funding for studies, it's perfectly reasonable
tos tart with a small sample and tehn ask for funding to do a larger study
once you have a working hypothesis.

~~~
ericdykstra
That doesn't mean it makes sense to make dietary decisions based on these
studies.

------
nonbel
Can anyone even figure out what carbonated beverages were used for this study?
Was there caffeine in it, etc? Then they say they started with 16 rats but
then elsewhere (when it is mentioned at all) they seem to have 4 groups of
triplicates. So it looks like 25% of the data floated away. They also don't
mention blinding.

Those are the type of basic questions you should ask when you read a paper
that will lead you to immediately dismiss something like this in under 20 min.

------
burntrelish1273
Oh crap. I drink a lot of CB flavored (diet) water, take a med which increases
hunger and having weight mgmt issues (also taking metformin for dual-purposes
of life extension and weight reduction).

Probably time to switch to diet flavor drops + plain water, and exercise more.

------
mtw
Q: Are there any effects in drinking natural carbonated water? Such as Evian,
Perrier from source.

I am skeptical if drinking more Perrier increases your food consumption

~~~
libdong
It makes no difference if the water is naturally carbonated or not.
Carbonation is caused by dissolved CO2 (in equilibrium with other carbonates)
and there is no way for you body to distinguish between "natural" and
"unnatural" CO2.

------
lerie
I do not think this study can prove that carbonated soda causes weight gain,
let alone obesity. People (and apparently mice) are not all "built" the same.
Obese people need more exercise (or just plain movement of the body) than
those who have less weight on their bodies, "it's not rocket science".

Sincerely, common sense.

~~~
emodendroket
The very fact that "common sense" can mislead us is half the reason for doing
experiments.

------
pvnick
Fascinating. Would have thought artificial sweetener would be implicated, not
the CO2.

------
salzig
so, the next iteration of coke light is without sugar/corn-syrup/gas?
Interesting.

------
developer2
This comment is a reply to many of the commenters here on HN, rather than a
direct response to the article.

How do you get to the point of debating the difference between soda vs. diet
soda, as if it's a must-have treat and you are "simply" choosing the lesser of
two evils? _All soda is UNEQUIVOCALLY bad for one 's health!_ You're drinking
a cocktail of chemicals that has _no nutritional value, and designed to be
addictive_. Artificial sweeteners are a gimmick to allow us to recuse
ourselves from the _innate_ knowledge of what it is healthy. Selecting a
supposedly "healthier alternative" is nothing more than a way to grant
ourselves asylum from being personally responsible for our choices. We pretend
that our "science" is _universally_ proven evidence backed by chemistry and
physics, vs. the truth: it's a manmade lie which no enlightened species would
tout as being scientifically valid.

The same mental masturbatuion occurs with vaping. "Vaping is better than
smoking!" As if inhaling _any_ mind-altering drug is necessary to "get by",
and so it must _surely_ be "better" to attach oneself to the "least worst
option", rather than kicking the habit entirely. If vaping is "better" than
smoking, what is better than vaping? Oh right, not inhaling anything other
than the air we evolved to breathe. Your body wasn't made to inhale chemicals
not produced in nature; it was also not made to drink soda. The fact that you
don't die instantly from consuming such products does not mean they are not
harmful.

The excuses many people make regarding their health is... I'm going to call it
what it is: _completely and utterly _PATHETIC__. As a species we pretend we
are intelligent, but a vast percentage (90-95%?) of the population can't even
overcome the most primal appetite for fats, sweets and drugs. Our species will
never be capable of rightfully calling itself "enlightened" until we drop
_all_ desires for this kind of bullshit. If you're playing mind games with
yourself to allow you to "cheat just a little" by consuming unhealthy
products, while falsely duping yourself into believing your decisions somehow
result in an overall net positive "compared to the (unnecessary)
alternatives", you're deluding yourself.

Advice to all alien civilizations: avoid us at all costs. Making contact with
us cannot possibly be beneficial to you. We'll either bomb you out of fear and
ignorance, or bombard you with our capitalist bullshit in order to pull you
into our way of living that will ultimately destroy you from the inside out.

What makes this truly disgusting is that people who _choose_ to destroy their
bodies - by drinking diet soda, vaping, or eating junk food - are in fact
aware that they are lying to themselves. You know that you are making the
wrong choices, but opt for the fallacy that somehow you are not in control.
Nobody _really_ believes the marketing companies are pushing out. People are
just looking for someone else to give them permission to be unhealthy,
desperately listening for someone to tell them what they want to hear. People
know they are too weak to have self-control, and are looking for a voice to be
their scapegoat.

tldr; Diet soda is not "better" than soda laden with unadulterated sugar. It
is simply worse than water, and the fluids you would get from fruits,
vegetables, and free-range animals and fish. Allow your brain's thought
processes to align with your species' natural evolution. Stop using product
manufacturers' claims as a scapegoat. Think for yourself, and don't make
excuses.

Edit: To those downvoting: do you downvote because my post is too long and you
declined to actually read it, or do you refute the facts? I am normally
abrasive in general, but what I've said here really is true. Anyone who reads
the whole thing, and still downvotes, is someone with their head in the sand.
You can be part of the 90-95% of morons I mentioned earlier. Be the reason our
species is doomed, for all I care.

~~~
Singletoned
I think people are downvoting it because you are ranting.

A general heuristic that is useful in life is that if someone is foaming at
the mouth and shouting, the things they say probably aren't that useful. (And
you definitely come across like that. EG someone scanning the text would see
"_PATHETIC_", and would assume that the emotional part of your brain has been
engaged rather than the rational part).

The use very early on of "All soda is UNEQUIVOCALLY bad for one's health!",
probably put a lot of people off. It is trivially hard to refute (any example
of any soda providing any health benefit (eg rehydration) proves you wrong),
and again makes it seem like you are making illogical, emotional arguments.

The use of "Anyone who reads the whole thing, and still downvotes, is someone
with their head in the sand" is a cheap nasty trick that will turn people
against you even if they agree with you.

Try waiting until you have calmed down and rewriting it in a better way.

~~~
developer2
The edit, insulting even further, was useless on my part. If I think that up
to 95% of people - and I sincerely believe the percentage to be that high -
are incapable of realizing that substituting diet soda and vaping in lieu of
sugar soda and smoking cigarettes equates to "healthier choices", I should
have expected 95% downvotes.

My mistake, born from a delusion of my own making, is believing that the
entirety of the HN crowd magically falls within the <= 5% of people I consider
to be legitimately intelligent, capable of thought relying on science that is
universally proven to be true rather than manmade speculation based on
tomfoolery. Without seeing any replies countering my statements, I can only
assume that these people are petty enough to vote with their trigger-happy
index finger rather than taking the time to absorb - and perhaps reply to -
the points of discussion I have raised.

Aside, meta: Please do not vote on _this_ comment. By upvoting, you'd be
granting my ego a reprieve. By downvoting, you'd be proving my point and also
feed my ego. Best bet is to abstain, and let bygones be bygones. This could be
-10 or +10 and I'd feel validated. Just don't vote; a 0-1 score says more than
anything.

------
kumarski
Humans are not mice.

~~~
kyriakos
without implying I agree with the particular study, mice are being used to
test a lot of chemicals that are then used on humans so I'd say there's a high
probability that how mice are affected could be similar to humans.

~~~
mattkrause
And ummm...the paper in question used rats, not mice.

------
GoToRO
What one can do is reset your body. Consume your own grown stuff and only
drink spring water, from a real spring, and see the effect on yourself for 4-6
months. The problem is that there are a lot of people that grew in urban areas
and they don't even know what they are missing. Simply put, most urban areas
are designed to be efficient and so not good for you.

~~~
hueving
Naturalistic fallacy. A water filter will do fine and water from a spring can
have heavy metals and other chemicals in it that make it significantly worse
than city tap water.

~~~
GoToRO
You can always test it. That was not my point.

