
Cats Cannot Taste Sweets (2007) - JumpCrisscross
https://www.scientificamerican.com/article/strange-but-true-cats-cannot-taste-sweets/
======
BearOso
> "This may be why cats are getting diabetes," Brand offers. "Cat food today
> has around 20 percent carbohydrates. The cats are not used to that, they
> can't handle it."

It's worse than that, usually 35-50% carbohydrates. The good (expensive) dry
stuff is usually 10-20%. Wet food is often lower, depending on the type, as
low as 7% as-fed with pates.

The weight-control labelled food is terrible both for weight and diabetes
risk. It trades protein for carbohydrates under the assumption that cats don't
absorb the carbohydrates as easily because the cat's liver has to process
them. But this means the liver processes them to body fat, and the lack of
protein leaves the cat less satiated, so it eats more food.

~~~
phonebanshee
Our vet did point out that cats eat carbohydrates; they tend to love the
innards of their prey, and those often contain the undigested things mice etc
eat. No idea what percentage of their diet that makes up though. (It wasn't a
conversation about carb percentages in cat food)

~~~
BearOso
That’s also an interesting point. People have an aversion to those innards, or
“by-products,” being included in food, but our disgust isn’t rational, and
cats don’t share it. Just because a cat food includes meat by-products doesn’t
make it any worse than just muscle meat, and it can be cheaper because of
that. Cats like the flavor and it’s good for them.

~~~
trhway
> innards, or “by-products,”

the tasty innards you're talking about and the “by-products” that are in the
industrial cat food are 2 very different things. The “by-products” is hide,
horns, hooves, etc. with very heavy dose of strong preservatives,
desinfectants and other chemicals.

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andrewla
I found this out when asking myself the question "are animals fooled by
artificial sweeteners". The rabbit hole that that led into is not only do we
not know the answer to that question, many animals don't even taste
"sweetness" (or if they taste it they don't like it or don't prefer it). Not
even all primates, if I recall correctly.

And we've seen drift -- apparently we used to be able to bait cockroaches with
sweet bait (through the middle of the century), but they have adapted to it
and it no longer works as bait.

Taste and smell are very strange and defy attempts at reductionism; our brains
are basically very evolved olfactory organs. Dealing with smells was so hard
that brains evolved to deal with the problem, and then it was just evolution
asking the question "what else can we do with this giant block of
computational power -- what about ... memory? vision? hearing?"

~~~
Chinjut
Whoa. Smell was more important than sight for brain evolution? Is there
somewhere I can read more about this?

~~~
bobbylarrybobby
There are lots of blind animals that can smell. I don't know of any sighted
animals that can't smell.

~~~
walshemj
some humans have a mutation that means they don't smell

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mattkevan
Some of the stuff I've seen our cat eating, it's both obvious and a blessing
that he doesn't have much of a sense of taste.

Goes nuts for the plastic wrappers you get around Pepsi cans and won't stop
licking them. Little weirdo.

~~~
MisterTea
I have a cat who loves to lick crinkly plastic wrappers and bags. I use
shopping bags for my bedroom trash can and I'll wake up to him just sitting
there licking the folded over edge for upwards of 10 minutes.

Two theories I've heard are that beef tallow is sometimes used in the
manufacture of such bags so they might be smelling that. Or it could be as
simple as they enjoy the sensation and/or sound of licking the bag. Though,
they certainly are weirdos.

~~~
MereInterest
Huh, one of our cats does the same. We don't want her to choke on plastic, so
we no longer leave any plastic bags out in the open. She also tries to lick
olive oil and butter, so the beef tallow theory would follow the same pattern
of looking for fat.

~~~
ncmncm
Try her on taffeta.

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JoelMcCracken
Knowing this, when my cats desire something sweet that I was eating, I have
always assumed they wanted something else they tasted in the food -- if ice
cream, then the cream, etc.

~~~
rbritton
Mine loves cantaloupe. I’m curious which part of that she likes other than the
sweetness.

~~~
hombre_fatal
This is probably the first time I've seen someone else say this online.

The cat I grew up with (lived 21 years) loved cantaloupe as well. It would
smell it from far away and come trotting into the kitchen. Seemed to be able
to eat as much of the fruit as we were willing to chop for it.

~~~
aYsY4dDQ2NrcNzA
Me three.

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cmiller1
Fun fact: the sodium lauryl sulfate in toothpaste dulls the sweetness
receptors on your tongue. The taste of orange juice after brushing your teeth
is what it would ALWAYS taste like to cats.

~~~
namdnay
I've always been suspicious of that. Why is it specifically OJ that tastes
awful, and not other juices, or chocolate, or bread?

~~~
hkjhreiou
You don't even need toothpaste. Taste is also a state of mind thing.

Bet a friend/family member that they can’t taste the difference between
whole/2%/1%/skim milk, or some combination thereof. Blindfold them and have
them begin tasting the milks. Now, replace the last milk with orange juice.
The brain prepares the body for milk, and the unexpected acidity usually
causes a gag reflex, and sometimes vomiting. Keep a bucket handy:

[https://www.youtube.com/watch?v=FlhfIN_qbEk](https://www.youtube.com/watch?v=FlhfIN_qbEk)

~~~
r00fus
I stopped drinking OJ as a teen after a decent run (4mi) and coming back super
thirsty and drinking OJ just caused my mouth to keep salivating continuously
(painfully) for minutes.

I vowed that day to stop drinking OJ and stick to water.

------
lightedman
This leaves me with more questions as I have a cat that absolutely will not
leave you alone if you're holding ANY fruit. She will cry and whine and do all
she can to get to that fruit. Apple, plum, orange, grapefruit, pineapple,
melons, it doesn't matter. She goes especially nuts for dragonfruit.

~~~
powersurge360
Citrus in particular is famous for cats disliking. Interesting that your cat
enjoys those.

~~~
efa
I had a cat that freaked out when he smelled oranges. I always thought he
associated it with an orange scented shampoo we used once on him.

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pcwalton
Evolutionarily, this makes sense. All felids are obligate carnivores that rely
on meat for nutrients—for example, they need taurine for vision, which they
can't synthesize and is only found in meat. So there's an evolutionary
advantage for cats to _not_ want to eat anything else.

~~~
lisper
> All felids are obligate carnivores

I think you meant "felines".

[UPDATE] Nope, the OP meant felids (though my old eyes parsed it as "fields"
(never heard of a "felid" before) which is why I thought it was spell checking
or voice recognition gone wrong).

~~~
journalctl
“felid” comes from “Felidae”, the family for cats. It’s synonymous, but a bit
more formal.

~~~
thaumasiotes
Etymologically, "felids" are "things descended from cats", while "felines" are
"things that are like cats".

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tygg3n12
Makes me wonder if this is just a result of genetic drift and/or
bottlenecking. They clearly have no need for it, and are very specialized
killers, but it being so widely present in mammals tells us that it's not
really a costly gene to have.

I found the part about being able to register ATP interesting, as controlling
for ATP is one of the most common techniques used to control the quality of
hygiene in food production buildings and equipment. I don't know how this
applies to nature where you would expect this to be found everywhere, but
maybe it's valuable in deserts, snowy areas and similar? Or maybe higher than
usual levels can be used to identify areas where rodents and other sources of
food could be found?

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zdragnar
For some reason, I had always assumed there were a number of mammals that
didn't care much for sweets, even though in retrospect I know that ferrets,
also carnivores, will obsess over sweet drinks.

~~~
eigenschwarz
Perhaps because mustelids have an extraordinarily high metabolism for their
size? [https://nyti.ms/1Ur6S6C](https://nyti.ms/1Ur6S6C)

~~~
zdragnar
As carnivores, I wouldn't expect them to have a use for tasting sweet things.
The article doesn't address that point, but I think anyone who owns a ferret
could tell you that they have a crazy metabolism!

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starpilot
If you're really interested in cat nutrition, comment history of alleged
veterinary student
[https://www.reddit.com/user/Pguin15/](https://www.reddit.com/user/Pguin15/)
is gold. He posted a link for example that shows cats and dogs readily digest
carbs, and that this is well known:
[https://en.wikivet.net/Digestibility_of_Carbohydrates](https://en.wikivet.net/Digestibility_of_Carbohydrates)

> Ground, cooked and extruded starches are almost 100% digestible in both dogs
> and cats, while digestibility of raw (uncooked) starches varies from 0-65%
> depending on the type of starch.

------
phonebucket
Related paper (from 2007):
[https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2063449/](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2063449/)

~~~
peterhj
Cool to see this on HN. I briefly worked there on a closely related project
during high school after this paper was published. It was my first real
experience doing wet lab work-- learned a bunch, met cool people, was fun.
(Also did a lot of pipetting and PCR.)

------
okonomiyaki3000
For some reason, our cat used to be absolutely crazy for anko. The first time
he ever encountered it, he stole a dorayaki out of someone's hands and hid
with it in the closet growling (it was wrapped in plastic so he couldn't
actually eat it). After that, I used to give him a tiny taste any time I had
some but I noticed he would always throw up soon after. Now that he's a bit
older he seems to have no interest in it at all.

Could it be that they can taste sweets at a young age but gradually lose that
ability?

------
HHalvi
I used to think my kitten was after the sweetness when i noticed that she only
likes/prefers milk based sweets. But then she does have same affinity for
chocolates and strawberries too.

~~~
immutate
Reminder: Chocolate can be lethal for cats...

------
bsenftner
About cats only eating meat: I have 3 cats, and all of them love any blades of
grass, eating a full 'salad' every day.

~~~
devb
Do you grow cat grass for them? Ours loves it. [https://www.hillspet.com/cat-
care/nutrition-feeding/cat-gras...](https://www.hillspet.com/cat-
care/nutrition-feeding/cat-grass-safety-and-information)

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goatinaboat
_There is a reason cats prefer meaty wet food to dry kibble, and disdain sugar
entirely_

This person has never met a cat. One of ours is obsessed with sweet foods like
yoghurt, honey, pastries. Which we don’t generally let her have because of her
teeth.

~~~
ceejayoz
You're discounting several possibilities.

Yogurt has protein, and many varieties have a lot of fat. Pastries tend to be
fatty (butter/lard). Honey's less obvious, but my cat would lick clean wooden
spoons just for the texture; perhaps yours likes something about the
stickiness?

~~~
TwoBit
My cat loves sweet things, regardless of the presence of fat. I need to make
videos of this to post.

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ppcdeveloper
Strange. My buddies cat loves sweets. Especially pecan pie. I'm not sure if
she's just trying to bond with him by eating the same food at the same time or
she has a sweet tooth.

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itsbenweeks
A friend of mine was born without the ability to taste sweet things. That
doesn't stop their body from reacting to it, though. Most of their favorite
foods are incredibly sugary.

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dbtx
{ plastic bags, various wires, a few DC adapter/chargers, the $10 soldering
iron's AC cord, a used paper napkin that smelled like the sub sandwich it came
with, crumpled up sheets of paper that are thrown and chased and batted around
for some time, peanut butter, American cheese, tortilla chips (with or without
Valentina and refried pinto beans and melted cheese), the spaghetti sauce or
chili residue on the bowl, fluffy white rice, beef jerky (any flavor incl.
peppered), roasted salted peanuts, dried fruits from trail mix, fresh voles }

------
benibela
What would happen if the cats eat miracle berries?

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RoutinePlayer
Yes, but this is only 8 out of 10 cats.

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29athrowaway
Large cats in zoos get treats like frozen blood ("bloodsicles").

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pro_af
Tell that to my cat, who fucking LOVES ice cream.

~~~
brycesbeard
It’s the milk fat they love! My kitty also goes crazy for coconut oil, which
helps with hair balls.

~~~
gwern
Yep. I recently tried this out with my cat: skim milk vs 2% vs whole milk vs
heavy cream. No prizes for guessing what his preference ordering was. (He
wouldn't even drink the skim! Just licked it, looked at me, and walked away.)

~~~
stoobs
Yeah, and will give you _that_ look too as he walks away...

My little chonk monster is actually pretty good with food, and isn't
interested in human food much at all, possibly because he had to fend for
himself for a few months before he imposed himself on me. He's certainly
partial to the odd pigeon which are too slow/stupid to get away.

He currently has mostly dry kibble and water, but with the odd wet pouch for
some variety.

I've tried him on a little milk before and he wasn't bothered, but I have
semi-skimmed lacto-free, so I don't know if it offends his taste-buds or not.

