5
$\begingroup$

Say I have a race of obligate carnivores (for simplicity, we'll say they're felinoid). They have carnivore dentition, and must eat meat as a major component of their diet, but they can also eat fruit and derive nutrition from it. They enjoy fruit (and vegetables), but for the complex flavor and tartness rather than for sweetness, which they cannot taste. (They react to fats much the way humans react to sugars. My theory is that they can break down simple sugars, but not carbohydrates, they need lots of protein, and there is something present in meat that they cannot get from other sources short of artificial supplements; possibly taurine.)

Now, obviously they aren't going to eat a lot of breads/grains, except maybe as a form of dieting, however there are all sorts of interesting culinary dishes that can't be made without grains (Wellington, burritos, fried chicken and so forth); in particular, grains give a certain "crunch" that's hard to replicate with pure animal products. Assuming that they've been exposed to these by other means (as they probably wouldn't invent cultivation of grain on their own), would they be able to eat such dishes? Or is there another way to make such dishes using only "meat" products or something else that is easier on their digestion?

I'll assume, first, that they want to eat such dishes, and second, that they aren't toxic. (That is, they can eat citrus, onions, grapes, cocoa, etc. without being poisoned. Grains might not be wonderful for their digestion, however, but they're willing to put up with a little extra "bulk" moving through their systems for the sake of excellent gastronomy.)

$\endgroup$
5
  • $\begingroup$ All animals in the world can eat whatever they want, at least they can digest it.... A cow can digest meat but is not going to eat meat because it lacks the predatory instincts to kill other animals and lack specialized teeth to eat meat. In the same way a carnivore can digest most plant matter with some exceptions, but they are not going to do it because they lack specialized teeth and they don't like the taste. We humans fall in between as we can digest a lot of things and we do eat a lot of things we are not supposed to even though our biology is specialized for eating rooths and fruits. $\endgroup$ – user75545 May 6 '20 at 16:50
  • $\begingroup$ As a rule of thumb, If it evolved on earth then it's most likely that it can digest most things that are also evolved on earth. Few exceptions being poisons. For example, if you wanted you could even eat wood and digest it, not every single protein, but a good chunk of them... We don't do it because we are not specialized for chewing that stuff. $\endgroup$ – user75545 May 6 '20 at 16:52
  • $\begingroup$ @Kyu : please note that almost all plants are poisonous, it's just that animals which eat them evolved a resistance to them in an evolutionary arms race. The less of a herbivore an animal is, the more plants are poisonous. $\endgroup$ – vsz May 7 '20 at 5:55
  • $\begingroup$ @vsz one could argue the same is true for animals, they are all poisons except to those who adapted to their toxicity, which in turn would make cannibalism always the safest and reliable source of food and also the healtiest. $\endgroup$ – user75545 May 7 '20 at 8:54
  • $\begingroup$ @Kyu : not really. Very very few animals are inherently poisonous, while most (or all) plants actively create chemicals which otherwise would not be necessary for their functioning. For example, all tree barks contain pesticides of some variety or other. $\endgroup$ – vsz May 7 '20 at 9:18
2
$\begingroup$

Yes

Still using cats as an example, there is no issue using sugar and starch in food such as bread for energy and as a source for sugars. Even if the beast is an obligate carnivore, its metabolism will still be based around sugars and it will almost certainly retain the ability to use free sugars from diet instead of having to generate them all internally. The benefits are simply too large and availability of carbohydrates in diet too universal.

Where being obligate carnivore does impact the diet in comparison to humans is that ability of cats to digest those carbohydrates is limited in quantity. If your diet generally contains relatively little carbohydrates, you do not need a high capacity to digest them. The surplus will simply get wasted. The excess would typically end up feeding bacteria, which may or may not cause issues.

So small and occasional starch or sugar rich treats would totally work for obligate carnivores. As long as the quantity is small enough, there will be no issues. And even if you indulge too much, the consequences should not be worse than for humans, they'll just happen sooner at lower quantity.

An obligate carnivore might have lost its ability to taste sweetness and actually prefer crunchy bread with lots of texture and dietary fiber to sweets.

Note that while individuals cannot adapt to having more carbohydrates in their diet than they can digest, the species can. If your obligate carnivores have a diet with excess carbohydrates over several generations, the individuals with higher ability to digest them will have an evolutionary advantage and the typical capacity to digest carbohydrates will trend up.

$\endgroup$
4
  • $\begingroup$ "And even if you indulge too much, the consequences should not be worse than for humans, they'll just happen sooner at lower quantity." This feels ripe for elaboration. I'm guessing we aren't talking about the stuff that Google finds, namely weight gain and diabetes, since (I believe) those require that the carbs are actually digested? (Although the linked article seems to suggest otherwise...) $\endgroup$ – Matthew May 6 '20 at 17:48
  • $\begingroup$ @Matthew Actually, that is apparently not known for sure. It has been assumed that obesity and diabetes will happen, hence those articles, but on the other hand, as you say, undigested sugar should not cause either of those things. I think being vague was the right call. It is not known and your carnivores are not actually cats, right? $\endgroup$ – Ville Niemi May 6 '20 at 17:54
  • $\begingroup$ @Matthew Bit of clarity I can offer : eating carbohydrates will still cause spikes in digested sugar and obligate carnivores might (or might not) be more sensitive to those because they would have evolved to those spikes being rarer. Cats specifically might be exceptionally sensitive since they seem to have very low levels of relevant enzymes but it is also speculated they just use something else we do not know instead. $\endgroup$ – Ville Niemi May 6 '20 at 17:56
  • $\begingroup$ They aren't Terran cats. While I try to generalize my questions when feasible, in this case I am specifically interested in "felinoids" (SF/F examples abound...). BTW, interesting article! (Now that I've had a chance to read, or at least skim, through most of it.) It sounds like eating carbs might actually result in a protein craving, which is neat (and useful!) to know. That actually helps with a point I've struggled with, which is that breads are tasty, but my characters (sometimes) don't want to eat them anyway. $\endgroup$ – Matthew May 6 '20 at 18:12
4
$\begingroup$

Using cats as an analogue, since they meet the criteria of felid obligate carnivores, I'd say that they'd be capable of eating bread.

A quick google image search is all that is needed to confirm this.

enter image description here

$\endgroup$
9
  • 3
    $\begingroup$ I think that is actually an Ewok. $\endgroup$ – Willk May 6 '20 at 16:07
  • 1
    $\begingroup$ There's a very highly likelihood that the cat was posed, given the preponderance of cute cat pictures on the Internet. I wouldn't call that evidence. It is kind of cute, though. $\endgroup$ – Halfthawed May 6 '20 at 16:17
  • $\begingroup$ @Halfthawed and given the human hands holding the arms $\endgroup$ – gen-ℤ ready to perish May 6 '20 at 16:27
  • $\begingroup$ @Halfthawed When I searched for cat eating bread I found lots of images of different cats eating bread unassisted. I just chose the most visually interesting one for this post. $\endgroup$ – sphennings May 6 '20 at 16:36
  • $\begingroup$ I'll just leave this here: i.redd.it/ffmu06ga10m41.png $\endgroup$ – Ton Day May 7 '20 at 1:34
4
$\begingroup$

You are correct that an obligate carnivore must eat meat (e.g. cats because they can't produce taurine), but that doesn't stop them from eating other foods, such as sugars and grains. Their sense of taste, their dentition, etc. are simply tuned by evolution to prefer foods they need to survive because those who don't would tend to die before passing on their bad genes.

However, once their nutrition needs are met, e.g. a housecat with a reliable food supply that doesn't require hunting, they may eat all sorts of things that aren't nutritious because they're interesting (e.g. bugs, string) or assist with digestion (e.g. grass, bones).

We humans put all sorts of weird stuff in pet food that they'd never eat in the wild, in some cases specifically because it isn't nutritious and we want to put them on a diet. Also, while many cats would prefer raw food if given the choice, others actually prefer canned or kibble, so it's not unreasonable for felinoids to have a more diverse diet than what biology dictates, and it may vary wildly by individual. There's just a floor to how much of it must be meat.

Note that some felines are allergic to grains, but only in parts of the world where grains simply aren't found. Felines that are around grains in the wild will eat them occasionally, even if only second hand in the digestive track of their prey, so allergies were long ago removed from their gene pool.

$\endgroup$
2
$\begingroup$

Yes

Bread contains little nutritional for cats, except for the sugar within it. Sugar itself isn't great for cats, especially given that they didn't evolve to deal with consuming large quantities of it, unlike omnivores such as Homo Sapiens. They also can't really digest plants. This is because their digestive system is too small. An obligate carnivore, such as a cat, will have a very short digestive system (specifically small intestine) because of how easy it is to break down meat. By contrast, an obligate herbivore, (such as, say, a koala) will have an incredibly long small intestine and very specializes enzymes. We humans, by the way, fall in between the two extremes.

And bread is pretty delicious. Not only the taste, but the various textures of bread isn't something that you can replicate given only meat. The cats would certainly be capable of eating them. Would there be problems? Yes - cats weren't exactly designed to eat grain. Still, they're more than capable of developing a tolerance for it, and such a tolerance is pretty pervasive among species that live near wild grains. Even if it isn't, by using small and constant exposure, it's possible to build up a tolerance enough for eating bread.

$\endgroup$
10
  • $\begingroup$ Humans are not designed to eat meat, but our livers adapted over the millenia, now it still kills us.... But way slower. I believe the same would apply to all animals. $\endgroup$ – user75545 May 6 '20 at 16:46
  • 2
    $\begingroup$ @Kyu No, that information is factually incorrect. Humans are designed to eat meat (our incisors, for instance, are solely there for meat). Meat also does not kill us, not even 'way slower'. Meat isn't poisonous to human. $\endgroup$ – Halfthawed May 6 '20 at 18:04
  • $\begingroup$ Human teeth can't chew raw meat like they can chew raw plant matter. Meat in per sé doesn't kill us but the way our digestive system and bacterial flora interact with substances found in meat like the protein carnitina or cholesterol result in the production of deadly toxins that can accumulate over time and damage our systems. Inform yourself on the TMAO cycle of the human liver. $\endgroup$ – user75545 May 6 '20 at 18:10
  • $\begingroup$ Some groups of Neanderthal (not all) had specifically developed livers to slow down to process and thrive better on carnivore diets, but throughout human history the remaining groups of Neanderthals where either completely vegetarian while others were all-eaters just like Homo sapiens, but archeologists suggest the stapple food for most groups of Sapiens where indeed starches such as roots and fruits or berries, obviously meat and other foods were present but they were not the staple food for classic African homo Sapiens. $\endgroup$ – user75545 May 6 '20 at 18:13
  • 2
    $\begingroup$ Also, yes, over consumption of meat can kill you and if you eat too much fat, that can kill you as well. That doesn't mean meat is dangerous. There's a rule in medicine - the difference between a poison and a drug is dosage. Everything can kill you in sufficient quantities. Including plants. $\endgroup$ – Halfthawed May 6 '20 at 18:32

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.