The Pet Obesity Epidemic

Half of all cats and dogs in the U.S. are overweight, some 20% being obese. So, what does that tell us about the human obesity epidemic? If cats and dogs are ballooning into caricatures of themselves at the same rate as humans, does that say anything about the causes of obesity?

It says something about the non-causes, perhaps. Dogs and cats don’t follow government guidelines for a low-fat, high-carb diet, so scratch that. It could be that pet food has become loaded with carbs, which seems possible.

Are pets eating a highly palatable diet, and thus setting themselves up for dopamine surges, tolerance, and an insatiable desire to eat more and more? I rather doubt it.

What this points to is a very unfashionable idea for the cause of obesity: volition. The same humans that don’t care about turning themselves into lardasses are doing the same to their pets by feeding them too much.


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Johnny Caustic says October 10, 2012

Are you kidding me? Cats and dogs are obligate carnivores, and they’re being fed kibble full of corn, soy, wheat, gluten meal, and even corn syrup. It’s perfectly obvious that they’re fat because they’re being fed metabolic poison.

JP says October 10, 2012

Ever looked at the ingredients in dry cat food? It is ALL carbs — cheap calories.

Vegetable Protein

The amount of grain and vegetable products used in pet food has risen dramatically over time. Plant products now replace a considerable proportion of the meat that was used in the earliest commercial pet foods. This has led to severe nutritional deficiencies that have been corrected along the way, although many animals died before science caught up.

Most dry foods contain a large amount of cereal grain or starchy vegetables to provide texture. These high-carbohydrate plant products also provide a cheap source of “energy” — the rest of us call it “calories.” Gluten meals are high-protein extracts from which most of the carbohydrate has been removed. They are often used to boost protein percentages without expensive animal-source ingredients. Corn gluten meal is the most commonly used for this purpose. Wheat gluten is also used to create shapes like cuts, bites, chunks, shreds, flakes, and slices, and as a thickener for gravy. In most cases, foods containing vegetable proteins are among the poorer quality foods.

Mangan says October 10, 2012

I wouldn’t deny that pet food loaded with carbs and other crap could make pets fat. The question for me is, how much has that changed over the past 40 years or so? (Assuming that the pet obesity epidemic parallels the human.) When I was a kid, we fed our dogs food out of a bag and they weren’t fat. So unless the composition of that food has dramatically changed, I’d say that the odds of something else going on here are good.

dearieme says October 10, 2012

It’s infection passing between master and pet.

JP says October 11, 2012

Given that things have changed in human diets too, is it really so implausible that pet food has changed?

Tschafer says October 11, 2012

Yes, the composition of cat food has changed significantly in the last 20 years, I’ve watched it, and now try to limit my cats to actual meat as much as I can. Any assumption that pet food has not changed in formulation over the last few decades is just plain wrong.

RS says October 13, 2012

Mangan, have you ever read much about trans fats and oxidated fats?

Catherine Shanahan — who has certain very loose ideas IMHO but is /aggressive/ and not one more mild lil sheep — focuses on this, inter alia. She says most vegetal fats are yielded by industrial processes not practiced before the 20th ; exceptions would be peanut oil and olive oil, and there are a few others.

Specifically she says they are extracted at high temperatures, resulting in extensive denaturation into trans fats and fats oxidated at their sites of unsaturation. Point being, these molecules are virtually absent from nature and from pre 20-C eating, making them prima facie suspect for that reason alone. Obviously, high temps were achievable a long time ago, but she says conditions have to be controlled nicely to prevent polymerization. Hence canola oil, etc, did not used to exist. I don’t believe there is anything wrong, in her opinion, with actually eating canola seeds (unless of course your body temperature is 800* C). To be complete, there are a few oils which she says can be extracted cleanly but will nevertheless be denatured by kitchen cooking.

But I’ve just been sticking with olive oil and peanut oil — plus I do take some fish oil — and shitloads of butter, and fatty ground chuck, etc. She says all animal fats are fine.

She says about 30 fucking % of the American diet (by energy value) consists of these vegetal lipids which, themselves, consist of a considerable fraction of denatured species. This strikes me as not implausible — and it makes the theory look very attractive, because we would expect ‘the problem’ to more likely be something of which we eat a whole lot. Even though in principle, it could quite easily be something consumed by Americans in microgram quantities per annum.

Notice that protection of ‘whole foods’ phreaks from obesity is not necessarily predicted by this theory, because they do not eschew these oils, to my knowledge. A virtue of the theory is that it doesn’t really predict the existence of any protected pops other than the ones we know about and can easily account for (EAsians, rich subpops where there is extreme sexual selection against overweight).

I appreciate your epistemic attention to the pets thing. Next time I hit the grocery I will check some labels to see what the vegetal fat content is (excluding, again, olive oil, peanut oil, palm oil, etc).

In fact, anyone truly interested could buy mice and (randomizing appropriately) feed them ad libitum on:

A. diet X, rather free of sugars and industrial vegetal oils, but containing whatever else

B. diet X-prime, which is the same except that it’s 20% industrial vegetal oils.

With proper randomization, it is wholly unnecessary that the mice have a uniform genetic background or any of that fancy shit. You could just get them at a pet store. Both groups get exercise wheels and equipment to prevent metabolic derangement from lack of exercise.

Combine this with the whole increased sugar consumption thing, which Shanahan also credits highly, and you might have most of the puzzle.

RS says October 13, 2012

I have eschewed these oils and had major success losing weight, mainly from the omentum (visceral fat), but also subQ. I think I lost about 20 lb rapidly. However I have also been on a very successful serotonergic treatment, causing greatly increased motority combined with relative anorectia. I probably ate 1900 kcal /d (fairly low carb tho nothing radical) and did not skip any meals, but I did tons of weight lifting and rapid (ie, energetically inefficient) walking… 5, 6, 8, once even twelve miles… as well as performing heavy labor jobs for pay.

But I lean more towards metabolic derangement theories. One of the Heads (not sure which) pointed out that an hour’s leisurely walk burns like 65 fucking calories. It’s thermodynamically trivial, what probably matters more is that it helps de-derange oneself endocrino-metabolically.

I about 65% believe all of the above, though I haven’t really looked into formal work on the subject.

She goes on to make very extensive claims about oxidated fats, which go beyond overweight and which I am a bit less hesitant to credit — namely she says they cause free radical reactions that are highly damaging to tissues and are the main cause of circulatory disease.

It is universally accepted by refereed science that hunter peoples do not have heart attacks and I think they don’t have atherosclerosis at all. Shanahan further claims that heart attack was comparably rare in the West in 1900 ; it was an insignificant cause of mortality. Orthodox cholesterol theory she wholly rejects.

RS says October 13, 2012

As a historigraphical note, he anti trans movement has been around for a long time, my premed gf made me buy LOW-trans margarine in 2001. –Shanahan of course would find ANY trans an appalling proposition. And trans is highly regulated in e.g. Denmark — severely so, I think. Denmark certainly isn’t very fat, so there’s a minor evidentium right there.

The US National Academy is quite concerned about trans, so that much is not really ‘alt med’. As I recall, they have however feared that a really thoroughgoing anti trans crusade might have undesired side effects — like basically, I think, causing people to eat sat fat and cholesterol. [[[[[[[[[[[I have become agnostic about whether sat fat or cholesterol are harmful. It’s not that I’ve /studied/ it, I just don’t place much faith (any, really) in those propounding the orthodoxy. FWIW I’ve seen it suggested by someone, somewhere, that sat fat might be harmful only in context of sugar consumption. I myself consume almost no sugar now — eat very little fruit, so my sugar intake is basically just moderate milk plus the not-inconsiderable fructose content of many vegetables, plus the starch I eat if you want to count that since it is after all a glucose polymer. I eat all of them with TTOOONNSS of fat (etc) which ought to slow gastric emptying, meaning there is going to be only a modest serum glucose spike.]]]]]]]]]]]

In contrast, I’m not sure when this concern about other denatured lipids — mainly oxidized ones — arose, or how widespread it is. And while this is ranging rather far from the heart of the matter, it’s not just linear lipids or whatever they’re called — Shanahan is also concerned with things like oxidated plant sterols.

RS says October 13, 2012

> I appreciate your epistemic attention to the pets thing. Next time I hit the grocery I will check some labels to see what the vegetal fat content is (excluding, again, olive oil, peanut oil, palm oil, etc).

Although, as pointed out by others above, carnivores may just do badly on carbs. So denatured lipids may not necessarily be so important in what’s happening to them.

Does the pet obesity epidemic extend to animals like rabbits/rodents? What other kinds of pets are there?

RS says October 13, 2012

I’m not super-clear on what she thinks of roasted nuts and seeds. Apparently she may find some (not all) of them OK if the temp of roasting suits the specific plant matter involved. However, she has expressed doubt that some seeds are ‘really’ roasted in peanut oil even when this is claimed — suggesting that there may be considerable temptation to cheat by using the ~10x cheaper canola oil.

I’ve just been eating all my seeds and nuts raw for simplicity, as I just really don’t want to get all /recherche/ about a bunch of essentially boring shit. Ars longa…

RS says October 13, 2012

So naturally, one’s mind turns farther afield. The brain is made of fat. Denaturated fats might be screened out of its structure to some extent, but why a priori would we think that they are wholly screened out? It seems much more likely prima facie that if you eat denatured fats that nobody ate before 1900, said fats are in your neurons. How you like them apples?

And if oxidated fats really do cause a high rate of radical reactions, which again I am a little more hesitant to believe, they may not be great for the genomic integrity of your eggs/sperm, how does that strike you. (Though even if there is such an effect, it may not necessarily be signficant.)

RS says October 13, 2012

Omental obesity (visceral fat) has some pretty creepy looking endocrine-y effects. These are directly measured. That’s in addition to omentum’s strong correlation with many severe diseases, which could be merely correlational or could well be largely causal.

That’s really how I got interested in all this stuff, I had modest or normal subQ fat but a large omentum, at one point very large. I’m not even so tremendously interested in preventing omentum-correlated diseases, as I am interested in its immediate effects on levels of energy and well-being.

Anyway I basically have no omentum now.

Shanahan suggests that, specifically, denatured fats make for rather denatured or ‘funny’ lipoproteins that tend toward uptake in the omental region, i.e. around the intestines, not far from their point of origin. Not that she necessarily denies that sugar/fructose or cortisol may be factors in omental fat deposition.

(Not all lipoproteins originate from the intestines but I think most do.)

Mangan says October 13, 2012

RS: Interesting. I’d only recently heard of Shanahan. Trans fats do appear to be bad news. Vegetable oils also are one of the main items that the paleo diet omits, these being not found in nature, need high heat / acid processing, etc. Trans fats have been implicated in the heart disease epidemic, which seemingly got going soon after the introduction of Crisco, which is hydrogenated vegetable oil. I’ve no idea whether the problem with these fats is as serious as you say, but they are certainly best avoided altogether.

RS says October 13, 2012

> I’ve no idea whether the problem with these fats is as serious as you say

Me neither, really. I find the whole thing terribly exciting, so I wrote a lot. But there are some disclaimers buried in my extensive text.

I maybe 66% believe the idea that denatured fats are way more important than the National Academy position indicates. So I grant 33% odds to the idea that the mainstream, NAS level of concern is appropriate.

Whether cholesterol and sat fat are harmless per se in the proper dietary context — I am more agnostic about that. But, I know a number of smart people have attacked orthodox cholesterol theory.

Whether denatured fats are the main cause of circulatory disease largely via radical reactions, I am /very/ agnostic about. This idea I never even heard of before.

I have Shanahan’s longer book, which has a passable amount of refs, but I’ve not dug in really at all. Shanahan herself is on the wild side IMO, with some very extravagant claims IMO. But there are certain people with those traits who are stupendous, even though the ‘dutiful drudge’ is ultimately more important to science.

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