
What we can learn from overweight pets about human obesity - pseudolus
http://www.bbc.com/future/story/20190109-what-we-can-learn-from-overweight-pets-about-human-obesity
======
alexandercrohde
Summary:

1\. Suggests pet obesity patterns may shed light on human obesity patterns

2\. Worldwide pet obesity is between 22% and 44%

3\. Concedes that pet obesity can at least partially be explained be feeding
habits and activity of owners.

4\. However, obesity is apparently increasing in some wild animals[1]

5\. Observes that obesity is increasing in humans, including 41 million
children under the age of five (who presumably don't control their own diet).

6\. Cites heritability of obesity in humans is between 40-75%

7\. Observes the role of antibiotics in weight-gain for both humans and
livestock.

8\. Cites that a mouse injected with gut microbes from an obese human leads to
weight gain! [2]

9\. Notes a link between processed food and decreased microbiome diversity.

10\. Points out constant light exposure increases BMI.

11\. Estrogens in our daily lives like BPA in receipt paper are considered a
potential culprit too. [3]

12\. Suggests that studies by the food industry appear to be biased.

[1]
[http://europepmc.org/backend/ptpmcrender.fcgi?accid=PMC56772...](http://europepmc.org/backend/ptpmcrender.fcgi?accid=PMC5677226&blobtype=pdf)

[2]
[http://science.sciencemag.org/content/341/6150/1241214](http://science.sciencemag.org/content/341/6150/1241214)

[3] [https://www.canada.ca/content/dam/phac-
aspc/documents/servic...](https://www.canada.ca/content/dam/phac-
aspc/documents/services/publications/health-promotion-chronic-disease-
prevention-canada-research-policy-practice/vol-37-no-12-2017/ar-02-eng.pdf)

~~~
michaelcampbell
Thanks.

This one I had to laugh at.

> 12\. Suggests that studies by the food industry appear to be biased.

------
ericb
This article doesn't mention it, but even lab rats with controlled diets are
heavier. If you add pets, wild animals, and lab rats, to humans you end up
with a compelling line of evidence for a common factor.

It fascinates me that so many of these comments ignore such an intriguing set
of facts in favor of a physics/moral failing line of argument--it is like the
idealogy blinds people to new evidence.

[https://www.scientificamerican.com/article/how-lab-rats-
are-...](https://www.scientificamerican.com/article/how-lab-rats-are-changing-
our-view-of-obesity/)

------
teslabox
I compulsively look at ingredients in packaged food, including pet food. Two
of the most common ingredients in cheap pet foods are soybeans and corn.
Neither of these are evolutionarily-appropriate for our pets.

Corn is mostly starch, with little in the way of nutrients. Humans
traditionally made corn more digestible with a little lime [1] -- modern corn
tortillas are all made this way, but corn chips are not. I don't think pet
food manufacturers properly treat their corn (I'm speculating here, and would
be happy to be incorrect).

Soybeans have some nutrients, but they also contain mega-doses of the
inflammatory Omega-6 polyunsaturated fatty acids.

Soy is also a potent source of phytoestrogens. These plant chemicals cause an
estrogen-like reaction in tissues. In healthy people estrogen is tightly
regulated. In unhealthy people, adipose tissue creates aromatase [2] to turn
testosterone into estrogen, creating a self-destructive feedback loop that is
hard to escape. Estrogen is removed from the body by the liver [3]. When the
liver is overwhelmed it can't keep up with excessive amounts of estrogen.

Pets, people, and food animals need evolutionarily-appropriate foods, fewer
soybeans, less corn.

One of my family would like to lose weight (more than one, but I'm thinking of
one in particular). He commonly has a "healthy" salad, but smothers it in
inflammatory soybean/canola oil (sold as "salad dressing"). Even expensive pet
foods are typically contaminated with canola oil (ostensibly for the
"omega-3's", but really because they're cheap calories that look good on the
label).

[1]
[https://en.wikipedia.org/wiki/Hominy#Production](https://en.wikipedia.org/wiki/Hominy#Production)
/
[https://en.wikipedia.org/wiki/Nixtamalization](https://en.wikipedia.org/wiki/Nixtamalization)

[2]
[https://en.wikipedia.org/wiki/Adipose_tissue#Physiology](https://en.wikipedia.org/wiki/Adipose_tissue#Physiology)
\- "Adipose tissue is the greatest peripheral source of aromatase in both
males and females,[citation needed] contributing to the production of
estradiol."

[3]
[https://en.wikipedia.org/wiki/Estrogen#Metabolism](https://en.wikipedia.org/wiki/Estrogen#Metabolism)

------
scythe
The short version seems to be that xenochemical effects, with varying genetic
sensitivities, cause excessive appetite in animals via similar pathways to
humans. In particular, food contaminants like antibiotics, emulsifiers, and
plastic monomers (bisphenol A) may disrupt gut bacteria thus affecting hunger.
The behavior of these animals is used as an example to argue that this hunger
is very difficult to ignore. The effect of emulsifiers on gut bacteria seems
particularly worthy of investigation because, unlike antibiotics and
plasticizers, emulsifiers are added to foods intentionally.

It seems likely that because all of these xenochemical effects are purportedly
mediated via effects on the gut ecosystem, they can probably be mitigated or
even eliminated by a diet which promotes the health of gut bacteria;
presumably, one with plenty of fiber and fresh vegetables.

The bit about wild animals getting fat links to a paper about marmots which
blames it on climate change extending the growing (non-hibernation) season.
Seems to be unrelated IMHO.

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didgeoridoo
I think part of the issue is also that humans don't actually know what a
healthy weight for a dog or a cat even _looks like_.

We get criticized all the time that we are underfeeding our dog; that you can
"see her ribs", that she's "way too skinny". Yet according to the vet, she's
about the right weight — maybe a tiny bit over.

------
arafa
The article quickly discussed fecal transplants, which seem to be an extremely
promising and underexplored avenue (for obvious reasons) for dealing with
obesity without surgery. I always figured if I got seriously overweight I
would try it. I first heard about it from the Freakonomics blog (different
episode than was mentioned in another comment:
[http://freakonomics.com/podcast/freakonomics-radio-the-
power...](http://freakonomics.com/podcast/freakonomics-radio-the-power-of-
poop/))

------
elchief
My friends like to shit on me for eating organic, but it looks like hormones
and pesticides lead to weight gain

[https://scholar.google.ca/scholar?q=pesticides+obesity](https://scholar.google.ca/scholar?q=pesticides+obesity)

On the flip side, there probably isn't enough land for everyone to eat
organic, so it's not a global solution

~~~
whatisthewhy
I looked at a few of those studies (including the top hits) and it doesn't
look like any of them bothered to control for patient income. Since organic
food and thus exposure to non-organic-farming hormone and pesticides is
basically a proxy for income nothing at all useful can be drawn from these
studies other than that poor people tend to be fatter.

Medical studies in general have a long way to go to catch up to even the stuff
coming out of social-science and public policy journals.

------
adrianhel
Is there any research that catogorizes how different foods impact satiety and
craving that anyone could point me to?

It would be interesting to see a study that examines how different foods
impact these when introduced in an average diet.

------
tashi
It is fascinating and a little bit scary to learn that adding antibiotics to
livestock's feed makes it possible to fatten up animals with less food!
Biology is full of surprises.

~~~
qihqi
It would make sense that for the immune system to fight property, calories are
consumed. The soldiers gonna eat after all. (I don't actually know what I am
talking about...)

