High-Fat Diets Are Bad For You? I Smell A Rat

Tonight I served my five-year-old a big bowl of rat chow for dinner, then asked her to recite the Pledge of Allegiance, which she (supposedly) learned in school yesterday.  She couldn’t do it.  This was annoying, because she recited the whole thing last night.

So I fed her some fish food.  That didn’t work either.  I tried dried cat food.  No better.  Rabbit chow.  Nada.

I was experimenting because I’d seen several articles on … what’s that called? … the spider web … no… the tennis net … volleyball net … ah, the internet!  There were all these articles about how a high-fat diet can adversely affect your mammary.  No wait, that’s not it … your mummery.  Hang on, it’ll come to me … nope, I’ll have to look it up again.

Got it.  There were these articles about how a high-fat can adversely affect your memory.  I found this disturbing because as a performer, I have to memorize a lot of material.  When I act in plays, I memorize every line in my scenes – mine and everyone else’s.  That way I know if another actor forgot a line and I can cover. 

(Once, in a bad production of “A Shot in the Dark,” I spent more time covering than I did saying actual lines from the script.  Strange, because the actor who forgot half his dialog was a vegetarian.)

When I perform on cruise ships, I do two different half-hour standup shows … alone, with no teleprompter and no one to cover for me.  So I take memory seriously.  I also eat a lot of fat, and my memory is just fine.  I still remember the phone number my parents had when I was a kid in Iowa.  My dad used to call me “Total Recall.”  So when I saw the headlines, I smelled a rat.

Yup, it was a rat, all right.  For this study, researchers fed some rats a low-fat diet (7.5%) then tested their physical endurance and memory by having them run on a treadmill and find their way through a maze.  Later, they fed the rats a high-fat diet (55%) and repeated the tests.  Wouldn’t you know it, the rats didn’t do so well on a high-fat diet.

Let’s set aside the possibility that after eating all that fat, the rats became much more intelligent and thought to themselves, “Running a maze is stupid.  I’m going to just sit here until that dumb @#$%ing researcher gets tired of writing on his pad and gets me out of here.  I haven’t finished reading the sports section on that newspaper lining the bottom of my cage.”

The point is, a high-fat diet isn’t natural for rats.  I looked it up, and rats are listed as omnivores who will eat pretty much whatever is available, but prefer cereal grains.  (They probably like looking at that American Heart Association seal of approval on the box.)  When you feed an animal – or a human – an unnatural diet, you’re going to get negative results.

The Lipid Hypothesis became accepted partly because when researchers fed rabbits lard and cholesterol, the rabbits rapidly developed heart disease.  Well, go figure … rabbits rarely attack pigs and eat them.  When other researchers tried the same experiment on dogs, they couldn’t induce heart disease, no matter how much lard they fed them.  So they concluded that dogs don’t get heart disease.  But they do – if you feed them grains.

If rats eat a lot of fat and then become lethargic and stupid, that says nothing about how a high-fat diet affects humans.  We’ve been eating fatty diets for hundreds of thousands of years.  We didn’t become fat until we started eating grains.  (And we didn’t become stupid until we started feeding fat to rats and thinking the results mean anything.)

In another rat study that hit the news this week, researchers suggested that high-fat, high-protein diet leads to insulin resistance.  Once again, we’re looking at animals that aren’t eating anything close to their natural diet.  If a high-fat, high-protein diet had the same effect on humans, the Inuits and the buffalo-hunting tribes should’ve been plagued by diabetes.  They weren’t.  But after Native Americans were herded onto reservations and forced to live on flour and sugar, they became one of the most diabetic populations on the planet – more than 50% in some tribes.

Studies on actual humans don’t show these results.  In fact, they show exactly the opposite.  In one recent study, Alzheimer’s patients showed improvements in memory when they were given ketones.  The natural way to produce ketones, of course, is to eat a high-fat diet and skip the carbs.

In another recent study, subjects who ate a Paleolithic diet – which means low-carb, consisting mostly of meats, nuts, vegetables and some fruits – showed a significant drop in insulin levels.  That hardly sounds like the path to insulin resistance.  Other studies have also shown dramatic improvements in diabetes symptoms when subjects went on a low-carb, high-fat, high-protein diet.

If you’ve seen these headlines, please, don’t worry.  You’re not a rat.  You won’t develop diabetes and forget where you parked your car unless you eat rat chow.

By the way, my daughter loves eggs, cream, meat, nuts, butter and cheese.  When we had lamb steaks last night, she begged – as usual – for some extra fat from my steak.  (She got it.)  Since she would just now be in kindergarten if she’d started school in Tennessee, her first-grade teacher had her come in for a reading test before the semester began.  Afterwards, the teacher told my wife, “Your daughter blew me away.  I can’t believe how many words she recognizes already.”

I’d say her memory is just fine, too.  And she actually knows the Pledge of Allegiance word-for-word.

If you enjoy my posts, please consider a small donation to the Fat Head Kids GoFundMe campaign.

25 thoughts on “High-Fat Diets Are Bad For You? I Smell A Rat

  1. Scott Moore

    Keep up the good work! I appreciate the help you provide in debunking all of these stupid “research” reports. I point my friends to your posts many times when I get questions about something they heard in the media. You are a part of “the war on stupidity”. It’s a seemingly never-ending war, but someone’s gotta fight it.

    It was a real eye opener, when I started researching the film, to realize how many so-called studies are agenda-driven. I mentioned that to Dr. Kilmer McCulley, who was basically fired from Harvard for disputing the Lipid Hypothesis, and he replied, “I’m sorry to say, it’s probably a lot worse than you even imagine. It’s disgusting.”

  2. Matt Brody

    I don’t think I buy that it’s because rats “prefer” cereal grains. Humans “prefer” cereal grans too – at least the ones who don’t read the sources we read. I have got to think that rats evolved not eating cereal grains, which would make them more like us in this regard. However I think the results occurred because switching from one type of diet which you have had your entire life, to a completely different diet, messes with you for awhile until you get used to it. “Low-carb fog” is a pretty well known side effect that hits some people for a few days or weeks.

    I wondered about that as well when I saw that the rats were given the second round of tests nine days into the high-fat diet. That’s not much time to adjust to a huge change.

    I’m not sure what the article authors meant by “prefers” cereal grains either. In nature, will rats choose to munch on wheat or corn if seeds and nuts are available? That would be rare for a mammal.

  3. Joe H

    Very interesting. Good thing I start my family with low fat premium breakfast cereals from Serial Cereals. Hopefully eating smart with help all our memories!

    Good luck selling low-fat cereal to my readership.

  4. Ailu

    It seems very suspicious that researchers would conduct such useless pseudoscience experiments. I would sure like to know who is funding these studies. Who wants us eating grains so badly that they will pay exorbitant amounts of money to fund fraudulent studies?

    This study was funded by the British Heart Foundation, which appears to be an exact analog to the American Heart Assocation. Their diet recommendations warn against fats and cholesterol, etc. I don’t know if they, like the AHA, rake in millions by putting their stamp of approval on processed grain foods.

  5. Dave

    The abstract of the paper doesn’t give the actual composition of the high-fat diet fed to the rats (maybe another reader with access to the full text can fill us in). But “high fat” rat diets are often just vegetable oil, sucrose, and vitamins. I think if you fed that to any animal, it would become “stupid and lazy”.

    I was wondering about that myself.

  6. Phyllis Mueller

    Thanks for providing the link to the high-fat/high-protein/insulin resistance study at Duke. I had seen the headline repeated in the media without a source cited and no mention of the fact that it was a rat study. I noticed the researchers equivocated a great deal in the press release. And I noted the Glaxo SmithKline/NIH sponsorship. Hmmm.

    Perhaps because of their shorter lifespans rats are more genetically adapted to grains than humans are. They will also eat Styrofoam, cardboard, and insulation on electrical wires, and they love dog biscuits.

    I had to read into the story a bit to find out it was a rat study.

    I tried the insulation and cardboard diet myself once. I lost weight, but my energy wasn’t good.

  7. Wanda

    Tom– ROFL at “They probably like looking at that American Heart Association seal of approval on the box.” Comedy at it’s finest!

    @Joe H– If I never touch another bowl of any kind of cereal, it will be too soon! Didn’t Tom do a post on comments like this one?

    That one seems to be posted by an actual reader; either that, or the post-generating software is getting better. Pretty sure they won’t sell any cereal to this crowd, though.

  8. Dave, RN

    A nine day study is a joke.
    A 48 year study? Now that’s something else. Even if fat shot my memory, I’d outlive the low fat folks!

    “In the Framingham Heart Study, as many as one third of all coronary heart disease (CHD) events occurred in individuals with total cholesterol <200 mg/dL. Considering that the average U.S. cholesterol level is approximately 210 to 220 mg/dL, almost half of all heart attack events and all stroke events that will occur in the United States next year will in fact occur among individuals with below-average lipid levels. For this reason, our research group has sought in our large-scale prospective epidemiologic studies to understand better other markers associated with cardiovascular risk”

    As we know, researchers aren’t above manipulating the length of a study to get the results they want.

  9. Kevin Croke

    I think this is another example of low carbers (of which i am one) double standards. Rat studies are used all the time by low carbers to put their point across. See for example the studies used by Dr Eades in demonstrating a metabolic advantage for fat over carbohydrate in rats. Gary Taubes book is rife with examples of rat studies demonstrating the benefits of high fat chow over high carb chow. We use them when it suits us and redicule them when they dont.

    To end on a positive I enjoy the blog though!

    That’s a fair point, although I’ve always believed rat studies should be taken with a grain of salt when it comes to extrapolating the results to humans. We’re not rats. When human and rat studies show different outcomes, I’m going with the human-subject results.

    The other problem with the memory study, as people have pointed out, is that nine days isn’t much time to adjust to radical change in diet. There was a human study in which subjects showed poorer memory after switching to a high-fat, low-carb diet for two weeks. That means they were probably still in the withdrawal phase. I also felt a bit foggy when I first eliminated sugar and starch, but it passed.

  10. Derrick

    I could have sworn that I read the rats were only given 4 days to adjust to the high fat diet. I have a strong feeling that the rats suffered the same effects and would have performed similarly to humans, if they had been the test subjects.

    It takes some people 2 weeks or more to adjust to a low carb/high fat diet!

    They were apparently first tested after four days, then tested for five days, which led the to the “nine days” figure quoted in some articles. Either way, it’s not enough time to adjust.

  11. TonyNZ

    “In nature, will rats choose to munch on wheat or corn if seeds and nuts are available?”

    The niche into which rats have evolutionarily expanded is to live in built up areas and get into grain stores. So, while historically they may have preferred seeds and nuts, the physiology of modern rats would be much changed. It’s called an adaptive radiation in the study of evolution, where species move into new niches.

    Good point. I seem to recall hearing they’re quite a problem around grain elevators. I guess they go where the easy food is.

  12. Ellen

    “So they concluded that dogs don’t get heart disease. But they do – if you feed them grains”..

    Dogs also develop atherosclerotic plaques if you open up a vein and drip insulin into it. What I get from both of these facts, is that dogs aren’t meant to consume high carb foods which induce high levels of insulin. You’d think that smart people would be able to extrapolate the fact that feeding a being an unnatural diet might result in unnatural health issues.

    But I’m reading a book that Dr. Eades recommended which is helping me understand why the people at the AHA, not too mention the New York Times, can’t extrapolate. It’s called cognitive dissonance.. “I can’t suddenly reverse position when I’ve told the world that fat is bad for humans for almost 40 years. My cognition would be dissonant, not too mention my bank account!”

    (The book is “Mistakes Were Made, But Not By Me” if you want a good read).

    That would be the logical conclusion. A dog I loved as a boy died of stomach cancer. I’m sure we fed her some kind of dried dog food garbage that contained grains or soy. When I get my next dog (my girls want a boxer) I’ll know better.

    I read Doc Eades’ review of the book. It’s on my list. I’ve only got about a dozen stacked up so far.

  13. Cynthia

    My understanding is that rats, like many rodents, live in fields of grasses and weeds and eat whatever seeds (and insects?) they can find. We have rats living outside our house that eat from our fruit trees and outside cat litter box (litter made from wheat chaff)! It’s the weirdest thing watching rats make the pilgrimage down the jasmine vines to the litter box, over and over. They don’t even seem to mind the cat’s contributions! So they seem to prefer starches, or maybe it’s just the easy pickings. I don’t put much credence in rats as models for human metabolism or diseases, but I think they are useful for understanding basic biochemistry and physiology.

    Those sound like some brave rats. I’m with you; I believe rats are useful for studies, but only to a point.

  14. gallier2

    @Kevin Croke

    The problem is not the double standard you imply on low-carbers, the problem is of misrepresentation of studies, whether it’s from low-carbers or from orthodoxers. In the example you give, with the metabolic advantage example of Dr.Eades, you have to remember what the question was. He didn’t try to show that following a low-carb diet will work because there is a metabolic advantage as shown in rat studies. His article was an answer to the attacks from Anthony Colpo on him and on Gary Taubes, stating that the metabolic advantage doesn’t exist at all and that only calories in/calories out is important.
    By using the rat studies he showed that the MA indeed exists and that the in/ou proposition is false. Nothing more, nothing less. He then even stated that one shouldn’t extrapolate the studies result as rats aren’t little furry humans.
    As for this rat study, it might even be relevant, if we knew what the question was they wanted to answer.

  15. Terry

    Here are the details on the high-fat diet in this study:

    “The fatty acid composition of the high-fat diet was 27% saturated fatty acid, 48% monounsaturated fatty acid, and 25% polyunsaturated fatty acid. Both diets contained adequate quantities of micronutrients.”

    Another interesting detail — the high-fat rats were fed more calories and therefore gained weight. Gee, what a surprise that they subsequently didn’t exercise as much. 🙂

    I still wonder what fats they were feeding them… corn oil, canola oil, lard, etc.

  16. Terry

    Regarding the high-fat diet again — all it says is “oil”:

    “During the 9-d testing period, 21 rats continued to be provided with chow ad libitum, while the remaining 21 rats were switched from standard chow to a custom-produced high-fat diet (diet code 829197; Special Diet Services), which had an AFE of 5.1 kcal/g, comprising 55% from oil, 29% from protein, and 16% from carbohydrate.”

    So for all we know, it could’ve been some nasty processed vegetable oil that produces inflammation.

    If you want to know just how bad science reporting often is today, think about this: several readers on this blog have asked more criticial questions than anyone reporting on the story, at least that I’ve seen.

  17. guest

    Hey check out this from the DC examiner Health column today on fat – its from a Q&A column by The YOU Docs Mehmet Oz and Mike Roizen. It’s amazing how much you can get wrong in such a short answer! It’s not just the reporting thats bad- its the advice columns too.

    Q: I’ve heard you say that we should stay away from “four-legged” fats. What do you mean by that? – anon

    A: A four-legged fat is simply a fat that comes from a four-legged animal, which includes the fats in butter, beef fat, bacon and cheese. What’s so dangerous is that the products from mammals contain saturated fat, and the “S” in saturated fat stands for “stay away”. While the fat in chicken (a two-legged fat) is somewhat better, the best fat has no legs at all (think avocados, fish, olives and almonds).

    Saturated fat turns on genes that are activated long after the taste is gone- those genes cause aging of your immune system, build plaque in your arteries, raise your cholesterol and inflame your blood vessels.

    On the other hand, the right amount of no-legged (unsaturated) fat helps your body absorb certain vitamins, boosts heart health, keeps nerves and cells working optimally, and raises your good cholesterol.

    Wow. I guess that explains why hunter-gatherers were plagued with heart disease and auto-immune diseases.

    I’ve asked the local supplier of grass-fed meats to please remove the legs from their cows before slaughtering them.

  18. M Lewis

    “I’ve asked the local supplier of grass-fed meats to please remove the legs from their cows before slaughtering them.”

    So, I guess ground beef is okay, right?

    Yes, if the beef is lying on the ground, apparently the fat will be okay. That’s my interpretation of Dr. Oz.

  19. Natalie

    “We didn’t become fat until we started eating grains. (And we didn’t become stupid until we started feeding fat to rats and thinking the results mean anything.)”

    HA! Don’t kid yourself, we were stupid long before we started feeding fats to rats – we were believing Ancel Keys in the 1950’s!

    But at least many doctors and researchers disputed Keys back then. So I’ve guess we’ve gotten more stupider … probably from not eating enough fat.

  20. KD

    As far as I know, coconuts have no legs, but are mostly saturated fat. I’m pretty amused at my current mental image of a coconut wandering away on four legs, though.

    It’s a good thing coconuts don’t have legs. They might get together and attack those poor legless cows I’m having my local rancher raise for me.

  21. Richard A.

    The ketogenic oils when consumed generate ketones. Ketones can be used as a substitute for glucose by the brain and improve your memory,particularly if you are tired. The ketogenic oils are the medium chain triglycerides that can be found in coconut oil. You can also buy 100% pure MCT oil. A 32oz bolttle will cost around 15 to $20.

    A memory pick me up drink —
    100 Calories of coconut milk
    4 teaspoons of 100% pure MCT oil
    artificial sweetener

    Stir the above and add enough nonfat milk to make this drink about one cup and stir. You could add wild blueberries to the above and blend with a blender.

  22. Scdeshmukh

    I recently started a low-carb diet and I supplement with 2.5 T of olive oil per day (a la the Shangri La Diet). I actually feel smarter and sharper since starting taking the extra fats. My memory is definitely BETTER with all the extra fat! Although it could be the absence of sugar/carbs giving my brain a boost!

    Probably a bit of both. But I think being a fat head helps.

  23. Lola

    I read these research articles all the time on how bad fat is for you. But they don’t tell you that the overwhelming majority of these studies use soybean oil, corn oil and canola oil as the source of ‘fats’, not butter, cheese or any other animal fat. Why don’t they come out and tell people to stop eating the baked goods and other foods that contain these oils? Won’t happen. People might actually get well…

    Oh, by the way – when do you think you will hear anything about poison white flour? Never.

  24. Akewataru

    If you think this study is terrible look at the Seven Countries Study by Ancel Keyes. This is THE study where they “correlated” a high fat diet to increasing the risk of Cardiovascular disease (CVD). Also, this study is why folks from your neighbor to your doctor and/or nutritionist STILL believe that saturated fats or fats in general are BAD. In reality, 22 countries were studied but he only included the seven that fit his standard curve line. However, he failed to realize that at the same time sugar consumption was increasing rapidly in the US, England & Wales, Canada and Austrailia, which coincidentally were the countries showing the the highest amount of death from CVD from increasing fat intake. Japan and Italy were way at the bottom of the graph, because at the time their diets weren’t Westernized just yet. Just yet…For you statistians out there this study was a multivariate linear regression analysis (MLRA). Keyes showed that by holding saturated fat constant there was no significant correlation between sucrose and CVD. This is debatable, but I disgress. However, in a MLRA you have to also to hold sucrose constant and see whether the saturated fat alone still cause a increase in CVD. This was never done. There is a BIG hole in this study. Finally, to top it all off, they only used MEN in the study. So, for the past 30 years the United States has based nutrition education, information, and policy on this study.

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