How a Carnivore Diet Can Mess You Up in the Long Run ( deficiencies, deceit and denial )

What Is The Carnivore Diet?

The carnivore diet is often described as the exact opposite to a plant-based diet. But in reality they are just very different ways of eating.

A stern looking adult male lion symbolising the extreme carnivore diet. Sometimes referred to as a ‘zero-carb’ diet, people who follow this way of eating avoid all plant foods and consume only animal products … meat, eggs and dairy.

Understandably, vegans are vehemently opposed to the carnivore crowd for reasons which should be pretty obvious. You’ll see heated exchanges on social media between the two camps.

Many proponents of this odd way of eating claim it has miraculously cured their various ailments and helped them lose weight. Some say it has improved their mood and helped to regulate their diabetes.

But are these reported benefits due to the high meat intake or the elimination of other foods?

In this article we’ll look at some of the long term risks and side effects of a carnivore diet. Obviously I’m going to be biased, being vegan myself, but I will try to be as objective as possible!


Common Short Term Side Effects of the Carnivore Diet

Seeing as this all-meat diet is a relatively new phenomenon, there are very few studies tracking the longer term effects. But we do have plenty of data on the short term side effects.

So let’s briefly get into those before we delve into the long term effects.

A cursory perusing of the carnivore forums reveals some very common short term issues. These include:

  • Diarrhoea
  • Constipation
  • Fatigue
  • Headaches
  • Food cravings

Diarrhoea seems like an odd one when you consider most carnivore dieters have a pretty low dietary fibre intake.

But oftentimes this dietary regime can result in gut inflammation, insufficient bile production, bile acid malabsorption, and gut dysbiosis. All of these conditions can lead to diarrhoea.

  • Psyllium husk has been used by some carnivore dieters to combat their diarrhoea, although it is plant-based so technically off limits!


A plasticine man sitting on the toilet.Constipation is to be expected on a carnivore diet. Meat has no fibre so you’re more likely to get bunged up if you exclude plants from your daily meals.

  • Drinking plenty of water and exercising more can help to alleviate constipation.


Fatigue is also very common because the body switches from carbs to fat for powering your cells. There is a transition phase during which you can feel very tired all the time.

  • Avoiding coffee can help with fatigue because caffeine inhibits nutrient absorption.


Headaches occur on carnivore for similar reasons as the fatigue along with dehydration and low electrolyte levels which are a common symptom.

  • Replacing lost electrolytes and staying hydrated may reduce the severity of headaches on the carnivore diet.


Food cravings are easy to understand. If you’re coming from a standard Western diet then your body is going to miss all that sugary, salty, fatty processed food.

  • Cravings are just something you’ll have to use your willpower to get past. Carnivore is a highly restrictive diet and you’ll miss your old ways!


Long Term Side Effects and Risks of the Carnivore Diet

As already mentioned, there are very few studies relating to the longer term effects of this dietary approach so we mainly have anecdotes to go on.

… but boy, do we have a lot of anecdotes!

We’ll get to some of those in a minute but here’s a quick list of some of the potential long term side effects of the carnivore diet:

  • Nutrient deficiencies
  • Heart disease
  • Kidney problems
  • Cancer
  • Digestive problems


Common Nutrient Deficiencies

Nutrient deficiencies seem to be quite a common longer term issue despite assertive claims from some of the carnivore ‘gurus’ that meat has all the nutrition you need.

Lots of colourful veggies and fruits all lined up on display.The glaringly obvious one is going to be dietary fibre and while this is not considered an essential nutrient, most nutrition professionals recognise fibre as an important nutrient to maintain overall health … especially gut health.

Of course, meat contains precisely zero dietary fibre so pretty much all carnivore dieters are going to be severely lacking that roughage which keeps us regular and promotes a healthy balance of the gut microbiota.

Other potential deficiencies over the longer term include vitamin A. But careful … if you’re a carnie who’s into their beef liver you can easily overdose.

Excess vitamin A is a massive no-no for pregnant women … if you’re expecting a wee one then carnivore is a minefield!

Vitamins B7 and B9 are potentially lacking in a carnivorous diet.

Again, liver meats are the answer here but it’s also easy to overdo it.

Vitamin C is a big one folks. It’s really difficult to get enough on a strict carnivore diet but of course is abundant in fresh fruits and veggies.

You’d need to consume raw organs like the lungs, spleen and thymus on the daily to even come close to the RDA. Eating raw meat, especially organs, is very risky.

Long term carnivores run a very real risk of developing scurvy and that’s no fun!

Other known strict carnivore diet deficiencies over the long term include vitamin E, vitamin K, calcium, boron, potassium, magnesium and others!

Man in a blue shirt holding a megaphone in front of his face so it looks like his head is the megaphone.Clearly, it’s no coincidence that some of these self-proclaimed carnivore diet ‘gurus’ either own their own supplement companies or heavily push supplements via affiliate programs!

The irony is that many carnivore dieters will castigate vegans for taking supplements of B12 and omega 3, claiming that it’s unnatural … oh dear!

If you want to have a bit of a laugh, look up the ‘Liver King’ … a now disgraced carnivore clown who was outed for pumping himself full of steroids while claiming his physique was all natural.

One of his best videos has him sitting down to a breakfast of bulls testicles in a big bowl of milk, sprinkled with some kind of chocolate supplement powder (from his own company of course) … I mean, this guy is just deranged.

On a more serious note …

I highly recommend a read of this comprehensive, evidence-based breakdown from ‘’ detailing 17 carnivore diet deficiencies you need to be aware of if you’re considering this way of eating.

Nutrient deficiencies are a big one but let’s move on to some other longer term problems you may experience on carnivore …


Heart Disease

The links between excessive red meat consumption and heart disease are very well documented. Hundreds of studies mostly conclude similar things.

The two main areas of concern are cholesterol and saturated fat.

Why is fast food so addictive? (McDonalds litter louts).Research into the effect of cholesterol on cardiovascular disease (CVD) has matured to such a degree that most experts now agree it’s not so much of a big deal as once thought.

… and while more research is needed to establish the facts it does seem that, for now at least, moderate dietary cholesterol consumption has a very weak link to CVD risk … at least in healthy individuals with few other CVD risk factors.

Everything has to be caveated!

Then there’s the fake news and dodgy research all muddying the waters … who knows what to believe any more.

Saturated fat, on the other hand, is far from exonerated and foods high in cholesterol tend to be high in sat fat.

So there has possibly been a false positive element to many of the studies which show dietary cholesterol is linked to CVD.

… it kind of is. But partly by association with saturated fat.

This would explain why eggs, once regarded as the devil incarnate for CVD risk, have now largely been accepted to be ok, in moderation.

The problem with the carnivore diet is moderation doesn’t get a look in.

So let’s just get real … let’s ground ourselves at this point before we all disappear up our own fundament.

Here’s a very recent study which draws on decades of vast datasets on the subject and aims to

“provide the current state of evidence on healthy dietary choices for CVD”

The conclusion?

“Increased consumption of plant-based components such as dietary fiber, nuts, fruits, and vegetables has been shown to be effective in reducing CVD risk factors.”

But not only that …

high intake of saturated fatty acids, sugar-sweetened beverages, red meat, and processed meat as well as high salt intake are associated with the increased risk of CVD.”

It’s very clear.

We can safely conclude here that eating lots of meat and eggs everyday, washed down with cow’s milk is absolutely going to increase your risk of a heart attack or a stroke.

Considering that over 26 million Americans have some form of CVD and 52% of all CVD deaths worldwide are attributed to diet-related risks then all you have to do is …

… join the dots!

Now do you really want to risk the carnivore diet?


Kidney Stones, Cancer & Gut Microbiota

Who knows what other long term problems might be caused by the carnivore diet?

We simply don’t have any studies to draw guidance from.

A cartoon of someone diving out of a person's flip top head as their brain explodes! Well … there was one recent pro-carnivore study undertaken which, even under the weakest of scrutiny, falls at the first hurdle.

Emotionally embraced by many carnivore grifters … sorry, influencers … enter stage left the Harvard Carnivore Diet Study, which sounds very grand doesn’t it?

But it is actually based on a 4 week social media survey involving just over 2000 people who self-identified as following a carnivore diet for 6 months or more.

These people were basically asked … “how do you feel?

I mean, this study is clearly a joke by any metric. There was no standardisation of dietary factors nor any kind of filter on who was responding to the survey.

It was essentially a free for all where any old disingenuous carnivore clown could skew the data. Let alone any accounting for bot traffic!

So absolutely no scientific method then.

Anyway … I digress!

Oh sorry … one last thing on the study which is a bit of a laugh … 9% of respondents said they chose the carnivore diet for “ethical reasons”.


Just solidifies my conviction that there’s absolutely no point in engaging with these people. They are invariably beyond help.

Ok back to the actual subject matter of this section … you’ll have to stop me when I go off on one like that 🙂

Some other long term side effects of the carnivore diet are likely to include kidney stones (nephrolithiasis), certain types of cancer and an increased risk of developing digestive problems.

I say ‘likely’ because again, we have no specific long-term studies to examine. But we do have plenty of studies into the health effects of excessive red meat consumption.

One way to look at the carnivore diet is to consider it an extreme form of the popular keto diet, where carbs are heavily limited.

Except on strict carnivore there’s pretty much zero carbs.

Since we know keto diets are associated with increased frequency of kidney stones then we can confidently assume the carnivore diet likely increases your risk of developing this often painful condition.

You can apply the same assumptions when it comes to cancer risk and potential digestive problems.

Although the carnies will insist their diet improves gut health … of course.

Then we have the large anecdotal body of evidence gleaned from the internet.

There’s a few very active carnivore forums online so go ahead and take a look at some of the posts emanating from these mildly disturbing, murky corners of the internet:

Carnivore diet and kidney stones. Definitely not TMI Mike, thanks for sharing …

Mike developed kidney stones on the carnivore diet.

Poor Jasmine found out the hard way. One of the replies to her was “You have a health problem”. No sh1t Sherlock … (click the image to enlarge)

Jasmine had a severe negative reaction to this highly restrictive diet.

Susan is putting her trust in carnivore to cure her of cancer …

This is how dangerous 'carnivore' influencers online can mess with your head.

I could go on and on with this … it’s one forum of many!

Just to mix it up a bit, here’s one from YouTube …

Possible need for colon surgery after going carnivore.

You can make up your own mind.


How to Minimise the Long Term Side Effects and Risks of the Carnivore Diet

The best way I can think of to minimise the risks associated with a carnivore diet is quite simple.

Just don’t do it.

But if you have some burning desire and feel you must then I would seriously recommend considering a psyllium husk supplement.

Yes, I know it’s plant based but you may just have to compromise if you want to try and keep your gut reasonably healthy on carnivore.

A decent vitamin supplement is probably also a good idea as well as upping your exercise levels. That might just help keep those arteries from clogging up completely.

Most of the well known carnivore influencers online are very physically active. It seems to go with the territory.

The ‘alpha-male’ thing and all that!

Speaking of which, Mr Saladino … aka the Carnivore MD (debunked all over the internet) actually eats quite a bit of fruit and veg.

At least, he was last time I checked.

He does seem to flip-flop somewhat and has received a lot of flak from the hardcore carnivores online.

You know the ones … “I only eat one cow a year” 🙂


Conclusion: Risks Outweigh The Benefits

So we’ve taken a good hard look at the short and long term side effects of a carnivore diet and found there’s a lot to think about before you dive in head first.

Hold on to your heart. Stick man floating off holding on to a red heart. It’s certainly not something to take on lightly.

Sure, there’s a few vocal proponents who claim it can cure all your ills but I honestly find these people even more disingenuous than those weird climate deniers on Twitter.

I fully believe the plant based diet (PBD) is the way to go. The main reason being we have reams and reams of solid scientific data backing up the health benefits of a PBD …

… and almost no grown-up science supporting a carnivore diet.

Oh sorry … the Harvard Carnivore Diet Study :-))

So I’d encourage you to do your own research on this before you make any decisions and try to be objective. Maybe this article has given you a slightly different angle.

… and we never even touched on the ethics involved in eating meat … but that’s another article.

I shall leave you with this thought-provoking, short thread on what the carnivore fad may actually be all about! Tin foil hat time 🙂

Have a peaceful day my friends …


Image of me. Rohan.Rohan McAvee is just another vegan blogger trying to navigate the sometimes choppy waters of veganism and plant-based living. Based in the UK, for more than a decade he has been walking the vegan walk, trying to do the right thing for the animals. He’s never really wavered or been tempted to stray from the path and now feels he’s at the point where he can offer advice to new vegans and those considering making the switch. Vegan and loving it!


Lion photo by Alexas Fotos




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