Rabbit Starvation: Can “Too Much Protein” Kill You?

So, you’ve taken the plunge into the world of weight loss diets, and perhaps you’re exploring the likes of the Atkins Diet, the carnivore diet, or any other protein-packed approach to bid farewell to those stubborn pounds.

But here’s where it gets interesting: While you’re on this quest for a healthier you, you stumble upon Reddit threads and Facebook groups where folks are sounding alarm bells about the perils of “too much protein.”

They’re tossing around terms like “rabbit starvation” and “protein poisoning,” painting a gloomy picture of potential doom and gloom. According to these doomsayers, your body might start cannibalizing itself, and you’ll waste away into oblivion.

Hold on tight because, in this article, we’re about to illuminate the murky waters and clear the air around rabbit starvation. Is it a genuine concern, or is it just another dietary myth?

Spoiler alert: Context is key! In our modern world, where calorie-rich foods abound and protein scarcity is rare, especially among folks carrying excess body fat, rabbit starvation or protein poisoning is more likely to be a phantom menace than a genuine threat.

Get ready to unravel the protein puzzle!

What Is Rabbit Starvation?

In case you’re wondering, rabbit starvation has nothing to do with fasting bunnies.

Rabbit starvation, also known as protein poisoning, mal de caribou, and rabbit malaise, is a form of malnutrition that arises when someone eats protein with too little energy from carbs or fat for too long.

Rabbit meat is super lean and contains very little fat.  Cronometer shows wild rabbit provides a massive 82% protein!    

Historically, some people have experienced rabbit starvation when eating only ultra-lean rabbits when other food is scarce.  However, only eating any extremely lean meat when you are already extremely lean can elicit the same effects.

Wild rabbits are not a great food choice if you’re starving in a famine and wasting away.  Because protein is a poor energy source, you can’t get enough usable energy. 

Rabbit starvation can be deadly if it goes on long enough and someone does not consume adequate energy from carbohydrates or fat.

Do You Need to Be Worried about Rabbit Starvation?

Now, with the ‘bad news’ out of the way, let’s consider whether you need to be concerned about ‘rabbit starvation’ or ‘protein poisoning’.

In reality, few people in our modern world need to worry about “rabbit starvation” or protein poisoning. 

Very few people in our modern world are extraordinarily lean and at risk of starvation.  Whenever we’re hungry, we can order pizza from our couch or even make a little more effort to buy super cheap, energy-dense food from the supermarket or nearby fast food restaurants. 

As shown in the figure below, obesity rates have been on the rise since the 1960s.  Thus, most of us have plenty of energy stored on our bodies to last a long time, even if we only have ultra-lean meat to eat. 

As we’ll discuss later, a diet with a higher protein % tends to lead to greater satiety and weight loss.  But once you reach a healthy weight, you should add back some energy from fat and carbs to ensure you don’t continue to lose weight. 

Very few people are eating only ultra-lean meat.  Domestic rabbit, presumably fed on more grains and less grass, contains 63% protein (compared to wild rabbit with 82% protein). Rib eye steak, which is popular in the carnivore community, has a lower 45% protein.  But people are consuming a lot less protein than this. 

As shown in the chart below, the average protein intake in the US is about 12%.  As you can see, the protein % of our food has fallen since the 1970s, while obesity rates have risen. 

We naturally tend to gravitate to energy-dense, low-satiety, nutrient-poor foods that provide less protein. 

So, it’s likely you have a lot of room to move before you get from your current protein intake to the 80% protein associated with rabbit starvation. 

What Are the Symptoms of Rabbit Starvation?

Symptoms of protein poisoning are a combination of starvation and a toxic state similar to ketoacidosis, depending on the duration you’ve only been eating lean animal meat.  These symptoms include:

• Cravings,
• Diarrhea,
• Fatigue,
• Headaches,
• Low blood pressure,
• Slow heart rate,
• Nausea,
• Fatigue,
• Moodiness, and
• Extreme weight loss and leanness.

Many of these symptoms can be traced back to low levels of other nutrients like potassium, sodium, calcium, and essential fatty acids.

The Cronometer screenshot below for 2000 calories of wild rabbit shows that, while we get plenty of amino acids and nutrients like B3, B12, iron and zinc, you’d be missing out on many nutrients like B1, B2, folate and fat-soluble vitamins A, D, E and K

Why Is Protein Poisoning Called Rabbit Starvation?

Rabbit starvation isn’t new; it has a long history.

It was first observed in Roman soldiers sent to battle in The Wars in Spain around 150 BC.  Many died of severe diarrhea after eating nearly all of their calories from rabbit meat due to food scarcity.

These Roman warriors typically ate a diet rich in meat (fat), wine (carbs), salt, and olive oil (fat).  When rations became harder to come by, they replaced them with a LOT of spice-less rabbit meat and meagre amounts of bulgur and barley.  As a result, many began experiencing symptoms of protein poisoning and dying.

Protein poisoning also threatened explorers and pioneer settlers when food was scarce.  These people had to eat whatever was available, which didn’t always contain enough energy or ample nutrients.  Subsequently, many died or went through protein poisoning until they could get adequate energy from fat and carbs.

Arctic explorers, like Villhauer Stefansson, were also familiar with rabbit starvation.  Stefansson spent many years consuming a high-fat, almost all-animal diet while living with Eskimos while exploring the Arctic.  While all he ate were foods derived from animals, he reported consuming substantial amounts of blubber and fat alongside his protein. 

In contrast to his day-to-day high-fat meals with the Eskimos, he reported a few instances of what happened when he and his team went to explore away from the Eskimo settlement, which nearly ended in death. 

Because of the bitter cold, the only animals they could hunt had little fat.  With their high activity levels and extreme cold, the lean meat alone didn’t contain enough energy for them to thrive. 

As a result, he explained, in an excerpt from his book, My Life With the Eskimo, ‘they would eat until their stomachs were distended, but they still would not feel full.’ All seven explorers developed diarrhea within the first several days, showing signs of protein poisoning on this particular exploration.  Additionally, they became so ravenous as their bodies sent them in search of other nutrients after they ate through their 60-day supply of animal meat in just under a month.

Stefansson noted a significant difference between the meals with the Eskimos, where he felt satiated and energised, and the meals in the wild, where he could feel himself battling starvation, which was relieved with just a teacup of oil.  Essentially, this small-but-energy-dense serving of fat gave the body the energy it needed.

Stefansson explained that Native Americans going hungry and starving in a similar manner was not unlikely.  In many instances, they would be unable to find fattier animals like moose or beaver.  This condition was well-known amongst native populations—especially those living in more frigid climates where food was scarcer.

‘The expression ‘rabbit starvation,’ frequently heard among the Athapsc Indians north-west of Great Bear Lake, means not that people are starving because there are no rabbits but that they are going through the experience of starvation with plenty of rabbit meat.  For this animal is so lean that illness and death result from being confined to its flesh.’

Stefansson, My Life with the Eskimo

Why and How Does Rabbit Starvation Occur?

Simply put, rabbit starvation occurs because you’re not getting adequate energy and nutrients from only ultra-lean protein, which your body can’t easily metabolise for energy.

Humans require adequate amounts of essential amino acids, fatty acids, vitamins, and minerals from the foods they eat to keep their bodies running optimally.  High protein foods provide amino acids and some vitamins and minerals, carbs and fat supply energy, and fatty acids along with vitamins and minerals. 

When someone either chooses to or is forced to eat extremely lean meat—and only lean animal meat—for some time, they become increasingly deficient in the nutrients that lean-protein foods fail to provide. 

Most importantly, this includes core electrolytes like potassium, calcium, sodium, magnesium, and essential fatty acids.  Before long, the body becomes deficient, partially contributing to the onset of this deficiency-associated disease.

Additionally, of the three dietary macronutrients—protein, fat, and carbs—protein is the least efficient energy source.  In fact, we lose around 25-35% of the energy we consume from protein when we convert it into adenosine triphosphate (ATP).  Hence, only consuming ultra-lean protein food makes it difficult to consume adequate energy.

For more on the amount of energy we lose when we convert it into ATP, check out Oxidative Priority: The Key to Unlocking Your Body Fat Stores.

How Long Does It Take for Rabbit Starvation to Set In?

Because protein is an inefficient energy source, the body will move to break down some of its stored fat for fuel after it burns through the glucose and glycogen in your system.  This results in a state of ketosis, meaning signs of keto-adaptation (i.e., the keto flu) can occur, especially if the diet lacks adequate electrolytes like potassium, sodium and calcium.

Your body can only release a limited amount of energy per day from fat stores without sounding the body’s stress signals.  When your energy demands exceed this intake, your body will respond with stress hormones, which increase your appetite.  

Hence, mild to moderate symptoms usually come on in a few days when someone begins experiencing symptoms of keto-adaptation, or ‘the keto flu.’  If someone is not eating only ultra-lean meat, they will likely binge on other foods to get enough energy and get out of the danger zone.  If they are stuck eating all-protein with no other options, more dangerous effects of an all-protein diet may occur.

It should be noted that the less body fat someone has, the sooner they may run into these side effects.  This is because body fat—like dietary fat—would provide your body with a source of slow-burning fuel.  If you’re carrying plenty of body fat, you will be able to release more stored energy, so you’re less likely to experience adverse symptoms of a very high protein diet.

The bottom line is if your goal is weight loss, you need adequate protein and an energy deficit, but not so much that you experience severe hunger and nutrient deficiencies.  We talk more about this in our other article, Secrets of a Nutrient-Dense Protein-Sparing Modified Fast (PSMF).

Will I End Up with Rabbit Starvation on a Keto, Atkins, Low-Carb, Carnivore, or Paleo-Style Diet?

Some mainstream nutrition and dietetics experts warn of the dangers of ‘high protein’ diets.  However, these diets are not dangerous themselves. 

While it can be challenging to find rabbit meat at your local supermarket, there are some high-protein foods available, like egg whites, tuna, protein powder and turkey breast. 

To get yourself into a state of protein poisoning, you’d have to eat almost all of your calories from these foods, which isn’t going to happen for most people without a lot of effort and willpower.  Hence, these diets will not directly lead to rabbit starvation if you eat adequate energy from carbs or fats while still consuming your protein.

As we mentioned earlier, the average protein % in the US is around 12%.  For comparison, the chart below shows the distribution of protein % that we see in people using Nutrient Optimiser, with a much higher average of 30% protein. 

Even here, very few people reach ultra-high protein % levels associated with rabbit starvation.  Free-living people in the modern world don’t manage to eat 80% protein!  Even in this highly motivated group, few people get above 60% protein. 

Can You Get Protein Poisoning from Eating Rabbits?

Rabbit meat is very lean, meaning it does not contain much fat.  Meat naturally contains very little—if any—carbohydrates, albeit glycogen stored in the muscle tissue.  Fat and carbohydrates are our primary energy sources, providing the most energy per calorie.

Because of what we know about oxidative priority, protein is a very inefficient energy source; we lose about 25-35% of the energy we consume from protein when we turn it into usable energy.

If we consistently only eat rabbit meat, we are not getting adequate energy to fuel our activity, forcing our bodies to move to use our stored fat for fuel.  Additionally, it leaves our bodies with a substantial amount of metabolic by-products to process from the breakdown of all the amino acids we’re consuming.

So, getting the right balance between protein and energy aligns with your context and goals is critical.

Can a Human Survive on Rabbit Meat?

Humans can survive for a short period—like a few days to weeks—on only rabbit meat.  However, if they are limited to only consuming rabbit meat because of food scarcity for a prolonged period and cannot consume any fat or carbs with it, they will likely die after some time.  Once you run out of stored fat, your body will begin to catabolise your muscles and organs for energy.

If you’re looking to lose weight, consuming super-high-protein foods alongside lower-carb fibrous vegetables in a protein-sparing modified fast (PSMF) approach can be safe.  This weight loss approach still includes fat and carbs, although it isn’t much.  If you have a lot of weight to lose, it can be wiser to take a less aggressive, more sustainable approach over the long term.

Is Too Much Protein Bad for My Kidneys? 

One of the common concerns about protein is that it is bad for your kidneys.

One of the primary functions of your kidneys is to filter your blood. The estimated glomerular filtration rate (eGFR) is a standard test that indicates how well your kidneys work. The eGFR is based on the amount of creatine—the substance produced from the breakdown of protein found in your muscles—in your bloodstream.   

Some people become concerned when they see high eGFR levels and think the protein they’re eating is causing kidney dysfunction. However, it shouldn’t be surprising that people eating more protein often carry more muscle than average. 

People supplementing with creatine may also see higher creatinine in their bloodstream.  Creatine is found in meat and fish and is one of the most well-researched and beneficial supplements for strength, cognitive performance, and allergies. 

We don’t tend to see active bodybuilders getting kidney failure because of their high-protein diets.  Instead, it is often the other way around: high-protein diets are often a problem if the kidneys have a pre-existing condition.  

If you have late-stage kidney failure and are on dialysis, it’s worth talking to your nephrologist about how much protein they think you should consume.  But if you don’t already have a nephrologist, then it’s unlikely that ‘too much protein’ will be a concern for your kidneys.   

According to Dr Ted Naiman, people consuming more protein tend to have larger, higher-functioning kidneys. Eating more protein is akin to beneficial ‘resistance training’ for your kidneys.  Similar to how you want to avoid your muscles weakening from disuse, you don’t want your kidneys to atrophy with age.

In a 2018 meta-analysis titled Changes in Kidney Function Do Not Differ between Healthy Adults Consuming Higher – Compared with Lower – or Normal-Protein Diets: A Systematic Review and Meta-Analysis by Professor Stuart Phillips, it was found that increased protein intakes do not adversely influence kidney function in healthy adults. 

What Are the Signs of Too Much Protein?

If you think you’re consuming too much protein or are worried about protein poisoning, there are some signs and symptoms you can look for to ensure you’re getting a healthy amount.

In the case of rabbit starvation, too much protein looks like the symptoms listed above.  If you think you’re at risk for rabbit starvation, you might also ask yourself if you’re consuming more than 30 grams of carbs or (and) 30 grams of fat per day with your high-protein diet.

Aside from the symptoms already listed, other symptoms of consuming a diet that’s too heavy in protein with too little energy include ravenous hunger and thoughts about food that seem never to end.  This could indicate that you’re either not consuming adequate calories or enough energy from fat or carbs.

Additionally, someone consuming too much protein despite consuming adequate fats and carbs on an omnivorous-style diet may experience constipation and feel excessively full after meals.

Practically, though, it’s difficult to overconsume protein if you’re not also overconsuming energy. Increasing your protein % is not simply a matter of eating more of your favourite foods like butter, bacon and nuts to get more protein. Instead, you need to adjust your food and meal choices to reduce the extra energy from fat and carbs. The remaining foods tend to have high satiety and thus extremely hard to overeat.

If you’re looking for some inspiration to nudge up your protein %, you can check out our optimised food lists, tailored to a range of goals and preferences.

How Much Is Too Much Protein in a Day?

Modern guidelines define ‘excess protein’ as an intake that exceeds the AMDR for protein, which is 35% of calories on a standard 2,000-calorie diet.   

However, many people consume much more than this, with no reported health implications.  And unless someone has a pre-existing kidney or liver condition or eats an extremely high amount of protein in the absence of carbs and fat, as we mentioned earlier, a higher protein intake is unlikely to be ‘too much’.

Protein is critical for satiety.  Our bodies require a lot of protein to build new muscle, repair old tissues, detoxify, make antibodies, and synthesise biological compounds like enzymes, which catalyse all bodily reactions. 

Depending on your activity output, age, height, sex, and current health standing, your protein demand could be more or less than the person next to you.  Hence, protein need is extremely bio-individual.

• If you are active, are bigger in size or stature, or are doing resistance training, you will naturally crave more protein range to fuel your muscles.
• If you eat a lower carbohydrate or carnivore diet, your body will crave more protein to supply some glucose via gluconeogenesis to satisfy the demands of organs like your brain.
• You will require more protein to optimise your satiety and nutrient density if you want to restrict calories, lose weight on a calorie deficit, and limit the loss of lean muscle mass. 
• If you are trying to lose weight—like on a PSMF—you will be trying to consume a large percentage of your energy intake from protein so you can maintain metabolically active lean mass and force your body to dip into your fat stores.

Bodybuilders regularly consume 200, 250, and even upwards of 300 grams of protein daily without any problems.  So, while mainstream nutrition would have us believing their kidneys would fail, they usually thrive! 

Thus, “too much protein” is a bit of a misnomer.   Because protein is highly satiating, we don’t accidentally eat “too much protein”.  It’s also tough to overeat protein when limiting your energy from fat and carbs.

How Much Protein Should I Eat in a Day?

The Recommended Daily Allowance (RDA) is set at 0.8 grams of protein per kilogram per day, or 0.36 grams per pound.  But remember that the RDA is the MINIMUM amount of protein we require to avoid diseases associated with a deficiency; it is by no means optimal!

According to Eat Right, the official website of the Academy of Nutrition and Dietetics (AND), most people require anywhere between 1.2-2.0 grams of protein per kilogram per day, depending on their current state of health.  Illness, physical activity, age, and whether someone is growing all influence someone’s protein demand.

Interestingly, bodybuilders and many others recommended consuming a minimum of 2.2 grams of protein per kilogram daily.  However, many eat anywhere from 2.3 to 3.1 grams of protein per kilogram while prepping or looking to cut.  Some even go as high as 4.4 grams per kilogram (yes, that’s per kg per day).  If you have more muscle mass and are doing a lot of resistance training, your body will naturally crave more protein to grow and repair the muscles.

Protein Requirements and Your Lean Mass

Our analysis of our data from one hundred and forty thousand days of data from forty thousand people using Nutrient Optimiser has shown that our protein and energy requirements are tightly correlated with our fat-free mass (i.e., your total weight minus your body fat, which includes your muscles and organs). 

So, the more muscle you have, the more protein you will crave.  The fact that many people are sedentary, over-fat and under-muscled is potentially a key reason that many are eating less protein.  If you have plenty of muscle and are using it, you’ll crave more protein!

In the article, The Relationship Between Fat-Free Lean Mass, Energy Requirements and Macros we showed that you could estimate your protein target using the following formula):

Protein (g) = 1.54 x FFM (kg) + 29

For example, my fat-free mass is 81.6 kg (according to my bioimpedance scale), so my estimated target protein intake would be 1.54 x 77.6 kg +29 = 148 g of protein per day. 

But this isn’t set in stone.  Your requirements may vary.  The chart below shows the distribution of protein intake (g per kg fat-free mass), with an average of 2.1 g/kg FFM, with some people consuming much more protein.

Do I Need More Protein if I’m Losing Weight? 

Advice for optimal protein intake varies dramatically.  It’s easy to understand why so many people are confused by the amount of protein they should consume.  So, who is right?

Well, what we know for sure is that protein intake and calorie intake are inversely proportional.  In other words, the more protein we consume, the less energy (calories) we are likely to eat.

The chart below shows the relationship between protein %, calorie intake and protein intake (in grams) from our Optimiser data. 

• The blue line shows that as we dial back our energy from fat and carbs while prioritising protein, protein % increases, and our energy intake drops dramatically. 
• The red line shows that as we increase our protein % to lose weight, our absolute protein intake (in grams) increases. 

It’s worth pointing out that, even at 50% protein, the average protein intake is only 142 g.  This is about 50% more than the average protein intake of the average US adult (according to the National Health and Nutrition Examination Survey, 2003 – 2004).

But even if you want to lose weight, you don’t need to jump to 50% protein overnight.  In fact, we advise against it! 

If you’re currently consuming 15% protein, you may only need to dial up your protein % to 20 or 25% to achieve sustainable weight loss.  You can nudge it up later if you stop making progress. 

This process of starting from your current diet and slowly dialling in your protein, fat and carbs is precisely what we guide people through in our Macros Masterclass to achieve sustainable long-term results!  You never need to jump to the extremes associated with “rabbit starvation” while continuing to make long-term progress.   

Protein and Nutrient Density

While no one source of protein—especially lean protein—provides all the essential vitamins, minerals, essential fatty acids, and amino acids, protein is incredibly nutrient-dense.  Maximum nutrient density tends to align with a relatively high 50% protein! 

Most animal meat and seafood sources contain ample amounts of B vitamins, omega-3 fatty acids, zinc, iron, and selenium, which play a role in satiety.  In addition to keeping you full by providing amino acids, whole-food protein sources also supply you with the nutrients that elicit a similar micronutrient leverage effect.  Thus, consuming more protein has an additional benefit. 

But there comes the point where Optimisers also need to prioritise minerals and vitamins that are nutrients that are harder to find in high-protein foods.  We guide Optimisers through this process in the Micros Masterclass to ensure they avoid the nutrient deficiencies associated with rabbit starvation. 

Summary

• Rabbit starvation occurs when ultra-high protein % foods are consumed without carbs or fat for a period ranging from several days to weeks to months.  While this can occur when there are no other options, it’s rare in our modern food environment.
• The condition results from excess nitrogenous wastes from the metabolism of amino acids overwhelming the kidneys and liver and a lack of energy (i.e., carbs and fat), which causes the body to break down its own tissues.
• Rabbit starvation is more common in indigenous and explorer populations dealing with food scarcity.  It is not a condition that will happen unless you are intentionally restricting your fat and carbohydrates to extreme levels for a long time. 
• While common ‘ancestral’ ways of eating like carnivore, keto, and paleo are sometimes questioned for being ‘too high of protein’, these diets themselves will not cause problems unless you only eat lean protein and forego energy from fat and carbs on purpose.
• While many say that a high-protein diet is unsafe for the liver and kidneys, many bodybuilders, performance athletes, and even the average Joe tend to thrive on much more than the protein AMDR recommends.
• Protein is by far the most satiating macronutrient.  High-protein foods like seafood, meat, poultry, and dairy products also contain other micronutrients, which contribute to satiety.
• Rather than jumping to unsustainable high protein extremes, it’s ideal to start with your current diet and make adjustments to move toward your goals.

More

• Protein Power: Visualizing 30g in Everyday Foods
• Keto Lie #4: Protein Should Be Avoided Due to Gluconeogenesis
• Secrets of the Nutrient-Dense Protein Sparing Modified Fast (PSMF) Diet
• High Protein vs High Fat: What’s Ideal for YOU?
• Highest Satiety Index Meals and Recipes
• Protein – Optimal vs Acceptable Macronutrient Distribution Range (AMDR)
• Optimised Food Lists (Free Download)