No change in eating plan comes without its side effects. This is also true when transitioning to a carnivore or more animal protein-based diet. The human body does extremely well on an animal-based diet and any negative side effects are only temporary.

Common Side Effects & Adaptations

Carnivore or an animal foods-based diet is often a huge leap from the existing diet and that means the body will need some time to adapt to digestive, hormonal and nutritional changes.

The main adaption your body will need to adjust to is the zero-carbohydrate aspect of the carnivore diet. Even a Ketogenic diet has some carbohydrates and going from some to zero can take just as much adjusting as going from high carb to low carb.

For some. the most common problems like headaches and flu like symptoms during the adaption phase, are simply resolved by increasing water and salt intake to replace what the body is losing. As insulin levels go down, so do electrolyte levels which can wreak havoc on your fluid levels.

Headaches, Nausea, Irritability, Lack Of Focus

Even if you are transitioning from a low carbohydrate ketogenic diet you will more than likely experience an adaption phase. During adaption you may experience some adverse symptoms and side effects due to your body’s natural response to carbohydrate restriction and the removal of excess additives and chemicals.

Some of these adaption phase symptoms include:

·       Brain fog

·       Headache

·       Chills

·       Muscle soreness

·       Sore throat

·       Digestive issues

·       Dizziness

·       Irritability

·       Bad breath/smells

·       Bad taste in mouth

·       Dry mouth

·       Cravings

·       Nausea

·       Diarrhea

·       Poor focus

·       Decreased physical performance

·       Cramping

·       Rapid heart rate

·       Insomnia

·       Night sweats

These symptoms are a result of your body undergoing major metabolic and hormonal changes.

When you drop from a many or simply a few carbohydrates in your diet to zero carb carnivore diet, your insulin levels will drop. Insulin helps your body retain sodium. Less insulin causes a drop in sodium. Water follows sodium so you'll likely see a significant loss of water weight in just a few days.

As your muscle glycogen levels begin to drop due to lack of carbohydrate intake, your body will need to re-learn how to use fat as a source of energy. This "switch" takes time and during that time you feel low energy, get intense cravings and feel irritable. Depending on how metabolically flexible you are will depend on how much you suffer.

As if that wasn't enough, you may also experience gastrointestinal issues like diarrhea while your pancreas and gallbladder respond to the extra fat intake.

Finally, as your body re-balances fluids, minerals and energy sources, your hormones will take a hit. In particular, T3 and cortisol. T3 is a thyroid hormone that relies on carbohydrate intake to regulate your metabolism and Cortisol is a stress hormone.

Action Steps

It is possible to reduce or even eliminate most of the symptoms of adapting to the carnivore diet using a few simple tricks:

Eat more - a carnivore diet is naturally high protein and high fat which means you'll feel full for a very long time. Unfortunately, this might mean your daily calorie intake is much lower. Work out how many calories you need to survive and then factor that in when deciding on food quantities.

Drink more - it's normal to lose a lot of fluids, especially in the first few days, but these fluids will need to be replaced if you don't want to suffer the symptoms.

Electrolytes - if more food and water don't help, you may need more electrolytes. To start with, try adding some extra salt into your diet but if you need to, consider an electrolyte supplement.

Sweat more - sweating is a great way to get rid of excess toxins and naturally re balance your electrolyte levels.

Leg Cramps

Leg cramps are a common complaint amongst those new to a carnivore-type diet.  They do usually subside with time.

Muscle cramps are cause by a mineral imbalance, specifically magnesium. Although it's also not uncommon to get leg cramps because of low sodium or potassium intake.

With that said, there are a few things you can do to prevent or eliminate leg cramps on your carnivore diet altogether.

Action Steps

The cure for leg cramps on the carnivore diet is to balance out your sodium, potassium and magnesium levels. You can do that in the following ways:

Increase sodium - perhaps the simplest way of balancing your mineral levels is by adding more salt to your diet to prevent loss of minerals. When sodium levels decrease, potassium and magnesium levels usually follow.

Supplement - in some instances, where more sodium doesn't help, supplementing with magnesium can alleviate symptoms

Slow down – if nothing else seems to be working, you may simply need a little more time to adapt. While it may be possible to push through, it is also OK to add in some safer carbohydrates and then reduce them slowly over time to give your body time to adapt.

Diarrhea

If you have diarrhea, feel uncomfortable on the toilet or get urgent signals from your digestive system, your gastrointestinal tract may be going through some changes.

Diarrhea can occur when food passes through your digestive tract too quickly. If your previous diet contained a high percentage of plant foods, transit times were probably slower to allow time for your body to deal with the excess fiber and draw nutrients from the food. When you transition to a zero-fiber diet, transit time can be disrupted and diarrhea occurs.

Action Steps

The cure for diarrhea on the carnivore diet is to:

Allow time for your body to adapt to a zero fiber diet - at first, food will pass through the large intestine too quickly for the large intestine to pull water from the food.

Reduce consumption of rendered fats - rendered fats are usually liquid fats like cream and tallow. These types of fats can pass through your system too quickly.

Bad Breath

When you switch from a high carb diet and using glucose as your main source of fuel, to a low carb diet, using ketones as a source of energy, one of the side effects is bad breath. Sometimes referred to as "keto breath".

The change in the smell of your breath comes from a compound called acetone. Acetone is created from the breakdown of acetoacetate, a ketone body and is the simplest and most volatile of the 3 main ketones. During ketosis, acetone diffuses into the lungs and exits the body when you exhale.

Action Steps

This side effect does not effect everyone, but for those for whom it becomes an issue, it usually goes away on its own in time. While you do have it, there are several things you can do to reduce halitosis while on the carnivore diet.

Wait - if it isn't that bad it's OK to sit it out and wait until it goes on its own.

Drink more - Ketones can also leave the body when you urinate so drinking more fluids can often get rid of excess ketones in the urine.

Stay fresh - keep your mouth, teeth, tongue and gums clean so that the air you exhale doesn't mix with any other bad smells.

Heart Palpitations

Heart palpitations, pounding heart and heart flutters are a common side effect of the carnivore diet but in most cases, these are temporary and are nothing to worry about.

When you first embrace a carnivore diet, it is often common to notice your heart rate becoming elevated or your stroke volume increasing. This is usually due to a lower blood volume which may be due to dehydration combined with a lack of electrolytes. The heart is then forced to work harder to maintain your blood pressure, which is why you might feel those pounding heart beats.

Action Steps

The simplest solution is drinking enough water and ensuring that you maintain the salt that your body needs can help to combat those heart palpitations. Other solutions include:

Supplement with magnesium - up to 400mg per day is the recommended daily allowance and safe for most people.

Get your salt intake on point - too much or too little can cause heart palpitations. It's certainly more likely that you are having too little instead of too much.

Add in some safe carbohydrates - if your heart palpitations don't go away after a few weeks, you may need to add in more carbs to increase blood volume.

Decreased Physical Performance

The Carnivore Diet is popular for increasing physical and athletic performance. Athletes use high levels of protein to prime their performance and reduce their recovery times. Being in ketosis offers better athletic performance; however, some people report diminished performance initially whilst the body becomes fat adapted. 

Until your body improves its ability to use ketones as a source of fuel, you may feel weak because your body is working hard to learn how to use a new fuel source.

Action Steps

Reduced physical performance is most often a phase that you go through until your body learns how to burn fat and ketones as a primary fuel source. There are, however, a few steps you can to stay on top of your game:

Ensure that you drink more water to keep your blood volume up.

Eat every 3-4 hours on days you're physically active.

Drink bone broth and electrolyte drinks to help you manage fluid balance.

Elevated Cholesterol

An animal foods-based diet is, by default, high in fat, sodium and cholesterol. Perhaps one of the most significant worries of the diet is the elevation of your cholesterol levels. The increase in saturated fat does in fact raise your cholesterol levels over time. However, cholesterol is not the evil death sentence it has been made out to be in the media. New research shows that low carb and higher fat diets can lead to an improved lipid profile.

Action Steps

First and foremost, get your cholesterol levels checked before you start any new diet so you have a baseline to work from. If you get a concerning lipid profile on a carnivore diet there are a few things you can do:

Reduce liquid fat intake. This can often improve your lipid profile on its own.

Consider fasting for at least 12 hours per day. There's good evidence to suggest that this will reduce overall cholesterol levels.

Consult with your doctor. Most doctors, especially younger, more open-minded ones, are willing to talk to you about your carnivore way of life and offer suggestions.