Expect adaptation symptoms: brain fog, headache, cramping, sugar cravings, digestive trouble and poor sleep. They come as insulin drops, water and sodium leave the body, and fuel switches from sugar to fat. Eating more meat, staying hydrated and replacing electrolytes get you through it.
The carnivore diet – also known as the all-meat diet or the carnivorous diet – means eating almost nothing but meat for every meal, every day. That means a lot of protein, a lot of fat, and almost zero carbs. This drastic change in eating is bound to leave your body reeling. What are the unpleasant symptoms? How can you manage them? In this article, we’ll walk you through what to expect. We’ll also share the tips and tricks that will get you through them.
- The Carnivore Diet – What are the symptoms? Are there any cures?
You may have significant symptoms while getting adapted to The Carnivore Diet. Often, nearly always, when you start a Carnivore Diet, you will have unpleasant symptoms and side effects. These symptoms are your body’s natural response to limiting carbohydrates and removing addictive agents and chemicals. Common symptoms include:
- Brain fog
- Headache
- Chills
- Sore throat
- Digestive issues
- Dizziness
- Irritability
- Bad breath/smells
- Bad taste in the mouth (metallic)
- Dry mouth
- Cravings (sugar!)
- Muscle soreness
- Jaw soreness
- Nausea
- Diarrhea
- Poor focus, and decreased performance, energy, and drive
- Cramping
- Rapid heart rate
- Insomnia
- Night sweats
- Nocturia (peeing a lot at night)
- Feeling hot or cold
Are you coming from a ketogenic (keto) or high fat/low carb diet (HFLC)? Then the change is generally easier (but there are still symptoms you need to be aware of!) than for someone coming from a high-carb Standard American Diet. These symptoms happen because your body is going through significant metabolic and hormonal changes.
- What are the 3 major adaptations?
If you decide to start the Carnivore Diet, your body is going to go through 3 major adaptations.
- Fluid Rebalancing: Because you are eating fewer carbs, your insulin levels drop. This signals the kidneys to release sodium from the body. Water follows sodium out of the body. So losing 10 lbs of water in a couple of days is not uncommon.
Glycogen is then turned into glucose as the last energy source before the body switches to mainly fatty acids.
- Transitioning from Sugar to Fat for Energy
Your body will start switching from burning mainly sugar to burning fat for energy. Your symptoms might be milder or more severe, depending on your metabolic flexibility. Metabolic flexibility is your body’s ability to adapt to different fuel sources. It depends on a number of factors, including genetics and especially how you ate before. If you are used to eating a lot of high-carb foods, it can feel a lot like going into withdrawal.
- Hormone Response and Rebalancing
Some hormones in your body will respond to the diet by rebalancing. Let’s look at thyroid and cortisol hormones.
- Thyroid Hormone
- Cortisol
T3 thyroid hormone levels may decrease. T3 is a hormone made by the thyroid that is closely tied to the carbohydrates you eat. It plays a major role in controlling body temperature, metabolism, and heart rate.
- Are there any cures for the Carnivore Adaptation Symptoms?
Fortunately for you, yes! You can greatly lessen, and perhaps even end, most of the suffering in the “Trough”. You do it by using some tricks to help bridge your body to the adapted state of bliss. Here are some tricks:
- Eat more meat.
Under-eating is the number one reason people suffer for no reason. Early on, it’s common to feel extremely hungry. While your body is getting used to the diet, eat, eat, and eat again. Don’t try to restrict calories or track macros. Don’t worry about gaining fat.
- Hydrate
Make sure you are drinking water. Do not overdo it, because that will make things worse. But you need to stay hydrated. After adaptation, you drink to thirst (no need to measure or track). But if you are feeling like crap during adaptation – make sure you are hydrating.
- Electrolytes
Replace your electrolytes. As you lose a lot of extra water, you also lose a lot of electrolytes: sodium, potassium, magnesium, chloride. Salting your meat generously is the first step. For some people, this may be enough. Other people need some help in the potassium and magnesium department as well though… These tricks can help you replace them:
- Drink Meaty Bone Broth– Besides water and sodium, this gives you some potassium. That will offset some of the discomfort at the cellular level.
- The bones need some meat on them, because that’s where the potassium is.
- Supplement–
- Potassium K+: 500 – 3500 mg/day (start with 1g – K+ chloride)
- Magnesium Mg: 250-500 mg/day (magnesium citrate)
- Sodium Na: 2-7g/day (5g is a good starting point – I like this brand)
- Solving GI Problems
Gastrointestinal (GI) issues are extremely common, especially if you are coming from a low-fat diet. Your gallbladder and pancreas might not be ready for the extra fat, even if you are. When first starting, you may not have enough bile and lipase to digest the extra fat. This leads to diarrhea and all kinds of GI distress. To help manage this, you can eat less fat by choosing leaner cuts of meat. A better solution, though, is to supplement for 2-4 weeks. You could take some lipase supplements a few minutes before meals. You can start with one tablet. If you still have some discomfort, go to 2. For most people, lipase alone does the trick. However, if it doesn’t work for you, you can take some exogenous bile (bile from a supplement) with meals. If you still have GI issues, especially GERD/acid reflux, take a Betaine HCl supplement. Many people make too little stomach acid for digestion and proper metabolic signaling. This is what results in GERD, heartburn and acid reflux. Don’t take this supplement with anti-inflammatories, because it could result in ulcers. It should already include pepsin, but check to make sure. Common dosage range between 3-5g/meal. Important note: Supplements are a bridging strategy and are not designed for long-term use. The goal is to be off all of them after the first month. They are meant to let your body catch up. It might also be important to drop rendered fats, because they could make the problem worse. It is normal to have less frequent bowel movements. Your body absorbs and uses meat very efficiently, and not a lot goes to waste.
- Sleep
Insomnia is common during adaptation. Since you are purging water, nocturia is also an interrupter. A few hacks that help: Keep your room pitch black (blackout curtains, cover LEDs) and COOL. Start winding down 2 hours before bed (no screens, or at least put them in night mode)
- Don’t eat within a few hours of sleep if you can help it
- Be conscious of how much you are drinking later in the day
- Be asleep before 11 (a cortisol spike happens if you are not asleep around this time)
- Sweat
Sweating is a natural detox mechanism. You are finally giving your body the nutrition it has been craving. So you give it the chance to expel toxins. Give your body a hand and help it detox by getting some exercise and sweating.
- Killing cravings and addictions–“Brain Changes”
Besides the metabolic and hormonal changes above, you may also have what I call “Brain Changes” that occur along the “brain-body highway”. This highway is a signaling control system between the gut and the brain. It affects everything from hormones to neurotransmitters like dopamine, serotonin, and GABA. These play huge roles in mood, cravings, and addiction. Much like many drug addictions, you may go through withdrawal from foods or other substances (especially sugar) that you have become physically and neurologically addicted to. Cravings are common. The best solution is to make sure you are eating enough fatty meat. The top mistakes are not eating enough meat and eating meat that is too lean.
- Are you now ready to start?
Most people have adaptation symptoms. They can range from annoying to a certainty that you are going to die. I’ll be the first to admit they aren’t all that pleasant. But with the information above to help identify and deal with them, your first attempt should be much easier. Yes, your bowel movements will change, and you will have some early fatigue and brain fog. But in my opinion, the benefits certainly outweigh these temporary symptoms. That is especially true if your goal is to lose weight fast. Be committed, don’t let them stop you, and give it a try.
Frequently asked questions
What happens when you first start a carnivore diet?
Your body goes through three adaptations. First, fluid rebalancing: insulin drops, your kidneys release sodium, and water follows it out. So losing 10 pounds of water in a couple of days is not uncommon. Second, you switch from burning mainly sugar to burning fat. Third, hormones rebalance, and T3 thyroid hormone may decrease.
What should you eat the first week of a carnivore diet?
Eat more meat. Under-eating is the number one reason people suffer. So eat whenever you are hungry, and do not restrict calories or track macros. Choose fatty meat to kill sugar cravings, salt it generously, and drink meaty bone broth for potassium. If the extra fat causes diarrhea, a lipase supplement before meals for the first few weeks helps. Or you can choose leaner cuts for a while.
Has anyone gotten sick from a carnivore diet?
Nearly everyone feels unwell at first. Brain fog, headache, chills, dizziness, digestive trouble, cramping, sugar cravings, a racing heart and insomnia are common. They are the body’s response to cutting carbohydrates and removing addictive foods. They are not a sign the diet is failing. People coming from keto usually have an easier change than people coming from a high-carb Standard American Diet.
Related reading
- How to Start the Carnivore Diet
- How Effective Is the Carnivore Diet for Obesity?
- From Keto to Carnivore: How to Switch
- Why Addiction Treatment Fails: 95.5 R&B Interview
- Is the carnivore diet a passing fad?
References
- Meat Health (2018): The Carnivore Diet – Symptoms and Cures. Retrieved from https://meat.health/knowledge-base/carnivore-diet-symptoms-and-cures/
- Mike Fishbein (2019): The Carnivore Diet: How to Survive the First Month. Retrieved from https://mfishbein.com/carnivore-diet/
- Carnivore Style (2018): Carnivore Diet Side Effects What Are the Symptoms, Risks & Dangers? Retrieved from https://carnivorestyle.com/carnivore-diet/side-effects/
Medically reviewed by Dr. Gurpreet Singh Padda, MD, MBA, MHP
Interventional pain physician, addiction medicine specialist and obesity medicine diplomate.
Licensed in Missouri and Illinois.
Last reviewed June 18, 2026
