The carnivore diet is precisely what it sounds like: a diet that focuses exclusively on animal-based foods, such as meat, fish, eggs, and occasionally dairy products.
It eliminates all plant-based foods, including fruits, vegetables, grains, and legumes (1).
Advocates claim that a carnivore diet and intermittent fasting for weight loss are possible and these methods may also reduce inflammation and even certain chronic conditions, but critics point to their restrictive nature and potential nutrient gaps (1).
Intermittent fasting is less about what you eat and more about when you eat.
It involves cycling between periods of eating and fasting, with popular methods including the 16:8 approach (16 hours of fasting followed by an 8-hour eating window) and alternate-day fasting (2).
Research suggests it can support weight management, improve metabolic health, and even promote longevity, though it’s not without its challenges (3).
Combining these two diet approaches may seem like a natural fit for those seeking to simplify their eating habits or maximize potential benefits. But is it a good idea?
Ahead, we explore the science behind both dietary strategies, weigh the potential pros and cons of combining them, and provide practical insights to help you make an informed decision.
Combining the carnivore diet with intermittent fasting is a bold dietary choice that can yield a range of outcomes. While the experience will differ from person to person, here’s a breakdown of the potential effects (both positive and negative) based on what we know about nutrition and the human body.
When it comes to weight loss, progress is made by inches, not miles, so it’s much harder to track and a lot easier to give up. The BetterMe: Health Coaching app is your personal trainer, nutritionist, and support system all in one. Start using our app to stay on track and hold yourself accountable!
Read more: Foods to Cut Out to Lose Weight In a Sustainable Way
This combination may appeal to those seeking weight loss, improved metabolic health, or a simplified eating routine. However, it’s not suitable for everyone.
It’s rather restrictive, and you can achieve many of the possible benefits by using more holistic, sustainable approaches.
Pregnant or breastfeeding individuals, those with a history of disordered eating, or anyone with specific medical conditions should consult a healthcare professional before attempting this approach or making any significant dietary changes.
It’s not uncommon to hear stories of rapid weight loss on the carnivore diet, especially in the early weeks. That said, it’s essential to understand why this happens and what the science says.
When you cut out carbohydrates, your body quickly uses up stored glycogen (a form of carbohydrate stored in the muscles and liver), and with it, water weight.
The decrease in water weight often leads to an initial drop on the scale, which may not represent fat loss (9). Over time, a high-protein, low-carb approach, especially a less restrictive one, may help curb appetite and simplify food choices, enabling some people to naturally consume fewer calories and maintain a calorie deficit —a key driver of weight loss (10).
However, weight loss is highly individual.
Factors such as starting weight, metabolism, activity level, and duration on the diet all play a role (11). Some people may experience significant changes, while others might plateau or even regain weight over time if they eat in a caloric surplus or their metabolism adapts.
One important consideration is that rapid weight loss on a restrictive diet may also increase the risk of nutrient deficiencies, fatigue, mood changes, or difficulty maintaining muscle mass (12). Long-term research on the carnivore diet is limited, so sustainable, balanced progress is usually healthier than aiming for a quick fix.
Absolutely. You can eat meat during your eating windows while practicing intermittent fasting. Many people following intermittent fasting choose nutrient-dense, protein-rich foods to help keep them satisfied during fasting periods, and meat fits that description well.
During fasting, you abstain from calories altogether (which means no food, including meat). Still, once your eating window opens, you’re free to choose the foods that align with your dietary approach.
If you’re following a carnivore diet food list, you would build your meals entirely around animal-based foods.
Here are a few considerations if you’re choosing this path:
Simply put, as long as you’re consuming meat during your eating window and maintaining overall nutritional balance, eating meat while intermittent fasting is possible—and for those on a carnivore diet, it’s the central feature.
Honestly, it depends. Combining intermittent fasting and the carnivore diet can be effective for some people, but it isn’t universally suitable. Your personal health goals, medical history, stress levels, and relationship with food all play a role.
For some, matching the structure of intermittent fasting with the simplicity of a carnivore diet can lead to greater consistency, improved satiety, and better focus on signals of true hunger and fullness. Others may find the routine restrictive, leading to increased cravings, mood swings, or social challenges, especially over the long term.
Before jumping in, ask yourself:
It’s also worth noting that both approaches can have a profound impact on hormones and metabolism, so listening to your body and adjusting as needed is key.
If you ever feel persistently fatigued, irritable, or unwell, it’s a sign to check in with a healthcare provider.
Combining the carnivore diet with intermittent fasting is a complex and ambitious approach requiring intention and self-awareness. If you’ve made this decision, here’s how to pursue a carnivore diet and intermittent fasting meal plan with both safety and success in mind.
We always advise starting with one change at a time, especially when both strategies are demanding.
Transition first to one: either begin with a carnivore diet to allow your gut and metabolism to adjust, or establish a baseline with intermittent fasting before switching to a group of foods.
The gradual approach reduces overwhelm, helps you tune in to how your body is responding, and makes it easier to pinpoint what works or what doesn’t.
Because a carnivore diet meal plan removes entire food groups, it’s critical to focus on variety within your animal-based choices.
Eating within a shortened window or with limited food variety can sometimes throw off your natural hunger signals. It’s easy to overeat “just in case” or undereat because you feel restricted. Mindfully check in with yourself during meals; are you satisfied or still hungry? Trust that these cues may shift during adaptation, and aim for balanced portions, not excessive ones.
Both diets can lead to increased fluid and electrolyte loss. Classic symptoms—such as headaches, muscle cramps, or fatigue—can often be attributed to dehydration or inadequate intake of sodium, potassium, or magnesium (17).
Make hydration a conscious habit. You might benefit from adding a pinch of salt to your water, drinking homemade bone broth, or using a well-balanced electrolyte supplement, especially if you’re highly active or sweating frequently.
Dietary changes can affect physical and mental energy, sleep quality, mood, digestion, and even athletic performance.
Pay special attention to persistent fatigue, dizziness, digestive distress (including constipation or diarrhea), or irregular menstruation—these are signs that you may need to slow down and reassess your approach, or seek professional support.
With both time and food choices limited, proactive carnivore intermittent fasting meal planning is your friend. Prepare simple, satisfying meals in advance.
Think:
Cooking in batches and organizing meal times can help you avoid decision fatigue and ensure you’re eating enough to support your needs.
These combined dietary choices can feel isolating in social or family situations where food is a central focus. Anticipate these hurdles and plan ahead by bringing your own food, communicating with hosts, or having a prepared response for curious friends or family.
Stay focused on your reasons for adopting this approach, and don’t hesitate to seek a support system, whether online or in person.
Regular self-reflection is key. Are you feeling better? Meeting your goals? If progress stalls, mental health suffers, or enjoyment wanes, give yourself permission to adapt or adjust. Sometimes, personalized tweaks, such as a slightly longer eating window or broader protein choices, are all it takes to restore balance.
Perhaps most importantly, consult a registered dietitian or trusted healthcare provider before embarking on or continuing this path, especially if you have underlying health conditions, take medications, or notice persistent symptoms. Individual needs can vary widely, and professional guidance can help keep you safe and empowered throughout your wellness journey.
Read more: How Long Does It Take To Lose 15 Pounds? What Science & Experts Say
Choosing to follow a carnivore fasting diet plan simultaneously is a significant lifestyle decision, and it’s essential to be fully aware of the possible challenges and drawbacks that could arise.
Let’s take a clear-eyed look at the concerns you might encounter, both from a nutrition science perspective and a whole-person wellness standpoint.
Fasting on carnivore diets involves excluding a wide range of nutrient-dense plant foods, such as fruits, vegetables, legumes, and whole grains, while further restricting your overall food intake.
These eating rules can also limit your intake of vitamins, minerals, and other nutrients over time.
The BetterMe: Health Coaching app will provide you with a host of fat-frying fitness routines that’ll scare the extra pounds away and turn your body into a masterpiece! Get your life moving in the right direction with BetterMe!
Nutrients most at risk on a carnivore fasting diet include vitamin C, fiber, folate, and various phytonutrients found only in plant-based foods. Over time, these gaps may affect immune health, digestion, and energy levels (18).
A shift to all-animal foods (especially when you have limited eating windows) can change your digestive rhythm. Many people who take this combination report constipation, bloating, or even diarrhea, particularly in the transition phase.
The lack of dietary fiber (which comes from plants) may further contribute to irregularity and long-term gut health issues (19). If you already have a sensitive digestive system, these effects can be more pronounced by an all-meat diet.
Restricting both food variety and eating windows can lead to significant fluctuations in energy levels, particularly during the adaptation phase.
Some people report feeling tired, irritable, or foggy-headed, sometimes referred to as the “keto flu,” as their bodies switch to burning fat for fuel (20). For others, periods of fasting may trigger episodes of low mood, difficulty concentrating, or even increased anxiety, as blood sugar levels drop (21).
Combining two highly restrictive eating styles can pose social hurdles.
Shared meals, celebrations, and spontaneous dining out can become stressful or isolating when your food choices are so limited and time-bound.
This isolation can impact your relationship with food and others, potentially leading to disordered eating patterns or feelings of frustration (22).
While some metabolic adaptation occurs with any new diet, the extreme calorie restriction that can occur with both carnivore eating and fasting may slow your metabolism over time. The metabolism slowdown makes it harder to sustain weight loss and easier to regain weight if you return to previous eating habits (23).
Especially for women, a combination of high dietary restriction and intermittent fasting can disrupt hormonal balance. This hormonal disruption may affect menstrual cycles, fertility, and even thyroid function (24, 25). Those with a history of hormone-related issues or eating disorders should proceed with extra caution and consult with a healthcare provider. Those who are pregnant, trying to conceive, or lactating should not fast or follow restrictive diets.
Lastly, it’s worth considering whether this approach is sustainable for you in the long run. Highly restrictive diets tend to be challenging to maintain, which can lead to cycles of strict adherence followed by periods of relapse or binge eating. The “all or nothing” mindset may take a toll on your overall relationship with food.
Purists of the carnivore diet aim to consume only animal-based foods, excluding all plant-derived foods and drinks, including coffee. For them, coffee deviates from the diet’s foundational rules. While coffee isn’t animal-based, many people include it as a personal preference. For those combining intermittent fasting with the carnivore diet, black coffee is often allowed during fasting windows because it’s calorie-free. Feeling unwell, often called the “keto flu,” is common during the initial transition. The sick feelings occur as your body adapts to burning fat for fuel instead of carbohydrates (20). Symptoms such as fatigue, headaches, and irritability are usually temporary and can often be alleviated by staying hydrated, replenishing electrolytes, and consuming a sufficient amount of calories. If your symptoms persist or interfere with your daily life, consider stopping the diet and talk to your healthcare provider about more sustainable options. The duration depends on your goals and how your body responds to the diet. Some people use it as a short-term reset for a few weeks, while others adopt it as a long-term lifestyle. Regularly assess your health and consult a healthcare professional to ensure your dietary choices remain safe and sustainable. Weight loss on the carnivore diet can be rapid initially due to water weight loss from reduced carbohydrate intake (26). Long-term weight loss depends on factors like calorie intake, activity level, and individual metabolism. While some find it effective, it’s not a guaranteed or universal outcome (27).Frequently Asked Questions
Can I drink coffee on a carnivore diet?
Why do I feel so bad on the carnivore diet?
How long should you stay on the carnivore diet?
Do you lose weight faster on carnivore diets?
If you’re contemplating combining the carnivore diet with intermittent fasting, please weigh the potential negatives as carefully as the possible benefits.
Everyone is unique, and what works well for one person may not be appropriate or sustainable for another. Checking in regularly with a qualified nutrition professional or healthcare provider can help identify issues early and adapt your plan to protect your long-term health.
This article is intended for general informational purposes only and does not serve to address individual circumstances. It is not a substitute for professional advice or help and should not be relied on for making any kind of decision-making. Any action taken as a direct or indirect result of the information in this article is entirely at your own risk and is your sole responsibility.
BetterMe, its content staff, and its medical advisors accept no responsibility for inaccuracies, errors, misstatements, inconsistencies, or omissions and specifically disclaim any liability, loss or risk, personal, professional or otherwise, which may be incurred as a consequence, directly or indirectly, of the use and/or application of any content.
You should always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition or your specific situation. Never disregard professional medical advice or delay seeking it because of BetterMe content. If you suspect or think you may have a medical emergency, call your doctor.