The ketogenic diet or the keto diet is a popular low-carb and high-fat diet. The ketogenic diet is a type of short-term diet. Although followers and some researchers of this diet claim that it has health benefits, research and evidence mostly coin it as a diet deficient in carbs and for regulating body weight. However, there is no actual benefit to your gut microbiome, as many studies specializing in gut health suggest. The theory behind this diet, the insulin carbohydrate hypothesis, suggests that people start to burn calories more quickly and burn off more fat. The ketogenic diet consists of 70% fat, moderate protein, and low carbs. It is only a meager 5 to 10%, depending on the person’s tolerance. It’s not a strict ratio because it may vary from person to person. We all have different carbohydrate tolerance, and our insulin resistance also varies. This means that a person on the keto diet may eat more carbs than another person who is on the same diet but may still successfully process through ‘nutritional ketosis.’
Where did the Keto Diet originate?
While the term “ketogenic” wasn’t used till the twentieth century, there’s a historical precedent for fasting to treat disease. Ancient Greek physicians advocated restricting one’s food intake to treat ailments like epilepsy and other health issues. Fasting also played a massive part in ensuring a healthy lifestyle.
Here is the history behind the ketogenic diet. It was a form of eating strategy that originated as a treatment for epilepsy. The research story originated in France in 1911 and studied fasting and its role in epilepsy. An analysis found that epilepsy patients who restricted calorie consumption and opted for dividing the eating period by periods of fasting experienced fewer seizures and had fewer adverse effects resulting from epilepsy. However, even though researchers had solid proof that fasting could control seizures, the obvious complications were over the fact that fasting and its effects on epilepsy are temporary at best. Numerous patients found that their seizures returned once they turned back to their regular diet. The ketogenic diet is a method of mimicking the metabolism that fasting produces.
The ‘classic keto’ approach has a simple rule where people limit their carbohydrate intake so that their bodies burn fats instead of glucose and carbs. Shifting the dietary ratio in favor of fats helps eliminate sugar from the bloodstream and triggers the human body to enter a state where ‘ketone bodies’ are produced. The ketogenic diet originates from the idea that limiting your carbohydrate intake and instead consuming fats will put your body in a ‘fasted state’ where it will burn ketones instead of glucose, resulting in better health and improved weight loss.
Such low-carb and high-fat diets and methods of eating have captivated popular culture, and more people than ever are wondering whether it will make a difference in their health. This eating plan has skyrocketed in popularity in recent years, partly due to its being embraced by several actors, reality TV stars, and sports stars. Ketogenic diets have won praise and received worldwide attention as a holy grail weight loss method by celebs like Jenna Jameson, and Halle Berry alongside many slimmed-down Instagram influencers. While all this sounds pretty great, keto is not exactly the golden ticket to eternal youth or weight loss. In particular, keto remains a bit controversial when it comes to slimming down.
Historically Acceptable Foods for the Ketogenic Diet
The following dietary recommendations are universally and historically accepted as a proper ketogenic diet.
- Non-starchy vegetables – Leafy greens, cabbage, broccoli, cauliflower, peppers, onions, spinach, collard greens, lettuce, arugula, escarole, frisee, bok choy, mustard greens, kale, and swiss chard.
- Herbs – Oregano, rosemary, thyme, sage, mint, parsley, cilantro, basil, lemongrass, and dill.
- Full fat dairy – Yogurt, milk, and cheese which is lower in carbs such as (brie, blue cheese, cheddar, Colby Jack, feta, cream cheese, goat cheese, Havarti, Limburger, chevre, halloumi, parmesan, pepper Jack, provolone, Romano, string cheese, Swiss cheese, mascarpone, mozzarella).
- Protein – Beef, poultry, fish, soybeans, pork, eggs, shellfish.
- Nuts and seeds – Pistachios, walnuts, sunflower seeds, pumpkin seeds, almonds.
- Fats – Both animal and plant-based.
- Fruits (in moderation) – Berries, avocado, rhubarb, and coconut in initial iterations of the ketogenic diet.
- Oils – Olive oil, butter, ghee.
- Beverages – Unsweetened coffee and tea, unsweetened sparkling water, etc.
List of Foods to Avoid on a Keto Diet
- Food grains – Oatmeal, wheat grains, whole wheat flour, rice, rye, barley, corn, quinoa.
- Fruits – Apples, grapes, bananas, dates, mangoes, peaches, pears, pineapple, and raisins.
- Vegetables – Potatoes (contains a lot of starch and carbs), sweet potatoes (high on glucose, starch, and carbs), baked potatoes, corn, peas, carrot, and yam.
- Legumes and beans – Black beans, baked beans, green beans, lima beans, lentils, lobia, kidney beans, green peas.
- Beverages – Cola, soda, margarita, fruit beer, vitamin water, iced tea, Frappuccino, lemonade, energy drinks.
- Low-fat dairy products – Low-fat milkshake, toned milk, condensed milk, low-fat cream, low-fat butter.
For how long should you continue the keto diet?
Our human bodies deal with nutrition, the environment, and diet in varied ways. Therefore, what may be good for one person can be different for another, especially when running on different fuel sources. If you want your body to shift to ketosis and start experiencing its benefits, you have to allow your body an adjustment period of a few weeks.
On average, it only takes 28 days to see the changes and experience a huge transformation in the gut microbiome and overall. However, you should only begin to follow it if you can maintain it as a lifestyle change.
The first two to six weeks are virtually the ketogenic adaptation phase. This is the first stage where our body is going through the process of adaptation of switching to relying primarily on fat and not on glucose or carbohydrates. After the first stage, you should follow the ketogenic diet for at least three months or a little more to achieve better results.
Mark Sisson from THE DAILY APPLE says that you’ll experience a few main indicators to make sure that you have gone into ketosis: –
- High energy levels – you will feel more energetic because your body now has a super fuel without carbohydrates.
- Keto breath – you might notice a change in your breath like a hint of metal also known as sweet rotten apple breath. It’s subtle; if it bothers you, drink plenty of water to flush out any odors.
Studies also advise starting small, you can start with one portion of a day of 15 to 25 gms of high-fiber carbohydrates. Eat it either before or after exercise because that is when the body will most efficiently use that carbohydrate as fuel for your workout or replenish what your body burned during the workout. The advertisements for this diet recommend following this pattern daily for five to ten days. Then, add the second portion to the opposite end of your workout. This way you’ll consume a small number of carbohydrates before and after your workout. Then slightly add to the pre-and post-workout a little more and slowly move forward. Once you get comfortable with all these, you can branch out, adding a little more to another meal of the day, and continue the process.
How does the ketogenic diet affect the gut microbiome?
Many researchers right out the gate does not like the ketogenic diet as far as the gut microbiome is concerned because it triggers a limitation of bacterial diversity in the gut which they assume is a bad thing. When you first begin a keto diet, you have a limit in gut bacteria diversity because you are not feeding yourself a bunch of starches or fibers which normally would feed the good gut bacteria. This may cause dysbiosis and lead to chronic inflammation. After weeks of following this diet, those numbers start to come back up. After six months sometimes even less, you have stabilized gut bacteria that are back to normal despite being on a ketogenic diet. It just takes time for the bacteria to evolve and possibly learn how to eat fat instead of starches. We know that keto is generally associated with two kinds of bacteria. These bacteria are muciniphila and parabacteroides, the two primary bacteria in the ketogenic diet.
A keto diet is a low-carb diet which means it is a very low-fiber diet therefore very low in prebiotic fibers that the bacteria in the gut microbiome need to survive and thrive. Therefore, a strict keto diet may disrupt your gut health and fail to properly nourish the gut microbiome.
Effects of a High-Fat Diet on Gut Health
High-fat diet links to ‘unfavorable’ changes in the communities of good bacteria in the gut, with negative effects on health. To understand this, we need to talk about the varieties of fats and how they are perceived in terms of nutrition and health. There are so many discussions about fat in the world of nutrition. It is mostly about the harms of saturated fat in particular. They are labeled as being ‘bad’ but, again this is relative. Everyone agrees that trans fat is unhealthy because they are a type of unnatural, man-made fat. However, research and the science of nutrition have created a disagreement over the effects and process of saturated fats. They claim that the things we have been often warned to avoid, like butter and beef are actually a healthy part of diets. However, that is only so if they are unprocessed and grass-fed. When on a keto diet, people are generally not discouraged from eating saturated fat in the form of grass-fed meat, grass-fed butter, healthy oils like coconut oil, olive oil, salmon and other Omega-3 fatty fishes, eggs, nuts, seeds, full-fat dairy, ghee, etc. Whereas, many of these items are discouraged on a standard high-carbohydrate and low-fat diet.
The AHA and some researchers claim that saturated fat causes heart disease. But it has come to light with recent research that we can not conclude this fact, as it is more likely that inflammation causes heart disease rather than saturated fats. Specifically, if those fats are from whole foods, and are nutritious dietary fats. So, if you’re going to include more fats in your diet, the only option is to lower the protein or carbs, regardless of keto or any other diet.
A high-fat diet increases biomarkers of inflammation.
Effects of Low Carbs on Gut Health
Carbohydrate is one of the most important nutrients you can eat for health and weight gain. It is the starchy carbs that are calorie dense that cause weight gain. The good carbs or the ‘slow carbs’ don’t spike your blood sugars like fruits, nuts, and vegetables do. This is because these carbs have a very low glycemic index and do not spike insulin and blood sugar. These are important for our guts because they contain amazing molecules called phytochemicals.
High glycemic carbs are bad, like pasta, bread, potatoes, rice, and processed foods. Another good carb is known as the resistance carbs which feed the good gut bacteria in your large intestines. It is a type of starch that does not spike your blood sugar but improves insulin sensitivity. It can even affect diabetes beneficially and acts as a prebiotic to help fertilize all the good bacteria in your gut. Low carb diet is good for weight loss, metabolism, cholesterol levels, etc.
However, discontinue if you feel tired, irritable, unnaturally sleepy, foggy, or insomniac. Research evidence showed in a particular study that in a very low-carb diet, the participants in the group saw the most weight loss and had a measurable shift in their intestinal bacteria.
Effect of High Protein on your Gut Health:
Protein is an essential building block for our health. It makes up your cells, allows your body to carry out essential functions, and the human body simply cannot survive without protein. Proteins make up around 20% of your entire body. Scientists have also found that a high-protein diet ends up reducing your appetite. Of all the nutrients you consume daily, protein is the only one that makes you feel the fullest because protein reduces the amount of a hormone called ghrelin in your body. Ghrelin is one of the molecules that tells your brain you are hungry. Therefore, the less ghrelin in your system, the less you feel hungry.
Protein also boosts the level of peptide YY, which signals the body that it is full. With the reduction of ghrelin and the increase of peptide YY, the body feels nutritionally satisfied for a long time. Thereby reducing the urge to overeat, which can help you lose weight and stay healthier. Interestingly, protein contains a much higher thermic effect than most other types of molecules like carbohydrates or fats. Studies have shown that by eating high-protein foods, your thermic rate can increase by 5 to 15 percent more than consuming food with little or no protein. This means that your body has to work twice harder to break down protein than other molecules. This causes you to use more energy during digestion while simultaneously increasing your metabolism. All these factors combined can cause your body to burn 80 to 100 more calories a day just from eating.
One side effect of a high-protein diet is that it can damage your bones. But is there any truth to this? The myth probably originated from the idea that protein can increase the body’s acidity level slightly, which in theory could cause calcium to lose from your bones. High proteins have several immediate and short-term benefits for the body. It also helps build muscle mass, improve performance, promote growth, and give low-carb fans the lean body they seek.
Benefits of the Keto Diet
- Good for diabetic patients
In the 19th century long before we discovered insulin, there was a need for a low-carb diet for diabetic patients. Of course, the keto diet did just that. In 1920 keto diet was introduced to epileptic patients in whom antiepileptic medications were ineffective. The keto diet has the potential to reduce blood glucose levels. It is because a low carbohydrate diet does not endanger diabetic patients as it means less glucose. Therefore, it is highly recommended for people with type 2 diabetes reduce their carbohydrate intake.
- Manage the symptoms of PCOS (Polycystic ovary syndrome)
Researchers have found that the keto diet may improve sensitivity to insulin, promote weight loss in people suffering from obesity and type 2 diabetes, and help balance hunger hormones. It is due to the fact that insulin is responsible for fat storage. Therefore, high insulin levels and resistance are often associated with unhealthy weight gain and obesity. In fact, if left untreated, insulin resistance may also cause type 2 diabetes. And since the keto diet may help improve such problems, it may be useful for PCOS management.
Doctors and scientists are still researching the exact mechanism for these beneficial effects in closely monitored settings for cancer and acne. One hypothesis is that low-carb keto meals lower the insulin levels in the body since insulin is a growth-stimulating hormone, its absence can slow down cancer, PCOS, and acne breakouts.
- Promotes healthy and fast weight loss
Since the 1970s, the keto diet achieved considerable popularity due to its weight loss potential, however, the exact mechanism is still not confirmed. One theory suggests that it takes more calories to convert fat into ATP than it takes to convert glucose into ATP. Another theory points out that the diet’s high amounts of fat and proteins satisfy your appetite faster. The Keto diet is beneficial for short-term weight loss but the side effects and difficulty of compliance question the use of the keto diet as a long-term weight loss plan.
However, the best part is that you will no longer crave sweets because once you eliminate the carb from your diet, you’ll likely find that you no longer desire them the way you did once.
- May protect and improve brain and cognitive function
Ketones (generated during the keto diet) may provide neuroprotective benefits which means they can protect the brain and nerve cells, and strengthen them. Therefore, a ketogenic diet may also help manage or prevent conditions like Alzheimer’s disease and dementia.
- Effective against metabolic syndrome
Patients experience symptoms of abdominal obesity, high blood sugar levels, high triglycerides, and elevated blood pressure. However, a low-carb diet is incredibly effective in treating all these mentioned symptoms.
These conditions are nearly eliminated after following this diet precisely.
- Improve the bad LDL cholesterol levels
People tend to have heart attacks and several heart diseases due to bad cholesterol levels. When you eat a low-carb diet, your ‘bad’ LDL particle sizes increase, which reduces their harmful effects. Cutting carbs also reduces the number of total LDL particles in your bloodstream.
Side effects of the Keto Diet:
No matter how widely popular this keto diet becomes, the many side effects that it has are rarely ever discussed. They are downplayed and diminished to a harmless scale. Contrary to those beliefs, we must properly consider and review the side effects before anyone joins the slimming-down diet bandwagon.
- You might experience the ‘keto flu’
Adjusting to any new diet can be hard but going keto may make you feel sick for the first few days. This is widely known as the keto flu because people experience flu-like symptoms and you might feel lethargic, sleepy, nauseous, sweaty, etc. To eliminate keto flu symptoms, you can also try the Keto Charge, the best BHB keto pills to aid in your Keto journey.
It’s just the physiological response that some people have when they make such a dramatic change in their diet and in response to going into ketosis. Drinking lots of water and getting solid undisturbed sleep may make it easier to get through the worst.
When you go keto, you cut carbs and fibers, aka the indigestible carbs found in whole grains, fruits, and veggies, that help bulk your stool, slow digestion and keep the stomach problems at bay. Unfortunately, this may affect your digestive health.
- Gut health disorders
The keto diet may disturb the human gut microbiota by disrupting the beneficial bacteria. This negative impact on the gut microbiome usually results in irritable bowel syndrome, ulcerative colitis, autoimmune disorders, gut inflammation, and destroying of the gut lining, etc. Eating fermented foods and high fat intake may dispel such disorders and help support gut health and the digestive tract. Other problems include inflammatory bowel disease, intestinal inflammation, leaky gut, increased intestinal permeability, etc.
- Keto acidosis
Going keto could trigger a potentially fatal side effect.
Ketosis is a good thing on a keto diet, keto acidosis on other hand is a seriously dangerous well rare side effect of the keto diet. High levels of ketone bodies especially in people with type 1 diabetes can cause this potentially fatal condition therefore it is always advised to consult your physician before you start a keto diet.
A high-fat diet may be challenging to maintain, you might develop symptoms of carbohydrate restrictions like hunger, fatigue, constipation, headache, and brain fog. As long-term side effects, you could increase the risk of developing osteoporosis and renal stones.
- Elevated heart rate
Some people experience increased heart rate known as heart palpitations or racing heart, as a side effect of ketosis. However, increasing your salt intake and staying hydrated can solve this issue.
How to Improve Gut Health while on the Keto Diet?
If you wish to participate in this diet, you might worry about possible digestive issues and other gut health problems. In such a case, you need not worry much. The effects on gut health and gut microbiome are short-lived and may not occur at all. As we said earlier, the effects of our lifestyle, food, culture, and environment, and their effects on human bodies differ individually. Even then, the keto diet may result in irritable bowel syndrome, gut inflammation, ulcerative colitis, etc.
Therefore, if you want to improve your digestion, gut, and immune system health during the span of time you are on keto, here are some of our expert recommendations.
- Adequate water consumption –
Water fulfills a generous fraction of our bodily needs. It helps flush out toxins and regulates our body temperature, alongside many other functions to help our gut microbiome thrive. Drink more water to keep your gut, skin, scalp, hair, lungs, muscles, bones, and heart satisfied!
- Regular exercise –
There are numerous exercises that can activate your natural healing factors. Here are some exercises that are simple and highly recommended – Jogging, cycling, long walks, core exercises, gut-improving yoga, Taichi, squats, martial arts, jumping ropes, aerobics, etc. These exercises boost your gut, immune system health, heart health, muscle and bone health, mood, cognitive abilities, and brain function. Try to get in at least 20 – 30 minutes of exercise daily. Here are a few more Gut Health Exercises, you can learn from here!
- Stress relief –
Try stress relief yoga or get more sleep. As per numerous medical studies and research, abundant sleep, rest, and low-stress levels do wonders for your gut and overall immune health.
- Eat healthy fibers –
The keto diet excludes several fiber-rich foods from its list. However, do try to consume some high-fat, low-carb foods, non-starchy, and low-sugar fruits and vegetables to fulfill your regular fiber needs. It acts as healthy prebiotic nutrition for your gut bacteria.
- Here are some keto-friendly foods that can help improve your gut health –
- Avocados, leafy greens (vegetables like arugula, kale, cabbage, spinach, etc), kimchi, etc.
- Try to consume healthy foods that contain beneficial and healthful nutrients like Vitamin C, Vitamin K, short-chain fatty acids, and antioxidants.
- Fermented vegetables and certain oils like Coconut oils are also recommended to boost gut bacteria.
- Many also recommend butter as it contains butyrate, one of the important short-chain fatty acids needed for our gut.
Conclusion: A Brief Review of the Keto Lifestyle
Media constitutes a huge part of our daily life. It contributes to our decision-making abilities and influences us to adapt to the newest trends. We often find ourselves copying the lifestyle trends and habits of such admired personalities and paying special attention to what lifestyle or diet or cosmetics they might recommend. Keto resembles exactly what influencers and celebrities label as a new diet trend. However, it is far from that. The Keto diet has been seen as an ancient remedy that involves cleansing our body from the inside out and making our body adapt to a healthy diet that helps prevent certain ailments.
Even then, there has not been much study to back up this theory and its popular practices in the early 19th and 20th centuries. Many researchers consider keto diets to be a part of the many types of clean eating diets that just help in losing weight. And nothing more. However, there are undoubtedly some redeemable qualities about this diet as discussed under ‘benefits’. But if we focus on the benefits that keto offers to our gut microbiota, you might feel disappointed to learn that it does nothing beneficial for your gut health nor for the good bacteria in your gastrointestinal tract. Some of the ways to undo or prevent disbalance or dysbiosis of the good bacteria from happening in your gut microbiome are discussed above or you could just add a probiotic supplement to your daily routine, here are the 10 Best Prebiotic and Probiotic Supplements you can take a look at. Choose your diet wisely and consult a physician or dietician to understand your body and gut health needs if required.
Tim Koping (Medical M.Sc Physiology, Founder of Original Eating, and a Professor at a Leading Health Institute in the US): I am a medical M.Sc physiology graduate and the founder of Original Eating, an online resource that provides information and advice about healthy eating. I have a strong interest in health and nutrition, and I am passionate about helping people to eat well and live healthily. I have over 15 years of experience working in the health and nutrition industry, and I am dedicated to providing accurate, reliable information that can help people to make healthy choices for themselves. My work with Original Eating has been featured in publications such as Men’s Health and more, and I am frequently consulted by journalists for expert commentary on dietary issues. However, in my spare time, I also enjoy reading, hiking, and playing the guitar.