Unlike many fad diets that come and go with very limited rates of long-term success, the ketogenic diet (or keto diet) has been practiced for more than nine decades (since the 1920s) and is based upon a solid understanding of physiology and nutrition science.
The keto diet works for such a high percentage of people because it targets several key, underlying causes of weight gain — including hormonal imbalances, especially insulin resistance coupled with high blood sugar levels, and the cycle of restricting and “binging” on empty calories due to hunger that so many dieters struggle with. In fact, these are some of the direct benefits of the keto diet.
What is the keto diet? Rather than relying on counting calories, limiting portion sizes, resorting to extreme exercise or requiring lots of willpower, this low-carb diet takes an entirely different approach to weight loss and health improvements. It works because it changes the very “fuel source” that the body uses to stay energized: namely, from burning glucose (or sugar) to dietary fat, courtesy of keto diet recipes and the keto diet food list items, including high-fat, low-carb foods.
Making that switch will place your body in a state of “ketosis,” when your body becomes a fat burner rather than a sugar burner. Fortunately, if you’re new to this type of eating plan, a keto diet for beginners, or keto basics, is surprising simple to follow. Here’s how to do the keto diet:
Table of Contents
What Is the Keto Diet?
What Is Ketosis? | How Do You Get Into Ketosis?
6 Main Benefits of the Keto Diet
How to Start the Keto Diet Plan | 9 Keto Diet Types
How to Know Keto Is Working
What to Eat on Keto? Keto Diet Recipes
Precautions When Following the Ketogenic Diet
What is the ketogenic diet exactly? The classic ketogenic diet is a very low-carb diet plan that was originally designed in the 1920s for patients with epilepsy by researchers working at Johns Hopkins Medical Center. Researchers found that fasting — avoiding consumption of all foods for a brief period of time (such as with intermittent fasting), including those that provide carbohydrates — helped reduce the amount of seizures patients suffered, in addition to having other positive effects on body fat, blood sugar, cholesterol and hunger levels. (1)
Unfortunately, long-term fasting is not a feasible option for more than a few days, therefore the keto diet was developed to mimic the same beneficial effects of fasting.
Essentially, the keto diet for beginners works by “tricking” the body into acting as if its fasting (while reaping intermittent fasting benefits), through a strict elimination of glucose that is found in carbohydrate foods. Today the standard keto diet goes by several different names, including the “low-carbohydrate” or “very-low-carbohydrate ketogenic diet”(LCKD or VLCKD for short).
At the core of the classic keto diet is severely restricting intake of all or most foods with sugar and starch (carbohydrates). These foods are broken down into sugar (insulin and glucose) in our blood once we eat them, and if these levels become too high, extra calories are much more easily stored as body fat and results in unwanted weight gain. However, when glucose levels are cut off due to low-carb intake, the body starts to burn fat instead and produces ketones that can be measured in the blood (using urine strips, for example).
Keto diets, like most low carb diets, work through the elimination of glucose. Because most folks live on a high carb diet, our bodies normally run on glucose (or sugar) for energy. We cannot make glucose and only have about 24 hours’ worth stored in our muscle tissue and liver. Once glucose is no longer available from food sources, we begin to burn stored fat instead, or fat from our food.
Therefore, when you’re following a ketogenic diet plan for beginners, your body is burning fat for energy rather than carbohydrates, so in the process most people lose weight and excess body fat rapidly, even when consuming lots of fat and adequate calories through their daily food intake. Another major benefit of the keto diet is that there’s no need to count calories, feel hungry or attempt to burn loads of calories through hours of intense exercise.
In some ways, it’s similar to the Atkins diet, which similarly boosts the body’s fat-burning abilities through eating only low-carb foods, along with getting rid of foods high in carbs and sugar. Removing glucose from carbohydrate foods will cause the body to burn fat for energy instead. The major differences between the classic keto and the Atkins diet is the former emphasizes healthier keto fats, less overall protein and no processed meat (such as bacon) while having more research to back up its efficacy.
In fact, those differences with Atkins outline some of the popular keto diet myths, such as it being another high-protein plan, recommending any type of fat and that barely any science research backs up the benefits. These are nutrition lies, plain and simple.
So is the keto diet healthy? If it’s done Atkins style? No. But if relying on healthy fats, greens and organic meats? Very much so.
What does “keto” stand for exactly? Keto is short for ketosis, which is the result of following the standard ketogenic diet, which is why it’s also sometimes called “the ketosis diet” or “ketosis diet plan.”
Following a ketogenic diet puts your body into a state of “ketosis,” which is a metabolic state that occurs when most of the body’s energy comes from ketone bodies in the blood, rather than from glucose from carbohydrate foods (like grains, all sources of sugar or fruit, for example). This is in contrast to a glycolytic state, where blood glucose (sugar) provides most of the body’s fuel (or energy).
This state can also be achieved by multiple days of total fasting, but that isn’t sustainable beyond a few days. (It’s why some keto diet plans for beginners combine intermittent fasting with keto for greater weight loss effects.)
Although dietary fat (especially saturated fat) often gets a bad name, provoking fear of weight gain and heart disease, it’s also your body’s second preferred source of energy when carbohydrates are not easily accessible.
So many people ask, does the keto diet work? Yes, of course, but only if you can get your body into ketosis. Here’s how you get your body into ketosis and start burning body fat for fuel in a keto diet for beginners:
Wondering how many carb foods you can eat and still be “in ketosis”? The traditional ketogenic diet, created for those with epilepsy consisted of getting about 75 percent of calories from sources of fat (such as oils or fattier cuts of meat), 5 percent from carbohydrates and 20 percent from protein. For most people a less strict version (what I call a “modified keto diet”) can still help promote weight loss in a safe, and often very fast, way.
In order to transition and remain in this state, aiming for about 30–50 net grams is typically the recommended amount of total carbs to start with. This is considered a more moderate or flexible approach but can be less overwhelming to begin with. Once you’re more accustomed to “eating keto,” you can choose to lower carbs even more if you’d like (perhaps only from time to time), down to about 20 grams of net carbs daily. This is considered the standard, “strict” amount that many keto dieters aim to adhere to for best results, but remember that everyone is a bit different.
Of the many benefits of a keto diet, weight loss is often considered No. 1., as it can often be substantial and happen quickly (especially for those who start out very overweight or obese). The 2013 study published in the British Journal of Nutrition found that those following a keto diet “achieved better long-term body weight and cardiovascular risk factor management when compared with individuals assigned to a conventional low-fat diet (i.e. a restricted-energy diet with less than 30 percent of energy from fat).” (2)
A 2014 keto diet review published in the International Journal of Environmental Research & Public Health states:
One of the most studied strategies in the recent years for weight loss is the ketogenic diet. Many studies have shown that this kind of nutritional approach has a solid physiological and biochemical basis and is able to induce effective weight loss along with improvement in several cardiovascular risk parameters. (3)
In part, keto diet weight loss is a real thing because high-fat, low-carb diets can both help diminish hunger and boost weight loss through their hormonal effects. As described above, when we eat very little foods that supply us with carbohydrates, we release less insulin. With lower insulin levels, the body doesn’t store extra energy in the form of fat for later use, and instead is able to reach into existing fat stores for energy.
Keto diets are high in healthy fats and protein also tend to be very filling, which can help reduce overeating of empty calories, sweets and junk foods. (4) For most people eating a healthy low-carb diet, it’s easy to consume an appropriate amount of calories, but not too many, since things like sugary drinks, cookies, bread, cereals, ice cream or other desserts and snack bars are off-limits.
Often caused by lymph node removal or damage due to cancer treatment, lymphedema occurs because there’s a blockage in the lymphatic system and results in the swelling in leg or arm. A 2017 study involved patients who suffered from obesity and lymphedema and who embarked on a 18-week ketogenic diet. Weight and limb volume was significantly reduced. (5)
Polycystic ovary syndrome (PCOS) is the most common endocrine disorder, and it affects women of reproductive age. Symptoms include obesity, hyperinsulinemia and insulin resistance. A pilot study took 11 women through 24 weeks of a low-carbohydrate ketogenic diet (20 grams or less per day). Among the five who completed the study, they lost 12 percent of their weight on average and reduced fasting insulin by 54 percent. Additionally, two women who previously experienced infertility problems became pregnant. (6)
This process of burning fat provides more benefits than simply helping us to shed extra weight — it also helps control the release of hormones like insulin, which plays a role in development of diabetes and other health problems. When we eat carbohydrates, insulin is released as a reaction to elevated blood glucose (an increase in sugar circulating in our blood) and insulin levels rise. Insulin is a “storage hormone” that signals cells to store as much available energy as possible, initially as glycogen (aka stored carbohydrates in our muscles) and then as body fat.
The keto diet works by eliminating carbohydrates from the your daily intake and keeping the body’s carbohydrate stores almost empty, therefore preventing too much insulin from being released following food consumption and creating normal blood sugar levels. This can help reverse “insulin resistance,” which is the underlying problem contributing to diabetes symptoms. In studies, low-carb diets have shown benefits for improving blood pressure, postprandial glycemia and insulin secretion. (7)
Therefore, diabetics on insulin should contact their medical provider prior to starting a ketogenic diet, however, as insulin dosages may need to be adjusted.
The keto diet can reduce the risk of heart disease markers, including high cholesterol and triglycerides. (8) In fact, the keto diet is unlikely to negatively impact your cholesterol levels despite being so high in fat. Moreover, it’s capable of lowering cardiovascular disease risk factors, especially in those who are obese. (9)
One study, for example, found that adhering to the ketogenic diet and keto diet foods list for 24 weeks resulted in decreased levels of triglycerides, LDL cholesterol and blood glucose in a significant percentage of patients, while at the same time increasing the level of HDL cholesterol. (10)
Certain studies suggest that keto diets may “starve” cancer cells. A highly processed, pro-inflammatory, low-nutrient foods can feed cancer cells causing them to proliferate. What’s the connection between high-sugar consumption and cancer? The regular cells found in our bodies are able to use fat for energy, but it’s believed that cancer cells cannot metabolically shift to use fat rather than glucose. (11)
There are several medical studies — such as two conducted by the Department of Radiation Oncology at the Holden Comprehensive Cancer Center for the University of Iowa, and the National Institutes of Health’s National Institute of Neurological Disorders and Stroke, for example — that show the ketogenic diet is an effective treatment for cancer and other serious health problems. (12)
Therefore, a keto diet that eliminates excess refined sugar and other processed carbohydrates may be effective in reducing or fighting cancer. It’s not a coincidence that some of the best cancer-fighting foods are on the keto diet food list.
Over the past century, ketogenic diets have also been used as natural remedies to treat and even help reverse neurological disorders and cognitive impairments, including epilepsy, Alzheimer’s symptoms, manic depression and anxiety. Research shows that cutting off glucose levels with a very low-carb diet makes your body produce ketones for fuel. This change can help to reverse neurological disorders and cognitive impairment, including inducing seizure control. The brain is able to use this alternative source of energy instead of the cellular energy pathways that aren’t functioning normally in patients with brain disorders.
A related clinical diet for drug-resistant epilepsy is called the medium-chain triglyceride ketogenic diet, in which MCT oil is extensively used because it’s more ketogenic than long-chain triglycerides. (13) Another dietary therapy for epilepsy called Low Glycemic Index Treatment (LGIT) was developed in 2002 as an alternative to the keto diet. LGIT monitors the total amount of carbohydrates consumed daily, and focuses on carbohydrates that have a low glycemic index.) (14)
Clinical improvement was observed in Alzheimer’s patients fed a ketogenic diet, and this was marked by improved mitochondrial function. (15) In fact, a European Journal of Clinical Nutrition study pointed to emerging data that suggested the therapeutic use of ketogenic diets for multiple neurological disorders beyond epilepsy and Alzheimer’s, including headaches, neurotrauma, Parkinson’s disease, sleep disorders, brain cancer, autism and multiple sclerosis. (16)
The report goes on to say that while these various diseases are clearly different from each other, the ketogenic diet appears to be so effective for neurological problems because of its “neuroprotective effect” — as the keto appears to correct abnormalities in cellular energy usage, which is a common characteristic in many neurological disorders.
In mouse models, a study showed that a keto diet could slow disease progression for both ALS and Huntington’s diseases. In fact, more than one animal study has discovered a potential benefits of the low-carb, high-fat diet or intermittent fasting in delaying weight loss, managing glucose and protecting neurons from injury. (17, 18)
Interestingly, it’s also been shown to slow disease progression in mouse models of both ALS and Huntington’s diseases.
Researchers believe that the ketogenic diet can also help patients with schizophrenia to normalize the pathophysiological processes that are causing symptoms like delusions, hallucinations, lack of restraint and unpredictable behavior. One study found that the keto diet lead to elevated concentrations of kynurenic acid (KYNA) in the hippocampus and striatum, which promotes neuroactive activity. Some studies even point to the elimination of gluten as a possible reason for improved symptoms, as researchers observed that patients with schizophrenia tended to eat more carbohydrates immediately before a psychotic episode. (19)
Although the exact role of the keto diet in mental and brain disorders is unclear, there has been proof of its efficacy in patients with schizophrenia. And, to boot, it works to reverse many conditions that develop as a side effect of conventional medications for brain disorders, like weight gain, type 2 diabetes and cardiovascular risks. More research is needed to understand the role of the ketogenic diet in treating or improving schizophrenia, as the current available studies are either animal studies or case studies, but the benefits of a low carbohydrate, high-fat diet in neurology is promising.
Now, there’s even evidence that a low-carb, high-fat regimen (as the keto diet is) helps you live longer, compared to a low-fat diet. In a study by the medical journal The Lancet that studied more than 135,000 adults from 18 countries, high carbohydrate intake was associated with higher risk of total mortality, whereas total fat and individual types of fat were related to lower total mortality. Total fat and types of fat were not associated with cardiovascular disease, myocardial infarction or cardiovascular disease mortality.
In fact, saturated fat intake had an inverse association with the risk for suffering from a stroke, meaning the more saturated fat someone is consuming on a daily basis, the more protection against having a stroke they seemed to have. (20)
The keto diet also appears to help induce autophagy, which helps clear damaged cells from the body, including senescent cells that serve no functional purpose but still linger inside tissues and organs. In animal studies when rats are put on the ketogenic diet, autophagic pathways are createdthat reduce brain injury during and after seizures. (21)
In fact, inducing autophagy is now a popular biohacking technique for helping remove signs of aging poorly and keto is one way to get there.
The exact ratio of recommended macronutrients (or your “macros”) in your daily regimen (grams of carbs vs. fat vs. protein) will differ depending on your specific goals and current state of health. Your age, gender, level of activity and current body composition can also play a role in determining your carb versus fat intake.
Historically, a targeted keto diet consists of limiting carbohydrate intake to just 20–30 net grams per day. “Net carbs” is the amount of carbs remaining once dietary fiber is taken into account. Because fiber is indigestible once eaten, most people don’t count grams of fiber toward their daily carb allotment.
In other words, total carbs – grams of fiber = net carbs. That’s the carb counts that matter most.
On a “strict” (standard) keto diet, fats typically provides about 70 percent to 80 percent of total daily calories, protein about 15 percent to 20 percent, and carbohydrates just around 5 percent. However, a more “moderate” approach to the keto diet is also a good option for many people that can allow for an easier transition into very low-carb eating and more flexibility (more on these types of plans below).
What can you eat on a keto diet? Here are some good keto rules for how to do the keto diet regardless of the plan you follow:
Something that makes the keto diet different from other low-carb diets is that it does not “protein-load.” Protein is not as big a part of the keto diet as fat is. Reason being: In small amounts, the body can change protein to glucose, which means if you eat too much of it, especially while in the beginning stages, it will slow down your body’s transition into ketosis.
Protein intake should be between one and 1.5 grams per kilogram of your ideal body weight. To convert pounds to kilograms, divide your ideal weight by 2.2. For example, a woman who weighs 150 pounds (68 kilograms) should get about 68–102 grams of protein daily.
Your “macros” are your grams of fat, protein and net carbs (not to be confused with calorie counting!). Tracking your macros and net carbs can be tricky, so I advise you download a keto app that includes a keto diet calculator. It will help keep you on track.
A popular keto supplement are exogenous ketones (popularly called “keto diet pills”) that may help you achieve results earlier as well as remain in that state. (Don’t confuse exogenous ketones with raspberry ketones, as the latter don’t raise ketone levels in the body or mimic endogenous ketones, so you wouldn’t use raspberry ketones in your regimen.)
Also, consider supplementing with the amino acid leucine, as it can be broken down directly into acetyl-CoA, making it one of the most important ketogenic amino acids in the body. While most other amino acids are converted into glucose, the acetyl-CoA formed from leucine can be used to make ketone bodies. It’s also present in keto friendly foods like eggs and cottage cheese.
It’s important to also drink lots of water, the most important of all keto drinks. Getting enough water helps keep you from feeling fatigued, is important for digestion and aids in hunger suppression. It’s also needed for detoxification. Aim to drink 10–12 eight-ounce glasses a day.
Lastly, no cheat days and not even cheat meals on the keto diet! Why?! Because a meal with far too many carbs will take you right out of ketosis and put you back at square one.
That being said, if you do succumb and indulge in a cheat meal, expect a return of some of the keto flu symptoms … but also be comforted by the knowledge that if you’re reached ketosis in the past, your body will be able to get back soon again and perhaps more quickly than originally.
What is the keto diet again? And is the keto diet safe and healthy? Well, with a diet this popular, many versions and keto meal plans tend to emerge, so the answer to both questions somewhat depends on what version of the ketogenic plan you try. At present, we’re at nine types of the keto diet!
Wondering how many carb foods you can eat and still be “in ketosis”? The traditional ketogenic meal plan created for those with epilepsy and is very strict with its percentages of macronutrients. But there are several other types of keto diet plans out there as well.
In the absence of glucose, which is normally used by cells as a quick source of energy, the body starts to burn fat and produces ketone bodies instead (it’s why the keto diet is often referred to as the ketone diet). Once ketone levels in the blood rise to a certain point, you enter into a state of ketosis — which usually results in quick and consistent weight loss until you reach a healthy, stable body weight. See this keto diet review, a before and after trying keto for 30 days.
To sum up a complex process, you reach this fat-burning state when the the liver breaks down fat into fatty acids and glycerol, through a process called beta-oxidation. There are three primary types of ketone bodies that are water-soluble molecules produced in the liver: acetoacetate, beta-hydroxybutyrate and acetone.
The body then further breaks down these fatty acids into an energy-rich substance called ketones that circulate through the bloodstream. Fatty acid molecules are broken down through the process called ketogenesis, and a specific ketone body called acetoacetate is formed and which supplies energy.
The end result of the “ketone diet” is staying fueled off of circulating high ketones (which are also sometimes called ketone bodies) — which is what’s responsible for altering your metabolism in a way that some people like to say turns you into a “fat-burning machine.” Both in terms of how it feels physically and mentally, along with the impact it has on the body, being in ketosis is very different than a “glycolytic state,” where blood glucose (sugar) serves as the body’s energy source.
So, is ketosis bad for you? Absolutely not. If anything, it’s the reverse. Many consider burning ketones to be a much “cleaner” way to stay energized compared to running on carbs and sugar day in and day out.
And remember, this state is not to be confused with ketoacidosis, which is a serious diabetes complication when the body produces excess ketones (or blood acids).
The goal is to keep you in this fat-burning metabolic state, in which you will lose weight until you reach your ideal set point. Some research suggests this may be a novel approach to reverse diabetes naturally.
To get you started, try some of these delicious, healthy and straightforward keto recipes, keto fat bombs and keto snacks.
Regarding specific foods to include on a ketogenic diet, plus those to eliminate, here is an outline of what you might choose to grocery shop for:
Remember, the ketogenic diet will actually change your metabolism, put you into ketosis and turn you from a sugar burner to a fat burner. Those are significant changes for your body, and you’re bound to notice some symptoms of the so-called keto flu.
Keto flu symptoms and side effects can include feeling tired, having difficulty sleeping, digestive issues like constipation, weakness during workouts, being moody, losing libido and having bad breath. Fortunately, these side effects don’t affect everyone and often only last for 1–2 weeks. (And yes, you CAN build muscle on keto.) Overall, symptoms go away as your body adjusts to being in ketosis.
If a ketogenic diet is being used for a child to treat epilepsy, close medical monitoring is necessary. If you’re very active and without much body fat, consider trying carb cycling or at least eating a modified keto diet that does not severely restrict carb intake.