What is Keto?

What is Keto?

You are likely here because you heard about this keto thing (or have a coworker that won’t stop talking about it) and you’ve decided to check it out for yourself.  I’m glad you landed on my website. I spent my graduate school time studying the keto diet and have spent the last 5 years creating educational resources and coaching people on this way of eating. In this article, I am going to tell you everything you need to know about keto so that you can decide if this diet is right for you.  

What is Keto?

The rise in popularity of keto in the last few years has allowed the diet to reach fad status making many think that this way of eating is something new.  The truth is the ketogenic diet has been around for over a century, dating back to its creation in the early 1920s for pediatric epilepsy treatment.

The ketogenic diet is considered a high fat, moderate protein, low carbohydrate diet.  On keto, bread, pasta, sugary snacks, and fruit are out but steak, broccoli, eggs, avocados, and nuts are in. While keto is classified as a low carb diet, this way of eating is different from other low carb diets like Atkins.

What is the Difference Between Keto and Atkins?

There are several key differences between keto and Atkins.  A big one is an emphasis on dietary fat.  While the Atkins diet was low carb, there was less emphasis on eating quality dietary fat and is pretty high-protein.  When we are on a low-carb diet, we have to replace the energy we get from carbohydrates with something else.  Protein is not a great provider of energy so that leaves us with fat.  But that doesn’t mean we guzzle any fat we can get our hands on keto, focusing on the right amount of the right fats is important for success with keto.

Another aspect that makes keto different from other low-carb diets is the focus on shifting our metabolism completely away from burning sugar and over to burning both dietary and body fat. Keto restricts carbs so low that it induces a unique metabolic state known as ketosis, putting the keto in ketogenic.  

What is Ketosis?

Ketosis is a metabolic state of low blood sugar, increased fat burning, and ketone production. Ketone bodies or ketones are little energy molecules that are produced by our liver and shuttled out into our bloodstream where they can be used as a source of energy.  We are said to be in ketosis when our bodies have achieved a certain blood concentration of ketones.

The purpose of ketones is to further supply our body with energy to replace carbohydrates.  Ketones are especially used by the brain because the brain cannot run on fatty acids.  Ketosis is thought to be an evolutionary survival technique existing to combat any period of time where food was scarce but the demand to be mentally alert was high.  While the evolutionary reasons for this process may no longer exist, being in a state of ketosis has a wide array of benefits that still apply to us today.  

Benefits of Keto

It’s no surprise that we have seen such a boom in keto dieting over the last 5 or so years considering the many benefits this way of eating can provide.  Let’s go over a few of the most popular keto benefits.

Fat Loss

Fat loss is without a doubt the most popular use of the keto diet and a major reason for the rise in popularity of this diet.  All for good reason considering, compared to other diets, keto has been shown to produce superior fat loss results. This is due to the metabolic nature of this way of eating.

Remember on a keto diet, your blood sugar and insulin levels lower which is a crucial component to fat burning.  When we aren’t eating carbohydrates, our body has to adjust by producing an alternative energy source found in fat and ketones, both of which require the burning of stored body fat.

What is crucial to point out about keto is that it’s not just weight loss that is experienced, but specifically fat loss.  While other diets may demonstrate comparable weight loss, keto ensures that more of that weight lost is coming from fat and not muscle. Especially compared to low-fat diets. When it comes to tackling our obesity epidemic, keto seems to be our best choice.

Blood Sugar

Blood sugar levels are a great indicator of our overall health. They provide us insight into the state of our metabolism, the function of our digestive system, and the ability of our body to utilize certain fuel sources.  High blood sugar, especially in the morning and hours after a meal, is a sign of prediabetes, a condition that has become a global epidemic.

Since keto cuts carbs out of the diet, naturally our blood sugar levels normalize which isn’t just key for disease prevention but also maintaining energy levels and managing hunger.


Inflammation is one of the biggest contributors to chronic disease.  Inflammation can cause our bodies to ache, our brain performance to suffer, and our digestive systems to strain just to name a few.  

Keto’s ability to combat inflammation is threefold.  On keto, you are eating less pro-inflammatory foods, producing less inflammation when burning fat and ketones, and promoting natural anti-inflammatory pathways.  This is one of the reasons why we hear so many keto dieters reporting less joint pain, more mental clarity, improved digestion, and even better inflammatory markers.

Insulin Resistance

Insulin resistance is another major contributor to chronic disease. When our bodies consume carbs they get broken down into glucose (sugar) and released into our bloodstream causing a rise in blood sugar.  When our bodies sense this rise, our pancreas is stimulated to produce insulin which tells our cells to open up and let sugar in out of the blood so it can be used for energy.

While this is not necessarily a bad process when it is overstimulated our cells can become resistant to insulin’s action, allowing our blood sugar to stay high, forcing the pancreas to secrete more insulin, and preventing our cells from getting much-needed fuel.  In essence, insulin resistance is an inability to effectively use carbs or carb intolerance.



On a keto diet, carbs are removed which allows this system to rest and restore itself.  When we are in ketosis, we are no longer relying on glucose and insulin but instead are fueled by fat and ketones

Brain Health and Function

While not always a primary reason for coming to the keto diet, many keto dieters will report enhanced brain health and function.  This is due to the fact that the brain has a preference for ketones and when we are producing them, our body saves most of them for our brain.  

Ketones promote better brain function and health because they provide more energy compared to carbs, create less inflammation in the brain, and even activate natural anti-inflammatory pathways that help keep our brain operating the way it should.

Digestive Health

Digestive health plays a major role in our health as a whole. Research is even finding that there is a link between our gut and our brain, known as the gut-brain axis, that allows what we eat to impact our brain function and mood.

A proper keto diet removes foods that are damaging to our gut health and replaces them with foods that are more easily absorbed and can help improve the strength of our digestive system allowing it to function optimally.


While so many people come to keto for weight loss, many stay for the energy.  Remember that when you are in ketosis, you are producing an additional fuel source that has a pretty profound impact on the brain leading to much better energy.

Many keto dieters will report having more energy to play with their kids, perform better at work, and even more motivation to work out, all while requiring much less coffee.


It should be no secret that if we are experiencing the many benefits listed in this section that we will also see a boost in our mood.  But this isn’t the only way keto can impact mood. On a keto diet, we see changes in our brain chemicals that help us feel better.  This change in mood can have profound impacts on our quality of life, a key consideration for any diet.


Our culture has become accustomed to associating dieting with hunger, but on a keto diet, this isn’t the case.  Stable blood sugar is a huge contributor to the lack of hunger reported on keto but research is also finding that keto dieting leads to changes in our hunger hormones that prevent us from constantly dealing with hunger and cravings.  Considering that typical weight-loss diets do the exact opposite, this is a great perk that makes sticking to this diet much easier. 

Disease Treatment/Prevention

The keto diet was first invented for its ability to mimic fasting in the treatment of pediatric epilepsy.  Despite the diet losing its popularity because of the development of antiepileptic drugs, keto can still be used for this reason today.

Type 2 diabetes is another condition where keto is showing a ton of benefit.  Companies like Virta health are now using keto to treat diabetes and are finding incredible success in reversing the condition and getting patients off of their diabetic medication.

Keto is also showing a ton of therapeutic promise in other areas like: 

  • Metabolic Syndrome
  • Alzheimer’s Disease
  • Cancer
  • Parkinson’s Disease
  • PCOS
  • Heart Disease
  • Certain Digestive Disorders
  • Blood Pressure

    What to Eat on Keto

    If you’re sold on keto after hearing the benefits, you are probably wondering what you can and can’t eat on this diet.  Here is a shortlist:

    Foods to Avoid

    • Bread
    • Pasta
    • Sugar
    • Rice
    • High glycemic fruit
    • Oatmeal
    • Sweets

      Foods to Eat

      • Meat
      • Fish
      • Eggs
      • Leafy green vegetables
      • Nuts
      • Some low glycemic fruit
      • Some dairy
      • Oils like coconut oil, olive oil, and avocado oil

        To get a full food list, check out the Keto Kickstart (it’s free). 

        Keto Macronutrients

        When talking about what to eat on keto, we have to discuss macronutrients or macros. If you’re not familiar with macronutrients, they are the primary nutrients that make up our food that we use for energy and as building blocks in our bodies. The three macros are carbs, fat, and protein. Here is what you need to know about each in relation to keto.

        Carbohydrates: Carbs are not an essential macronutrient.  Your body can produce all of the sugar it needs naturally and does not need dietary carbs for this.  While it is safe to have a 0 carb intake, it is not necessary to do so on keto.  It is just important that carbs only make up a small portion of your diet and they should come from veggies not bread, pasta, fruit, or other sugars. There is some debate as to whether keto dieters should track total carbs or net carbs.  If you don't know what net carbs are, thats okay.  I recommend that beginners stick to tracking total carbs and sticking to under 30 grams of carbs per day.

        Fat: Fat has been misunderstood for decades.  Fat has been mistaken as being bad for us.  The reality is that fat consumed without carbohydrates is safe and actually very healthy.  Fat provides energy and nutrients needed to carry out important body functions like hormone production and even generate new cells.  On keto, it is good to get a mix of different types of fat including omega-3 and medium chain triglycerides (MCTs).

        Protein: Protein has been a confusing topic when it comes to keto.  Many people believe protein intake needs to be limited to keto.  Unless for certain therapeutic reasons, I disagree.  I think it is more important to make sure you are eating enough protein.  Especially since studies have shown low protein on keto can lead to muscle loss (9).  Be sure to get enough protein from a variety of sources like red meat, eggs, and fish.

        There are no one-size-fits-all macronutrient recommendations for keto.  Most websites and resources out there will recommend 70% of your total calories coming from fat, 25% from protein, and 5% from carbs.  However, these recommendations are far too generalized and do not take specific goals into consideration. 

        The optimal macronutrient ratio will vary slightly from person to person based on goals and other health parameters like insulin sensitivity, current body composition, gender, and activity level.  To calculate your macronutrients and get help putting together an eating plan, check out the Perfect Keto macronutrient calculator. 

        Getting Into Ketosis

        Since ketosis is what makes keto fundamentally different from other diets, understanding how to get into ketosis is important which involves grasping a little bit of the science here.

        When we are eating carbohydrates, the sugar from those carbs is our body's primary fuel source. We eat the carbs, our body breaks it down to sugar, our pancreas secretes insulin to drive that sugar into our cells, our cells burn that sugar for energy. 

        On keto, something much different happens.  The removal of carbs allows blood sugar and subsequently insulin levels to lower.  Low blood sugar and insulin signal our bodies to start releasing stored body fat to be burned for energy and shuttled to the liver for ketone production, a process known as ketogenesis.  Once we are able to detect ketones in the blood, which can be measured similar to how we measure blood sugar, we are said to be in a state of ketosis.

        How to Know if You Are in Ketosis

        There are many devices out there that can give us insight into our ketone levels such as urine strips, blood meters, and breath meters.  While each has its pros and cons, choosing one of these techniques can be beneficial for getting a pulse on your keto diet.

        Ketone testing can get expensive though so if you are not looking to purchase a device to test, you can also rely on subjective feelings of ketosis such as:

        • Increased energy
        • Mental clarity
        • Lack of hunger
        • Weight loss
        • Improved mood

          Optimal Ketone Levels 

          If you decide to measure ketone levels, you may be wondering what the optimal level is.  While research has suggested from 0.5-3.0 mmol as the optimal level, the truth is we do not have the answer to this question.  When measuring ketones in the blood, we are only measuring what is currently available in the blood 

          Becoming Keto-Adapted

          Your body will start producing ketones to some degree within hours of carbohydrate restriction, however, it takes time for our bodies to actually put these ketones to use.  Being able to do so is called keto-adaptation and the time it takes to achieve this is different for everyone ranging from 1-4 weeks depending on what your diet looked like before keto. 

          Is Keto Safe?

          There is a lot of concern around the safety of keto for two primary reasons:

          1. People confuse nutritional ketosis with diabetic ketoacidosis (DKA)
          2. People think fat is bad

            There is a huge difference between nutritional ketosis and diabetic ketoacidosis or DKA. When in nutritional ketosis, we see a controlled rise in blood ketones and low insulin and blood glucose levels. This is completely healthy and safe. DKA, which occurs in diabetics, is characterized by an uncontrolled dangerous rise in ketones, much different from ketosis experienced on a keto diet.

            Besides DKA, we have been programmed to believe that fat is unhealthy. How could a high-fat diet be good for us? Won't it destroy our cholesterol levels? Much of our fear of fat has come from poorly conducted and manipulated research dating back as far as the 1950s that still shape our society today. To learn more about this and the war on fat, be sure to check out the book: The Big Fat Surprise by Nina Teicholz.

            We are actually finding out that the problem isn’t fat.  It’s carbs and even worse, high carb and high fat consumed together. The body loves to take the path of least resistance and it is easier for the body to burn carbs for fuel because it has been trained to do so.  This means when we consume fat and carbs together, the fat we eat is more likely to be stored than used for energy.  Removing the carbs fixes this problem! Additionally, fat is incredibly important to our overall health, we cannot have an optimally functioning human body without healthy dietary fat. 

            The truth is that keto is not only safe but extremely healthy for the majority of people. There are certain conditions such as pyruvate carboxylase deficiency, porphyria, and other fat metabolism disorders that keto may not be recommended for. Additionally, other potential concerns for keto dieting that have not been well researched are pancreatitis, impaired liver function, gallbladder disease, gastric bypass surgery, and kidney failure. 

            Finally, if you are taking medication for conditions like heart disease or diabetes, you will want to check with a doctor (one that knows keto) to see if keto is right for you and to make sure that your medications are being adjusted accordingly.

            Common Side Effects on Keto

            While keto is completely safe, there are some short-term side effects that can accompany induction to this diet. These side effects are typically referred to as the keto flu.  Keto flu symptoms can include:

            • Headache
            • Brain fog
            • Fatigue
            • Muscle cramps
            • Weakness
            • Constipation
            • Poor mood
            • Poor sleep

              It is important to point out that not everyone will experience these symptoms and they are avoidable. While it is commonly thought that keto flu is a result of carbohydrate withdrawal, it is actually a result of dehydration and electrolyte deficiency.  On low carb diets, our insulin levels lower causing our bodies to release more water and electrolytes (which is why we lose so much water weight at the beginning of the diet).  Since electrolytes play a role in nearly every bodily function, we should expect to see some symptoms when we are deficient.

              The good news here is that these symptoms can be reduced or avoided altogether by focusing on drinking plenty of water and consuming whole food and supplemental electrolytes. The main electrolytes to focus on are sodium, magnesium, and potassium. 

              Take Away

              The ketogenic diet is one of the most popular diets out there because of its ability to alter our metabolism in ways that produce a plethora of health benefits.  From weight loss to a better mood, keto is a great option for anyone looking to kickstart their health journey and progress towards their health goals.  

              If you are ready to take the jump and try keto, check out this free Keto Kickstart guide I helped create for Perfect Keto which contains more info on the diet, a shopping list, sample meal plans, and more. If you are looking for a little extra hand-holding, check out our coaching program which provides you with a diet plan and support, resources, and motivation to start keto the right way and find the success you are looking for.

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