Ketogenic Diet Primer

This article contains the very basics of the Keto diet. As with many diets and eating protocols, covering all of the nuances of a successful eating plan would be quite an endeavor. Others have put together much more information on the diet. This article is meant to be a high-level overview for information only. Use it as a means to decide if further exploration into this diet is still of interest to you. There are many worthy diets out there and this is just one of them. So, if after reading this, you don’t think that the Keto diet is for you, that is perfectly acceptable. If you want more information, I’ve included some links to other sources on the Keto diet.

History

The history of the Ketogenic diet is quite long and interesting. As early as 2500 years ago fasting was recognized as a treatment for many ailments. While it was less recognized, fasting was a method for treating epilepsy. In the early 1900s, studies were starting using fasting (prolonged fasting such as 3 or more days) for the treatment of seizures. Fasting was shown to reduce the occurrence of seizures while the patient was fasting. That meant, that once the patient began eating again, symptoms would return. As you can imagine, fasting indefinitely is not conducive to a healthy active life.

Originally, the Ketogenic diet was created to mimic the effects of fasting. Most notably, the body enters a state of ketosis during which it switches to burning ketones for energy instead of blood sugar (glucose) from carbohydrates. Therefore, the first Keto diet was used to treat epilepsy. It was thought that making a diet that could mimic the effects of fasting would be easier to stick to than starving (eating something every day vs not eating anything for up to 3 days). I also imagine overall it would be more sustainable than fasting. (Note here, that we are talking about all-out fasting, not intermittent fasting which is popular today as an eating protocol.)

It would seem that most of the research on epilepsy was focused on children. Therefore the diets devised were also made for children. The original Ketogenic diet consisted of 1 g of protein per kg of body weight in children, 10-15 g of carbohydrates per day, and the remainder of calories from fat, and was created by Dr. Peterman at the Mayo Clinic in 1925. Successful implementation of the diet required very precise measurement of carbohydrate, protein, and fat to keep proportions in the proper ratios.

In 1938 attention shifted away from the ketogenic diet to new antiepileptic drugs being created. As more and more medications came on the market with positive results, the ketogenic diet was used much less. Part because it was less palatable, and even with Dr. Peter Huttenlocher creating a medium-chain triglyceride oil diet (MCT oil) to make KD more palatable in 1971, fewer patients were being put on it for treatment. Fewer people using it meant fewer dieticians were trained in it. Ultimately the decline in ketogenic diet knowledge resulted in some cases of the diet being ineffective because the macronutrients (carbs, fat, protein) were incorrectly calculated.

The Ketogenic diet largely went into hibernation between 1970 and 2000. But in 2000 a dateline episode brought it back into the focus following the successful treatment of a boy with epilepsy when no other treatment worked. This resurgence of interest in the Ketogenic diet has resulted in an order of magnitude increase in documents published in Pubmed since the year 2000. There are many potential benefits of the Keto diet being studied all similar to that of fasting. These benefits include reduction of diabetes and heart disease, treatment of Alzheimer’s disease, treatment of Parkinson’s disease as well as improvements to mental clarity.

More recently, however, people are turning to the Keto diet for weight loss.

How does it Work?

Much like the fasting that the ketogenic diet was originally designed to mimic, eating keto forces your body into a state called Ketosis. Because of the ultra-low consumption of carbohydrates (especially starchy or sugary ones), your body needs to find an alternate source of fuel. While it is true that your body prefers to run on glucose (made from the carbs that you eat), it runs equally well on ketones. Ketones are made in your liver from fat. These ketone bodies are then able to be used for fuel for both muscle and your brain just as blood glucose would be.

Where does this fat come from? Well, it comes from your food first. The ketogenic diet is quite high in fat. But, when it runs out of that, it pulls it from storage in your body. (That’s pretty cool.) And, moreover, as you adapt to burning ketones for fuel, your body becomes more efficient at pulling fat from your body for fuel, and you rely less on dietary fat.

It’s important to note here that if you have been eating a diet moderate to high in carbohydrates and you switch to a ketogenic diet, it will take some time for your body to adapt. Once it does, it’s often referred to as being “fat adapted”. This simply means that your body is efficient at burning fat for fuel. It’s possible that you will notice that you no longer crave the carbohydrates you once did.

Is it safe?

For most people, it is presumed safe. However, if you have chronic diseases such as diabetes or are at risk for hypoglycemia talk to your doctor before switching diets. Certain medications may need to be adjusted, especially if you are taking insulin or blood pressure meds. Likewise, if you are pregnant or breastfeeding it’s always good to check with your doctor as well.

A few things to keep in mind:

Eating Fat doesn’t make you fat. Eating more calories than you can use makes you fat, regardless of where those calories come from.
High quantities of fat haven’t been shown to increase the risk of heart disease. In fact, even saturated fat got a bad reputation, but the evidence is weak that it has any negative impact on most people.
The brain runs just fine on ketones, rather, it doesn’t need dietary carbohydrate (or sugar) to function. The body actually can make glucose for your brain and other cells that need it from both protein and fat. And keep in mind, a Ketogenic diet isn’t carb-free, it’s just low-carb, so you will be eating carbohydrates (mostly from vegetables).
Nutrient deficiencies are rare if you eat the right foods. Most notably eggs, a staple of the ketogenic diet, are highly nutritious – they need to provide everything a chicken needs to form and thrive! And you will be eating vegetables, lots of them (If you do Keto right).
Kidney damage should not be a concern. A good Keto diet is moderate in protein, not high in protein. And people with normal kidney function can tolerate pretty high amounts of protein without any issues for the kidney. If you need to limit your consumption of protein due to damaged kidneys, you can still eat Keto with a low protein content.
Osteoporosis is not a concern. In fact, some studies show that higher protein actually contributes positively to bone health. The theory of keto being bad for bones is predicated on the idea that the blood pH would change, making it more acidic. Generally, blood pH is controlled by your body. It needs to stay in a narrow range otherwise we would die. The good news is that normally, what you eat doesn’t affect your blood pH.
Being in Ketosis is not the same as Ketoacidosis. Ketoacidosis is actually a rare condition associated with type 1 diabetes (usually if they don’t take insulin). Some folks with type 2 diabetes can also develop ketoacidosis on certain medications. If either of these describe you, you should talk to your doctor about any potential increase in risk for ketoacidosis.

Some side effects you may experience:

Constipation – As your body adapts to the change in dietary composition, you may experience constipation. You may need to drink more water, add salt or fiber to alleviate symptoms. Or, take an over the counter medicine for constipation like Milk of Magnesia. You may also experience fewer bowel movements without constipation. There is no concern with this as long as you are not bloated or have pain or discomfort from it.
Symptoms like depression (Lethargy, irritability, brain fog, and tiredness) – Early in the diet when you are still adapting to the change (like the first 2 weeks), you may experience some of these symptoms. To combat, make sure you are getting enough fluids and maybe add some salt to your diet. Generally, over time, not only do these symptoms go away, most people report more energy and higher mental clarity on a ketogenic diet. Also, if you have eliminated a food you had an addiction to (like sugar) you are likely to go through a withdrawal period similar to that anyone experiencing withdrawal symptoms from other addictions such as alcohol or nicotine. If you stick with it, you can beat the addiction and in the long run, feel much better.
Hair Loss – yes, this could happen. It can happen because of the change in diet (any diet, not just Keto), or from some other stressful experience. As you adapt, it could grow back. But make sure you are getting enough nutrients; avoid starvation.
Exercise Capacity decrease – in the beginning, you may feel sluggish while trying to train. This is typically just the body adapting to using fat for fuel over blood sugars. Regardless of your diet, when you start exercising, your body initially uses stored glucose in your muscles. That depletes quickly forcing your body to turn to other sources of energy. Once you are more fat-adapted, your body will be more efficient at producing this fuel from fat. Depending on your sport, you may actually increase performance on a Ketogenic diet. However, if your sport is non-endurance in nature (think more explosive short-duration bursts of energy like sprints), you may need more carbohydrates in your diet to support training and performance.

What can I eat on a Keto Diet?

The actual breakdown of macronutrients seems to be quite varied across the internet. The original ketogenic diet that was developed to treat epileptic patients as mentioned above had about 90% of their calories come from fat. With this large quantity of fat and a small amount of protein and even less carbohydrate, it’s no wonder a more palatable MCT oil diet was proposed.

However modern proponents of the keto diet propose a lower ratio of fat to carbs and protein.

Let’s start with the premise of what a ketogenic diet is. First, it’s meant to be a Low Carb, High Fat (LCHF) diet, not a low carb high protein diet. Therefore, the calories from protein is far outweighed by the calories from fat. Fat has more than twice the calories of protein per gram, though, so the actual amount of food doesn’t seem that weird. You generally won’t need to eat sticks of butter of gulp bottles of olive oil.

Foods to Avoid

Because the Keto diet focuses on forcing the body into ketosis by severely limiting carbohydrate consumption, there are several high-carb foods that one should avoid. Mostly, these are high starch or high sugar foods. These include grains, fruit, candy or pastries, pasta, rice, beer, and most root vegetables.

These food tend to be higher glycemic and spike insulin.

Foods to Eat

Now that I got the dreaded “thou shalt not have” list out of the way. There are a TON of foods that are perfectly good to eat.

Meat, fish, poultry, eggs
Full Fat Dairy (Yogurt, cheese)
Nuts, seeds (Pistachios, Walnuts, Almonds, Sunflower seeds, pumpkin seeds)
Vegetables such as leafy greens, broccoli, cauliflower
Fats like Olive Oil, butter, avocado oil. (It’s good to get both animal and plant-based fats)

How to Eat a Ketogenic Diet

A good place to start is to have about 70% of your total daily calories come from fat. Aim to have no more than 50g of carbs and about 1g of protein for every kg of body weight(that’s about .5g for 1 pound body weight). If you need to eat fewer calories for weight loss, take out the carbs first.

This gets more complicated because leading proponents of this diet sometimes still break out vegetables and carbs. Vegetables grown above ground have a lower quantity of carbohydrates and a LOT of nutrients. It is generally considered good to eat quite a bit of these. In fact, getting most, if not all, of your daily carbs from vegetables, nuts, and seeds would be ideal. Meaning, you could have carrots, tomato, beets, and berries in small quantities.

Note that some foods like coconuts, avocado, and nuts also have carbs and that must be considered when calculating your carbohydrate for the day.

One way to make this easier would be to imagine a plate, and make half the plate vegetables, and the other half meat (or some type of protein) and fat. Often protein comes with fat. Plus you can douse your salad with olive oil or saute your vegetables in avocado oil.

Choose high-quality whole foods over processed foods.

Over time, as your body adapts to burning fat from your body (not your diet), you can reduce the amount of fat you are eating.

Additionally, many proponents of the Ketogenic diet also suggest combining it with intermittent fasting (Read my primer on Intermittent Fasting). This compounds the benefits of Keto and adds the benefits (namely autophagy) of fasting.

Conclusions

The Keto diet has a rich history of success in treating epilepsy and it mimics the benefits of fasting without having to abstain from eating for long periods. More recent science is pointing to it being beneficial for other metabolic or chronic diseases as well. However, in order to reap the benefits of this diet, one must follow it rather precisely. The science of ketosis is sound but westernized culture has produced an abundance of products that have hidden carbs and sugars that can spike insulin when eaten and kick you out of ketosis. It is important to make good quality food choices.

The ketogenic diet isn’t for everyone. If your culture enjoys pasta, rice, potatoes, and beans, it may be tough (impossible) to give these up forever. And the diet isn’t quite as successful when it is not followed fully. The good news is that, while it is effective for weight loss, it isn’t the only way to eat for sustainable weight loss. But, should you choose to follow it, know that adapting to a ketogenic diet is only the first part, you will need to stay on the ketogenic diet or risk slipping back to old habits and weight gain.

Are you still on the fence regarding a diet? Here’s my overview of popular diets. Or, you can choose to eat healthy without dieting.