Ketosis 101: A Complete Guide

What is Ketosis

The term ketosis may sound unfamiliar to most but it’s been recently gaining popularity due to its immensely beneficial effect on both physical and mental health. It is metabolic state of the body which can be attained from carbohydrate insufficiency.

Ketosis is deeply embedded into our most primal genes – it has helped humans survive prolonged periods of ice ages when carb-rich plant foods were scarce. During these periods, early humans relied on animals for food, meaning all they took in was fat and proteins. Naturally, the human body had to adapt to its new primary fuel source, thus prompting ketosis.

Carbohydrates may be the most available source of energy of the modern world, but they can easily be replaced by fats. When replacing carbohydrates with fat, the body will eventually enter ketosis and start producing ketones as a byproduct of burning fat.
These ketones, are what’s responsible for a slew of health benefits when undergoing ketosis.

What are Ketone Bodies?

Ketones are molecular byproducts produced within the body once it starts burning fats. They are created within the liver to help it metabolize the fat cells your body starts burning through during the beginning stage of ketosis. They can be used as a fuel source by both the body and brain, and provide much more energy output per gram than carbohydrates.

In fact, they are roughly 70% more efficient than carbohydrates or any other carb-derived molecule. Once ketones begin powering the body and brain a wide range of positive symptoms and health benefits occur. The body becomes much more energized, (physically and mentally) performs better in both aspects and staves off a myriad of diseases both physical and neurological.

Ketones come in three main forms: Acetoacetate, Beta Hydroxybutate and Acetone.

Acetoacetate are the first ketones to be developed within the body. These ketones end up being used as fuel or shift into the other two ketone forms. They make up for roughly 20% of all produced ketones within the body during ketosis.

Beta Hydroxybutate are the most prevalent ketone within the body, making up for roughly 78% of all ketones during ketosis. They are created from acetoacetate oxidation. They aren’t technically ketones due to their differing molecular makeup, but are considered as such due to their prime role in ketosis.

Acetones are non-usable ketones that are spontaneously created via acetoacetate oxidation. These ketones are quickly broken down and expelled from the body primarily through fluids or air.

Once these aforementioned ketones reach millimolar levels of 0.5mmol/L within the body, ketosis is in full effect. However, acquiring this level of ketones requires a strict minimal-carb diet, also known as the ketogenic diet.

What is the Ketogenic Diet?

As was previously mentioned, the ketogenic diet’s fundamental rule is to keep carb intake to a minimum. Minimal carb intake leads to ketosis, and the ketogenic diet establishes which foods and food groups should be focused on when attempting to reach ketosis. There are a great deal of foods and food groups that it permits, however it may come as a surprise to most to find out just how many foods are filled with carbohydrates:

Foods to AVOID during the keto diet:

The following carb-rich foods and food groups should be avoided when keto-dieting:

  • Vegetables that grow below ground (starchy vegetables such as potatoes, carrots, corn, beets, and pumpkin contain moderate to significant amounts of carbohydrates)
  • Bread (bread is a carb-rich staple food that must be substituted when keto-dieting)
  • Fruits (the sweeter the fruit, the more carbs it packs)
  • Grains (avoid cereals when keto-dieting – this includes oats, wheats, rye and quinoa)
  • Rice (a carb-rich staple food grain)
  • Pastas (all kinds of pastas pack plenty of carbs, this includes macaroni and noodles)
  • Beans & legumes (these two food groups while healthy, do pack significant amounts of carbs)
  • Cashews, pistachios & pumpkin seeds (these contain the most carbohydrates out of all seeds and nuts)
  • Low fat dairy products (most low-fat dairy products are chock-full of carbohydrates to add taste)
  • Milk (milk and skim milk contain up to 50g of carbs per cup)
  • Processed meats (cold cuts, sausages, salami and other processed meats tend to have high amounts of carbs added for flavor)
  • Processed sauces (ketchups, bbq sauce, mustards and other common sauces are packed full of carbs)
  • Pastries (anything made from dough has a high carbohydrate content)
  • Sodas (fizzy soda drinks are essentially all carbohydrates)
  • Candies, chocolate sweets (this one’s a no-brainer)
  • Beer & Sweet liqueurs (beer contains significant amounts of carbohydrates, as do sweet liqueurs)
  • Artificial sweeteners (Artificial sweeteners can have a counteractive effect towards ketosis despite the fact that they’re not carbohydrates)

Despite the keto-diet’s restrictions on carbohydrates, it does allow plenty of tasty foods and food groups to be consumed:

Foods to eat during the keto diet:

  • Vegetables that grow above ground (preferably leafy greens)
  • Eggs (eggs contain plenty of healthy fats and protein)
  • Poultry meats (meat should be eaten sparingly while keto-dieting to keep from overly-high protein intake, which counteracts ketosis)
  • Fish & Seafood (all seafoods contain very low quantities of carbohydrates and plenty of fat – avoid breaded seafood)
  • Cheese & full fat dairy products (fatty dairy products and cheeses  contain very low carb levels)
  • Avocados (one of the only fruits containing almost no carbohydrates)
  • Natural fat cooking oils (olive oil, coconut oil and full-fat sauces contain almost no carbs)
  • Olives (olives are packed full of healthy fats)
  • Nuts and seeds (in moderation due to high caloric content – avoid cashews pistachios and pumpkin seeds)
  • Berries (in moderation due to not-so-low carbohydrate content)
  • Unsweetened teas and coffees (avoid artificial sweeteners)
  • Cocoa powder & dark chocolate (great low-carb alternatives for chocolate)

No matter with which meal plan the keto-diet is attempted, it’s fundamental to stick to the aforementioned foods while avoiding carb-heavy foods.

Different Keto Diet Styles

There are four different methods within ketogenic dieting, and they are as follows:

1. Standard Ketogenic Diet  – The most common variation of the ketogenic diet consists of minimum carb intake (5% of all nutritional intake) and a moderate protein intake. (25% of all nutritional intake) The remaining nutritional intake is composed of fats. (70%)

2. Protein Ketogenic Diet – This variant is essentially the same as the standard keto diet except with additional protein intake. (+5-10% added proteins) T
This keto diet is commonly used by weightlifters attempting to increase muscle hypertrophy.

3. Targeted Ketogenic Diet – This version of the ketogenic diet consists of exercise following carb intake in an attempt to focus on weight loss.

4. Cyclical Ketogenic Diet – This variant is preferred by those whose bodies react especially badly towards carb deficiencies. It consists of increasing the allowed carb intake for a select amount of days before returning to the traditional low carb intake of the standard keto diet.

The general rule for all variations of the ketogenic diet is to keep carb intake within 20g-50g per day, which should make up 5% of your entire nutritional intake. Your fat intake should be composed of the aforementioned foods which contain healthy fatty acids. Your protein however, should by all means be restricted to moderate levels:

A Note on Protein

Excess protein levels will keep you from achieving ketosis. When the body is starved of carbohydrates, it is capable of converting protein-derived amino acids into glucose – the same fuel source derived from carbohydrates. Glucose is what you’re trying to avoid, so make sure to keep a low to moderate protein intake so as not to delay ketosis.

The best way to figure out how much protein you need is to use a keto macros calculator to figure out your lean body mass. (your body mass without included fat)
Once you’ve figured out your lean body mass, apply the following rule to figure out how much protein you’ll require under the ketogenic diet:

  • 0.08 multiplied by your lean body mass (if using keto macros calculator in imperial system)
  • 1.8 multiplied by your lean body mass (if using keto macros calculator in metric system)

The end result will be how much grams of proteins you’ll need to receive per day under the ketogenic diet.

Following the aforementioned intake rules as well as any of the diets will eventually lead to ketosis, and there are a number of ways one can find out whether they’re in ketosis or not.

How to Know You’re in Ketosis

Ketosis typically occurs 2-10 days after following a ketogenic diet. While it yields a lot of health benefits once in full effect, there are a few negative symptoms that come before it as a result of carbohydrate insufficiency. This transitional period is known as the ‘Keto Flu’, and usually lasts up to a week, subsiding once optimal ketosis takes effect.

The keto flu is commonly experienced by keto-dieters, however the intensity of its symptoms as well as its duration largely depend on a person’s genetic makeup. The symptoms of the keto flu are as follows:

  • Increased thirst
  • Frequent urination
  • Digestive problems
  • Fatigue and weakness
  • Irritability
  • Mild-to-moderate nausea
  • Bad breath
  • Sugar cravings
  • Digestive problems
  • Brainfog

It’s important to remember that the keto flu is only a temporary condition triggered by carbohydrate deficiency. It’s uncommon for the symptoms to have a high intensity and they almost always begin disappearing after a week at most. The keto flu is a natural reaction to onset ketosis, which means if you’re experiencing these symptoms then you’re dead-set for ketosis so long as you stick to the diet.

There are a number of ways to alleviate keto flu symptoms:

  • Drink plenty of water
  • Drink bone broth soup
  • Drink electrolytes
  • Eating fatty food
  • Rest or nap

Ketosis Symptoms

Once the grueling symptoms of the keto flu have passed, the real benefits of ketosis can be felt. One of the best things about ketosis is that its benefits are largely the same symptoms as the keto flu, although reversed – instead of fatigue and brainfog, ketosis imbues the body and brain with an abundance of energy.

The constant flow of ketones to your cells provides an incredibly pleasant feeling which could even increase quality of life. Here are some of the most distinguishable ketosis benefits:

Increased energy: The ketones will provide a constant influx of energy, and no carbs means no sugar crashes.

Increased mental performance: The brain will be able to work cognitive processes much more efficiently when powered on ketones, and mental fatigue will decrease.

Hunger suppression: Your body will constantly be burning through fat and be fueled by ketones, which will result in infrequent signaling for hunger.

Increased physical performance: A ketone-energized body will be able to exert much more force and perform better physically than when powered on carbohydrates.

Improved mood & motivation: Mood is linked to health, and when your body and brain are powered on the healthiest natural fuel source it will undoubtedly improve mood and increase motivation.

Fat Loss: Your fat stores, especially visceral and other kinds of fat that’s hard to burn through, will gradually diminish under ketosis.

What is the Keto Flu?

The keto flu is the body’s natural reaction to being starved of carbohydrates. While the body is perfectly capable of burning fat as a prime source of fuel, it will react negatively towards being robbed of its long-time favorite energy source. People attempting the keto diet usually experience the keto flu 1-2 days after cutting down on carbs. The flu itself usually lasts around a week, and it’s symptoms are:

  • Dehydration
  • Cravings for sugar
  • Irritability
  • Stomach pains
  • Nausea
  • Poor focus and concentration
  • Brain fog
  • Dizziness
  • Cramping
  • Confusion
  • Muscle soreness
  • Constipation

Keep in mind that these symptoms are transient and only last while your body is undergoing the metabolic switch from carbohydrates to ketones ( 2-7 days). There are a number of remedies to help ease these symptoms:

Remedies for the Keto Flu:

  • High water intake
  • Drinking electrolytes
  • Eating more fat
  • Exogenous ketones
  • Rest

The Keto Flu Varies Depending on the Person:

The intensity of keto flu symptoms as well as its duration depend on the individual’s genetic makeup. Some people barely experience these symptoms, while other can have quite an unpleasant experience. The main thing to remember is that the symptoms are temporary and should start disappearing within a week. Once your body adapts to the ketosis you will feel fuller, more energized and more focused than ever before.

The keto flu is common with those attempting the keto-diet, however there is another condition that’s commonly mixed up with ketosis due to the similarity within the names and the function of ketones within both conditions: Ketoacidosis

Ketosis Health Benefits

The many health benefits yielded by ketosis are as follows:

Improved blood sugar health: The low carb-lifestyle which comes hand-in-hand with ketosis means you won’t be eating foods that can be detrimental to blood sugar.

Improved cardiovascular health: The ketogenic diet focuses on foods abundant in healthy fats. These foods and food groups promote the production of HDL (‘good’) cholesterol while at the same time suppressing the production of VLDL (‘bad’) cholesterol.

Keeps cancers from developing: It is believed that many classes of common cancers develop from the extra glucose we add to our bodies by eating too much carbohydrates. Ketosis cannot be maintained while regularly eating carbohydrates, which means that a ketosis lifestyle will likely prevent these cancers from developing or possibly becoming malignant. Additionally, the body’s cells will be running on ketones which provide much more energy than carbs, which can inhibit cancer cells from developing.

Regulates hormones: Most hormones that govern appetite and weight regulation are directly affected by carbohydrates in an adverse way. The carb-free lifestyle supported by the ketogenic diet will help keep hormone levels regulated.

Keeps several diseases at bay: On a physical aspect, ketosis helps with cardiovascular health (preventing heart disease), blood sugar levels (which prevents diabetes) stops cancers from spreading, improves stomach function and regulates hormones. On a neurological aspect, ketosis helps keep your brain healthy and energized, which is directly linked to decreasing the likelihood of the development of several brain diseases and conditions. (Alzheimer’s, Parkinson’s, seizures, etc)

Improves mental health: Not only does ketosis help keep your brain sharp and disease free, but it also keeps it from developing certain psychological disorders by keeping its neuroplasticity healthy. Several mood disorders such as anxiety, depression, bi polar behavior and more are directly linked to poor brain health and excessive carbohydrate intake. A carb-free diet together with a ketone-powered brain means less chance of these disorders developing.

Measuring Ketosis

It’s also possible to measure ketosis by using several apparatuses in order to test for ketone levels in the blood. This is a much more accurate way of establishing whether you’re undergoing ketosis or not as opposed to observing the symptoms. There are three main methods of ketone measurement:

1. Urine strips – urine strips are the most convenient and cost-effective way of measuring ketones. There are several brands of affordable ketone-measuring urine strips available for purchase online and in some pharmacies. These strips work by being dipped in a urine sample, showing ketosis levels within millimolar measurements roughly 15 seconds afterwards. These tests measure for the acetoacetate ketone. Keep in mind that it’s best to use an alternative method to get the most possibly accurate results, as ketone levels in the urine subside after the initial stages of ketosis. Proper timing is crucial when measuring for ketones via urine strips.

2. Breath analyzer – breath analyzers are more accurate than urine strips for measuring ketones. They aren’t as cheap as urine strips, but one breath analyzer is enough to test for ketones essentially countless times. Breath analyzers which measure ketone levels work by measuring the levels of acetone within the breath of the testee. This testing apparatus also typically gives a ketone indication in millimolar measurements. They can be purchased in some pharmacies or online.

3. Blood meters – this is the most accurate method of testing for ketones. Blood meters work by examining a tiny blood sample which is deposited onto a testing tab. This ketone testing apparatus gives an accurate measurement of beta hydroxybutate levels within the bloodstream within millimolar levels.

If any of these aforementioned tests result in a millimolar level of 0.5mmol/L or greater then ketosis is in effect. Optimal ketosis (the intensity of ketosis which yields the best benefits) occurs at 1.5mmol/L through to 3.0mmol/L. There are four different ‘intensities’ of ketosis depending on the ketone levels within the bloodstream:

Ketosis Levels

  • 0 – 0.5 mmol/L – Ketone levels below 0.5 mmol/L are too low to induce ketosis.
  • 0.5 – 1.5 mmol/L – These ketone levels are sufficient for light nutritional ketosis to take place. This is an early stage of ketosis that keto-dieters will experience during their first few days of keto-dieting. This level of ketosis is usually when the effects of the ‘keto flu’ can be felt.
  • 1.5 – 3.0 mmol/L – These ketone levels indicate optimal ketosis. This is when the positive symptoms of ketosis can be felt at their peak, and when the body has begun to use ketones as its primary source of fuel.
  • 3.0 – 5.0 mmol/L – These excessively high levels of ketosis do not yield any additional positive symptoms or benefits. This is what’s known as starvation ketosis – these levels of ketones signify a severe lack of insulin causes by nutritional deficiency. Type 1 diabetics can reach these levels when in need of an insulin shot or carbohydrates.
  • 5.0 mmol/L  + – Ketone levels over 5.0 mmol/L indicate ketoacidiosis – a serious medical condition caused by severe nutritional deficiency or extremely low insulin levels. Ketoacidosis is commonly mistaken for ketosis due to the similarity of the name as well as the roles that ketones play in both conditions, however it is NOT the same thing.

What Ketoacidosis Really Is

This potentially fatal state of the body occurs under two conditions: severe starvation, or a lack of insulin which type 1 diabetics suffer from. Ketoacidosis cannot be achieved by any means from healthy people regardless if they’re attempting the ketogenic diet or not.

Unlike ketosis, which is a completely natural metabolic state, ketoacidosis is characterized with a series of adverse symptoms which continuously progress if not treated. They are as follows:

  • Nausea – Commonly the first symptom of ketoacidosis.
  • Vomiting – Vomiting takes place soon after ketoacidosis starts.
  • Weakness – Weakness typically follows vomiting when ketoacidosis takes place
  • Confusion – When the body is in shock due to ketoacidosis, the brain begins to panic and thinking becomes impaired
  • Coma – If not treated on time, ketoacidosis could lead to coma and possibly death

Again, it is almost impossible for ketoacidosis to happen to a healthy individual undertaking the ketogenic diet. Type 1 and 2 diabetics are the most prone demographic to ketoacidosis, which is why it’s not recommended for them to take on the ketogenic diet.

Bottom Line

  • Ketosis is a natural metabolic state reached by holding off on carbs for a prolonged amount of time.
  • Ketosis occurs once ketone levels within the bloodsteam reach 0.05mmol/L, or when the body has completely adapted to relying on fat as a primary fuel source.
  • Ketosis takes full effect once ketone levels reach 1.5 mmol/L – this is when its positive symptoms can be best experienced.
  •  It takes roughly 2-10 days to reach ketosis depending on individual metabolism and genetic makeup.
  • Ketosis is greatly beneficial for physical and mental health.
  • The ketosis lifestyle promotes minimal carbohydrate intake, which leads to additional beneficiary effects towards physical health.
  • The ‘keto flu’ is a range of negative symptoms experienced once carbohydrates have been withheld from the body for a few days. The symptoms usually pass after a week before full ketosis sets in.
  • Ketoacidiosis is a life-threatening state which occurs from severe insulin deficiency – it usually does not affect non diabetics.
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