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A few weeks ago I contemplated fasting. Digging deeper into the science of fasting I stumbled upon the Keto diet. I found this introduction by . It is the most easily comprehensible introduction I was able to find. A vegan myself I can tell the Keto diet is perfectly adaptable to a plant based diet. If you are a vegan, just ignor the references to animal products.

How to Transition Through Every Ketosis Phase: Part 1

Adapting your body to burn fat instead of carbs involves five specific phases. Each Ketosis phase happens in a predictable order that has been researched and studied. Scientists documented the body’s transitions by entering patients into a fasting study. They fasted for forty days. Each phase marks changes in your blood chemistry and occurs at specific, scientifically predictable times. With hopes of not overwhelming you, I will take three blogs to cover all five phases. Each phase teaches how much of your body is using ketones versus glucose. Take note specifically of what fuels the brain in each phase. This post gets us through phases one and two.

Ketosis Phase 1: Use Up The Sugar In Blood


  • STATUS: Your fuel is 100% glucose during phase one. The glucose you burn comes from the carbs you just ate or drank. NOT ONE section of your body runs off ketones.
  • BRAIN: Powered only by glucose.
  • Entering Phase 1 is the easiest part of getting into ketosis. You do this every night when you go to sleep. You simply use up the sugar that’s currently in your bloodstream. Every time you eat more than a spoonful of sugar or a handful of carbs you reset your system back to the beginning of Phase 1.

Phase 1 begins by processing the glucose that’s already in your blood. This glucose came from the food you ate over the last 4 hours. Phase 1 is short. It ends after 4 hours unless you reset things by eating more carbs. Then it starts over. Don’t do that.

Go to bed two hours after your last carbohydrate. Before you wake up, you are through Phase 1.


Ketosis Phase 2  Burn Sugar Stored In Liver

  • TIME: 12+ HOURS
  • STATUS: Your fuel is still 100% glucose, but now your carb fuel is coming from your stored sugar called glycogen.
  • BRAIN: Powered only by glucose.
  • You burned up those circulating sugars in your bloodstream. With no more food coming into the body through your mouth, your system will use your stored sugar. This stored sugar is called glycogen, and you keep it in your liver cells. Phase 2 fuels your body using this stored energy.

How Long Will Your Storage of Glycogen Last?  Good Question.

The answer depends on a couple of things: the size of your liver and the level of energy usage in Phase 2. Sleeping during this phase takes less fuel than running for 45 minutes. Fighting cancer or infection requires more fuel than living without those issues. Mending a broken bone or repairing from surgery requires more energy than sitting at your desk writing a blog.

In addition, how large is your storage tank? Asked another way: How big is your liver? I bet you’ve never thought about that. Its size depends on how much stress you’ve put on your life in recent years. Your liver constantly grows new cells to meet your body’s needs.

If you drink excessive alcohol for twenty years, you will make additional liver cells to keep up with your drinking. Similarly, if you eat lots of extra carbohydrates for two decades, your liver will expand to store your extra sugar.

From my experience, patients with the largest livers are not alcoholics. Instead, the biggest livers belong to my patients addicted to carbs. If they are not already diabetics, they will be. They have overstuffed their livers with the age-old habit of constantly eating carbohydrates. They don’t allow enough time to empty stored sugars before eating more.

Long before diabetics are diagnosed as such, their livers strain from the pressure of the carbs they eat. They make more and more liver cells to keep up with the carbohydrate onslaught. If they cannot make extra liver cells as fast as they overeat, sugar remains in their bloodstream longer than normal. Insulin works overtime whipping the glucose into the mitochondria’s furnaces or into storage. The danger signal of insulin rings constantly. They keep eating and therefore more sugars enter the bloodstream before the abundant pine needle-like fuel gets burned or stored. The screaming alarm signal of insulin becomes a constant noise. This hormone’s danger signal becomes less and less effective as blood sugars steadily rise.

Diabetes is defined as a state of constantly elevated blood sugars. Diabetics never empty their storage. I do mean NEVER. Their liver cells are stuffed with glycogen. Their cells have no more room. In an attempt to store their extra sugar, they grow additional liver cells.

Did you empty your liver last night? Let’s check. After 12 hours with only water, prick your finger and check your fasting blood sugar.

Don’t roll your eyes. You must know someone who has diabetes and checks their blood sugar. Borrow their glucose monitor for one day. No, they won’t die if they don’t check their sugars for a day.

If you burned through all your glycogen and emptied your storage [emptied your liver] your fasting sugars will fall between 55-80 mg/dL. That’s a surefire sign you have a normal sized liver. If your liver has been stretched and stuffed with too many extra carbs in recent years, you won’t burn through all the storage in 12 hours. It might take you 20 hours to burn all those pine needles. Some severely overweight patients take a week. If your blood sugar is greater than 120 mg/dL at 12 hours of fasting, you have DIABETES. No joke! That’s the rule of how to diagnose a diabetic.


  • THIS STARTS: 24 HOURS after you ate your last carbohydrate.
  • STATUS OF THE BODY: Your fuel is still mostly glucose, but your liver begins making ketones. Only a couple of areas in your body use ketones as fuel in phase 3.
  • YOUR BRAIN: Still powered only by glucose.

You will know the exact point when you complete phase 2 and enter phase 3. How? You start peeing ketones! Transitioning from phase 2 to 3 happens at different times for different people because of the liver’s variables described previously.

If you pee ketones by the end of the second day of cutting out carbs, do a little dance. You are not likely to be the owner of a stubborn liver. Keep track of how long it takes you to get to ketosis phase 3. This time-to-first-urine-ketone predicts the size of your liver. Much like your fasting blood glucose results, this information tells you and your medical team what has been happening under the surface.

What is the key? Reduce your daily carbs to 20 grams or less. This shocks your sugar-dependent system. In ketosis phase 1, every cell in your body fueled their furnaces with glucose; specifically, your brain is 100% dependent on sugar.

In phase 3, certain parts of your body switch to using ketones for fuel. The first tissues to adapt is your liver. Yep. That stubborn liver makes the first ketones. In fact, your liver supplies the majority of your ketones. The rest of your body will slowly learn to BURN ketones. Only the liver and a few other types of cells make ketones.

Once ketones are circulating in your blood, the first cells to use them are your fat cells and your muscle cells.

Other sections of your body are more protective of which fuel they use. Those tissues wait to see if this ketone fuel will be available only temporarily or long term.

Here’s a cell ranking from most to least adaptable to use ketones: fat cells, muscles, skin, internal organs (heart, lungs, and kidneys) and brain.

The brain is the most resistant to fuel transition. That makes sense.  We don’t want our most vital organ flip-flopping between fuel sources. The brain waits the longest to convert to fat-based energy. When the brain finally switches over though–it feels good. SO GOOD!

Here is the play-by-play transition that I recommend for you. Just follow these steps:

Eat your final carb-based-meal and a couple of hours later go to bed.

When you awake, you are nearly 10 hours into your transition.

Within the next 12 hours, your liver will empty your stored sugar.

Throughout the day, use MCT C8:C10 oil or heavy whipping cream in your coffee. Drink water. Eat all the eggs you want. Cook them in butter.

Eat a couple of sausage patties or bacon for lunch. For work, take along some high-fat cheese and slices of pepperoni in case you feel like eating in between meals.

That evening, go out to eat and order buffalo wings dipped in blue cheese dressing. Be sure to order the wings in buffalo sauce and not honey mustard or barbecue sauce. Those have carbs in them. You want the buffalo sauce. Eat wings until you are full. No beer. No soft drinks. No breading on your buffalo wings. Keep the skin on. Double dip them in blue cheese dressing. Add only water for a drink.

By 8 o’clock that night, your liver should be cleared entirely of glycogen. It should be completely clear of stored sugar. Your early-adapting organs will gradually begin to switch their fuel source to ketones.

Go straight to bed. Forget about getting a carb-rich snack like you’re used to. If you followed instructions, your cupboards should be emptied of all those temptations anyway.

You’ve made it 24 hours since your last helping of carbohydrates. These next 12 hours are best dealt with by sleeping and staying SOBER: Don’t drink booze. Touch any alcohol, and you can kiss ketosis goodbye.


I have had some patients report their bedtime as 8 PM that first night. They did not know how else to get off their normal routine. I don’t care how you do it, just get to the next morning.

Wake up the next morning. It’s been 36 hours since your last high dose of carbohydrates. This puts you almost always into ketosis phase 3. Check your ketone strips. Even a slightly pink color on the strip is a win.

Stubborn livers beware! If your liver is overworked, stretched out or engorged with stored sugar, you might not be there yet. If you’ve been a huge carb junkie, overweight for many years, or a full-blown diabetic, you might have another day ahead before your ketone test turns positive.

Make this your morning ritual: Check your ketone urine strip.

Put four more strips in your pocket. These little urine-strips break down when exposed to air for too long. You have only that day to use the strips in your pocket. Otherwise, throw them away. Each time you pee, check your urine for ketones.

Use those ketone strips to see exactly which ketosis phase you are in. Are you in ketosis phase 2 or have you arrived at ketosis phase 3? The answer is hidden unless you look.

ketosis phase

Before I insisted that patients check their ketones, several patients who needed this lifestyle the most gave up. I lost them in frustration. This sets in when you don’t know what is going on inside your system. Changing eating patterns shocks the daily routine of most patients. They are delighted when the results hit them – mentally and physically. But if the results never come, frustration leads to failure. They ask for my help, and I need reliable information to help them. Keep track of how long it takes your liver to empty. Check your urine ketones.

My experience with peeing my first ketone involved a full month of frustration. I was insulin resistant and then I ate too much protein. I realized I had one of those stubborn livers. I was also unaware of the carbohydrates hidden in gum, toothpaste, cough drops and sauces. I didn’t know the mayonnaise I was using had carbs in it. I also ate soups made with flour. I would be doing well and then BAM-no more ketones.

Had I not been looking at that urine ketone strip the first month, I would have certainly given up. The mistakes I was making would have been unknown without that feedback.



  • STATUS: Your fuel is now a blend of ketones and glucose. Gradually more sections use ketones as fuel.
  • BRAIN: Powered mostly by glucose, but a few cells use ketones.

This phase focuses on converting stubborn parts of your body to burning fat for fuel. Your ketone resistant cells begin transitioning. By Phase 4 your liver is really good at making ketones from fat. Your blood abounds with these compounds because all liver cells turned on their ketone-producing engines. Slowly the rusty, unused cell parts that make and burn ketones have come to life. If we checked your blood, we would find a hearty amount of ketones ranging from 2-3 mMol/dl.

As the liver pumps out a steady stream of this fuel, the rest of your body is still getting used to processing ketones. Over the two weeks of Phase 4, your ketone efficiency catches up with your liver’s abundant production. By the end of this ketosis phase, your blood ketones will settle into the 0.5-1.5 mMol/dl range.

Now might be a good time to remind you why in the world those ketones are in your urine. Weren’t you supposed to make ketones to fuel your body? Why are they in your urine? Why didn’t we keep them all circulating in the blood?

When you are in Phase 4, the mismatch between how well your liver makes ketones and how efficiently the rest of your body uses them leaves you with too many. Your kidney closely watches your body’s chemistry. Too many ketones trigger the kidney to pass them into the urine. The kidneys and your lungs act as an overflow valve for the extra.

Before you get disappointed about wasting those valuable ketones, keep in mind, they used to be fat calories. You are literally peeing out extra calories! What a magical weight loss plan! Right?

By the end of Phase 4, nearly every cell has processed its own ketone. Your cells may not yet use this fuel steadily, but all of them activate their ketone burning furnaces. Even your most resistant organs have a few cells running on this fuel.

If you kept those carbs less than 20 grams per day, your storage tank is sure to be empty. Your body makes glucose less and less as more cells use ketones instead.

Wait a minute. If you’re not eating carbs and you burned through all the ones you had in storage, where is all this glucose coming from?

ANSWER: It is coming from your fat too. Your fat chains, called fatty acids, travel in groups of three. These three chains are held together by a little glucose-based molecule. Your liver clips off the fat to turn into ketones. A tiny amount of glucose is left over. This tiny source of glucose is saved for your stubborn organs that have a difficult time switching over to pure ketones.


  • STATUS: Your fuel is mostly ketones with a sprinkle of glucose.
  • BRAIN: Powered mostly by ketones, but still uses glucose.

Phase 5 is a when your body becomes the well-oiled machine it was designed to be. Each mitochondrion that can use ketones now efficiently handles this fuel type. Thanks to the steady, constant supply of ketones your cells efficiency to process them increased. They are produced and burned at almost equal rates. Because your production and usage are better matched,  your ketones no long circulate as long. Phase 5 is marked by a significant drop in your blood ketones. Subsequently, the amount spilling into your urine drops, too.

In a rare moment, your ketone production and usage match perfectly, leaving no extras in your urine. This can be tricky if you are only checking urine ketones. Did your ketones stop showing up in your urine because you ate a bunch of carbs? Drank booze? Maybe the bottle of strips was left open and went bad? Or did your urine ketones stop appearing because your system had a perfect match? Rest assured, the first three options are much more likely. In previous phases, the perfect matched situation was not an option.  In Phase 5, it is an option.

Phase 5 is the holy grail. Once your brain reaches this state, you will better appreciate all the hype surrounding a ketosis lifestyle. It borders on euphoric. When patients enter Phase 5, their depression symptoms lift, their focus improves, their attention lasts longer, their sleep is more restful, and their energy is contagious.

How do you get to Phase 5?

There is a fast way and a slower way. The fast way is a strict fast. That is not a play on words. I am referring to an absence of foods. A strict fast is a time of no calories. Only water, tea, or coffee. That’s all. Strictly limit yourself to only those items, and you will be at Phase 5 in about 30 or 40 days. That’s a tough sell.

I DO NOT recommend this option; especially if you are eating a high-carbohydrate diet right now. High carbohydrate means eating over 60 carb grams per day. There are just too many chemistry shifts that have to happen in your system. It’s too unsettling, too uncomfortable, and in many of my chronically ill patients, it’s dangerous.

Instead, transition to Phase 5 using a high-fat diet. Patients transition to a high-fat diet and pee ketones for several weeks. This allows time to adjust. It also provides time to see how much social pressure is placed on eating carbohydrates and low-fat foods.

Screw-ups often happen when first eating high-fat low-carb. They drink alcohol. They eat too much protein. They get stingy on their fat consumption. They mindlessly binge on ice cream after a stressful day. [or maybe that is just me!]

Or someone near them celebrates an occasion with sugary treats, and the temptation becomes too great at the moment. The bottom line?

Changing habits is hard.

The idea that a smoker wakes up one day and stops smoking for the rest of his life is a fantasy. That person who ‘suddenly’ quits smoking had months, maybe even years, of thoughts and false starts about quitting before they stopped for good. Their environment played a significant role in their success. If their world tempted them with cigarettes at every turn, their chances of achieving a smoke-free life one year later are unlikely. People in keto transition need support. Without it, temptations win out.

MY GOAL: a healthy life.

Not a sprint to ketone positive urine tests. The key to sustainability is the LONG GAME.

Ultimately, it doesn’t matter whether you get to Phase 5 in 6 weeks or 6 months. Boost your chances of lifelong success by keeping your priorities straight. Remember why you decided to go keto in the first place. Write it down. Say it out loud. Share it with a friend. My personal reason for going keto: Brain fuel, brain fuel, brain fuel.

If you want to learn more about the ketogenic diet, check out the book ANYWAY YOU CAN on Amazon or Audible by Annette Bosworth, MD.