Curious about what happens to your body during the course of your ketogenic diet journey? That’s what this article is all about. Here, you’ll find a timeline of the changes that your body will undergo starting from day one.
I really believe that a balanced low carb diet is one of the easiest ways to become healthy. This is especially true for those of us that don’t live in the gym 24/7.
I used to wonder how it would be possible to go long periods of time without eating. “40 days without food!? There’s no way!”. Back then, If I skipped even a single meal, I would be ‘hangry’ and lack energy.
I have come to realize that carb-centric diets are actually creating these problems… That feeling that you need to eat all the time… but really, It’s not the way you should feel.
Carb dependance makes food seem like an addiction.
Keto is a saving grace when it comes to how we treat food. After you fat adapt, you are no longer a slave to food. You eat when you actually need food. Keto puts us in control by making changes to the foods we crave.
It does take time though (normally 2–3 weeks). The body has to go through an induction phase where it ramps up its metabolic machinery for fat burning. I don’t want to make it seem like its easy though because it’s not.
There are a variety of changes that your body will go through on keto. And, side effects are common (while only temporary). In this article, I am going to discuss the timeline of events that take place after you start keto – week by week.
Before continuing, I do want to say that this is only a rough keto timeline. Your individual experience on the diet could vary.
Most people would probably say that the first two weeks are the most difficult. You’ll likely experience a few keto flu symptoms while your body adjusts to a lack of sugar. But trust me, if you do this right – it will all be worth it in the end.
Glycogen (Sugar) Depletion Begins
Your body can run on glycogen stores from the liver for about 24 hours before it runs out. After that, it will try to make sugar from other sources such as protein in your body. It uses a process called gluconeogenesis to do this.
Your muscle glycogen will decrease by about half over the course of a 24 hour fast (keto would be comparable). After that, it will try to preserve what glycogen it has left. [*]
Induction Flu Symptoms Start
There is something called the “induction flu” or “keto flu” that can happen right after starting keto. And there are a variety of symptoms that can come from this. It can last a few days to a few weeks. Check out our common side effects article to learn more about these.
I would recommend that you really stick to the diet for at least 3 weeks in order for your body to properly fat adapt. Some symptoms could extend for longer periods of time if you cheat. Let your adaptation finish first.
Reduced Physical Performance
As glycogen levels drop, you may find it difficult to perform intense exercise. This is normal. Your body is struggling to find sugar to fuel your muscles. I would recommend sticking to light exercise for the first two weeks.
As you approach day 3, your hunger should increase. You may start craving carbs. Don’t give in!
Fat, vegetables, and coffee (in moderation) are your friend. Fat satiates you and coffee helps to boost dopamine to suppress hunger. Green leafy vegetables provide fiber to your gut microbiome which may trigger hunger.
A 2017 study found that obese patients that were put on the ketogenic diet, experienced higher levels of hunger starting on day 3. This continued until about 3 weeks in. After that point, these people didn’t see any further increases in hunger. [*]
This falls right in line with your adaptation period.
Ketones are Excreted Through Urine
Ketone test strips should be picking up acetoacetate in your urine at this point. Around day 3, you should be able to reach .5 mM blood ketone readings. This is at the lower end of the “technically in ketosis” scale.
Muscle wasting can happen in the first few weeks of the diet. The problem is that if a person is carb-dependent, their body will do whatever it can to resupply sugar levels. Unfortunately, that can sometimes be your muscles. Sugar can be made in your body through protein breakdown.
This is why I would recommend taking it easy at first with exercise. It also wouldn’t hurt to add a bit more protein to your diet initially if you are very active. This will help prevent muscle breakdown. [*] [*]
After several weeks, your body won’t do this. Ketones themselves will preserve your muscles. [*]
Reduced Need for Certain Medications
Dr. Phinney and Dr. Volek highlight that some people may be withdrawn from certain medications after 7 days on the ketogenic diet. Both patient and doctor should agree on a plan going forward and do so cautiously.
It is common to see reductions in diabetes, hypertension, and congestive heart failure symptoms.
If insulin is withdrawn, it should be noted that symptoms will return if the person goes back to eating carbohydrates. 
At the beginning of week 2, you’ll probably still be experiencing some induction side effects. Normally, by week 3 most of these are gone.
Water, Salt, and Potassium Loss
Your body starts going through something called the “natriuresis of fasting”. This means that your kidneys switch from retaining salt and water to rapidly excreting it. You could be dropping a few pounds of water weight during this period. It’s not uncommon for someone to lose up to 9 pounds of water in their first 3 months on keto. [*]
The scale isn’t going to be accurate during this time. It can’t differentiate between water loss and fat loss. The best way to check your actual body composition would be a DEXA scan.
Blood Glucose Levels Start to Become Normalized
Once your adaptation is completed (somewhere between 2 and 6 weeks), blood sugar levels are brought to normal ranges regardless of your carbohydrate intake. 
Your Brain Utilizes More Energy from Ketones
As you become adapted, your brain will sense ketones crossing the blood-brain barrier. It will begin using more of them for energy. Over time, your brain and body will become more and more efficient at using fat. The brain can get over 50 percent of its energy requirement from ketones. The rest of it comes from the breakdown of proteins and the healthy carbs you eat. 
Your Body Speeds Up Its Rate of Fat Burning
After you stop eating carbs, your body has no choice but to get good at using fats. It will literally stop turning the carbs you eat into fat.
This also means that your body will change how it handles saturated fat specifically. After adaptation, saturated fat is cleared from the bloodstream and is used for energy. Our bodies prefer burning this type of fat over other types of fat. 
Uric Acid Levels Rise (Urine Acidity)
In the first two weeks of keto, uric acid levels rise. This is due to the competition between circulating acetoacetate and uric acid for release through the kidneys. This is only temporary. 
Some people have experienced kidney pain as a result of this.
By week 3, almost all of your keto induction side effects should be gone.
Inter-organ Ketone Exchange Accelerates
The body becomes better at shuffling different types of ketones between organs. For example, the muscles assist in converting acetoacetate into beta-hydroxybutyrate which is used for fuel by the brain.
There is little waste. Your body reduces the amount of acetoacetate that it is released through urine because your muscles are now using more of it.
Uric Acid Levels Return to Normal – Kidney Adaptation
After 4–6 weeks, the kidneys adapt in response to higher levels of acid in the urine and improve organic acid metabolism. Levels begin to return to normal. 
Digestive System Adjusts to Fat Consumption
Your liver is going to be ramping up on bile production as you continue to eat more fat. Bile assists with fat breakdown. The gallbladder will be storing bile to release into the intestine. Your pancreas boosts digestive enzymes that assist in fat breakdown. [*]
Bile salts are a great supplement for anyone with digestive problems or if you are lacking a gallbladder.
Blood Cholesterol May Elevate During Weight Loss
It is possible that blood triglycerides elevate once weight loss begins. This is especially true if you are dropping 2 or more pounds per week. The reason for this is that during weight loss, fat cells in adipose tissue contain dissolved cholesterol. This is released during weight loss.
Week 6 +
Metabolic Adaptation Completes
Studies have shown that physical performance in athletes returns to baseline after 6 weeks of keto-adaptation. Multiple organs in your body are now way more proficient at using fat for energy. They either burn fatty acids directly or use ketone bodies. [*]
Reduced Appetite and Easy Weight Loss
This is the point at which serious weight loss should occur. Everyone is different but you should expect to be losing around 2.5 lbs per week of body fat. 
Keto makes it really easy to eat less and lose weight. After adaptation completes, expect to have a reduced appetite. This is especially true if you have excess weight to lose.
Weight Maintenance Period Starts
As you approach your weight loss goal, expect to have an increased appetite. Your body should be telling you that it needs more calories from external sources. You would want to increase your calories from fat at this point.
My hope is that you are able to to get to this final step. And if this is you, I want to congratulate you on a job well done!
Welcome to the new you!
There are many benefits to keto that sit on the other side of this small adaptation period. Any problems you are experiencing should be resolved within 6 weeks. What is 6 weeks when you can enjoy the perks of keto your entire life? Its nothing!