What is ketosis?
Ketosis is a process that occurs when your body uses fat as its main fuel source. Normally, your body uses blood sugar (glucose) as its key energy source.
You typically get glucose in your diet by eating carbohydrates (carbs) such as starches and sugars. Your body breaks the carbohydrates down into glucose and then uses the glucose as fuel. Your liver stores the rest and releases it as needed.
When your carb intake is very low, these glucose stores drain down. Since your body doesn’t have enough carbs to burn for energy, it burns fat instead. As your body breaks down fat, it produces a compound called ketones. The ketones, or ketone bodies, become your body and brain’s main source of energy.
The fat your body uses to create ketones may come from your diet (nutritional ketosis), or it may come from your body’s fat stores. Your liver produces a small amount of ketones on its own. But when your glucose level decreases, your insulin level decreases. This causes your liver to ramp up the production of ketones to ensure it can provide enough energy for your brain. Therefore, your blood has high levels of ketones during ketosis.
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What is the ketosis diet?
The ketogenic (keto) diet changes the way your body uses food. Typically, carbohydrates in your diet provide most of the fuel your body needs. The keto diet reduces the number of carbs you eat and teaches your body to burn fat for fuel instead.
The keto diet is high in fat, moderate in protein and low in carbohydrates. The standard keto diet consists of 70% to 80% fats, 10% to 20% proteins and 5% to 10% carbohydrates.
Many nutrient-rich foods contain high amounts of carbohydrates. This includes whole grains, fruits and vegetables. Carbs from all sources are restricted on the keto diet. So you’ll have to cut out all bread, cereal and other grains and make serious cuts to your fruit and vegetable intake. The types of foods that provide fat for the keto diet include:
- Meats and fish.
- Eggs.
- Nuts and seeds.
- Butter and cream.
- Cheese.
- Oils such as olive oil and canola oil.
How many carbs do I need for ketosis?
You’ll need to stay under 50 grams of carbohydrates per day to enter and stay in ketosis. That’s about three slices of bread, two bananas or 1 cup of pasta.
How long does it take to get into ketosis?
If you eat between 20 and 50 grams of carbohydrates each day, it will usually take you two to four days to enter ketosis. However, the time it takes to enter this state varies based on several factors. It may take you a week or longer to get into ketosis. Factors that may influence how long it takes you to achieve this state include your:
- Age.
- Carbohydrate, fat and protein intake.
- Physical activity level.
- Metabolism.
- Sleep health.
- Stress level.
If you eat a high-carb diet before starting a keto diet, it may take you longer to reach ketosis than someone who consumes a low-carb diet. That’s because your body needs to exhaust its glucose stores first.
You may be able to get into ketosis faster with intermittent fasting. The most common method of intermittent fasting involves eating all of your food within eight hours. Then, you fast for the remaining 16 hours of a 24-hour period.
What are the benefits of ketosis?
Research has shown that ketosis may have several health benefits. One of the biggest benefits of ketosis may be weight loss. The process can help you feel less hungry, which may lead to eating less food. It can help you lose belly fat (visceral fat) while maintaining a lean mass. Other possible benefits of ketosis include treating and managing diseases such as:
- Epilepsy: Healthcare providers often put children with epilepsy on the keto diet to reduce or even prevent seizures by altering the “excitability” part of their brain.
- Other neurologic conditions: Research has shown the keto diet may help improve neurological conditions such as Alzheimer’s disease, autism and brain cancers such as glioblastoma.
- Type 2 diabetes: The keto diet can help people with Type 2 diabetes lose weight and manage their blood sugar levels.
- Heart disease: The keto diet may lower your risk of developing cardiovascular disease by lowering your blood pressure, improving your HDL (“good”) cholesterol levels and lowering your triglycerides.
- Metabolic syndrome: The keto diet may reduce your risk of developing metabolic syndrome, which is associated with your risk of heart disease.
Ketosis has also been shown to increase your focus and energy. The keto diet delivers your body’s energy needs in a way that reduces inflammation. Research suggests your brain works more efficiently on ketones than on glucose.
What are the side effects of ketosis?
The keto diet has many benefits, but it may come with some side effects. One of the signs of ketosis may include “keto flu,” which includes symptoms such as upset stomach, headache and fatigue. Other symptoms of ketosis may include:
- Bad breath (“keto” breath).
- Constipation.
- Insomnia.
- Dehydration.
- Low bone density (osteopenia) and bone fractures.
- High cholesterol (hyperlipidemia).
- Kidney stones.
FAQs
Ketosis is a metabolic state that occurs when your body burns fat for energy instead of glucose. The keto diet has many possible benefits including potential weight loss, increased energy and treating chronic illness. However, the diet can produce side effects including “keto” breath and constipation.
Does ketosis have side effects? ›
Common short-term side effects resulting from the initiation of KD have been referred to as “keto flu,” which encompasses symptoms including fatigue, headache, dizziness, nausea, vomiting, constipation, and low exercise tolerance [6].
What are the pros and cons of ketosis? ›
Possible benefits of ketosis include weight loss, improved blood sugar management, and reduced seizures in children with epilepsy. However, following a strict ketogenic diet to induce ketosis can be difficult and lead to unwanted short-term side effects like headaches, stomach upset, dehydration, and bad breath.
What organ does ketosis affect? ›
Ketosis is a metabolic adaptation to allow the body to survive in a period of famine. Your body will break down ketone bodies, a type of fuel the liver produces from fat, instead of sugar or glucose from carbohydrates.
Is keto hard on the kidneys? ›
The ketogenic diet is becoming more popular as a weight loss regimen; however, the evidence has failed to show clinically significant benefits over comparator diets. Even worse, it may cause hyperlipidemia, vitamin and mineral deficiencies, fatigue, and kidney damage, among other complications (Figure 1) [6].
How long is it safe to be in ketosis? ›
Gulotta recommends staying on keto for six months max before reintroducing more carbs to your diet. And Scott Keatley, RDN, of Keatley Medical Nutrition Therapy in New York City, agrees: “The science hasn't gotten to the point where I would be comfortable recommending it as a forever diet,” he says.
Who should not do keto? ›
Keto is not safe for those with any conditions involving their pancreas, liver, thyroid or gallbladder. Someone new to the keto diet can also experience what's called the “keto flu” with symptoms like upset stomach, dizziness, decreased energy, and mood swings caused by your body adapting to ketosis.
Is ketosis hard on your body? ›
Ketosis is likely safe for most people, especially if they follow it with a doctor's supervision. However, it can have some negative effects, especially at the start. It's also unclear how a ketogenic diet may affect the body long term ( 7 ).
Is ketosis actually healthy? ›
Research has shown that ketosis may have several health benefits. One of the biggest benefits of ketosis may be weight loss. The process can help you feel less hungry, which may lead to eating less food. It can help you lose belly fat (visceral fat) while maintaining a lean mass.
Is ketosis hard on your liver? ›
Your liver breaks down fat and converts it to energy and cholesterol. A high-fat diet like the keto diet can cause fat to build up in your liver and lead to fatty liver disease. Animal studies suggest the keto diet can cause non-alcoholic fatty liver disease, or NAFLD, and raise liver enzyme levels.
Classic studies of ketosis induced by fasting or starvation in humans showed that brain function was maintained which was attributed to the utilization (oxidation) of ketone bodies as alternate energy substrates to glucose by the brain6.
Is ketosis hard on the pancreas? ›
In some people, the pancreas can not handle the increased fat of the ketogenic diet. In these instances, the pancreas becomes swollen or inflamed and the entire gastrointestinal (GI) system stops working. The patient experiences severe abdominal discomfort and the abdomen is very tender to touch.
What color is urine when in ketosis? ›
Any color on the ketone strip, from pink to purple, indicates fat burning (ketosis). Some people get a darker ketone strip color and achieve the same weight loss results as someone with a lighter color. Your “positive” color result can vary throughout the day for many reasons.
Do you pee more in ketosis? ›
Increased Urination – Keto is a natural diuretic, so you have to go to the bathroom more. Acetoacetate, a ketone body, is also excreted in urination and can lead to increased bathroom visits for beginners. Dry Mouth – The increased urination leads to dry mouth and increased thirst.
Does urine smell when in ketosis? ›
When a person eats a lot of protein instead of carbohydrates, their body uses protein and stored fat for energy instead of using carbohydrates as it would usually do. As a result, the ketone level in the blood will rise. When these ketones leave the body in the urine, the urine may smell sweet or similar to popcorn.
How will I feel when my body goes into ketosis? ›
One of the signs of ketosis may include “keto flu,” which includes symptoms such as upset stomach, headache and fatigue. Other symptoms of ketosis may include: Bad breath (“keto” breath). Constipation.
Is it good for your body to be in ketosis? ›
Ketosis can have a few significant health benefits: Promotes weight loss: In the short term, ketosis can help you lose weight by reducing your body's stores of glycogen, the storage form of glucose in muscles and liver, and water. In the long term, it can suppress your appetite and cause you to eat less.
Is it OK to be in ketosis all the time? ›
But for weight loss and general well-being in healthy adults, there's no need to be in ketosis all the time. People who typically do keto might benefit from short periods out of ketosis, and people who aren't fully on the keto train might benefit from switching to a fat-burning metabolism every now and again.
