Ketogenic diets are very effective at achieving two common aims of diabetes control, lowering blood glucose levels and reducing weight

What is the ketogenic diet?

A ketogenic diet is a very low-carb diet, considered to be when you eat a level of carbohydrate of around 30g of

carbohydrates
per day or below.

This encourages the body to get its energy from burning body fat which produces an energy source known as ketones.

The diet helps to lower the body’s demand for insulin which has benefits for people with

type 1
and

type 2 diabetes

Note that it is important that you speak to your doctor if you are considering following the diet as precautions may need to be taken before starting.

How a ketogenic diet works

On a ketogenic diet, blood glucose levels are kept at a low but healthy level which encourages the body to break down fat into a fuel source known as

ketones

The process of breaking down or ‘burning’ body fat is known as

ketosis

People on insulin will typically require smaller doses of insulin which leads to less risk of large dosing errors.

The diet helps burn body fat and therefore has particular advantages for those looking to lose weight, including people with

prediabetes
or those otherwise at risk of type 2 diabetes.

How to follow a ketogenic diet

Based on the understanding that

carbohydrate
is the macronutrient that raises blood glucose the most, the primary goal of a ketogenic diet is to keep consumption lower than that of a traditional low carbohydrate diet with moderate protein and a very high fat content.

This will determine the nutrient density of the ketogenic diet as well as how to follow it, as different foods will have different effects on insulin and blood sugar levels.

There are a number of different types of ketogenic diet with variations in the level of carbohydrates and protein allowed in the diet and/or the amount of time someone is looking to spend in ketosis.

Note that some of the types of ketogenic have been designed specifically for people that are athletes or are otherwise working out very hard and often.

Benefits of a ketogenic diet

Ketone bodies produced from burning fat for fuel have been shown to have potent weight loss effects, help lower blood glucose levels and reduce people’s reliance on diabetes medication.

The diet has also shown evidence of having benefits on:

• Reducing high blood pressure
• Reducing triglyceride levels
• Raising HDL cholesterol levels (a good sign of heart health)
• Improving mental performance

Read more about the

benefits of ketogenic diets

In addition to that, there has been a lot of interest in therapeutic ketosis for other long-term conditions, such as cancer, epilepsy, Alzheimer’s disease or dementia.

• 
  How can a keto diet help other conditions

Do I need to measure ketones?

Significant weight loss and blood glucose control benefits can be derived from even a mild state of ketosis. There are a few methods you can use to measure the levels of ketones in your blood, urine or breath – each having their pros and cons.

Side effects of a ketogenic diet

With every change in the diet comes an adaptation period. With a ketogenic diet, the adaption is significant as the body has to switch its fuel source from glucose to fat. When this happens, it is not uncommon to experience a collection of side effects called ‘keto-flu’. This usually goes away within about four weeks.

• 
  Ketogenic diet side effects

Ketosis and ketoacidosis (DKA)

Diabetic ketoacidosis
(DKA) is when someone with type 1 diabetes, or very late-stage, insulin-dependent, type 2 diabetes, can’t produce any insulin and make very high amounts of ketones without stopping to prevent an effective state of starvation, which can lead to that person becoming critically ill.

Keto-adaption is a state, achieved through significant reduction of carbohydrate where the body changes from relying on glucose as its main source of energy to relying on ketones from fat burning.

Ketosis should only be a danger to someone on insulin if they have

missed a dose of insulin
or they are rationing their food intake, and therefore their insulin doses, too severely.

This is another good reason to ensure you have spoken with your doctor before starting the diet.

Safety on a ketogenic diet

There is generally a lack of long-term studies into the safety and effectiveness of ketogenic diets and, this is why a doctor’s opinion is needed before starting the diet.

There are a few groups of people for whom a ketogenic diet may not be suitable, or at the very least, warrants close supervision.

These include pregnant women, children, people at risk of hypoglycemia, people with a very low BMI, and those with conditions that a ketogenic diet may exacerbate.

• 
  Should children eat a ketogenic diet

If you look online for information about ketogenic diets, you may come across a number of supplements that are listed as being helpful for ketogenic diets.

When considering the value of supplements, it’s helpful to understand that people follow ketogenic diets for different reasons.

Ketogenic diets have become popular with a range of people including athletes, bodybuilders, people with epilepsy, diabetes and people that are looking to shed excess body weight.

Our guide will help you to see which supplements are relevant for people with diabetes and which are less relevant.

This page is to provide information on the supplements available and should not be read as encouragement to take supplements. Speak to your doctor first if you are considering taking a supplement to support a ketogenic diet.

Medium Chain Triglycerides (MCTs)

Medium chain triglycerides (MCTs), found in

coconut

products, are considered by some researchers to be a superior source of dietary fat as the body is able to produce more ketones from MCTs than from other dietary fats.


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MCTs have an advantage in allowing people to stay in ketosis despite having a slightly higher carbohydrate intake than would normally be the case.

The diet is sometimes used by people with

epilepsy

as it allows them to remain in ketosis, and therefore control seizures, without having to restrict their carbohydrate intake so much.

Research has yet to show whether MCTs have any benefit over other forms of fat in terms of weight loss.

If you are considering having MCTs, be wary of taking too much at once as it can cause an upset stomach.

Magnesium

The body needs extra magnesium to regulate

sodium

and potassium levels which are important salts to replace, particularly when starting a ketogenic diet.

Low levels of magnesium can result in issues like leg cramping and muscle discomfort during physical activity, as well as insomnia.

Getting too much magnesium usually isn’t a problem as, unless kidney function is impaired, excess magnesium the body doesn’t need is easily flushed out in the urine.

Branched Chain Amino Acids (BCAAs)

Both the essential amino acid lysine and the BCAA leucine are readily converted into ketone bodies. The theory is that lysine or leucine are protein sources that won’t knock you out of

ketosis

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Whilst this may potentially confer some advantages to bodybuilders there’s no significant evidence that BCAAs will support weight loss or otherwise help people with diabetes.

Ketone supplements (ketone esters)

Similar to MCTs, ketone supplements known as keto esters increase energy availability.

The most common type of ketone supplements commercially available today are BHB salts, which is a combination of sodium, potassium, and the ketone body beta-hydroxybutyrate (BHB).

Consuming a BHB salt directly puts ketones into your blood and so prevents the body needing to burn body fat for ketones.

As a result, keto esters are of more interest to athletes than for any people with diabetes that are actively looking to

shed body fat

Cinnamon

Researchers have theorised that

cinnamon

might improve insulin response and speed up the metabolism of glucose.


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Whilst cinnamon appears to show potential in post-meal blood glucose levels, in clinical trials run over a number of weeks, cinnamon has failed to demonstrate a significant benefit on overall insulin sensitivity.


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Consuming a teaspoon or two of cinnamon before a meal may have a modest effect in reducing blood sugar levels after meals if combined with a healthy diet overall.

Note that a natural chemical called coumarin in cinnamon has been linked with a small increase in risk of liver disease, so people with liver disease should avoid consuming large amounts of cinnamon.

Maintaining the ketogenic way of eating while being on vacation can sometimes be challenging but preparation can make things easier.

In this guide, we look at different ways to keep up with a high-fat ketogenic lifestyle when

travelling

Plan ahead

Do not assume that the hotels or places you’ll be staying at will have ketogenic options or

low carb food

swaps. However, if you contact them in advance, they may be able to accommodate your diet.

When booking where to stay, you may wish to consider places that offer self-catering or that feature a kitchenette so you can cook some nights.

Most of the major travel sites will have an option to do an advanced search for self-catered accommodation. Another option is to rent an apartment.

You can, for example, make your own dinner from products picked at local farmer’s markets in the area where you’re staying to enjoy the tastes of the local cuisine.

Come prepared

Preparation goes a long way. It’s always good to look up various

food places

, including restaurants, diners, coffee shops, and grocery stores, when you’re visiting somewhere you’ve never been before.

You can use Yelp or TripAdvisor to get good insights on places people have visited and enjoyed.

You can also plan for the ride itself. Stock up on some healthy

ketogenic snacks

, such as nuts and seeds, and pack a meal that can fill you up for a few hours, like a frittata.

Shop for groceries

It may sound daunting to stock up on groceries when on vacatio, but it’s the best way to eat well while staying in ketosis.

Typically, hotels will include some sort of

breakfast plan

They almost always have eggs, bacon and sausage. For the rest of your meals, try to keep it simple and buy staple keto food items, such as avocados, sardines in extra virgin oil, nut butters, cheese and olives.

Make keto coffee on the go

A

bulletproof or ketoproof coffee

is an excellent way to make sure you hit your fat macronutrient ratio on vacation. It is quick and easy to prepare and you can take it with you on planes, trains, automobiles, even camping.

You’ll just need to grab some unsalted butter, coconut oil and/or heavy whipping cream while grocery shopping. Under

hot weather

conditions, MCT powder may be more travel-friendly as a creamer for coffee than butter or oil.

You can then portion these out before you start the day and carry it around with you everywhere for a great mid-morning snack.

Eat healthy while eating out

If you’re eating out and decide to have a burger or sandwich, ask for no bun and that it’d be wrapped up in big lettuce leaves instead.

Hold off on pre-made salad dressings, as they often pack a lot of sugar. Ask for a salad without dressing, olive oil, and a bit of balsamic vinegar in order to make your own vinaigrette.

Combining a ketogenic diet with exercise is a powerful way to reduce blood glucose levels and achieve weight loss.

Some people may be concerned that a ketogenic diet and

exercise

may be incompatible, however, this is far from being the case as we will investigate in this guide.

We will also look into the important topic of safety when exercising on a ketogenic diet which applies if you are ion any diabetes medications that can cause hypos.

How the body copes with exercise on little carbohydrate

For years, the world’s leading exercise and diet science institutes have advocated consuming a high level of

carbohydrate

prior to exercise.

However, modern research is showing that a very-low-carbohydrate ketogenic diet can unlock your body’s capability to tap into your own storage fat for energy.

A great benefit of this is that this source of energy is almost inexhaustible, as each of us are carrying tens of thousands of calories as body fat.

Famous athletes, like

Chris Froome

, and other endurance athletes, have been able to excel in their sport thanks to a low-carbohydrate diet.

Exercise at the start of a ketogenic diet

In the first weeks on a ketogenic diet, you may find you need to go easy on the exercise until your body has adapted to the diet. This reportedly takes around two to four weeks.

After you’ve become ‘keto-adapted’, you should be able to step the exercise up.

Is this style of eating in combination to exercise an easy transition?

It is important to keep in mind that both a ketogenic diet and exercise can be effective for lowering

blood glucose levels

Therefore, if you are currently on hypo-causing medication, you should speak with your health team about how to manage exercise on a ketogenic diet.

Benefits of exercise and keto on diabetes and heart health

Combining exercise with a ketogenic diet can be useful in terms of controlling blood sugar levels, reducing

insulin resistance

and losing weight.

The ketogenic diet is designed to burn body fat and adding exercise on top can help to accelerate the process.

The benefits of going low carb or ketogenic don’t stop at fat loss or better glucose control. Following a ketogenic diet and exercising can also help maintain balanced

cholesterol levels

, especially higher levels of protective HDL cholesterol.

Whilst ketogenic diets are these days acknowledged as being beneficial, there is currently a lack of research studies examining just how beneficial the combination of exercise on a ketogenic diet is.

Exercise and keto when on insulin or other hypo causing medication

If you are on

insulin

, or other hypo causing medication, the advice is usually to take carbohydrate before exercise to prevent hypos occurring.

However, on a ketogenic diet, you’re meant to limit carbohydrate intake which can present a question of what is best to do.

If you’re able to plan exercise in advance, then you may be able to reduce your medication prior to exercise.

If you’re on an

insulin pump

, this gives you the advantage of being able to reduce your insulin just before exercise.

Note that some forms of activity involving sprinting or upper body exercise can initially increase sugar levels. If you know you get this effect, then you may find you don’t need to take carbohydrate or reduce your medication before exercise.

If you have been following a ketogenic diet for long enough to become keto-adapted (typically two to four weeks), you may find your body is able to largely run on

ketones

rather than glucose and therefore you may have a lower risk of hypos during and following exercise.

If weight loss is not a primary goal, then having carbohydrate around exercise should not be such an issue and is worthy of consideration if you are going low during or after exercise.

Precautions

People on diabetes medication that can cause

hypos

need to be careful in monitoring their sugar levels around exercise, when on a ketogenic diet, to prevent hypos from occurring.

Note that exercise can increase

insulin sensitivity

for up to 72 hours which can increase the risk of hypos within this period.

The blood glucose lowering effect of exercise may be more significant if you are exercising longer or harder than usual, or if you’re getting back into exercise after a break of several days.

Exercise on insulin and hypo causing medication is a complicated topic with a number of factors to consider. For individual advice, discuss your goals and precautions to take with your diabetes health team.

Ketogenic diets show promise for improving mood and research suggests that the diet may possibly benefit a number of mental health conditions such as:

• Depression
• Bipolar disorder
• Schizophrenia
• Dementia

In this guide, we look at the theory behind using a ketogenic diet for the treatment of these

mental health

conditions and how running on ketones can help stabilise mood.

Whilst research shows promise, there’s currently a lack of robust clinical studies that have investigated the effectiveness of a ketogenic diet on mental health. Therefore, the benefits on mental health of ketogenic diets is currently unproven.

How does the ketogenic diet work to improve mental health?

Ketogenic diets appear to affect the brain in a number of positive ways, such as:

• Providing a ‘feel good’ effect
• Bolstering brain power
• Having antioxidant effects

Boosting ‘feel good’ neurotransmitters

Being in a state of

ketosis

has been shown to increase production of a common neurotransmitter in the brain called GABA. There is evidence that various anxiety disorders result from dysfunctional GABA activity.

Studies conducted on the use of the ketogenic diet in seizure disorders, for example, tend to show that a good balance of GABA leads to better mental focus,

reduced stress

and anxiety.


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Bolstering brain power

Contrary to common belief that glucose is essential for the brain, ketone bodies produced from

fat

, such as beta hydroxybutyrate, can provide an alternative ready fuel for the brain. Research suggests that ketones may even be a more efficient fuel for the brain than glucose.

It is believed that ketones increase the number of energy factories (mitochondria) in brain cells, which boost the energy levels in those cells. This is important, as many mental disorders share one major problem – deficient energy production.


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Exerting potent antioxidant effects

Studies have suggested that the ketogenic diet may reduce oxidative stress and inflammation in the

brain

Researchers believe that lower levels of inflammation combined with enhanced energy with ketones used as fuel may contribute to improved brain function.

As it turns out, studies have shown that one way the ketogenic diet could work in treating seizures could be by increasing levels of a major antioxidant, called glutathione, that protects us against oxidative stress.


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What the science says about ketogenic diets and mental health

Whilst there’s a lack of robust clinical studies into the effects of ketogenic diets, there’s been enough evidence to suggest that the diet could help a number of mental health conditions.

Depression

Recent studies in animal models have demonstrated that there may be a case for the use of a ketogenic diet in the treatment of

depression

The mechanism of action of how the diet may work is currently unclear.

It is thought that the ketogenic diet has similar effects to conventional antidepressant drugs, but further studies are needed in humans to confirm it.


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Bipolar disorder

Many of the drugs proven to help with bipolar have anti-seizure properties, which has established a link between the

low-carb, high-fat diet

and its effects on the brain.

The data supporting the use of a ketogenic diet as a treatment for bipolar is limited, but there are nonetheless a few recorded clinical cases which have shown promise.

A 2013 paper showed, for example, that two women with type II bipolar disorder, who went on a ketogenic diet for more than two years, both achieved better mood stabilisation with the diet than with medication.


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Schizophrenia

Low carbohydrate diets

and ketogenic diets have been shown to relieve symptoms of schizophrenia in animal studies and small scale human studies.

The diet may help manage schizophrenia through all the different mechanisms of action discussed previously, especially through the increase in GABA levels and bypassing the need of glucose as a fuel.


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Dementia

Studies have shown that higher ketone levels may help with mild cognitive impairment (MCI), a condition that makes someone more likely to develop dementia.

One suspected cause of cognitive impairment is a high level of inflammation in the brain that stems from the build-up of amyloid plaques, like those seen in

Alzheimer’s disease

Studies have shown that a ketogenic diet may be beneficial for reducing the formation of these plaques and inflammation. Further research will be needed to confirm this.


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Many people have questions about the ketogenic diet before they get started. So, we’ve compiled a list of answers to the frequently asked questions that people have.

What is keto-adaptation and what does it feel like?

The term keto-adaptation refers to your body’s transition from burning primarily glucose as fuel, to being able to also use ketones produced from burning body fat.

It will take a few days or weeks to feel your absolute best on keto. You may experience symptoms of carbohydrate withdrawal at first, but once you become fat-adapted, you’ll find that you won’t crave carbs as much anymore.

What is the “keto flu” and how can I avoid it?

Your body has always relied on glucose as its primary source of energy. Therefore, when you cut carbohydrates drastically, the body is essentially freaking out, until it eventually switches its metabolism to burning fat.

This period of adaptation causes the mild physical weakness or lack of energy typical of the flu. This state is temporary and the transition can be facilitated by a few preventive measures, such as keeping hydrated and having enough salt. Visit our

keto side effects page

to know more about effective ways to help circumvent the keto flu.

How long does it take to become keto-adapted?

Most research papers and anecdotal evidence you’ll come across state that keto-adaptation can last up to four weeks. The more determined you are to avoid carbs in the first weeks of a ketogenic diet, the quicker you’ll be over the hump on your keto-adaptation. You can also hasten it by engaging in any form of sustained physical activity which will force your body to tap into its fat stores.

What does being in a state of ketosis mean?

Being in a state of ketosis means that your body, more precisely your liver, is producing higher levels of ketone bodies to supply energy for your brain, heart and muscles. For that to happen, carbohydrates need to be sufficiently restricted and your protein intake capped at a certain level – which is explained in our protein and keto page. A state of ketosis can come and go through any day but with time you’ll learn how to stay ketotic for longer.

How can I tell if I am in ketosis?

There are a few telltale signs that you are in ketosis. If you wake up with a fruity, metallic taste in your mouth, also called keto breath, it is an indication that your body is effectively manufacturing ketones. You could also experience a certain mental sharpness when the body runs high on ketones.

For those looking to be more sure of whether ketosis is taking place, you can use home tests such as blood tests, urine tests or a breathalyser to

test your level of ketosis

What may put me out of ketosis and how can I get back into it quickly?

It is easy to get out of ketosis. It will usually happen immediately after meals, even if they contain a small to medium amounts of carbs, and can last for up to a few hours. This is normal, your body will always choose to revert back to glucose if some is available.

We don’t recommend hacking ketosis with keto esters (essentially artificial ketones you ingest), as they are not fully clinically tested yet. However, there are a few things that can help promote a state of ketosis. These include incorporating periods of fasting or consuming certain types of fat that are very ketogenic, like MCTs.

You can visit our

supplements on keto page

to find out more about this..

Should I track my ketones levels? If yes, how?

Should I track my ketones levels? If yes, how?

There are a few ways that you can track your ketone levels, depending mainly on your budget. Urine ketone strips are the easiest to come by and they are relatively cheap, which enables you to test more often. However, they only give you an estimation of the range of your ketone levels. If you want to gain a bit more insights about how your body is handling your ketogenic diet, you may want to check out our guide to

measuring ketones on a ketogenic diet

Will the diet help with weight loss and improve my sugar levels?

Two of the main

benefits of the ketogenic diet

is its effect in helping people to lose weight and lowering blood glucose levels.

If you take medication that can cause hypos, such as insulin, sulphonylureas or glinides, you will need to take care to avoid hypos occurring. Speak to your doctor who will be able to advise you on what precautions to take to reduce the risk of hypos occurring.

Do I need to count or restrict calories?

No, although there is a subset of ketogenic diets, known as a

calorie-restricted ketogenic diet

, which is specifically restricted in calories. If and when followed correctly though, a ketogenic diet can be eaten to satiety.

This is, in part, because the diet does not usually promote weight gain, as it lowers levels of the fat storage hormone insulin.

What does insulin load and glycemic index refer to?

Different foods will influence insulin levels differently, this is known as the insulin load of a food. The glycemic index (GI) tells you how slowly or quickly that food is likely to increase blood glucose levels. On a ketogenic diet, you’ll want to avoid high GI foods as they will not support ketosis. You can visit our

page on which foods to eat on a ketogenic diet

to learn more about this.

I’m physically active, can I still do a ketogenic diet?

Many people are concerned that a ketogenic diet might not be compatible with a high-energy lifestyle. Research actually suggests the opposite, in that ketones can improve performance.

However, you should reduce your workout intensity or not engage in anything that demands a ton of glucose while you try to get fat-adapted. You can read about this subject in our page about

exercise on a ketogenic diet

Do I need to incorporate carbohydrate re-feed days?

Different types of ketogenic diets exist, some of them giving the flexibility to live a slightly more sane life with carb re-feed days. These can be helpful as an induction phase to a ketogenic diet, for active people who might need carbs around the time of their workout, or to accommodate social circumstances. You can visit our page on the

types of ketogenic diets

to decide which one is best or right for you.

What is the difference between a low-carbohydrate diet and a ketogenic diet?

Ketogenic diets are a slightly more extreme form of low carbohydrate diets. While up to 150 grams of carbohydrates a day may be regarded as low carb, entering a state of ketosis usually requires lowering carbohydrates to a level of under 50 grams a day. A ketogenic diet is also a lot higher in fat and lower in protein.

Can I practice intermittent fasting on keto?

Yes, you can. It is a very useful tool to boost ketone levels and fat burning. However, you should get keto-adapted first before attempting it.

If you are on diabetes medication that can cause hypos, it is important to check which precautions to take before adding intermittent fasting to a ketogenic diet.

Choosing a ketogenic diet for diabetes management offers a range of valuable benefits.

Research shows that being in a state of nutritional ketosis notably leads to significant improvement in

blood glucose control

and weight loss.

Other common benefits provided include:

• Reduced dependence on medication
• Improvements in insulin sensitivity
• Lower blood pressure
• Usually improvements in cholesterol levels

In this guide, we review the science behind the ketogenic diet and how it works to provide all of these different benefits.

Weight loss and maintenance

A primary benefit of the ketogenic diet is its ability to achieve rapid

weight loss

Restricting carbohydrates enough to be in a state of ketosis leads to both a significant reduction in body fat and an increase or retention of muscle mass.

Studies show that low-carb, ketogenic diets are able to achieve strong weight loss over an extended period. An Australian study showed that obese people were able to lose, on average, 15 kg over a period of a year. This was 3 kg more than the low-fat diet used in the study achieved.


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Blood glucose control

The other main reason for people with diabetes to follow a ketogenic diet is its ability to lower and stabilise

blood sugar levels

Carbohydrate is the nutrient (macronutrient) that raises blood sugar the most. Because ketogenic diets are very-low in

carbohydrate

, they eliminate the larger rises in blood sugar.

Studies into ketogenic diets show them to be very effective at reducing

HbA1c

– a long-term measure of blood glucose control. A 6-month study ran by Eric Westman and colleagues in 2008 showed an average reduction in HbA1c levels of 17 mmol/mol (1.5%) for people with type 2 diabetes.

People with other types of diabetes, such as type 1 diabetes and

LADA

, should also expect to see a strong reduction in blood sugar levels and an improvement in control.

Note that if an improvement in blood glucose control is maintained over a number of years, this can reduce the risk of complications occurring.

It is important that anyone on insulin, or otherwise at risk of

hypos

, takes precautions to prevent hypos occurring. Speak to your doctor for help with this.


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Reducing reliance on diabetes medication

Because they’re so effective at reducing blood sugar levels, ketogenic diets have the additional benefit of helping people with type 2 diabetes to reduce their dependence on

diabetes medication

In the study by Westman mentioned above, 95% of the people in the study were able to reduce, or come off completely, their diabetes medication.

People on

insulin

and other hypo-causing medication (such as

sulphonylureas

and

glinides

) may need to reduce their doses in advance of starting a ketogenic diet to prevent hypos. Speak to your doctor for advice on this.

Insulin sensitivity

A ketogenic diet has been shown to help restore

insulin sensitivity

, as it eliminates the root cause of insulin resistance – which is too high levels of insulin in the body.

This diet helps promote sustained periods of low insulin, as low levels of carbohydrate mean lower levels of insulin.

A high carbohydrate diet is like putting petrol on the fire of

insulin resistance

High carbohydrate means a greater need for insulin and this make insulin resistance worse.

By comparison, a ketogenic diet, turns insulin levels down, as fat is the macronutrient that requires the least

insulin

Getting the levels of insulin down also helps with fat burning, because high insulin levels prevent the breakdown of fat. When insulin levels drop for a number of hours, the body is able to break down fat cells.

High blood pressure control

It is estimated that 16 million people are living witha

high blood pressure

in the UK.

A range of health conditions are associated with high blood pressure, such as heart disease, stroke and kidney disease. It is also a feature of

metabolic syndrome

A number of studies have shown that a ketogenic diet can decrease blood pressure levels in people that are overweight or with type 2 diabetes.


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Cholesterol levels

Overall, ketogenic diets usually result in improvements of

cholesterol

levels. It is usual for LDL cholesterol levels to go down and HDL cholesterol levels go up, which is healthy.

One of the strongest measures of healthy cholesterol is the ratio of total cholesterol to HDL. This can be easily found by taking your total cholesterol result and dividing it by your HDL result.

If the number you get is 3.5 or lower, this indicates a healthy cholesterol. Research studies show that ketogenic diets are usually effective at improving this measure of cholesterol health.


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Note that some people may show an increase in LDL and total cholesterol after starting a ketogenic. This is usually regarded as a negative sign but if your total cholesterol to HDL ratio is good, this does not necessarily represent a worsening in

heart health

Cholesterol is a complicated topic and your doctor is the best source of advice if your cholesterol levels change significantly on a ketogenic diet.

In the UK you should have your cholesterol levels monitored at least once per year so that any negative effects on cholesterol can be spotted and dealt with appropriately.

Stronger mental performance

Mental clarity, an increased ability to focus and a better memory are other commonly reported benefits of eating a ketogenic diet.

Increasing intake of healthy fats with omega-3, such as those found in oily fish like salmon, tuna and mackerel, can improve mood and learning ability. This is because omega-3 increases a fatty acid called DHA that makes up between 15 to 30 per cent of our brain.


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The production of beta-hydroxybutyrate, a form of ketone, helps support long-term memory function.

Satiety

Ketogenic diets have positive effects on appetite. Once the body adapts to being in a state of ketosis, it gets used to getting energy from breaking down body fat and this can reduce appetite and cravings.

They are effective at:

• Reducing cravings
• Helping you feel full for longer
• Reducing preference for
  
  sugary foods
  

Weight loss as a result of a ketogenic diet can help lower leptin levels which can improve leptin sensitivity and benefit satiety as a result.

Candida

Ketogenic diets can be good at reducing

thrush

and yeast infections as they lower blood sugar, which reduces glucose being passed out in the urine.

It is glucose in the urine that bacteria feed off that leads to a fertile breeding ground for yeast and bacterial infections.

In addition to that, a higher intake of a saturated fatty acid called lauric acid – found in

coconut

oil, a staple keto food – has been shown to have anti-microbial properties. It can kill off candida albican and help with yeast infections.

When followed well, a ketogenic diet is a very nutritious diet. It should be based around real foods with a strong vegetable intake, particularly leafy greens.

The aim of ketogenic diets is to allow

ketosis

to happen through the day. Ketosis is the process of burning body fat for energy and, for this to happen, insulin levels in the body need to be low.

So, by sticking to foods that won’t cause a surge of insulin, you give your body a chance to go into ketosis and burn body fat.

What does a ketogenic diet plan look like?

The content of the diet will vary, depending on an individual’s goals, personal health and financial situation. But, the focus should invariably be on eating nutritious minimally processed, real foods.

A ketogenic diet will usually be:

• 
  Low carbohydrate
  
• Moderate protein
• High fat

The challenge can sometimes be to get enough fat without having too much protein.

Energy balance

Whilst there are different ways to follow a ketogenic diet, the following is a good guide for people with diabetes, looking to control their sugar levels and lose weight.

This will determine the nutrient density of the ketogenic diet as well as how to follow it, as different foods will have different effects on insulin and blood sugar levels.

Carbohydrate

Carbohydrate

intake should be low. Usually carbohydrate intake will be under 50g per day to maintain ketosis.

Some people may restrict themselves to under 30g of carbs per day to maximize the chance of maintaining in ketosis through the day.

Protein

Protein

intake should be moderate at around 40 to 50g per day for women and around 50 to 60g of protein for men.

These are rough guidelines. If you are struggling to lose weight, despite having very little carbohydrate, the next step to look at is whether you are having too much protein. Note that foods such as cheese and nuts have significant protein in that some people may miss.

Fat

Fat

is generally free to have on a ketogenic diet, within reason. You can afford to have a good amount of fat on a ketogenic diet, except it’s advisable not to snack between meals on a ketogenic diet.

Low-carb veggies

We’ll start with vegetables as research shows that all truly healthy diets share one thing in common, they have a good foundation of vegetables to provide a range of nutrients.


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Aim to eat vegetables at every meal. Vegetables are also a great way to get more fat into the diet with, for example, high-fat salad dressings, avocado, nuts, olive oil or butter.

People following a stricter ketogenic diet can limit their vegetable intake to those containing less a very-low-carbohydrate content, such as leafy greens, tomatoes, asparagus and broccoli.

Watch out for

starchy root vegetables

such as any form of potato, parsnips and beetroot.

150g of boiled broccoli (

non-starchy vegetable

) contains about 5g of carbohydrate whereas 150g of boiled sweetcorn (starchy vegetable) contains 30g of carbs.

Meat and eggs

You’re good to have meat on a ketogenic diet and this includes

fatty meat

such as pork belly, lamb and poultry with the skin on. This is good news for the taste buds as fat helps to add a lot of flavour.

Eggs

are a staple for most ketogenic dieters. They’re low in carbohydrate, filling, a good source of protein and very versatile.

Note that it is possible to come out of ketosis if you’re having a large amount of protein. This is because a high protein intake can cause the liver to convert the protein into glucose – a process known as gluconeogenesis.

For this reason, try to keep your intake of meat to a moderate level.

Fish

Fish

provides a good source of protein and oily fish, such as mackerel, salmon, tuna, sardines, trout or herring, contains essential omega-3 fatty acids.

The consumption of significant amounts of fatty fish is widely advocated for heart health and longevity.

Dairy products

Dairy products

are a strong source of fat so are another staple of ketogenic diets.

People going onto a ketogenic diet after coming from a low-fat diet will be pleased to know that cream and full fat dairy are back on the menu.

Avoid low-fat dairy as this is has no benefit for people on a ketogenic diet.

Note that some dairy, such as milk and yoghurt, will have some carbohydrate, in the form of lactose, and very-low-carb dairy such as cheese has a significant amount of protein.

Where possible pick butter that comes from grass fed cows. Grass-fed butter is higher than grain-fed butter in omega-3 fatty acids, CLA, beta-carotene, vitamin A, vitamin K, vitamin D, vitamin E than non-grass fed butter.

Grass-fed butter is also high in butyrate, a short-chain fatty acid that can both prevent and decrease inflammation. It has also shown some benefits to protect against mental illness, improve body composition, increase

metabolism

, and improve gut health.

Avoid margarine as this is a form of processed food.

Nuts and seeds

Nuts and seeds

are high in fat, low in carbs and have moderate protein and so match the energy requirements of a ketogenic diet very well. Nuts and seeds are also a good source of dietary fibre and magnesium.

Whilst nuts are generally a good choice, it is possible to overeat nuts and seeds if you graze on them through the day. Choose unsalted nuts as salted nuts can become addictive and lead to overeating.

The nutrient content of nuts and seeds can vary. Whilst Brazil nuts, macadamias, flax seeds, walnuts, almonds and hazelnuts are low in carbohydrate, other nuts, such as cashews, have significantly higher carbohydrate content.

Like any significant change to your diet, when starting a ketogenic diet, it is normal to experience one or more side effects as the body adapts to a new way of eating.

When going on a ketogenic diet, the body has to switch its fuel source from the glucose in

carbohydrate

to using its own fat stores, and this can lead to experiencing some of the following side effects:

• Loss of salts
• Keto-flu
• Changes in bowel habits
• Leg cramps
• Bad breath
• Loss of energy

Usually these side effects are temporary and can usually be remedied.

Loss of salts

There are some changes with fluid balance that can typically occur within the first couple of weeks of a ketogenic diet.

This happens as the body uses up its stored sugar (glycogen) which releases water into the blood that gets passed out of the body through urine. As fluid is passed out of the body, salts in the body can get depleted too.

As a result, you may experience a loss of fluid and salts as you move into and maintain ketosis.

Make sure you

keep yourself hydrated

through the day. Water is the best drink for hydration but tea and coffee are also fine as long as they’re not very milky.

Ensure you have enough salt as this can prevent side effects such as headaches and wooziness. You are free to add sea

salt

to your food and can take salts by drinking vegetable or bone broths and bouillons too.

Potassium and magnesium are other important salts. As long as you are eating healthy, natural foods (such as nuts, meat, fish, dairy and a range of vegetables), you shouldn’t have a problem getting enough magnesium and potassium.

Keto-flu

The first few weeks of transitioning to a ketogenic diet can be challenging for some people. Whereas others adapt to it more easily.

Your body may be used to relying mainly on glucose for energy and so it will need to switch to using

ketones

for fuel. This adaptation process is known as keto-adaption.

Keto-adaption may result in some initial ‘brain fog’, but this will disappear once the body has fully adapted and some people feel sharper at this point.

It is estimated that keto-adaption takes around four weeks on average but the side effects themselves often disappear sooner.

During that time, and especially at the end of the first week, it is likely that you may feel some

symptoms

that are similar to the flu, such as:

• Brain fog / slow thinking
• Dizziness
• Fatigue
• Racing heart rate when lying down
• Insomnia
• Cravings

You may find that allowing your body to ease into ketosis helps to lessen the effect of side effects. This can be done by gradually lowering carbohydrate intake over a few weeks.

Our

Low-Carb Program

is a great way to do this as it will help you to reduce your carbohydrate intake gradually rather than suddenly.

Whether you jump directly into a ketogenic diet or go gradually, remember the first point about having fluid and salts as this will help prevent you feeling lousy.

Changes in bowel habits

Changing to a ketogenic diet may bring about changes in bowel habits such as

constipation

This is often the case with any major change in diet as the body’s own gut bacteria will need to adapt to handle different foods in different amounts.

Bowel habits should usually improve within a couple of weeks. If they don’t, it could be that you’re not getting enough

fibre

Drink plenty of water and consider increasing your consumption of non-starchy, fibrous vegetable, legumes, nuts and seeds, as these are all good low-carbohydrate sources of fibre.

Leg cramps

The development of muscle cramps is a possible side effect of a ketogenic diet. These cramps are typically benign in nature, but they can be bothersome.

One of the causes of leg cramps on a ketogenic diet is a condition called hyponatremia, which occurs when the level of sodium (salt) in the blood is too low.

This can be alleviated by the recommendation we gave above about keeping hydrated and having enough salt.

Bad breath

Bad breath

, sometimes referred to as keto-breath, can sometimes occur as you enter the fat-burning state of ketosis.

Ketones can be released in the breath, as well as in the urine and sweat. Acetone is a form of ketone that when released on the breath may lead to a metallic taste in the mouth or a less-than-pleasant smelling breath.

This is usually temporary and will likely disappear after a few weeks without having to come out of

ketosis

by reintroducing carbs.

If bad breath is a problem, minty sugar-free gum or breath freshener can help mask the smell.

Another solution is to consider extra rigorous oral hygiene by brushing teeth and using mouthwash more frequently through the day.

Lack of energy

One of the biggest misconceptions about ketogenic diets is that a lack of glucose depletes the body of energy.

Maintaining steady energy levels is actually more challenging on a standard diet as it varies according to fluctuations in

blood sugar

, which is dependent upon the insulin response to carbohydrate intake.

Eating a lower amount of carbohydrates on a ketogenic diet does not prevents the roller-coaster of sugar levels.

Once in ketosis, the body can draw energy from its own fat stores and the

liver

is able to create as much glucose as the body needs -and not too much. As a result, by cutting out carbs, the body finds it easier to regulate sugar levels and energy.

Whilst you may notice a dip in energy initially during the adaptation phase, this should pass within a few weeks.

The use of ketogenic diets in children with diabetes is relatively rare but research shows the diet to hold promise.

Research that exists suggests that children treated with a ketogenic diet have found improvements in the quality of their life through the diet without any major adverse effects.

Most research in children has been carried out in those with

type 2 diabetes

or obesity, and currently there is a lack of research into the effects of the diet in children with type 1 diabetes

It is important that a ketogenic diet is followed by children only if it has the approval of the child’s doctor.

Ketogenic diet and type 2 diabetes

The ketogenic diet may be an effective short-term, and possibly long-term, therapy for pre-adolescent and

adolescent children with type 2 diabetes

Within a few days on the diet, blood sugar levels can decrease to a normal, healthy range, sometimes up to a point where the use of

diabetes medication

may become no longer needed.

In one study looking at the effect of a very-low-calorie ketogenic diet in the treatment of teenagers with type 2 diabetes, the diet resulted in a significant decrease in

HbA1c

, from to 73 to 57 mmol/mol (8.8 to 7.4 %), while average daily blood glucose values fell from 8.9 to 5.5 mmol/l.

The teenagers also lost significant weight over the study period with their

BMI

falling from 44 to 39 over a period of up to two years.


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Whilst this was a

very-low-calorie ketogenic diet

, it suggests that other forms of ketogenic diets, such as low-carb ketogenic diets, may benefit children with type 2 diabetes too.

Ketogenic diet and type 1 diabetes

There has been a lack of research studies investigating ketogenic diets for children with

type 1 diabetes

The research that does exist is limited to case studies.

In children with type 1 diabetes, there is evidence that a ketogenic diet lowers the need for insulin, reduces the number of hypos and leads to improved HbA1c levels. A case study from 2010 showed these results from a three-and-a-half-year-old girl with epilepsy and type 1 diabetes.


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A case study by Hungarian doctor Csaba Tóth has showed that a ketogenic Paleo diet may help to slow down the development of type 1 diabetes in children.

A nine-year-old boy who had been recently diagnosed with type 1 diabetes, was able to

come off insulin for two years

by following a ketogenic Paleo diet.

This was possible because the boy was recently diagnosed and was being medically supervised. It is important that people with type 1 diabetes do not attempt to come off their

insulin

Ketogenic diet for obese teenagers

Ketogenic diets show significant promise for helping obese teenagers to lose weight.

A number of studies have shown a ketogenic diet to lead to greater weight loss in overweight adolescents than low-fat or low-calorie diets.


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As we saw, when we looked at the diet’s use in children with type 2 diabetes, the diet can be adhered to and produce weight loss over a lengthy period of time -up to two years and possibly longer.

As with any significant change in eating habits, there may be safety issues you need to be mindful about.

In this guide, we break down the information you should be aware of to make sure you get the most out of the

ketogenic diet

and don’t run into trouble.

Any significant change in diet should be discussed with your doctor before starting it. This is particularly important for very-low-carb ketogenic diets.

Pregnant women

Prolonged maternal

ketosis

has been associated with development problems for the baby which could affect brain development or increase the risk of neural tube defects such as spina bifida.

As the risk of harming the baby from being in ketosis during

pregnancy

is too high, a ketogenic diet is not recommended by doctors.


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Breast feeding women

There is a lack of studies on the safety of ketogenic diets whilst

breastfeeding

and therefore it is recommended that people maintain a conservative carbohydrate intake rather than going for a very-low carb intake.

The thinking here is, we don’t know what the result of a ketogenic diet on breastfeeding is so adopt a moderate carb intake as we know that it is safe.

People on hypo-causing medication

The following medications can lead to hypos occurring:

• 
  Insulin
  
• 
  Sulphonylureas
  
  (glibenclamide, gliclazide, glimepiride, glipizide, tolbutamide)
• 
  Glinides
  
  (nateglinide, repaglinide)

This is because these medications are all designed to increase insulin in the body, which lowers blood sugar levels.

Following a low-carbohydrate ketogenic diet whilst on these medications can increase the risk of

hypos

and so it is very important that you speak with your doctor to take precautions against hypos before you start a ketogenic diet.

Regular blood glucose tests will help you to spot and avoid hypos. It is advisable to test more often than normal whilst you are adjusting to a change in carbohydrate intake.

People on other medication

Other

diabetes medication

should not pose a significant risk on the diet but may need to be reviewed to ensure it is still appropriate and needed.

Your doctor will advise you if any changes to your medication or doses are needed.

Blood pressure medication may also need to be adjusted by your doctor as blood pressure will often drop on a ketogenic diet.

Low to very low BMI

People with a low BMI looking to follow the diet for the non-weight loss benefits (such as improved blood glucose control) will need to prevent weight loss from occurring.

Your doctor or dietitian should be able to help you to take precautions, such as modifying the diet, to ensure your body weight is healthy.

Children

The ketogenic diet has been used safely, with medical supervision, for many years in

children

for the treatment of seizures.

There are a number of considerations to bear in mind before starting a ketogenic diet including ensuring the balance of macronutrients (carbohydrate, protein and fat) is appropriate for the growth of children.

For this reason, a doctor and dietitian should be consulted before a ketogenic diet is started in children.

Gallstones

People with gallstones used to be advised to avoid fat but this is no longer the case and the NHS now states that very-low-fat diets may actually promote gallstone growth.


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If you have gallstones, eating fat may initially lead to some gallstone pain. If you wish to follow a ketogenic diet, you may need to introduce it slowly or go onto the diet once the gallstones have been removed or dissolved.

A review of studies from 2014 shows that high fat diets appear to prevent gallstones formation which suggests a good long-term benefit.

Gallbladder removed

Whilst the gall bladder contains bile, that helps the body to break down dietary fats, some people report that it is possible to follow a low-carb, high fat diet without a gallbladder.

Beachbag is one of our forum members who has been following a low-carb, high-fat diet for a number of years despite having had her gallbladder removed.

Red more:

Low-carb, high-fat and no gallbladder

A ketogenic diet is a diet that is designed to bring about ketosis, the breaking down of body fat into ketones, and allow the body to largely run on ketones rather than glucose.

There are a number of ways in which ketosis can be brought about and therefore there are a number of different variants of ketogenic diet.

Because the end goal of these diets is the samen, the different types of ketogenic diet usually share a number of similarities, notably in being low in carbohydrate and high in dietary fat.

The figures in this guide are for information only and are not an instruction to follow. For advice on how to put together a diet, speak to a dietitian as they will be able to give you personalised guidance based on your individual needs.

Standard Ketogenic Diet (SKD)

This is a very-low carb, moderate protein and high fat diet. It typically contains 70 to 75 per cent fat, 20 per cent protein, and about 5 to 10 per cent carbs.

In terms of grams per day, a typical standard ketogenic diet would be:

• 20-50g of carbohydrate
• 40-60g of protein
• No set limit for fat

Fat in the diet

should provide the majority of calories for it to be a ketogenic diet. No limit is set as energy requirements can vary significantly from person to person.

Ketogenic diets should include a strong intake of vegetables, particularly non-starchy vegetables, as these are very low in carbohydrate.

Standard ketogenic diets have consistently shown success in helping people to lose weight, improve blood glucose control and improve heart health.


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Very-low-carb ketogenic diet (VLCKD)

A standard ketogenic diet is very-low-carb and therefore a VLCKD will usually refer to a standard ketogenic diet.

Well Formulated Ketogenic Diet (WFKD)

The term ‘Well Formulated Ketogenic Diet’ comes from Steve Phinney, one of the leading researchers into ketogenic diets.

The WFKD follows a similar blueprint as a standard ketogenic diet. Well formulated means that the macronutrients of fat, protein and

carbohydrate

meet the ratios of the standard ketogenic diet and therefore provide the best chance of ketosis occurring.

MCT Ketogenic Diet

This follows the outline of standard ketogenic diet but has a focus on using medium chain triglycerides (MCTs) to provide much of the fat content of the diet.

MCTs are found in

coconut

oil and is available as MCT oil and MCT emulsion liquids.

MCT ketogenic diets have been used to treat epilepsy because the theory is that MCTs allows people to consume more carbohydrate and protein whilst keeping in ketosis. This is because MCTs provide more

ketones

per gram of fat than the long-chain triglycerides that are present in normal dietary fat.

Note that MCTs can lead to stomach upset and diarrhoea if consumed largely on its own. To prevent this, it’s best to have meals with a balance of MCTs and non-MCT fat.

There is a lack of studies, however, investigating whether MCTs have wider benefits on weight loss or blood sugar.


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Calorie-restricted ketogenic diet

A calorie-restricted ketogenic diet is similar to a standard ketogenic diet except in that calories are restricted to a set amount.

Research shows that ketogenic diets tend to be successful whether calorie intake is restricted or not. This is because the satiating effect of eating fat and being in ketosis tends to help prevent over-eating in itself.

Cyclical Ketogenic Diet (CKD)

The CKD diet, also known as carb backloading, involves days in which more carbs are eaten, such as five ketogenic days followed by two higher carb days.

The diet is intended for athletes which can use the higher carb days to replenish

glycogen

lost from muscles during workouts.

Targeted Ketogenic Diet (TKD)

The TKD is similar to a standard ketogenic diet except that carbohydrates are consumed around

workout

times.

It is a compromise between a standard ketogenic diet and a cyclical ketogenic diet that allows you to consume carbohydrates any day you exercise.

It is based on the concept that carbohydrate consumed before or after a physical effort will be processed much more efficiently, as the muscles’ demand for energy increase when we’re being active.

High Protein Ketogenic Diet

This diet includes more

protein

than a standard ketogenic diet, with a ratio of 35 per cent protein, 60 per cent fat, and 5 per cent carbs.

Research suggests that a high-protein ketogenic is effective for

weight loss

in people that need to lose weight.


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As with other forms of ketogenic diet, there is a lack of research into whether there are any health risks if followed for many years.

Ketosis is the process of burning body fat for energy and can be measured when following a low-carb ketogenic diet.

You don’t have to

test for ketones

for a ketogenic diet to work but some people may find it helps to check they’re on track and to tailor their diet towards more effective weight loss.

Whilst ketosis is a natural process in the body, it’s important to know the

safety implications

of being on a ketogenic diet which will apply to people on certain diabetes and blood pressure medications.

How measuring ketosis can help

Whilst we can all measure our weight to see whether weight loss is occurring, there are a number of reasons why measuring ketosis can be better.

Our weight can go up and down through the day but this won’t tell us whether we are actually burning body fat. Simply going to the toilet, for example, will involve a certain loss of body weight but that won’t give us any idea whether we’ve burned any body fat over the past hour or two.

Additionally, if you’re exercising and putting on

muscle

, the scales will only show weight loss stalling or a gain in weight and won’t show you whether you’re gaining muscle whilst also losing body fat.

Measuring ketone levels can help much more directly therefore as the production of ketones is a direct result of fat burning.

Just as

blood sugar levels

vary through the day, depending on what we’ve eaten and how our body is coping with metabolising the food, ketones levels can also change through the day in response to the food we eat and how our body copes in response.

How to measure ketones

There are a few different methods of measuring ketones which each have their pros and cons.

Urine ketone strips

Urine testing strips are cheap but measuring ketones in the urine rather than the breath or blood tends to be less accurate as ketones. The results from urine testing strips also reflect ketone levels over the past few hours rather than at the time of testing.

Testing ketones in the urine is good if you just want a rough idea of the level of ketosis you’re hitting.

Blood ketone tests

Blood ketone tests can be performed using certain

blood glucose meters

that have been specifically designed to test for ketones.

Blood tests are the most accurate method of measuring ketone levels but the cost of the test strips is relatively expensive if you intend to test your ketones on a regular basis.

Breathalyser

It is possible to measure ketones on the breath. The method is not as accurate as blood ketone tests but is better than urine test strips.

Another advantage of using a breathalyser is that it involves a single up-front cost, which means that once you have the device, you can test your ketone levels as often as you wish.

This can be useful for people looking to seriously understand how well they’re achieving ketosis through the day.

When to measure ketones

When and how often to test ketones will depend on what you’re looking to find out.

If you’re looking to compare whether you’re keeping in ketosis from day to day or week to week, then it makes sense to test at the same time (or times) of day. This will ensure you get consistent results.

As ketones vary through the day, and are affected by different types of meal and

exercise

, you may want to test at different times through the day to see how your level of ketosis varies.

The ketone breathalyser is very useful for this as you don’t pay for each test as you do with say blood ketone testing strips.

Guideline targets

The sweet spot for weight loss is 1.5 to 3.0 mmol/l. This level of nutritional ketosis is recommended by researchers Stephen Phinney and Jeff Volek.

Ketone levels of 0.5 to 1.5 mmol/l, light nutritional ketosis, is also beneficial although not to the degree of full nutritional ketosis.

The longer you stay within these levels, particularly within the sweet spot of nutritional ketosis, the more fat you will burn and the more effective your

weight loss

efforts will be.

If you are starting (or re-starting) a ketogenic diet, it can take up to a few weeks for your body to switch to using ketones as its main fuel source so don’t give up too early.

Achieving ketosis

A number of factors can influence the achievement of ketosis. Carbohydrate intake, protein intake and level of exercise are primary factors.

For detail on how each of these factors can affect ketosis and weight loss, read our guide to

weight loss on a low-carb diet

Ketosis with type 1 diabetes

Ketosis becomes a slightly more complicated topic when it involves people with type 1 diabetes or that are otherwise completely reliant on insulin.

If this applies to you, it is important that you understand the difference between

ketosis

and

ketoacidosis

If you are in any doubt, it’s important that you discuss your insulin management with your doctor or consultant.

Ketosis is a natural state the body finds itself in when it is using fat as its main fuel. This occurs when following a very low carb, ketogenic diet, and often during intermittent fasting too.

Ketosis can be beneficial for a number of people but there are certain groups, such as people with type 1 diabetes, that need to be more careful. In these groups, very high ketone levels would lead to diabetic ketoacidosis, a dangerous situation caused by a lack of sufficient insulin.

What is nutritional ketosis?

Ketosis is a state the body goes into if it needs to break down body fat for energy. The state is marked by raised levels of ketones in the blood which can be used by the body as fuel.

Ketones which are not used for fuel are excreted out of the body via the kidneys and the urine.

Is ketosis the same as ketoacidosis?

Nutritional ketosis occurs when there is not enough carbohydrate in the diet to meet the body’s energy requirements. In this situation, the body switches over from burning sugar to burning fat as its main fuel.

Fat, whether from the diet or the body’s stores, is broken down into ketones in the liver. These ketones are an efficient energy source for many organs, particularly the brain.

Everyone has ketones in their blood at very low levels, under normal conditions. When the body enters ketosis, and so switches to burning mostly fat, levels of ketones in the blood increase.

Groups at greater risk of ketoacidosis

Some people are at risk of ketoacidosis.

Groups at risk of ketoacidosis include, but is not limited to, people with:

• Type 1 diabetes
• Cystic fibrosis-related diabetes
• Pancreatectomy
• Type 2 diabetes with very little pancreatic function

It is possible, and can be beneficial, for people in these groups to follow a ketogenic lifestyle. However, it is important that your doctor is aware of your intention before you start.

Your health team can help you with regard to how best to monitor for ketones and prevent ketoacidosis occurring.

Ketosis vs ketoacidosis

Whereas ketosis is an important natural state allowing the body to run on fat for energy, diabetic ketoacidosis (DKA) is a dangerous and potentially fatal condition.

DKA occurs during situations of ‘internal starvation’ mainly in people with type 1 diabetes, when not enough insulin has been administered.

In this case, the body does not have enough insulin to allow blood glucose into cells. The body believes it is starving and so breaks down fat and protein into ketones at an alarming rate, far above what is seen in nutritional ketosis.

In most cases, ketoacidosis develops when there are both high ketone levels and high blood glucose.

Benefits of nutritional ketosis

In most people nutritional ketosis is beneficial.

Regularly achieving nutritional ketosis has been linked with improvements in:

• Weight loss
• Blood glucose control in diabetes
• Epilepsy
• Overall metabolic health

Research also suggests that nutritional ketosis may have benefits for people with Parkinson’s disease, Alzheimer’s disease and may help to reduce the chance of developing certain forms of cancer.

Measuring ketones

Ketone levels between 0.5 and 3 mmol/L are considered nutritional ketosis.

Ketones are measurable in a number of ways, including blood monitors, breathalysers and urine testing strips. Of these, urine strips are the least effective, as they only measure the ketones that your body is getting rid of, and not the ones it’s using.

The graph below shows the range of blood ketone levels for ketosis and ketoacidosis.

Note that people at risk of ketoacidosis, such as people with type 1 diabetes, should interpret ketone levels in the way laid out by their diabetes health team.

From The Art and Science of Low Carbohydrate Performance by Jeff S Volek, PhD, RD and Stephen D Phinney, MD, PhD. (Page 91)