The Ketogenic Diet: Could It Optimise Your Health?

Everything you need to know about following a ketogenic diet.

Is keto the key to optimal health?

The food we eat is the fuel for our body. It’s also what can tip the scale between health and disease. The ketogenic diet, or keto for short, has exploded in popularity in recent years with many people claiming effortless and drastic weight loss alongside dramatic health improvements. Strict low-carbohydrate diets have been successfully used for years for weight loss and several health conditions, like type 2 diabetes, so is keto the key to optimal health?

What is the ketogenic diet?

Believe It or not, the ketogenic diet is not a new concept. It originated in the 1920s when starvation studies discovered that seizures (fitting/epilepsy) stopped after several days without food.1 It was later discovered that the same results could be produced by introducing an extremely low carbohydrate diet. The diet was and still is used to treat epilepsy although now mostly only when anticonvulsant medications don’t work.

The human body generally runs on glucose as fuel, sourcing it primarily from carbohydrates and storing fat only to be used in times when carbohydrates are in low supply. The ketogenic diet is an eating plan in which carbohydrate intake is severely restricted. The reduction in carbohydrates puts the body into a metabolic state called ketosis, in which the body is forced to use fat for fuel. As the body breaks down fat, it produces compounds called ketones. Ketones are an efficient energy source for many organs, particularly the brain. Ketones are measurable in a number of ways, including fingerprick blood test, breath analysis and by using urine testing strips.

Intermittent fasting, where you limit your intake of food to within a period of around 8 hours or less, while fasting for the remaining 16 hours of the day, can help people to reach ketosis faster.

It’s important for any diet to include adequate protein and fat for the body to function properly, however, it’s mainly the adjustment in the ratio of carbohydrate to protein and fat that determines the body’s primary fuel source. Each macronutrient (carbohydrate, fat or protein) makes up a percentage of your recommended daily calorie count, so if one macronutrient is limited, another has to be increased. A ketogenic diet is often formulated to contain more fat and, sometimes, protein in order to compensate for the carbohydrate restriction.2 This is why the ketogenic diet is often referred to as a ‘high fat diet’.

Foods to include on the ketogenic diet

This diet may seem too restrictive and some versions of it rely on processed foods but, when undertaken with an eye on nutritious wholefoods, it can provide a varied and healthy eating plan.

  • Fats and oils are an important part of a ketogenic diet, but not all fats are the same. Saturated fats such as grass-fed butter, ghee (clarified butter), coconut oil, MCT (Medium-chain triglycerides) oil and lard are recommended. These fats make up 50% of our cell membranes and are also used to make our hormones in the body.
  • Monounsaturated fats from extra virgin olive oil, flaxseeds, avocados, and macadamia nuts are also commonly included in a ketogenic diet. Avocado oil and extra virgin olive oil can be drizzled over salads and vegetables or used for cooking. Monounsaturated fats have been linked to decreased inflammation and reduced blood pressure.3
  • Polyunsaturated fats that are found naturally in grass-fed meat and wild fatty fish are also useful additions to a ketogenic diet plan. Polyunsaturated fats from these sources may help lower LDL cholesterol. Wild-caught salmon and trout are particularly good sources of Omega 3 fatty acids. Alternatively, you could consider a good quality fish oil supplement to ensure optimal levels of anti-inflammatory Omega 3. Omega 3 is anti-inflammatory and supports heart health and brain function. Polyunsaturated fats to avoid are those from processed vegetable oils.
  • Protein is also an important cornerstone of the ketogenic diet, and the amount can be adjusted to suit the individual’s specific needs. While excess protein intake could stop ketone production, some individuals such as athletes find that they can eat higher protein to suit their needs without sacrificing the state of ketosis.
  • Wherever possible, choose organic, grass-fed meat or wild-caught fish for lower levels of environmental chemicals and a better Omega-3:Omega-6 ratio. A balanced ratio is more desirable in reducing the risk of many chronic diseases, including cardiovascular disease, cancer, and inflammatory autoimmune diseases.4
  • Wild-caught fish like cod, mackerel, halibut, salmon, and trout are all good sources of fish protein to include in a ketogenic diet. Other types of seafood such as crab, scallops, mussels, and squid are also good options.
  • Meats to include in a ketogenic diet are fattier cuts of beef, lamb, and free-roaming pork. Dark meat from poultry such as chicken and duck is better to include compared to the white meat as it has a higher fat content. Wild game is also an option to include as a protein source on this diet. Wild meat is truly grass fed and has a good amount of iron, zinc, and vitamin B12.
  • Organ meats such as heart, liver, and kidney provide protein as well as an array of vitamins and minerals.
  • Eggs are a wholesome and versatile protein source. Ensure to look for organic, free-range eggs. One egg contains about 6 grams of protein and 5 grams of fat. Eggs are also a great source of choline, a vital nutrient used by the liver and brain to function optimally.
  • Nut butters are a plant-based source of protein. Be sure to check for added sugars and oils. Almond butter and macadamia nut butter have a higher fat profile, which is more suitable on a ketogenic diet.

Vegetables and fruit are important for general health, but some are really high in natural sugars and should therefore be avoided on this diet. A good rule of thumb is to choose vegetables that grow above the ground such as spinach, broccoli, cauliflower, cabbage, and Swiss chard. These can be eaten freely. Minimizing root vegetables such as carrots and beetroot is best on the ketogenic diet. Berries are a low-sugar fruit so can make a nutritious treat, while the tropical fruits such as pineapple are much higher in sugar.


It’s important to maintain good levels of hydration on the ketogenic diet. Carbohydrates hold on to water and as carbohydrates are restricted you therefore retain less water, which could lead to dehydration. Choose water, herbal teas and black coffee. Another good beverage is bone broth, which is loaded with minerals and nutrients and can be seasoned with salt to help prevent ‘keto flu’ – see below.

Foods to avoid on the ketogenic diet
  • Sugary and processed foods are strictly prohibited on the keto diet. Avoid foods such as biscuits, fizzy drinks, desserts, pastries, pizza, ice cream, cereals as well as sweetened yoghurt.
  • It’s important to check food labels for hidden sugars and processed oils in foods such as ketchup, salad dressings and pasta sauces.
  • Natural sweeteners such as honey and maple syrup are still sugars and should be minimized or avoided.
  • High-starch foods turn into sugar when digested and should therefore be avoided on the ketogenic diet. Starchy foods to avoid include grains, pasta, bread, rice, fries, porridge, oatmeal, legumes, potatoes, sweet potatoes, carrots, beetroots. Even wholegrains are rich in starch.
  • Avoid fruits except for berries.
  • Higher-carb alcohol drinks such as beer should be avoided, however, lower carb drinks such as gin or vodka with soda water could be a good substitute in moderation.
  • Avoid unhealthy fats from processed foods and vegetable oils and margarines.
Health benefits of the ketogenic diet

Low-carbohydrate diets have been shown to be more effective than low-fat diets for weight loss.2 The diet encourages lower insulin levels, allowing the body to use stored fat for energy production.

It’s the weight loss that draws most people to start the ketogenic diet initially However, the benefits go way beyond a leaner waistline:

Improved blood sugar control

The supply of energy to our tissues is at the core of our metabolism and blood sugar regulation plays an important part in this. The sugar crash that many people experience is a result of consuming foods that are highly processed carbohydrates that result in rapid rises in blood sugar levels. The insulin response that follows reduces our blood sugar levels too quickly, often leaving us with low energy levels. Therefore, by consuming less carbohydrate, blood sugar levels are better regulated, avoiding these insulin spikes and energy dips.

Controlling blood sugar levels is critical for individuals with type 2 diabetes. Science has shown the power of the ketogenic diet in the management of type 2 diabetes.5 A blood test marker commonly monitored in diabetes patients is HbA1c. A recent review on published data found that the evidence for improved levels of HbA1c with very low carbohydrate diets was consistent across all studies.6 It can in fact help some individuals with type 2 diabetes achieve remission.6

Improved cardiovascular risk markers

A common concern for some people is the high fat intake of the ketogenic diet and its effect on cardiovascular health. The science actually shows that the restricted carbohydrate intake on a ketogenic diet lowers the markers that are commonly associated with heart disease.

A 2017 review found that ketogenic diets are effective in the reduction of total cholesterol, an increase in HDL (good cholesterol), a decrease in triglycerides, and reductions in LDL (bad cholesterol).7

High blood pressure is still considered to be the single biggest risk factor for heart attacks and strokes. Data suggests that the ketogenic diet may help lower blood pressure.8

Reduction of fatty liver disease

When it’s not caused by alcohol, fatty liver disease is primarily caused by the excessive intake of refined and processed carbohydrates. Promising studies have shown a rapid reversal of fatty liver disease with a low carbohydrate ketogenic diet.9

Reduced inflammation and cancer risk

Excessive consumption of highly processed carbohydrates has been shown to illicit an immune response in the body in the form of inflammation. Chronic inflammation over time can have a detrimental effect on the body’s immune system, however, it may also lead to damaged DNA, which has been associated with an increase in risk of cancer.10

Obesity has now been recognized as the second leading cause of cancer. There is therefore a correlation between weight loss, reduced inflammation, and cancer risk. Ketogenic diets are currently being investigated for how they may help prevent and treat certain cancers.11 Some studies have demonstrated how the ketogenic diet may be complementary in chemotherapy treatment.12

The reduction in inflammation that is accomplished on a ketogenic diet is also being widely researched in autoimmune disease.

Improved brain health

Being in a state of ketosis means that the brain will be using ketones as an energy source. Many individuals report an improved sense of clarity and concentration relating to this.

For decades ketogenic diets have been a cornerstone in the management of treatment-resistant epilepsy, particularly in children.13

The ketogenic diet is currently being researched to manage or prevent conditions such as Parkinson’s disease, Alzheimer’s, ADHD, and some sleep disorders.14 Higher blood sugar levels cause inflammation that can result in cognitive decline associated with neurological conditions.

Improved skin health

Studies have shown that the ketogenic diet has a positive effect on our gut microbiome. Diets that consist of highly processed carbohydrates have the ability to alter the bacterial microbiome, promoting an overgrowth of bacteria that is associated with acne.15

What is the keto flu?

The keto flu is a way of describing some physical and emotional side effects some people experience shortly after starting a ketogenic diet. Symptoms include nausea, sleeplessness, irritability, muscle cramps, stomach pain, and lack of energy.

A few factors may be the reasons behind the keto flu:

  • The introduction of more fats if a person has low levels of bile may put strain on the liver and the gallbladder and this may result in feelings of nausea and bloating.
  • When insulin levels drop, they trigger the kidneys to release sodium, magnesium, and water. It is imperative that hydration is maintained on a ketogenic diet and that salt and other minerals are included in the diet – see below.
  • The ketogenic diet may deplete some key nutrients due to a reduced intake of foods where these nutrients are found. In particular, the B vitamins and potassium. This may contribute to some fatigue and dizziness. Some care should be taken to replenish B vitamins and electrolytes – see tips below.

The good news is that while these symptoms may occur soon after starting the ketogenic diet, they usually only last about a week while your body adjusts to the new way of eating.

Important supplementation on the ketogenic diet

If the ketogenic diet is implemented correctly and your digestion is good, the majority of the nutrients needed will come from food. There are however a few supplements that individuals on keto would benefit from:


Minerals are essential to many of the body’s biochemical processes, including the production of energy. Due to the increase of water excreted on the ketogenic diet, the loss of magnesium, sodium, and potassium increases too.16 A good electrolyte powder is recommended to ensure replenishment of lost minerals.

B Vitamins

Vitamin B1 is particularly important to support the body’s transition from predominantly burning sugar to predominantly burning fat for fuel. Vitamin B5 is another key vitamin that is essential in this adaptation to fat burning. A deficiency in vitamin B1 & B5 results in increased fatigue. Additionally, vitamin B3 might promote better cholesterol levels and support general liver health.17

Vitamin D3

Vitamin D facilitates the absorption of calcium, which could be lacking on a ketogenic diet, especially if dairy is also excluded. The journal of Diabetology & Metabolic Syndrome published a study which showed that vitamin D3 improved glucose tolerance.18 Unless you live in a country with constant sunshine, it’s unlikely that you’ll meet your optimal levels of vitamin D3 from food alone. It’s important to take vitamin K2 along with vitamin D3.


It is essential to maintain good levels of fibre intake while adapting to a ketogenic diet. Fibre is important to maintain healthy gastrointestinal function and minimize the risk of constipation. Include abundant leafy green vegetables, nuts and seeds in your keto diet, but consider psyllium husk or ground flaxseed if you need a little more fibre.

Tips for getting started on the ketogenic diet
  • Ensure you are reading food labels to avoid those hidden sugars
    • Consider using an app to track your macros and ensure you are not overeating carbohydrates
    • Stay hydrated and be sure to replenish your minerals
    • Food prepping for the week can help you stay accountable and sustain the diet
    Simple ketogenic meal ideas
    • Strawberry avocado smoothie
    • Bacon and egg muffins
    • Scrambled eggs with avocado and bacon
    • Avocado and prawn salad
    • Grilled chicken salad
    • Tuna salad
    • Keto beef stew
    • Garlic & rosemary pork chops with tender-stem broccoli
    • Salmon with leafy green salad

    The ketogenic diet is a diet formulated to be very low in carbohydrate and higher in fats, with the purpose of achieving ketosis. It has proven not only effective for weight loss but also for the management of multiple health conditions. Above all, the keto diet’s ability to reduce insulin levels suggests that it is a lifestyle shift that may just be an integral component of optimal health.

    1. Wheless J. History of the ketogenic diet. Epilepsia. 2008, 8:3-5.
    2. Yancy W, et al. A low-carbohydrate, ketogenic diet versus a low-fat diet to treat obesity and hyperlipidemia: a randomized, controlled trial. Ann Intern Med. 2004,140(10):769-77.
    3. Pérez-Jiménez F, et al. Protective effect of dietary monounsaturated fat on arteriosclerosis: beyond cholesterol. Atherosclerosis. 2002, 163(2):385-98.
    4. Daley C, et al. A review of fatty acid profiles and antioxidant content in grass-fed and grain-fed beef. Nutr J. 2010, 9:10.
    5. Alarim R, et al. Effects of the Ketogenic Diet on Glycemic Control in Diabetic Patients: Meta-Analysis of Clinical Trials. Cureus. 2020, 12(10):e10796
    6. Goldenberg J, et al. Efficacy and safety of low and very low carbohydrate diets for type 2 diabetes remission: systematic review and meta-analysis of published and unpublished randomized trial data BMJ. 2021, 372 :m4743
    7. Kosinski C. & Jornayvaz F. Effects of Ketogenic Diets on Cardiovascular Risk Factors: Evidence from Animal and Human Studies. Nutrients. 2017, 9(5):517.
    8. Unwin D, et al. Substantial and Sustained Improvements in Blood Pressure, Weight and Lipid Profiles from a Carbohydrate Restricted Diet: An Observational Study of Insulin Resistant Patients in Primary Care. Int. J. Environ. Res. Public Health. 2019, 16(15):2680
    9. Luukkonen P, et al. Effect of a ketogenic diet on hepatic steatosis and hepatic mitochondrial metabolism in nonalcoholic fatty liver disease. Proc Natl Acad Sci. 2020, 117(13):7347-7354.
    10. Kawanishi S, et al. Crosstalk between DNA Damage and Inflammation in the Multiple Steps of Carcinogenesis. Int J Mol Sci. 2017, 18(8):1808.
    11. Li , et al. Cancer Treatment With the Ketogenic Diet: A Systematic Review and Meta-analysis of Animal Studies. Front. Nutr. 2021, doi:
    12. Tan-Shalaby J. Ketogenic Diets and Cancer: Emerging Evidence. Fed Pract. 2017, 37S-42S.
    13. Winesett S, et al. The ketogenic diet in pharmacoresistant childhood epilepsy. Expert Review of Neurotherapeutics. 2015, 15(6):621-628
    14. Włodarek D. Role of Ketogenic Diets in Neurodegenerative Diseases (Alzheimer’s Disease and Parkinson’s Disease). Nutrients. 2019, 2(169) 1-11
    15. Paoli A, et al. Nutrition and acne: therapeutic potential of ketogenic diets. Skin Pharmacol Physiol. 2012, 25(3):111-7
    16. Kenig S, et al. Assessment of micronutrients in a 12-wk ketogenic diet in obese adults. Nutrition. 2019, 67-68:110522.
    17. Zheng Y, et al. B Vitamins Can Reduce Body Weight Gain by Increasing Metabolism-related Enzyme Activities in Rats Fed on a High-Fat Diet. Curr Med Sci. 2018, 38(1):174-183
    18. Talaei A, et al. The effect of vitamin D on insulin resistance in patients with type 2 diabetes. Diabetol Metab Syndr. 2013, 5:8 (2013)