You may have read about the ketogenic diet of late as it is has raised a lot of interest in the world of natural health and fitness. Besides it’s use in weight loss, there has been
increasing evidence to suggest that very low carbohydrate ketogenic diets could play a therapeutic role in numerous disease states.
Ketogenic diets have been used therapeutically for the treatment of epilepsy since the 1920’s, and they became popular for weight loss during the 1960’s and 70’s. More recent research has shown therapeutic potential for many other pathological conditions such as neurological diseases, diabetes, polycystic ovary syndrome, cancer, and a reduction in the risk of cardiovascular and respiratory disorders (1).
There are both advantages and disadvantages to ketosis, a state in which your body is burning fat as opposed to carbohydrates (glucose) for energy.
When there isn’t enough glucose available to use for energy, the body switches into a state where ketones are generated during the metabolism of fats, and then used for energy instead of glucose. An absence of dietary carbohydrates also results in reduced insulin levels leading to a reduction in lipogenesis and the accumulation of fat.
Therefore one of the main advantages to the ketogenic diet would be weight loss (which could also be seen as a disadvantage for those who don’t need to lose weight).
Recent studies show that low-carb/high fat diets may lower inflammation, improve blood sugar regulation, and potentially lower the risk of heart disease if followed correctly (3,4)
Other advantages include improved health, sporting performance and endurance.
Eliminating all whole grains, fruit, starchy vegetables, and legumes, may lead to deficiencies such as dietary fibre and some plant-based nutrients. It is well known that adequate dietary fibre is essential for the maintenance of a healthy gut microbiome and for reducing the risk of colorectal disease (5).
Potential risks include a very high protein intake, which could lead to possible kidney damage (2), however, true ketogenic diets should only be relatively high in protein. Most ketogenic diets tend to focus on a high intake of fat (70-75% of your calories), only 5 or 10% of your calories from carbohydrates, and the rest from protein (15-20%).
Problems may occur if too many saturated fats are consumed, which may increase your risk of heart disease.
Furthermore, this diet can be difficult to adhere to long-term, as it can be very socially challenging and isolating.
Ketogenic diet tips
The type of fat consumed is very important. It is best to avoid oils high in omega-6 fats such as soy, safflower, sunflower, corn oil etc. (as found in mayonnaise and salad dressings) as they can be inflammatory when consumed in large amounts.
It is generally recommended to consume foods high in monounsaturated and saturated fats, such as olive oil, grass fed or organic meat, butter and cheese, eggs, and avocados.
Foods high in omega-3 fats, such as oily fish (sardines, salmon, herring, trout, anchovies, mackerel), walnuts and chia seeds are anti-inflammatory healthy fats and should be included.
Medium-chain triglycerides such as coconut oil and MCT oil are also recommended. These fats are necessary for the absorption of fat-soluble nutrients A, D, E and K.
Include a good variety of non-starchy vegetables such as broccoli, cabbage, cauliflower, courgette, peppers, asparagus, green beans, and salad greens, to ensure a plentiful supply of vitamins, minerals, fibre and phytonutrients.
As nutritional therapists, we know that we are all genetically individual, meaning that there is no "one size fits all" approach to dietary management, and although useful for many disease states, the ketogenic diet may not suit everyone.
It has been suggested that further studies are still needed to investigate the therapeutic effectiveness and long-term safety, and the potential mechanisms of action. Always ensure to check with your health care provider whether it’s safe for you depending on your health.
Paoli, A. et al., 2013. Beyond weight loss: A review of the therapeutic uses of very-low-carbohydrate (ketogenic) diets. European Journal of Clinical Nutrition, 67(8), pp.789–796.
Martin WF, Armstrong LE, Rodriguez NR. Dietary protein intake and renal function. Nutr Metab (Lond) 2005;2:25.
Steckhan, N. et al., 2016. Effects of different dietary approaches on inflammatory markers in patients with metabolic syndrome: A systematic review and meta-analysis. Nutrition Journal, March 2016. Volume 32, Issue 3, Pages 338–348
Rayghan, F. et al., 2016. Comparative effects of carbohydrate versus fat restriction on metabolic profiles, biomarkers of inflammation and oxidative stress in overweight patients with Type 2 diabetic and coronary heart disease: A randomized clinical trial. Arya Atherosclerosis 12(6): 266–273.
Simpson, H.L. & Campbell, B.J., 2015. Review article: Dietary fibre-microbiota interactions. Alimentary Pharmacology and Therapeutics, 42(2), pp.158–179.