The ketogenic diet (KD) has gained lots of attention in recent years as a means to lose weight, reduce inflammation and improve metabolic markers. But is it right for you?
The ketogenic diet is a form of a very low carbohydrate diet where you deprive your body of carbohydrate so it learns to burn fat for energy. In this process ketones are formed. Ketones are then used as a source of fuel for the brain, heart and muscles.
There are various forms of the ketogenic diet ranging from the classic which recommends: 90% of diet from fat, 6% protein, 4% carbohydrates of total energy. Others are less restrictive and allow up to 50g of low glycemic load carbohydrates, 20% protein and 50-60% fat. However, even the less restrictive form will still require immense changes to your regular diet.
Why Are People Trying Keto?
The keto diet is not new, it has been around since the 1920s and is often prescribed to patients with specific type of epilepsy as it has been shown to be effective in reducing seizures.
Most people jump on the keto bandwagon in the hopes of reducing body weight. There are a number of studies that have found that following a KD can reduce one’s BMI and improve metabolic markers including increased HDL, decreased LDL, total cholesterol, triglycerides and glucose levels.
The KD or other low-carbohydrate diets may be most effective for those with insulin resistance. The key feature of insulin resistance is an impaired ability of muscle cells to absorb blood sugar (glucose) and convert it to energy. Instead, those with insulin resistance will divert the glucose to the liver to be converted into fat. If dietary carbohydrates are restricted to a level where they are not significantly converted to fat (a level which varies person to person) improvements in insulin resistance have been noted.
Metabolizing fats into ketones has been shown to reduce the generation of reactive oxygen species that increases inflammation and cause oxidative damage to our cells. KD may help reduce pain associated with inflammation and could potentially reduce the risk of cardiovascular disease due to improved metabolic markers and reduction in inflammation. However, read on to see the flip side of the coin.
Research is ongoing as to whether the KD has neuroprotective effects that could also help in the treatment of neurological diseases including Alzheimer’s, Parkinson’s, and even brain trauma. Early studies show some success in reducing the symptoms of these conditions; however, more research is needed to support the early findings.
Recent studies have shown that some food items can stimulate pathways that develop acne. Food with a high glycemic load and milk are two such culprits. More clinical trials are need to conclude this issue; however, some persuasive evidence exists that point to the benefits of a reduced high-glycemic carbohydrate diet on the severity and progression of acne.
Polycystic Ovary Syndrome is characterized by obesity, insulin resistance, ovulatory dysfunction and high levels of androgen hormones (male sex hormones). Suggested treatments include those that target insulin resistance, such as, the KD diet. It has been shown that improvements in insulin resistance and a reduction in body weight may also be effective in reducing androgen hormone levels and normalizing ovulation. Results are preliminary but “watch this space” for further clarification in the future.
THE FLIP SIDE
Despite the fact that some early trials show benefits of the KD on various ailments, there is not concordance in the literature about their absolute effectiveness and doubts remain about their safety.
I tell my clients “don’t start a diet you can’t stick to for the rest of your life”. One of the key downsides to the KD is that compliance is very low as it can be a very challenging pattern of eating to stick to for the long term. Optimizing adherence is the most important factor for long-term weight loss success.
Entering into a ketogenic diet can lead to a variety of symptoms colloquially termed “the keto-flu”. These include: head-aches, dehydration, shivers, foggy brain and nausea. Some people don’t get past this stage before they throw in the towel. Entering into ketosis slowly, that is, reducing carbohydrates and increasing fat intake over a period of time can reduce the symptoms of the keto-flu.
Rebound Weight Gain
The initial weight loss in a KD is due to the loss of water as your body burns through its water-filled carbohydrate (glycogen) stores. Further, as your body is deprived of energy from carbohydrate sources, it will look to, not only fat, but protein reserves to break down and convert to useable energy. It is possible, therefore, to lose lean tissue when following a KD. Preserving muscle mass while aging is key to injury prevention and mobility. Further, reduction in muscle mass can slow the metabolism and lead to rebound weight gain if/when normal eating resumes.
Lack of Nutrients
The KD diet is incredibly restrictive and many of the forbidden foods are colourful plants rich in fibre and phytonutrients. Although low-carb veggies are allowed and encouraged (such as leafy greens) most fruits, all grains and legumes as well as certain higher carb veggies like carrots and beets are prohibited.
The KD can end up being quite low in fibre which can lead to constipation and other lower gastro-intestinal disorders. Supplements are often recommended to those following a KD as deficiencies could occur in any or all of the following: B-vitamins, calcium, sodium, potassium, vitamin D and the antioxidant vitamins A, C and E. Further, there is also an increased risk of developing kidney stones. These are a couple of reasons why those prescribed a ketogenic diet (for example for epilepsy) are also monitored by an experienced nutritional professional.
Photo cred: @tlbvelo
Not For You
Those who should not go on a KD include children, teenagers, women who are pregnant, breastfeeding or trying to get pregnant, those suffering from adrenal fatigue, poor thyroid function or high -level athletes. As athletes know, carbohydrates are the primary source of fuel for high intensity training. Without them, athletes will have a marked- reduction in performance and increased levels of perceived exertion, that is, everything will feel very difficult and they won’t go as fast or be as strong.
You can see there are potential benefits for some people in following a KD but many drawbacks and a fair amount of uncertainty. What is interesting to note is that exercise and fasting can evoke a similar physiological state to that triggered by the KD.
Further, being in the state of ketosis is not a requirement for weight loss or improved metabolic markers. There is ample evidence that those who suffer from metabolic syndrome* would see favourable changes in following a diet that moderately restricts carbohydrates to 26-44% of their daily diet. The emphasis would be to consume low-glycemic, high fibre, phytonutrient rich sources of carbohydrates. This dietary pattern would minimize many of the potential negatives associated with the more restrictive KD.
If you want more information or to discuss a diet that is right for you contact me for a consultation.
* Metabolic syndrome: is a cluster of conditions that occur together including: high blood pressure, high blood sugar/ insulin resistance, excess abdominal fat and abnormal cholesterol and triglyceride levels that can increase your risk of heart disease, stroke and diabetes.
Dashti HM1, et al. Long-term effects of a ketogenic diet in obese patients. Exp Clin Cardiol. 2004 Fall;9(3):200-5.
Smyl C1. Ketogenic Diet and Cancer-a Perspective. Recent Results Cancer Res. 2016;207:233-40. doi: 10.1007/978-3-319-42118-6_11.
Tinsley GM1, Willoughby DS. Fat-Free Mass Changes During Ketogenic Diets and the Potential Role of Resistance Training. Int J Sport Nutr Exerc Metab. 2016 Feb;26(1):78-92. doi: 10.1123/ijsnem.2015-0070. Epub 2015 Aug 12.
Tagliabue A1, Ferraris C2, Uggeri F3, Trentani C2, Bertoli S4, de Giorgis V5, Veggiotti P5, Elli M3. Short-term impact of a classical ketogenic diet on gut microbiota in GLUT1 Deficiency Syndrome: A 3-month prospective observational study. Clin Nutr ESPEN. 2017 Feb;17:33-37. doi: 10.1016/j.clnesp.2016.11.003. Epub 2016 Dec 18.
A Paoli1, A Rubini1, J S Volek2 and K A Grimaldi3 Beyond weight loss: a review of the therapeutic uses of very-low-carbohydrate (ketogenic) diets. European Journal of Clinical Nutrition (2013) 67, 789–796; doi:10.1038/ejcn.2013.116; published online 26 June 2013
Rietman A1, Schwarz J1, Tomé D2, Kok FJ1, Mensink M1. High dietary protein intake, reducing or eliciting insulin resistance? Eur J Clin Nutr. 2014 Sep;68(9):973-9. doi: 10.1038/ejcn.2014.123. Epub 2014 Jul 2.
Merino J1, Kones R2, Ferré R3, Plana N3, Girona J3, Aragonés G3, Ibarretxe D3, Heras M3, Masana L3. Low-carbohydrate, high-protein, high-fat diet alters small peripheral artery reactivity in metabolic syndrome patients. Clin Investig Arterioscler. 2014 Mar-Apr;26(2):58-65. doi: 10.1016/j.arteri.2013.11.004. Epub 2013 Dec 21.
Liebman M1. When and why carbohydrate restriction can be a viable option. Nutrition. 2014 Jul-Aug;30(7-8):748-54. doi: 10.1016/j.nut.2013.11.021. Epub 2013 Dec 4.
Thom G1, Lean M2. Is There an Optimal Diet for Weight Management and Metabolic Health? Gastroenterology. 2017 Feb 15. pii: S0016-5085(17)30158-0. doi: 10.1053/j.gastro.2017.01.056. [Epub ahead of print]
Ebbeling CB, Swain JF, Feldman HA, Wong WA, Hachey DL, Garcia-Logo E, and Ludwig DD. “Effects of dietary composition on energy expenditure during weight loss maintenance.” JAMA 307: 267-2634 (2012).
Ebbeling CB, Leidig MM, Feldman HA, Lovesky MM, and Ludwig DS. “Effects of a low–glycemic load vs. low-fat diet in obese young adults”. JAMA 297: 2092-2102 (2007).