In recent years, a lot of diets have sprung up and faded away but Ketogenic (or simply keto) diet is still holding its own when it comes to promises and delivery. It may surprise some to learn that Keto diet was never conceptualized for losing weight rather, it was designed to help patients suffering from epilepsy. To understand the diet better let’s first understand the science behind it.
Ketone bodies are molecules which have a ketone groups produced from fatty acids by the liver and are substrates for production of energy through a process called the citric acid cycle. Carbohydrate is the preferred fuel for our body but when there is very low consumption of it, the body enters a state called ketosis during which production of ketone bodies rises and the body essentially switches to fat as form of fuel. It is also important to note that ketosis is different from ketoacidosis, a state in which the blood becomes overly acidic due to very high amounts of ketone bodies in circulation. Ketosis can normally occur in our bodies due to long periods of fast or very low carbohydrate consumption and is completely safe while ketoacidosis occurs when levels of insulin are critically low in the body which can occur in people who are type 1 diabetic. Dangerously low blood pH can impair organ functioning and can be life threatening.
A standard keto plan will consist of 70% fat, 20 % protein and only 10% carbs of total calories, aiming to create the state of ketosis. Being on a keto diet has shown benefits beyond weightloss such as improved insulin sensitivity in type 2 diabetic patients, reduced risks of heart disease and cancer, reduced symptoms of Alzheimer’s and epilepsy, and alleviation in symptoms of PCOS. Increased rates of fat burning, improved insulin sensitivity and decreased intake of calories due to feeling of fullness (satiety) are keys to the success of the diet. There are currently 10 types of keto diets based on the dieter’s goal and preferences.
Therapeutic Ketogenic Diet: this is the original version from 1920s which aims to treat or reduce symptoms of epilepsy. A typical plan will have 90 % of calories from fat, 6% from proteins and only 4% from carbs and hence it is the most ‘strict’ with the most dropout rates.
Standard Ketogenic Diet: this is the most common version followed today. Typical macro split ranges from 80-70% fats, 20-15% proteins and 10-5% carbs.
Cyclical Ketogenic Diet: this type keto plan has carb re-feeding days. For example, you can follow a standard keto diet for 5 days and switch back to carbs for 2 days in a week. This ‘cycling’ of carb intake may be beneficial for people who feel lack of energy while on ketosis or have a hard time controlling cravings for carb rich foods.
Targeted Ketogenic Diet: this is mainly designed for athletes involved in high intensity or muscle building exercises. A standard keto diet is followed throughout the day but around 30 mins before training the athlete is allowed to have 20-25 grams of easily digestible carb rich food to enhance training performance.
High Protein Ketogenic Diet: as the name suggests, this keto plan will have about 30-35% protein, 60-65% fat and 5% carb calorie split. This type is for those looking to preserve their muscle mass such as bodybuilders and older peoples or for those have protein deficiency related issues.
The Mediterranean Keto Diet: this combines the food types of the Mediterranean diet into calorie split of keto. The idea is to consume foods rich in unsaturated fats such as olive oil and fatty fish as advised in the Mediterranean diet, in high amounts as required in the keto diet. This incorporates health benefits such as lowering of LDL, cholesterol and inflammation by consuming monounsaturated fatty acids and omega 3s.
The ‘Dirty’ Keto diet: this is the type for those who could care less about planning their meals or are just too busy to cook or shop healthy. The idea is to accomplish you fat eating goal in a day through whatever type of food you can get, processed or organic. This can be a beneficial approach for beginners, those having issues committing to diet regimes or those who are travelling.
The ‘Lazy’ Keto Diet: this for those who find counting calories a daunting task. The principle is to just focus on monitoring carb intake and occasionally reviewing protein consumption while mostly eating fat rich foods.
Clean Keto Diet: this is exact opposite of the Dirty Keto diet and somewhere inline with the Mediterranean Keto Diet. The focus is to source fat from healthiest food sources possible such as organic, grass-fed, cold-pressed etc. It may become quite expensive to follow for some and often become challenging to procure minimally processed versions of food items.
Keto 2.0: this is for those who feel that standard keto diet is a bit too restrictive for them and widens the intake window for carbs and its variety in the plan. Amount of fat is reduced to 50% while increasing carbs and protein to 20% and 30% respectively. This type of keto diet may not put your body on ketosis but significantly reduces amount of carbs for beginners thus emulating the Atkins diet. The principle is to focus on making it easier for people to be consistent with healthy eating habits by making ‘Keto diet’ seem a bit more flexible. This can also be a good bridging diet for people to prepare them for a standard keto plan in future.
Foods to have (not an exhaustive list)
Dairy (full fat milk, full fat cream, butter and cheese).
Meat (fatty fish, red meat, pork, chicken and turkey).
Non starchy vegetables (peppers, cabbage, broccoli, cauliflower, cabbage, mushroom, onion, tomatoes and leafy vegetables).
Fruits (avocados, rhubarb, moderate amount of berries and coconut).
Nuts and seeds (walnuts, almonds, pistachios, sunflower seeds, pumpkin seeds).
Pure alcohol drinks (rum, vodka, gin, tequila etc).
Oils and spices.
90% dark chocolates.
Foods to avoid (not an exhaustive list)
Sweet and sugar rich foods: soft drinks, candies, fruit juices, chocolates, ice-cream etc.
Carbohydrate rich foods: baked items, beans, legumes, grain and grain based products like pasta.
Starch rich foods: sweet potatoes, potatoes, parsnips etc.
Most fruits: except minute amounts of berries.
Beer, wine and mixed drinks.
Symptoms, Side Effects and Risks:
General symptoms of being in ketosis are excessive thirst and urination, dry mouth, and decreased appetite. During the initial weeks of embarking on a Keto diet, you may experience some side effects too which are known as the ‘Keto Flu’. Most if not all of these symptoms recede once you and your body adapts. Common side effects of keto flu are:
Lethargy, headaches and mental fog.
Decreased exercise performance and cramps.
Digestive issues like constipation and vomiting.
Issues in getting a good sleep.
There are some risks of following a keto diet, especially for type 1 diabetics who are susceptible to experience ketoacidosis. People who take SGLT2 inhibitor medications for managing type 2 diabetes are also strongly recommended against going on a keto diet. Other risk factors are:
1) Nutrient deficiencies.
2) Cardiovascular disease risk due to very high consumption of saturated fats.
3) Excessive fat accumulation in liver.
The takeaway box:
I find the ketogenic diet promising in improving health markers than most of the fad diets but I don’t find it ‘essential’ for weight loss or healthy eating. For athletes, the jury is still out and research has mixed data which needs to be sorted out through further studies. Keto is a bit more complex and demanding than other diets and thus sticking to it may become a challenge for many including my own self, especially long term. But if it works for you then its great! As listed above there are multiple approaches to keto you can try depending on your comfort level and desired results. I would recommend type 1 diabetics to go for easier versions like keto 2.0 or maybe avoid it altogether due to the lethal risk of ketoacidosis. There are fair concerns about elevated LDL and cholesterol risks on keto diet and the research data available seems to show no negative (and marginally positive effects) on blood lipid profile of healthy subjects on a keto diet but the caveat is higher consumption of unsaturated fats over saturated fats in most studies. Two important suggestions from health experts are to limit intake of saturated fats and try to include more unsaturated fats like olive oils, nuts, nut butters, avocados etc. while monitoring levels of blood triglycerides at regular intervals as suggested by a health practitioner to avoid inflating the increasing risks of CVD.
Bonikowska K, Magnusson P, Sjöholm Å. LCHF-kost gav svår ketoacidos hos patienter med typ 2-diabetes - Intensivvård krävdes för att häva livshotande tillstånd [Life-threatening ketoacidosis in patients with type 2 diabetes on LCHF diet]. Lakartidningen. 2018;115:E4AD. Published 2018 Jun 29.
Bueno NB, de Melo IS, de Oliveira SL, da Rocha Ataide T. Very-low-carbohydrate ketogenic diet v. low-fat diet for long-term weight loss: a meta-analysis of randomised controlled trials. Br J Nutr. 2013;110(7):1178-1187. doi:10.1017/S0007114513000548
Lawler, M., 2020. 10 Types of the Keto Diet and How They Work | Everyday Health. [online] EverydayHealth.com. Available at: <https://www.everydayhealth.com/ketogenic-diet/diet/types-targeted-keto-high-protein-keto-keto-cycling-more/> [Accessed 22 June 2021].
Migala, J., 2020. What Happens to Your Cholesterol When You Go on a Keto Diet? | Everyday Health. [online] EverydayHealth.com. Available at: <https://www.everydayhealth.com/ketogenic-diet/what-happens-to-your-cholesterol-on-a-keto-diet/> [Accessed 24 June 2021].
Mullins, G., Hallam, C. and Broom, I. (2011), Ketosis, ketoacidosis and very-low-calorie diets: putting the record straight. Nutrition Bulletin, 36: 397-402. https://doi.org/10.1111/j.1467-3010.2011.01916.x
Westman EC, Tondt J, Maguire E, Yancy WS Jr. Implementing a low-carbohydrate, ketogenic diet to manage type 2 diabetes mellitus. Expert Rev Endocrinol Metab. 2018;13(5):263-272. doi:10.1080/17446651.2018.1523713