Ketogenic diet is a high fat, moderate protein, low carbohydrate, ratio-specific diet. Ketogenic diet or ‘keto’ might be the most popular diet trends of current time. Ketogenic diet is majorly practiced for quick weight loss; sometimes the diet is clubbed with intermittent fasting for faster result.
A classical ketogenic diet restricts carbohydrates to less than 10% of calories and limits protein to 20% to 25%, fats make up for the rest. In practice, the ketogenic diet is primarily used as a medical nutrition therapy to treat neurological disorders such as uncontrolled epilepsy (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6836058/), Parkinson’s (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6175383/), Alzheimer’s disease (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6720297/), etc. But the latest evidence suggests this diet can offer benefits against obesity (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3945587/), diabetes (https://pubmed.ncbi.nlm.nih.gov/30289048/), cancer (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5842847/) too.
The ketogenic diet, by mimicking the metabolism of fasting, became popular as a therapy for epilepsy in 1920s. However, the utility of the diet decreased eventually with the introduction of new anti-epileptic drugs. These drugs still failed to reduce seizures in around 20% to 30% of patients and the ketogenic diet was re-introduced to these patients particularly among pediatric patients for managing the condition (https://onlinelibrary.wiley.com/doi/10.1111/j.1528-1167.2008.01821.x).
How the diet works
The fundamental of ketogenic diet involves low carbohydrate intake and replaces the source of energy with fat. Severe restriction of carbs puts the body into a metabolic state called ketosis, which leads to accelerated fat burns and production of ketone bodies that are used as fuel instead of glucose.
Basics of the classic ketogenic diet
Ketogenic diets are majorly classified according to the composition of macronutrients (carbs, protein, and fat) and type of fats. The classic ketogenic diet is composed of 70-80% fat, 20-25% protein and 5-10% carbohydrate. The diet also follows a specific ratio between fat, carbohydrate, and protein to ensure optimum ketosis. The ratio usually ranges between 2.5:1 to 4:1 and is calculated by the ketogenic diet expert as per individual need.
The diet protocol advises to follow a no-carb diet before you start following keto to ensure complete washout of carbohydrate from the body. This process is known as carbohydrate-washout phase and can be extended up to 7 days until the ketosis begins. The diet requires measuring urine ketone levels at least four times a day to ensure you don’t fall out of ketosis. In fact, your toothpaste needs to be sugar free.
You are only allowed to eat the recipes provided by the ketogenic diet expert and nothing else. All ingredients in each menu are to be measured in kitchen weighing scale before cooking to maintain the ratio.
Which foods are allowed?
Animal foods are widely used in the ketogenic diet as they have almost zero carbs and high-quality protein. Grass fed, organic, ethically raised fresh cut meats, chicken and turkey are the primary choices for keto. Other common foods are fatty fish like salmon, trout, tuna, and mackerel, eggs, ghee, butter and cream; unprocessed cheese like cheddar, goat, cream, blue, or mozzarella, nuts and seeds likes almonds, walnuts, flaxseeds, pumpkin seeds, sesame seeds, chia seeds, etc.; cold-pressed, unrefined oils like extra virgin olive oil, coconut oil, and avocado oil and avocado. Spices are allowed without any restriction. Low sugar fruits and vegetables are allowed, but in small quantity.
Foods that are not allowed
All foods that contain white refined sugar, syrup, jaggery, grains wheat-based products, rice, pasta, cereal, fruits, beans, peas, lentils, chickpeas, potato, sweet potato, alcohol. The keto dietitian can still manage to include some of these in your menu if you crave any except sugar and sugary products.
The ketogenic diet, which is preached and practiced by a large section of people, often doesn’t involve a ketogenic diet expert; instead it’s perceived from the internet, a peer who’s following keto or gym trainers. Ketogenic diet is found to be associated with some side-effects, which can only be managed by an experienced keto coach.
Most reported side-effect is keto flu, which happens when you start the diet in response to the body adapting to the low-carb state. The symptoms of keto flu (https://www.ncbi.nlm.nih.gov/books/NBK499830/) are headache, irritability, fatigue, weakness, nausea. In some people, the keto flu also includes constipation and insomnia. The long-term health risks of following ketogenic diet is still under investigation and demonstrates mixed results.
Ketogenic diet is not appropriate for everyone. If you want to start ketogenic diet, get evaluated by a physician and a ketogenic diet expert first. A constant monitoring is also recommended to tackle mild to moderate side-effects. If you have any micronutrient deficiency, ketogenic diet might worsen that. Additionally, the diet is often non-sustainable as it eliminates an entire food group.
So far, medically supervised ketogenic diet for weight loss has been found to be effective and safe. But ketogenic diet is extremely precise, requires a group of experts to design and monitor the diet.
A ketogenic diet that lacks scientific precision may yield several health complications.
(Subhasree Ray, Doctoral Scholar, Clinical and Public Health Nutritionist, Certified Diabetes Educator. She can be followed on her Twitter @DrSubhasree)