What is the Ketogenic diet?
Ketogenic diet or Keto diet also commonly known as a low-carb, high-fat diet is composed of high fats and a reduced amount of carbohydrates (less than 50g/day) with moderate protein.
In simple terms, when you consume a low carb and high-fat diet you are following a Keto diet (1).
How does the Keto diet help in weight loss?
It may seem counterintuitive to consume a high-fat diet for body fat reduction. But the idea of taking a high-fat diet for weight loss is based on how the human body utilizes energy.
By depleting the body of glucose, the goal of the Ketogenic or Keto diet is to force our bodies to use fat as an energy source.
Carbohydrates (glucose) are the main energy sources in our bodies but when the body is deprived of carbs (less than 50g/day), insulin release declines.
Further prolonged depletion of glucose and more energy requirement forces the body to start producing ketone bodies from fat bodies i.e Ketogenesis.
This switches the energy utilization from glucose to fat as in a process called Ketosis (4). When you provide your body with a low-carb high-fat diet (ketogenic diet), the energy is mostly derived from fats.
Since insulin is an inhibitor of lipolysis (fat burning). Thus, low levels of insulin on the Keto diet may promote lipolysis leading to fat utilization and overall weight loss (5).
Furthermore, Low carbohydrates vs Low fats research shows that a low carbohydrate diet performs better than a low-fat diet.
Severely obese individuals with metabolic syndrome were separated into low carbohydrate and low-fat diet groups. Low carbohydrate diet groups lost more weight than low-fat groups over the course of 6 months (11).
The research so far shows the possible ways ketogenic diet promotes weight loss are: Increase fat burning and decrease fat storage and Satiety or fullness effects of protein in the body.
Thus, Low carb ketogenic diet could have an overall effect due to lowering hunger and energy utilization switch fat burning.
Types of Keto Diets
There are 4 major Keto Diet types (12)
Standard Keto Diet (SKD): the most widely used type of keto diet. It follows 70% fat, 20% proteins, and 10% carbs, making it a low carb, high fat, and moderate protein diet. This keto diet has been studied the most in the research setting. It is also the most recommended keto diet type.
High-Protein Keto Diet (HPKD): This is an extreme version of a Keto diet with only 5% carbs/day. The rest is 60% fats and 35% protein.
Cyclical Keto Diet (CKD): This involves cycling between high carbs and the Keto diet. For example, five keto diet days and two high carb days will constitute one cycle. This is used mostly, athletes and bodybuilders.
Targeted Keto Diet (TKD): It is a high-fat, low-carb diet but carbs are added around the periods of high intensity work out. Mostly used by bodybuilders who want to maintain lean body muscle mass.
Benefits of Keto Diet
1) Keto diet and weight loss
Animal and human studies provide good evidence that the Keto diet promotes weight loss.
Research has shown that a Ketogenic diet reduces weight and other metabolic markers such as blood pressure, insulin sensitivity, and glucose levels.
A study with 83 obese patients showed weight loss and reduction in BMI with long-term (24 weeks) Ketogenic diet use (15). There was a gradual decrease in mean body weight during the trial period from over 220 to nearly 191 pounds in a 24 week period.
In another randomized control trial, weight loss was observed over a period of 8-weeks in men who were doing resistance training (17).
In comparison to the non-Ketogenic group, the Ketogenic diet group had a fat mass reduction without losing muscle mass.
However, more muscle mass growth was observed in the non-Ketogenic diet suggesting that the Keto diet may preserve lean muscle mass but it may not be the strategy to gain muscle mass.
A study on the Spanish Ketogenic Mediterranean Diet (SKMD) composed primarily of extra virgin olive oil (> or = 30mL/day), fish, salad and red wine (200-400mL/day) showed a decrease of mean weight from 108.62 kg to 94.48 kg in 31 obese individuals (18).
Furthermore, other metabolic markers e.g. glucose levels, triglycerides, LDL, and Blood pressure were reduced. Thus, a Ketogenic diet with quality fats from olive oil, protein from fish, and carbohydrates from vegetables could promote weight loss.
Ketogenic diet is proven to influence weight loss in studies done in animals and humans.
2) Keto diet can help in Diabetes management
Reducing dietary carbohydrates may provide benefits in diabetes because blood glucose levels are elevated in patients with diabetes.
Studies in mice have revealed that the ketogenic diet- aerobic exercise combination improved insulin sensitivity after six weeks (19).
Ketogenic diet can help in diabetes management by reducing glucose levels in the body.
3) Ketogenic diet is good for brain health
A ketogenic diet can be beneficial for brain health in many different ways.
The ketogenic diet was proposed for the treatment of epilepsy because the ketogenic diet mimics intermittent fasting at the cell level (27).
Currently, the ketogenic diet is studied for its role in improving epilepsy and it is widely used as a dietary treatment of epilepsy around the world (28).
Studies in children have been shown to reduce seizures by the ketogenic diet (29,30,31).
Studies in mice and rats have shown the benefits of the Keto diet in the protection of nerve cells and improve cognition (32).
The Keto diet has been shown to improve mitochondrial function to decrease reactive oxygen species (ROS) and protect nerve cells from the harms of free radicals (33,34). The reduction in ROS has been shown to improve the seizure condition with the Ketogenic diet (35).
Parkinson’s disease research with a ketogenic diet shows positive results. It is also noted that the ketogenic diet was safe for patients for at least 8 weeks. Moreover, patients showed improvements in motor and non-motor function (36,37).
Ketogenic diet can improve cognition, epilepsy condition, and motor function in Parkinson’s disease patients.
4) Ketogenic diet can reduce Alzheimer’s symptoms
The risk is associated with increased insulin resistance. For this reason, reducing foods with a high glycemic index could help in preventing the onset of Alzheimer’s disease.
Medium-Chain Triglyceride (MCT) is very popular among keto diet followers because of its easy digestibility. In humans, the use of MCT supplements in people with Alzheimer’s and lack of a particular genetic marker Apolipoprotein E (APOE) ε4, had improved cognitive performance, memory, visual attention, and task switching (40).
Thus, increasing ketones in the body via a ketogenic diet or supplements e.g. MCT can improve Alzheimer’s conditions in humans. The benefits are greatly enhanced in humans with the absence of the APOE ε4 gene marker (44,45).
Alzheimer’s patients with the lack of genetic marker APO-E show improvement with a ketogenic diet. MCT supplement can be beneficial
5) Ketogenic diet can improve the quality of life in cancer patients
In human cells, fasting improves chemotherapy treatment by protecting cells from the harmful effects of chemotherapy (49).
A study in humans has shown to improve the quality of life of patients with advanced cancers with a ketogenic diet (50).
Ketogenic diet is shown to slow down tumor progression and it can improve quality of life in patients with cancers.
6) Ketogenic diet aids in cardiovascular protection
Obesity, diabetes, and high blood pressure are major cardiovascular disease risk factors.
The ketogenic diet can be effective in weight loss and diabetes. Furthermore, studies have shown that the Ketogenic diet (low carbohydrate diet and high fat) in obese or normal-weight individuals can be beneficial for reducing LDL cholesterol levels (51), Increasing HDL (good cholesterol) (52,53,54,55), and decreasing the triglycerides (56,57,58).
Moreover, a low carbohydrate diet was associated with improved glycemic control which is important for diabetes medication reduction (59).
The ketogenic diet may also have blood pressure lowering effects (60) but more studies are needed to conclusively define the role of the Ketogenic diet.
Keto diet can help improve metabolic markers ( diabetes, blood pressure, obesity ) that are important for cardiovascular health.
Keto food list
In a study in Italy, a ketogenic diet was proposed which contain fat source from lard, cow butter, 35% milk cream, olive oil, sunflower oil, wheat germ oil, etc, Protein sourced from fish, sausage, mortadella, bacon, eggs, tofu, and Carbohydrate sourced from avocado, coconut and green olives with nuts and cheese (61).
Another study with the Spanish Ketogenic Mediterranean Diet (SKMD) composed of extra virgin olive oil (> or = 30mL/day), fish, salad, and red wine (200-400mL/day) showed a substantial weight loss in obese individuals (62).
Based on the research the recommended Keto Diet will look something like below.
Fats (Approximately 70%)
Fat is the majority of intake in the Keto diet. You should choose healthy fats. Some examples are given below
- Oils: Extra Virgin Olive oil, Coconut oil, Flaxseed Oil, Fish oil, MCT oil, Avocado oil, Sesame seed oil
- Miscellaneous: Grass-fed butter, lard and milk cream (35%), Olive oil mayonnaise, tallow, bacon, etc.
Proteins (approximately 20%).
Choose wild-caught fish and grass-fed/ free-range meat. You can go for fatty parts of meat.
- Meat: Go for organic grass-fed Beef Steak, Lamb, Pork, Ham, Veal, etc.
- Poultry: Free-range chicken
- Eggs: Organic eggs provide omega-3 fatty acids
- Fish: Choose fatty fish e.g. wild Salmon, Codfish, Tuna, etc
- Sea Food: Oysters and Clams, Shrimps, Prawns, etc
- Dairy: Unprocessed cheese e.g. Mascarpone, Cheddar, etc
Carbohydrate (only 5-10%)
Choose fiber-rich leafy green vegetables. You can choose berries from fruits
- High fiber vegetables: Cauliflower, Celery, Eggplant, Bell Pepper, Cabbage, Brussel’s sprout, etc
- Green vegetables: Asparagus, Lettuce, Kale, Spinach, Zucchini, Broccoli, etc
- Other examples: Cucumber, green beans, mushrooms, olives, onions, sauerkraut, squash, onion, tomato, etc.
- Fruits: Raspberries, strawberries, cherries, Blackberries, Lemons, Lime, etc
Condiments: Garlic, ginger, hot sauce, vinegar, salsa, horseradish, jalapenos, mustard, pesto, pickles, soy sauce, etc
Keto-friendly snacks: Only a handful should be included in the diet.
- Nuts: Almonds, Cashews, Walnuts, Pistachios, Pecans, Peanut, Macadamia nuts
- Seeds: Flaxseed, Chia seeds, sunflower seeds, pumpkin seeds, sesame seeds
Dressings: Lemon/lime juice, oil, and vinegar, Caesar, bleu cheese
Always, choose no sugary drinks.
- Soft drinks: club soda (diet)
- Coffee: Without sugar
- Teas: Herbal teas, green tea, white, black, yellow, and oolong tea.
- Low carb alcohol: vodka, rum, whisky, brandy, gin, tequila
Sugar substitutes: Xylitol, Stevia, Splenda, Saccharin
Keto Diet Food Pyramid
Food pyramids are designed to visually represent the relative importance of food groups. The food taken in large quantities is placed at the bottom. Foods to be taken in small quantities are placed at the top of the pyramid.
In essence, important food types take the base of the pyramid and the apex of the pyramid is occupied by less important foods for the particular diet type.
In the case of the Keto Diet, the healthy fats are at the bottom of the pyramid because they are the principal food types, while the fibrous carbs are at the top taken in low quantities.
The processed carbs and foods are totally eliminated in the Keto diet.
Foods to avoid
The general rule is to avoid any processed food because it is most likely to contain a lot of sugar and unhealthy fats.
Drinks: Soft drinks(sugar-free included), energy drinks, thirst quenchers, etc
Grains: Beans, chickpeas, lentils, wheat
Staple carbs: pasta of all kinds, pizzas, bread, rice, fries
Fruits: Fruits are high in carbs and will offset your ketosis
Confectionary: Most bakery products e.g., sweets, candies, cakes, pastries, croissants, etc
Ketogenic meal plan example as per the Diabetes Council (63).
|Day 1||Keto Coffee with cream (35%)||Grilled Chicken & kale salad lime dressing||Salmon with butter and tomatoes||Berries and coconut whipped cream||Cheese sticks|
|Day 2||Scrambled eggs with avocados||Chicken salad wrap||Steak with cauliflower rice||Keto coconut cupcakes||Dark chocolate|
|Day 3||Egg feta spinach scramble||Almond flour Chicken with Butter Broccoli||Beef ragu with zucchini pasta||Peanut butter cookies||Almonds|
|Day 4||Keto Smoothie||Tuna salad with lettuce and bell peppers||Roasted Beef with asparagus||Keto chocolate Cookies||Salary sticks with almond butter|
|Day 5||Frittata with veggies||Garlic butter stuffed chicken breast with green olive salad||Pork steak with broccoli||Keto chocolate mousse||fried pork rinds|
|Day 6||Eggs with bacon and tomatoes||Ham with cheese||Meatballs and mushrooms and salad||Brownie Fat Bombs||olives|
|Day 7||Omelet with ham and goat cheese||Shrimps, guacamole, and salsa||Italian sausage with broccoli||Keto walnut snowballs||Mixed nuts|
- Breakfast: Keto coffee with cream (35%)
- Lunch: Grilled Chicken & kale salad lime dressing
- Dinner: Pan-fried Salmon with butter and tomatoes
- Dessert: Berries and coconut whipped cream
- Snacks: Cheese sticks
- Breakfast: Scrambled eggs with avocados
- Lunch: Chicken salad wrap
- Dinner: Steak with cauliflower rice
- Dessert: Keto coconut cupcakes
- Snacks: Dark chocolate
- Breakfast: Egg feta spinach scramble
- Lunch: Almond flour Chicken with Butter Broccoli
- Dinner: Beef ragu with zucchini pasta
- Dessert: Peanut butter cookies
- Snacks: Almonds
- Breakfast: Keto Smoothie
- Lunch: Tuna salad with lettuce and bell peppers
- Dinner: Roasted Beef with asparagus
- Dessert: Keto chocolate Cookies
- Snacks: Salary sticks with almond butter
- Breakfast: Frittata with veggies
- Lunch: Garlic butter stuffed chicken breast with green olive salad
- Dinner: Pork steak with broccoli
- Dessert: Keto chocolate mousse
- Snacks: fried pork rinds
- Breakfast: Eggs with bacon and tomatoes
- Lunch: Ham with cheese
- Dinner: Meatballs and mushrooms and salad
- Dessert: Brownie Fat Bombs
- Snacks: Olives
- Breakfast: Omelette with ham and goat cheese
- Lunch: Shrimps, guacamole, and salsa
- Dinner: Italian sausage with broccoli
- Dessert: Keto walnut snowballs
- Snacks: Mixed nuts
Ketogenic Diet plan (Vegetarian) Example (64)
- Cheese/paneer pakora
- Bullet coffee (coffee/tea mixed with coconut oil, cream, and butter)/coffee with cream/coconut milk
- Grilled mushrooms with buttered vegetables scrambled tofu
- Coconut milk or almond milk
- Mushroom and onion frittata
- Cabbage rolls with coconut
- Apple crumb pie with walnut crust cream of tomato soup with stir-fried broccoli and cheesy crackers
- Spinach pancakes made with flaxseed flour and lots of cheese
- Cauliflower curry in coconut milk and coconut oil
- Soya nugget curry
- Chilli beans with sour cream, cheese, and salsa
- Tofu puddings with full-fat yogurt
- Simple salad stir-fried in butter topped with lots of cheese
- Red channa salad with olive oil dressing
- Vegetable spring rolls wrapped in lettuce with peanut sauce
- Pumpkin smoothie with coconut milk
- Carrot and cucumber sticks with peanut butter
- Cheesy muffins topped with strawberries and blueberries
- Green tea/lemon water (without sugar)
- Stir-fried peanuts
- Almond flour and chia seeds pancakes
- Baked tofu with cheese and cream
- Fried paneer pakora
- Stir-fried French beans with cheese topping
- Cream of mushroom with ghia kofta
- Stir-fried ladyfinger with peanuts (Maharashtrian style)
- Spinach cooked in milk, cream, and cheese
- Stir-fried veggies with spices and cream dressing
- Cheesy cauliflower curry
- Apple and zucchini cake
- Poached pears topped with cocoa butter
- Soya cheesecake
- Chocolate silk pie with almond crust
Mediterranean diet is considered a healthy diet with more emphasis on fruits and vegetables and minimum consumption of meat. Mediterranean diet practiced without processed foods can be great for health and well-being.
Frequently asked questions
Short-term side effects of the Keto diet are called Keto Flu that includes nausea, vomiting, headache, fatigue, dizziness, insomnia. Constipation and diarrhea (mostly with MCT) can also occur (65) but overall, the keto diet is considered safe for humans (66).
Keto diet should be adopted after a physicians consultation if you are:
- A diabetic
- Taking medication for any condition
- Pregnant or trying to conceive
The side effects normally go away after continued use of the Keto diet in a few weeks without medication. To minimize the risk of side effects, eat small meals throughout the day, keep hydrated with electrolytes, take more fibrous food, use multivitamins and exercise every day (67).
Taking external sources like creatine and whey protein may help. MCT oil has become a popular choice for people who follow the keto diet for weight loss.
The use of MCT oil supplements has been shown to induce ketogenic effects (68). Therefore, MCT oil is a potential supplement for weight loss.
Whey protein use can also help.
Because you don’t eat many fruits and starchy vegetables, there is a strong chance that you may develop a deficiency of vitamins and minerals. For this reason, taking multivitamin pills can help too.
When your goal is to use the ketogenic diet for weight loss research has shown that weight loss peaks at 5 months. After 5 months the weight maintenance becomes a challenge (69). Therefore it is best to cycle the keto diet to maximize the potential of the keto diet.
The review of a large number of clinical studies showed that people on the keto diet lost 2 kg (approx. 4lbs) more weight than those on low-fat diets in 1 year period but more stringent studies did not find the difference (70). Thus, the Keto diet could provide a weight loss solution but sustaining the weight loss over a long period could be an issue. Weight loss depends on current weight, adherence to diet, and physical activity. Setting realistic goals is key to shedding extra weight.