What does the ketogenic diet consist of?
The ketogenic diet, also commonly referred to as “keto”, is a diet plan that contains very few carbohydrates and a great deal of fat. It was first used as early as in 1921 by Russel Wilder, who used it to treat epilepsy. Later, its popularity did not wane – it was used for various diseases, and today it is one of the most famous diets to help the body fight overweight and obesity.
As we mentioned, the keto diet will include very few carbohydrates, that is bread, pasta, groats and starch products, with a lot of fats and some protein instead. Where did the idea come from? As one study [1] reads:
“Carbohydrates are the primary source of energy production in the body’s tissues. When the body is deprived of carbohydrates due to a reduction of intake to less than 50 grams per day, insulin secretion also decreases and the body enters a catabolic state. Glycogen stores become depleted, forcing the body to undergo certain metabolic changes”.
The whole process is quite complicated, but the general idea is to deprive the body of glucose, which makes the necessary fuel for energy production, called ketones, begin to be produced from fat. This happens only a few days after starting the diet.
Bottom line: the keto diet changes the way the body produces, but also burns energy, because converting protein and fat into glucose results in increased calorie expenditure. Besides, since insulin levels are reduced, we feel less hungry, especially as fats and proteins take longer to digest than carbohydrates.
Is the ketogenic diet effective?
As studies show, yes, it is very effective. One study [2] involved 83 obese patients (39 men and 44 women). After 16 and then 24 days on the keto diet, there was significant weight loss as well as reduction in bad cholesterol and blood glucose levels. Interestingly, the use of the ketogenic diet did not cause any complications in the patients, but it should be borne in mind that they were eating meals developed by specialists.
However, this does not mean that side effects do not exist. In some cases, for example, there is fatty liver disease, kidney stones and vitamin, mineral and protein deficiencies (hypoproteinemia). After a few weeks, the so-called “ketone flu” may also occur, caused by loss of water from the body. It manifests itself with headaches, fatigue and constipation. Therefore, when using any special diet, you should do regular (once every six months) examinations and be in contact with your doctor or dietitian.
It is also worth knowing that scientists have so far studied the duration of the keto diet for up to two years. It is unclear what effects it may have over the long term.
Is the ketogenic diet good for athletes?
It’s hard to have a definitive answer, but studies have not shown the harm of the keto diet for active people [3]. It is especially valued by runners and cyclists, i.e. endurance athletes. However, it is known that for people who do not play sports professionally, this type of nutrition will rather work well – unless there are contraindications from a doctor. Researchers indicate that the keto diet can make us feel more energetic or experience less frequent inflammation, muscle aches and gastrointestinal problems.
However, before switching to the keto diet, remember to do a basic package of tests for active people and consult a specialist.
What can be included in the ketogenic diet?
There is no single, general scheme for developing a keto diet. It all depends on the given person, but it is generally accepted that the menu includes less than 50 g of carbohydrates per day (for example – a slice of rye bread has about 13 g of carbs). Often, a keto menu contains as little as 20 grams or even only 10 percent of carbohydrates, 70-80 percent of fats and 10-20 percent of protein [4].
Examples of products that can be eaten on a keto diet:
Meat:
- poultry
- beef
- giblets
- pork, including bacon.
Fish:
- salmon
- mackerel
- tuna
- seafood
- cod
- herring.
Read also: “The 5 tastiest and healthiest fish.”
Sources of healthy fats, that is those that are not chemically processed:
- avocado
- eggs
- vegetable oils, especially olive oil
- nuts
- butter
- mayonnaise
- lard.
Dairy products:
- butter
- natural yoghurt
- cream
- cheese: mascarpone, ricotta, cheddar, parmesan and others, based on natural ingredients.
Vegetables with low carbohydrate content, so mainly those that grow “above the ground” (i.e. avoid root vegetables):
- all green, leafy vegetables
- cauliflower, broccoli
- cucumbers, zucchini, squash
- pepper
- radishes
- tomatoes
- onion
- mushrooms.
Fruits with low carbohydrate content:
- raspberries
- strawberries
- berries and their derivatives.
Read also: “Six superfruits grown in Poland, providing unique benefits to athletes”.
What to avoid on the keto diet?
- sugar (including from fruit)
- starch products
- unhealthy trans fats (often found in sweets)
- alcohol
- battered fried meat and fish.
Sample menu on the keto diet – one day:
- Breakfast: two egg omelette with parmesan cheese and fresh spinach and cherry tomatoes.
- Second breakfast: natural yoghurt with fresh strawberries.
- Lunch: roast salmon with vegetables: pepper, zucchini and broccoli, topped with olive oil.
- Afternoon snack: cottage cheese with a spoonful of peanut butter.
- Supper: a salad of arugula (or other green leaves), avocado, red onion and tomatoes, served with grilled chicken breast.
………..
References:
1. Wajeed Masood; Pavan Annamaraju; Kalyan R. Uppaluri, Ketogenic Diet, https://www.ncbi.nlm.nih.gov/books/NBK499830/.
2. Dashti HM, Mathew TC, Hussein T, Asfar SK, Behbahani A, Khoursheed MA, Al-Sayer HM, Bo-Abbas YY, Al-Zaid NS. Long-term effects of a ketogenic diet in obese patients. Exp Clin Cardiol. 2004 Fall;9(3):200-5. PMID: 19641727; PMCID: PMC2716748.
3. McSwiney FT, Doyle L, Plews DJ, Zinn C. Impact Of Ketogenic Diet On Athletes: Current Insights. Open Access J Sports Med. 2019 Nov 15;10:171-183. doi: 10.2147/OAJSM.S180409. PMID: 31814784; PMCID: PMC6863116.
4. Diet Review: Ketogenic Diet for Weight Los, https://www.hsph.harvard.edu/nutritionsource/healthy-weight/diet-reviews/ketogenic-diet/.