Could eating fat help you lose weight? That's the promise of the keto diet. This diet is increasingly popular for weight loss, but also for improving the body's function and preventing certain diseases. But what's the reality?
The keto diet is based on a very low carbohydrate intake balanced by a high fat intake. Appreciated by some athletes and those looking to lose weight, this diet is said to be ideal for slimming, but also for preventing certain serious diseases. However, it's highly controversial, and some experts warn against attempting a keto diet without medical supervision. So, how does this diet work? Is it safe?
The keto diet: what is it?
The ketogenic diet, also known as the "low-carb" diet, was invented in the 1920s as part of research into treatments for severe epileptic disorders. Its effectiveness was proven throughout the 20th century, significantly improving the lives of many children with these disorders.
It was then increasingly promoted as a weight loss diet, with many books promoting it with very high-flown promises.
But what's the principle behind it? Carbohydrates are converted into glucose, which serves as our energy source. However, if they are reduced to a minimum, below 50g per day, our body will produce another source of energy from fats to compensate: ketone bodies. Literally, a ketogenic diet is a diet that produces ketone bodies, based primarily on lipids.
There are different versions of the macronutrient distribution. The classic, historical version provides 90% of calories from fat, with about 6% from protein and 4% from carbohydrates. There are also slightly more flexible versions that have developed with its popularity, with slightly more protein and slightly less fat, with a minimum of 70% fat and a maximum of 50g of carbohydrates.
It is essential to eliminate foods richest in carbohydrates: grain products, products with added sugars, and to severely limit the richest fruits and vegetables such as tubers. On the other hand, we will favor all sources of fat: fatty meats and fish, oils, nuts, cream, cheese, avocado, coconut, etc., and fruits and vegetables low in carbohydrates such as green vegetables, cruciferous vegetables or berries. Finally, it is a moderate protein diet, too much can take you out of ketosis but there is no scientific consensus on the exact limit.
How does the ketogenic diet work?
The ketogenic diet is supposed to work simply. The state of ketosis caused by the lack of carbohydrate intake is supposed to force the body to find the energy it needs from its stored fat.
In the absence of carbohydrates, the liver will transform fatty acids into 3 types of ketone bodies: acetoacetate, beta-hydroxybutyrate, and acetone. This process is called ketogenesis. Since ketone bodies are water-soluble, the liver can send them into the bloodstream to serve as an energy source for organs, including the brain, instead of glucose. You are therefore considered to be in ketosis from the moment your blood ketone level reaches a certain threshold. With a standard diet, you have a maximum of 0.1 mmol per L of ketones in the blood. In studies, researchers generally consider that you are in ketosis from 0.5 mmol per liter, and ketogenic promoters often advocate a range between 1.5 and 3 mmol per liter. It is also possible to measure your ketone level with a breath test or urine strips.
Ketogenic Diet: What to Eat? How?
The keto diet is a strict regimen that allows few foods and prohibits many. The diet is primarily based on fat consumption. Therefore, it's important to increase your intake of fat.
Allowed foods
Permitted foods are those that contain primarily fat. They can be derived from animal or plant products. These include:
- Vegetable oils;
- Mascarpone and crème fraîche;
- Petits-suisses and white cheeses;
- Butter, margarine;
- Mayonnaise;
- Lawyers;
- Chocolate with more than 85% cocoa;
- Meats, cold cuts;
- Eggs;
- Fish (especially oily fish);
- Oilseeds (nuts, almonds, etc.);
- Low-sugar fruits such as red berries, watermelon, lemon (50g per day).
The most recommended foods are those containing monounsaturated fats such as olive oil, avocado, peanut butter, and nuts. Milk, plain yogurt, wine, and unsweetened coffee can be consumed in moderation.
Foods that are prohibited or to be limited
There are many foods prohibited by the keto diet. These include all foods containing carbohydrates, which includes foods that are sometimes difficult to exclude from your diet. These include:
- Sugar, honey, sweets;
- Sugary drinks and sodas;
- Jams, compotes;
- Bananas;
- The rusks, the bread;
- Dried fruits;
- Breakfast cereals;
- Potatoes, sweet potatoes, parsnips;
- Dried vegetables (lentils, chickpeas, beans, etc.);
- Peas;
- Fruits (except the less sweet ones);
- Industrial ready meals;
- Chips and snacks;
- Cookies, ice cream, dairy desserts, cakes all enriched with sugar.
How to replace foods to avoid?
Since the list of foods to avoid is long, there are a number of tricks to replace those that are most difficult to do without.
- Sugar and honey can be replaced with erythritol or stevia;
- Pasta, semolina and rice can be replaced with cauliflower semolina, vegetable spaghetti or konjac.
- Cereals (wheat, oats, rice, etc.) can be replaced by lupin, flax, soy, coconut flours or hazelnut, almond or coconut powder;
- Bread can be replaced with low carb bread;
- Potatoes can be replaced with celeriac, turnips or zucchini;
- Biscuits can be replaced with low carb biscuits and cakes;
- Pie and pizza doughs can be replaced with almond powder or cauliflower doughs;
- Sweet fruits such as bananas, pears, apples, mangoes and grapes can be replaced with raspberries, strawberries, blackberries, gooseberries or blackcurrants;
- Breakfast cereal can be replaced with chia pudding or low-carb granola;
- Corn and potato starch can be replaced with egg yolk, gelatin, konjac powder, or agar-agar.
Ketogenic Diet Menu Examples
Does it seem complicated to create menus with the long list of forbidden foods? We've done it for you! Here are some examples of menus you can eat while following the keto diet.
Breakfasts
Whether you're a fan of sweet or savory breakfasts, there are ways to adapt them to the ketogenic diet!
- Savory breakfast: cheese, scrambled eggs with curry, low-carb bread;
- Sweet breakfast: small bowl of almonds, a square of 85% cocoa dark chocolate;
- Classic breakfast: buttered keto bread (75g almond flour, 25g butter, baking powder, 3 eggs, a pinch of salt), unsweetened almond milk;
- Breakfast with cereal: keto muesli (crushed hazelnuts, Brazil nuts, flax and hemp seeds, 100% cocoa chocolate chips), unsweetened almond milk;
- Breakfast with yogurt: Greek yogurt, red fruits, nuts.
Lunches
Here's what a week's worth of keto lunches might look like:
- Monday: Roast chicken, ratatouille, square of 85% cocoa dark chocolate;
- Tuesday: green salad with vinaigrette, beef steak, sautéed broccoli, 50g raspberries;
- Wednesday: arugula with vinaigrette, salmon fillet, spinach with whole cream, square of 85% cocoa dark chocolate;
- Thursday: raw radishes, 20% fat ground beef, celeriac fries, soy yogurt;
- Friday: cucumber with mackerel rillettes, lamb chop, vegetable curry, square of 85% cocoa dark chocolate;
- Saturday: mozzarella tomatoes in olive oil, grilled pork chop, roasted fennel, 100% cocoa chocolate mendiant;
- Sunday: veal blanquette, small vegetables, keto pecan-chocolate tart.
Dinners
A week of keto diet dinners might look like this:
- Monday: sardines in oil, cauliflower tabbouleh, 30g almonds;
- Tuesday: omelet with 2 eggs, cold avocado and coconut milk velouté, 30 g of comté cheese;
- Wednesday: wok of shrimp, marinated peppers, dry goat cheese;
- Thursday: raw ham, eggplant parmesan, currants;
- Friday: grilled pollock fillet, creamy courgette gratin, 50g raspberries;
- Saturday: Caesar salad with walnuts (without croutons), Greek yogurt with blackcurrants;
- Sunday: red cabbage, smoked herring, slice of keto bread, 30g of Cantal cheese.
What are the benefits of the keto diet?
The ketogenic diet is so popular because it's known for several health benefits. Beyond its positive effects on children with epilepsy, the keto diet can also help with weight loss.
Indeed, like any diet that eliminates entire food groups, it necessarily leads to a calorie deficit, and it is this deficit that will induce weight loss. Contrary to what some claim, no study has demonstrated an increase in metabolism when following a ketogenic diet. There are also numerous studies that have compared a low-carb diet with a low-fat diet, with similar average weight loss results, which depend in particular on individual tastes.
The keto diet may also be effective in combating type 2 diabetes or prediabetes. A study conducted by researchers at Duke University showed that the keto diet significantly lowered blood sugar levels in patients with type 2 diabetes.
Many other studies are underway to reveal whether the keto diet can help treat or prevent certain diseases. Some sources claim that a ketogenic diet may play a role in the treatment and prevention of Parkinson's disease or Alzheimer's disease, but these effects have not yet been proven. Currently, the keto diet is only approved for the treatment of severe cases of childhood epilepsy and must be supervised by a physician.
The effect of the keto diet on weight loss has been proven by numerous studies on the subject. At least 13 studies have revealed that the ketogenic diet is more effective for weight loss than a low-fat diet. In fact, people who followed this diet lost almost an extra kilo for a similar calorie intake as those who followed a low-fat diet.
Weight loss through the keto diet is explained by several factors:
- According to several scientific studies , a higher protein intake promotes weight loss because protein allows, among other things, to feel full more quickly. This is one of the reasons why the keto diet is known as an appetite suppressant.
- The appetite suppressant effect is also due to hormonal changes, caused by this change in diet.
- Reduced fat storage. Excess carbohydrates are stored in the body as fat. However, with a ketogenic diet, carbohydrate intake is minimal and fat is used for energy.
Be careful not to overconsume protein, however, as excess protein will convert to carbohydrates and knock you out of ketosis. Also, be careful to meet your calorie needs, as studies have shown that cutting calories too much can slow your metabolism, making weight loss more difficult in the long run.
Numerous studies are being conducted to analyze the positive effects of the ketogenic diet on a multitude of diseases. Some are still ongoing, so they should be taken with a grain of salt. Here are the various diseases for which the ketogenic diet has been studied or is still being studied as a treatment:
The keto diet for type 2 diabetes or prediabetes
The ketogenic diet is not suitable for type 1 diabetes because type 1 diabetics must continue to consume carbohydrates. Since they inject themselves with continuous doses of insulin, a low carbohydrate intake would increase the risk of developing acute ketoacidosis.
However, the ketogenic diet is believed to be beneficial for type 2 diabetics due to its effect on blood sugar and weight.
Several studies have shown results that the ketogenic diet can reduce insulin levels. In fact, one study conducted on people with type 2 diabetes for four months even demonstrated a significant 16% reduction in blood sugar. It also states that a third of the participants were able to completely stop all their diabetes medications! Another study revealed that after two weeks of the ketogenic diet, insulin sensitivity improved by 75%.
The keto diet would therefore improve insulin sensitivity as well as fat loss, making it possible to improve the health of people with type 2 diabetes or stabilize the health of people with prediabetes.
The keto diet for epilepsy
We already explained this in the origins of the ketogenic diet. It is an officially effective treatment recommended by doctors for seizures in children with epilepsy. Currently, this diet is still used and recommended in an attempt to reduce seizures.
The keto diet against cancer
Initially, specialists became interested in this diet after several observations. Among other things, in 1922, scientist Braunstein noted that glucose disappeared from the urine of diabetic patients after being diagnosed with cancer. This disappearance suggested that glucose was being recruited to cancerous areas and consumed at higher than normal rates. Several studies then led him to believe that depriving cancer cells of glucose could harm them and therefore promote healing.
The keto diet is currently being studied as a treatment for several cancers. Several studies have already been conducted and suggest that a ketogenic diet can help slow tumor growth, even stop growth, and even eliminate the tumor in the best cases. Scientists are also studying the effect of the diet on the sensitivity of tumors to chemotherapy.
Numerous studies, always conclusive, have been able to report a significant effect on brain tumors, prostate, colon, pancreatic and lung cancers.
However, every cancer is different, and each includes several genetic subtypes. The effectiveness of the ketogenic diet depends not only on the individual but also on the tumor entity and its genotype. Unfortunately, it is still impossible, at this time, to promise that adopting a ketogenic diet will be beneficial for the treatment of cancer. However, numerous studies are underway. So far, however, the keto diet shows promise in fighting several cancers.
The Keto Diet Against Alzheimer's Disease
Many studies are underway, so the few results we have so far should be taken with a grain of salt. However, several studies already conducted suggest that the ketogenic diet may help reduce the symptoms of Alzheimer's disease and slow its progression.
Indeed, according to several studies , the presence of ketone bodies has a neuroprotective impact on the aging of brain cells. Adopting the diet is also linked to improved cognitive performance in older people with the disease. However, the improvement in cognitive outcomes depends on the level and duration of ketosis.
It should also be noted, however, that applying the ketogenic diet to the elderly raises some concerns. These individuals are at risk of malnutrition and are generally very sensitive to such a drastic dietary change.
The keto diet for the prevention of Parkinson's disease
A neurodegenerative disease like Alzheimer's disease, several studies are currently still underway to determine the real effects of this diet on individuals affected by this disease.
Currently, studies show that the diet may help improve the symptoms of Parkinson's disease. In fact, daily motor and non-motor functions may improve.
Just as with the fight against Alzheimer's disease, it must be taken into account that adopting a ketogenic diet in the elderly is subject to taking additional precautions.
To learn more about the benefits of this diet, I invite you to listen to my friend Francois BLEUEZ who gave this mini-conference on my YouTube channel here :
https://www.youtube.com/watch?v=5bOdbridds8
