With a severe restriction on carbohydrates, the ketogenic diet has become famous for allowing you to lose weight in record time. However, it can also cause hormonal imbalances, vitamin deficits and (even) increased appetite.
The success of this diet doesn't start with weight loss. Developed in the 1920s, the ketogenic diet has since been used in medicine as an alternative therapy to stop seizures in children with drug-resistant epilepsy. Around half of the children who follow it have a big decrease in epileptic episodes and one in seven stop having them altogether, reads the WebMD website.
Its effectiveness in weight loss was discovered more recently, in 2012, through a study conducted by Gianfranco Cappello, Professor of Surgery at Sapienza Università di Roma. After 19,000 volunteers were put on a liquid ketogenic diet, fed through a nose tube, there was an average loss of nine kilos per participant, most of whom managed to maintain this loss for at least a year.
"Today, several versions of this diet (with real food) are described in books, blogs and Facebook posts," says U.S. News & World Report, which in its annual ranking, Best Diets U.S. News, after analyzing the effectiveness and safety of 40 diets, placed the Keto Diet - the diet based on the principles of the ketogenic diet - in 39th place. Teresa Branco, a weight management physiologist, explains the pros and cons of adopting this high-protein diet and all the precautions you should follow if you really want to put it into practice.
How does the ketogenic diet work?
It's a high-protein diet based on foods rich in protein and fat (saturated and unsaturated), but its main feature is the severe restriction of carbohydrates, which induces a chemical process called ketosis that allows you to lose weight more quickly. When we stop consuming carbohydrates, there is a drastic reduction in insulin levels in the blood, which causes the body to start producing ketone bodies to meet its energy needs. To produce these ketone bodies, the body uses body fat, leading to weight loss.
How does a food day work?
In a traditional diet, around 50 to 60 percent of the daily diet is made up of carbohydrates; in the ketogenic diet, the percentage of carbohydrates is only five to ten percent, which represents around 20 to 40 grams a day in a 2000 calorie diet. Meals are mostly made up of protein and fat sources, such as meat, fish, eggs, bacon, cheese and sausages. Protein sources should account for 25 percent and fat sources for 65 to 70 percent.
"After analyzing the efficacy and safety of 40 diets, U.S. News & World Report placed the Keto Diet - the diet based on the principles of the ketogenic diet - in 39th place"
What foods are forbidden?
Foods such as bread, fruit, yogurt, potatoes, rice, pasta, beans or grains and sweets; as well as colorful vegetables such as pumpkin and carrots, which usually have a higher amount of carbohydrates. Alternatively, you can eat vegetables with a very low percentage of carbohydrates, such as green leafy vegetables (kale, spinach, watercress, lettuce, arugula, broccoli and cauliflower).
Which fat sources should we choose?
There are no restrictions on the type of fat. Even the "least healthy" fat - saturated fat - can be consumed in the desired quantities. This is not a diet based on the number of calories, but on the type of calories, which should be rich in fat and protein.
What kind of foods can we include in our snacks?
Because it's a very restrictive diet, people end up eating the same foods all the time. Snacks usually include ham, cheese, bacon, eggs and tuna. Occasionally, they may include a yogurt that includes around five grams of carbohydrates.
"Because it's very high in protein, it can lead to kidney overload"
Does this diet consist of different phases?
The diet starts with a drastic reduction in carbohydrates (20 grams) and its continuity depends on various factors, in particular the adaptation of each organism and the weight you want to lose. Some people are able to maintain this restriction for several weeks or even months. In other cases, people can only maintain this low percentage of carbohydrates for three or four weeks.
What differentiates this diet from others that also reduce carbohydrates?
If you reduce carbohydrates to 60 grams, you're already on a high-protein diet, but you're not on a ketogenic diet. This requires an even greater cut in the amount of carbohydrates and the body can only enter ketosis if there is this severe restriction.
10% of the ketogenic diet is made up of carbohydrates. In a traditional diet, carbohydrates take up 50 to 60 percent of the day's food
What are the main risks of the ketogenic diet?
Firstly, this is a very difficult diet to follow in the long term, as it requires a major restriction on carbohydrates. On the other hand, as it is very high in protein, it can lead to kidney overload. The dietary restriction required, which includes all sources of carbohydrates, such as fruit, cereals, yogurt and some vegetables, causes a water imbalance and can lead to vitamin and mineral deficits that can lead to changes in thyroid function. Although people never adopt this diet for a long time, just sticking to it for six months can trigger all these changes.
How long can we safely maintain the ketogenic diet?
It varies greatly from person to person. People can start the ketosis process at different times and each body reacts differently. That's why it's essential that the diet is monitored by a specialist and its continuation - which I don't advocate - depends on the physiological response of each organism.
What are the advantages of the ketogenic diet?
I don't see many benefits. Although it's a diet that promotes great weight loss in the short term, it's very difficult to stick to it for long. Most people abandon the diet and regain the weight they lost. There is research showing that there are a number of benefits related to metabolic risk factors, reducing the likelihood of metabolic syndrome and considerably lowering triglyceride, insulin and cholesterol levels. Even so, these benefits are relative, as it is not possible to follow this diet for the rest of your life.
In which cases is the ketogenic diet contraindicated?
This diet is contraindicated for anyone thinking of following it without supervision; people who tend to lose muscle mass or who want to increase muscle mass; diabetics; people with high uric acid levels; those with joint problems and/or those prone to eating disorders. These diets can further trigger eating disorders.
"As soon as you reintroduce foods prohibited by the diet, there is a strong likelihood of weight gain. There are even studies that show a tendency to gain weight"
Who can benefit from this diet?
People who want to lose weight quickly and people who already know that they have good self-control over their weight and the type of food they eat. Some studies have also shown that this approach can be beneficial in controlling epilepsy. Other studies show that this type of diet can extend average life expectancy. However, more scientific evidence is needed to make these claims. The biggest benefit is rapid weight loss, which can be interesting, for example, for people who need to lose weight quickly in order to stay motivated.
How soon can you see results?
Studies say that the first results are visible after two to four days. However, the weight loss that occurs in this initial phase of the diet is often related to water loss and not to the loss of body fat. If the diet is maintained, it is obvious that people will start to burn fat and then there could be sustained weight loss, but it will depend on each person's ability to stick to the diet rigorously.
Are the results long-lasting?
Usually not. As soon as you reintroduce foods prohibited by the diet, there is a strong likelihood of weight gain. There are even studies that show a tendency towards weight gain.
Ketogenic diet: watch out for these signs
The ketogenic diet can trigger some side effects that you should check with your nutritionist, recommends Teresa Branco, a weight management physiologist.
- Dizziness
- Tremors
- Cold sweats
- Hypoglycemia
- Tiredness
- Irritability
- Lack of concentration
- Difficulty falling asleep
- Decreased appetite
{ Essential care }
Do you really want to go on this diet?
Teresa Branco, a weight management physiologist, shares with Revista Prevenir six precautions that you (really) need to follow.
- Go on this diet under the supervision of a specialist to see how long you can prolong the diet.
- Drink plenty of water, around 1.5 to 2 liters a day. Drinking water is essential to compensate for the water imbalance caused by this diet.
- Take sodium bicabornate every day on an empty stomach to alkalize your body. All high-protein diets make the body more acidic and a more acidic body ages very quickly.
- Prefer oily fish such as salmon, tuna and sardines, eggs and avocado. These are excellent sources of protein and healthy fats.
- Eat more often and more satiating foods, such as nuts, full-fat cheeses, avocado and eggs.
- Slightly increase the amount of carbohydrates (to 40 grams, for example) if you experience energy deficits. Halitosis (bad breath) and very concentrated urine are other signs that the body is producing too many ketone bodies.
