Nutritionists warn about keto diet: ‘The physical toll can be devastating’

In recent years ketogenic diet rose to fame by promising a radical transformation: losing weight while enjoying a high-fat diet. Specifically, this eating pattern asks you to forget about bread, rice and potatoes, among other foods, and instead invites you to indulge in cheeses, avocados, nuts and healthy oils. Sounds tempting, right?

We are talking about an almost surreal sentence: eat more fat to lose weight. Its advocates praise it as a true metabolic revolution, a trick that hack your body burns fat at full speed. But, Is this really a game changer or are we taking a blind bet?

The reality is that the ketogenic diet has both devoted followers and fierce opponents. For some, it was the magic key that allowed them to lose weight and increase their energy and mental clarity. For others, it’s a path fraught with danger: dizziness, fatigue, bad breath, and even more serious health risks, both physical and psychological, if taken to extremes.

We tell you how this diet actually works, what its promises are and, more importantly, what risks may accompany it. Because behind every nutrition trend there is always more than what meets the eye, and the ketogenic diet is no exception.

What is the ketogenic diet: main goal and types

Elena Rivero, a dietitian at the Sarai Alonso Nutrition Clinic, an advanced clinical nutritionist and expert in eating disorders (ED), women’s hormonal health and obesity, explains that the ketogenic diet, also known as keto dietThis is a type of diet low carb, high fat The purpose of which is to introduce the body into a state of ketosis. “The goal of this type of diet is to mimic the state of fasting without experiencing the negative effects of fasting,” says the nutritionist.

Thus, both the ketogenic diet and the low-carb diet have the common goal of reducing carbohydrate intake. The main difference is that the ketogenic diet is based on… induce a state of ketosis, and for this to happen, the reduction in carbohydrates must be extremely low and the intake of fats must be significantly increased.

On the contrary, on a low-carb diet It is not necessarily designed to get you into a state of ketosis.

Elena Rivero identifies five different types of ketogenic diet:

• Standard ketogenic diet (SKD): This is the most common type of ketogenic diet and at the same time stricter. The goal of this regimen is to constantly maintain a state of ketosis in the body. In this nutritional plan, consumption carbohydrates 5-10% total calorie content (TCV) and abundance fat intake providing 70-80% VCT.
• Cyclical ketogenic diet (CKD): this alternative diet 5 days of ketogenic diet and 2 days of high carbohydrate intake. This ketogenic diet is commonly used by athletes to replenish muscle glycogen without leaving them in ketosis in the long term.
• Targeted ketogenic diet (DCD): This is actually a standard ketogenic diet, but introduce carbohydrate intake before and after sports training to improve performance.
• High Protein Ketogenic Diet: This is a variation of the standard ketogenic diet. In this type of diet, carbohydrate intake remains 5-10% of VCT, but reduce the amount of fat to 60% to be able to introduce more protein into the diet: This type of plan is designed to improve diet compliance or adapt to the athlete’s needs.
• Therapeutic type of ketogenic diet: It is a diet that is used only in clinical situations to improve the treatment of certain pathologies, such as, for example, refractory epilepsy in children or neurological diseases such as Parkinson’s disease. They are usually more strict and are supervised by the entire medical team.

Health Benefits Associated with the Ketogenic Diet

The ketogenic diet may provide health benefits when the extreme state of ketosis has not been achieved. Among the advantages, Elena Rivero highlights:

• A decreased circulating glucose, decreased fasting insulin levels, and decreased insulin resistance. Therefore, it may be of interest to patients with diabetes.
• The ketogenic diet may improve metabolic profile in healthy people. During the period of 6-12 months you can observe transient decrease in blood pressure, triglyceride levels and increase in HDL cholesterol.. But due to increased fat intake, LDL cholesterol levels also increase. Therefore, this diet may not be suitable for everyone and you should consult your doctor before trying it.
• Reduced markers of oxidative stress and inflammation.
• Maybe reduce migraine attacks and symptoms of certain neurological diseases such as epilepsy, Alzheimer’s and Parkinson’s disease.
• The ketogenic diet may help obesity management. While there is limited scientific evidence for the ketogenic diet’s effectiveness in weight loss, there is evidence that the ketogenic diet can help. reduce appetite by increasing fats and proteins in the diet. In addition, the state of ketosis affects the secretion of hormones associated with appetite regulation. However, according to the nutritionist, comprehensive studies guaranteeing the safety of use for weight loss are not enough. You can also lose weight quickly in the short term, but by losing body water rather than losing fat.

Side Effects of the Ketogenic Diet: Everything You Need to Know

Although the ketogenic diet has gained popularity as an effective tool for weight loss, not free from side effects. Elena Rivero explains that when the body enters this mode, a process known as keto adaptationwhich can lead to the following complications:

• “Ketogenic flu”: When changing the source of energy, when moving from carbohydrates to fats, the so-called “keto flu” often occurs. “This is a phenomenon that causes symptoms such as fatigue, headache and lethargy. Although these effects tend to improve over time as the body adapts to using fat as its primary source of energy, many find it difficult to cope with at first,” explains Rivero.
• Gastrointestinal discomfort: Another common complaint among those starting a ketogenic diet is digestive problems such as constipation or nausea. “This may be due to changes in fiber intake and changes in metabolism, which take time to adapt,” the expert adds.
• Nutrient Deficiency: The ketogenic diet can also lead to imbalances in the body. “Hydroelectrolyte changes, dehydration and hypovitaminosis. These are some of the risks associated with poor planning of this diet. It’s critical to pay attention to your mineral and vitamin levels, as limiting certain food groups can cause significant deficiencies,” warns Rivero.

Additionally, according to the nutritionist, those who follow this regimen may also face an increased chance of developing kidney stones, increased uric acid levels in the blood and an increased risk of osteoporosis in the long term.

The process of adaptation to ketosis: what happens in the body?

Elena Rivero explains the physiological changes the body experiences when entering a state of ketosis. Under normal conditions, the body obtains energy from carbohydrates, converting them into glucose. However, when carbohydrate intake drops sharply, the body has to look for an alternative source of energy.

“The main thing is insulin”offer. “When you reduce your carbohydrate intake, your blood glucose levels drop significantly. Typically, glucose is the body’s preferred source of energy, and insulin is responsible for transporting this glucose into cells for use,” Rivero elaborates. “When glucose decreases, insulin levels also decrease. This is very important because low insulin levels make it easier for the body to access fat stores for energy,” he adds.

First the body resorts to glycogen stores stored in the liver and musclesbut they deplete after about three or four days of eating low-carb foods. “Once glycogen stores are depleted, the body needs a new source of energy. That’s when fat comes into play, says the women’s hormonal health expert.

Later, as the body begins to break down fat, free fatty acids are transported to the liver, where they are converted into ketones. These ketones act as an alternative source of energy for the brain, muscles and other organs. “The state of nutritional ketosis turns the body into a kind of “fat burning machine” that mainly uses ketones and fatty acids instead of glucose to do its work,” explains the specialist.

The transition into ketosis can take several days, and during this period symptoms such as fatigue, dizziness and headaches, known collectively as the “keto flu,” often occur. These effects usually disappear when the body fully adapts to the new energy source.

Is the ketogenic diet suitable for everyone?

Despite its growing popularity, “it is not recommended that anyone dive into the ketogenic diet as it may have adverse effects on certain groups,” experts warn.

For example, Children and pregnant women should avoid this regimen.. “During these stages of life, nutritional needs are different and more complex. Subjecting the body to such severe carbohydrate restriction can have negative effects on development and overall health,” nutritionist Saray Alonso says in a blog post.

These groups were also joined people with kidney pathologies and those who have an imbalance in metabolic homeostasis. For them, ketosis can make certain conditions worse or cause additional complications. In addition, Alonso emphasizes that for people with eating disorders (ED)the ketogenic diet is “totally undesirable.” “This is a type of diet that limits the number of foods and subjects the person to very strict dietary controls, which can cause or worsen mental health problems in those suffering from ED“he adds.

With all this, the expert emphasizes the importance of medical supervision. “It is very important that anyone interested in following a ketogenic diet do so under the supervision of a physician. Ideally, it should be led by a specialized dietitian who can tailor the plan to individual needs and monitor the patient’s health throughout the process,” concludes Alonso.