Ketogenic diets have become one of the most popular trends when it comes to losing weight. Better known as the “keto diet,” this diet promises drastic results in no time. According to research, it can even improve exercise performance in athletes, burn fat and maintain muscle mass. This article aims to answer questions about the keto diet, one of the most discussed is: Is there enough evidence to support keto diets as an effective way to lose weight and help athletes? If more preambles, let’s start.
What Exactly is the Keto Diet? Is it Safe?
The ketogenic diet or keto, can be defined as a very low carb, high fat and moderate protein diet, which stimulates metabolic changes in our body. It is said that this diet forces our body to use fat as fuel instead of glucose (sugar). The ketogenic diet theory implies that if we are not consuming carbohydrates, our body will burn fat, causing us to lose weight. Healthy caloric intake is maintained; however, the carbohydrate food group is basically eliminated. Because it is such a strict diet, many people are not able to maintain it for long periods of time. The keto diet implies that you should avoid all grains, beans and legumes, most fruits, starchy vegetables, alcohol and all sugars. Certain milks and dairy product are also eliminated along with some fats. Because the diet eliminates essential nutrients, some certified clinical dietitians indicate that keto diets only work in the short term and can be unhealthy. The keto diet usually contains less than 20% energy from carbohydrates, variable protein and more than 50% energy from fat intake. Some keto diets are lowering carbohydrate intake to an amount as low as 5% of total daily calories consumed. According to the research, the recommended daily protein intake in ketogenic diets should be between 1.3 to 2.5 g / kg to maintain muscle and burn fat efficiently. The ketogenic diet is based on a very minimal consumption of carbohydrates, you can choose one of these 7 low carb meals that you prepare in less than 10 minutes .
How Does it Work?
The ketogenic diet places our body in ketosis. This happens as a result of insufficient carbohydrate intake (below 20 g daily), which makes our glucose levels very low. This action triggers a chemical response in our body, to create ketone bodies as an alternative energy source. Ketone bodies are chemicals produced during fat metabolism, and that the body uses as energy during periods of fasting and shortage of carbohydrates. Thus, what is happening during ketosis is adding only one drop in our blood sugar (glucose), causing our body to use fat as an alternative energy source.
How can this be Good or Safe?
According to some research, ketosis is listed as safe for overweight people or people fighting obesity. It has also been shown to be an effective treatment for children suffering from epilepsy. Other research claims that keto diets can improve chronic diseases in the general population, while other studies indicate that ketogenic diets can help athletes maintain proper body composition.
What do Research Say About Ketogenic Diets?
A review of ketogenic diets examined whether athletic performance could be improved by using low-carb diets high in fat ( LCHF), Low-Carb, High-Fat. This is surprising, since for decades of research on sports nutrition, high-carb and high-fat diets ( HCLF) had been supported to enable athletes to perform be optimal. The success rates of LCHF diets, such as the Keto or Atkins diet for weight loss and other clinical conditions, have helped broaden the scope of ketogenic diet research to athletes.
“According to research, keto diets can help athletes control body weight, reduce body fat and maintain muscle mass in weight-sensitive sports”.
It seems that endurance athletes adapt better to LCHF diets, and are able to burn fat more efficiently than their HCLF diet counterparts. Athletes under a ketogenic diet regimen have also shown a similar content of muscle glycogen and tissue repair, in the same proportion as an athlete who consumed an HCLF diet. Increased fat oxidation and glycogen return rate can be of great benefit to endurance athletes. The results of the study also reported some negative aspects for athletes using the keto diet, since elevated levels of free fatty acids and ammonia appeared in the bloodstream during exercise. High levels of free fatty acids and ammonia contributed to a deterioration of metabolism and fatigue of the central nervous system. Apparently, it takes several months for an athlete to adapt to LCHF or ketogenic diets, for positive metabolic changes and muscle glycogen to occur. For endurance athletes to improve their exercise performance using a keto diet, an adaptation period of several months is recommended. Without that long-term adaptation to the keto diet, the athlete would experience adverse effects including reduced muscle glycogen, hypoglycemia, and impaired athletic performance, according to research results. Other findings indicated that ketogenic diets in combination with resistance training may allow athletes to maintain muscle mass and lose fat mass.
How Does the Keto Diet Affect Strength and Endurance?
Other studies indicated that elite male gymnasts who used a keto diet maintained maximum strength and significantly reduced body weight and fat. On the contrary, a similar study in athletes using an LCHF diet for three weeks showed a loss of muscle mass and decreased anaerobic performance. However, resistance performance for the ketogenic diet groups increased compared to the HCLF group. Apparently, the results and the improvement of athletic performance would depend on how the keto diet is applied. According to the research, endurance athletes who followed the diet for 9 to 36 months could achieve maximum fat oxidation (burning) better than carbohydrate-adapted athletes. Other research shows that keto diets do not generate any benefit in high intensity exercise. This is because our body requires energy from the anaerobic system for short-term high intensity exercise. The anaerobic system is based on glycolysis or the breakdown of glucose for energy and because the keto diet uses fat for energy instead of glucose, it would have nothing to consume. For example, elite off-road cyclists significantly reduced peak power after 4 weeks using a ketogenic diet. However, researchers are demanding more studies considering the decrease in body weight, fat and the impact on anaerobic performance. LCHF diets also show that they affect the central nervous system (CNS) during exercise. Obviously, metabolic changes and how our body uses fuel during exercise can affect brain function since it seems that brain absorption of amino acids (proteins) and our brain’s ability to communicate with our muscles would be affected.
This response stimulates the release of a greater amount of free tryptophan to our brain, causing lethargy, fatigue and central fatigue. Central fatigue (fatigue of the central nervous system) adversely affects the functioning of exercise and muscle function. Studies indicate that the high protein content of the keto diet can also lead to high levels of ammonia during exercise, and high levels of ammonia in our bloodstream can negatively affect brain function, causing fatigue in the central nervous system. Because there are limited studies on central fatigue and ketogenic diets, additional research is recommended to increase knowledge in this area.
The conclusions of the expert reviews include:
- The ketogenic diet can be safe for the general population and reduce the risk of chronic diseases.
- Low carb and high fat diets (LCHF) can be an excellent way to control body weight, reduce fat and maintain muscles for athletes in weight sensitive sports.
- Keto diets appear to be beneficial for endurance athletes, after a period of adaptation.
- More research is required on the potential benefits of the keto diet for high intensity athletes, who depend on strength and power for the sport.
- More research on the keto diet and the impact on fatigue of the central nervous system (CNS) is required.
Does the Keto Diet Really Work?
Surely it is the question that surrounds the minds of many people who seek to lose weight easily or with some proven method, and although the ideal diet to reduce obesity is still in doubt, the ketogenic diet has become one of the strategies Nutritional researches for weight loss. According to the investigation, three important issues should be considered:
- Does the ketogenic diet work?
- Is there a yo-yo effect?
- Is a ketogenic diet safe for obese people?
Several studies relate to the ketogenic diet as an effective method for weight loss. What seems to be an ongoing topic of debate are the underlying effects on weight loss.
Clinical reviews have summarized the following based on evidence about keto diets and weight loss:
- Keto diets are designed to reduce appetite due to the high satiety effect of protein in the diet.
- Keto diets seem to have a positive impact on appetite control hormones.
- Ketone bodies are designed to provide an appetite suppressant action.
- Keto diets work by decreasing fat formation and increasing fat burning.
- There is a greater metabolic function that consumes healthy fats.
Other conclusive recommendations for ketogenic diets and weight loss:
- Keto diets can help control hunger by improving the way our body burns fat and leads to weight loss.
- Improve the diet by adding foods with carbohydrates similar to the Mediterranean diet, which could make it healthier and better tolerated in the long term.
- The renal function of individuals who use the keto diet should be controlled.
- The transition from a keto diet to a normal healthy diet should be gradual and well controlled.
- Keto diets are designed to be administered for at least 2-3 weeks to enter the ketosis phase, and a maximum of 6-12 months to lose weight.
- It is claimed that the keto diet can be a useful tool to treat obesity.
Last but not least, it is advised that people, who have a thorough knowledge about the keto diet, before performing it, are under the supervision of a doctor.