Report on current research trends influence on athletic performance and physiology
Introduction
In recent decades, there has been an increase of interest level in the following of a low carbohydrate, low-carb (LCHO) diet, which several authorities advocate as producing certain health benefits, including weight loss. This trend derives motivation from the fact that fats can create the necessary energy the body needs and therefore act as substitutes of carbohydrates in the body. However, if some strict recommendations do not implement the low-carb diet, the consumption of foods with high-fat content may be potentially dangerous to the body.
A low-carb diet is also referred to as a ketogenic (keto) diet and is defined as composed of high fat, moderate protein, and low carb in ratio. By eating a diet rich in fats and low in carbohydrates, one’s body goes into a ketosis state, which is a metabolic state that works by burning fat instead of glucose to produce energy. As a result, one enjoys health benefits, such as weight loss. Although this sounds plausible and backed by some scientific research findings, several peer-reviewed papers support an opposing view on this subject. Among their findings is that the long-term effects of this diet are likely to harm an individual’s future health, especially if the diet’s follow-through is not strict.
In the context of this paper, we shall be considering the keto diet and its effects on the performance and physiology, aesthetic appearance, and maintenance of optimal body weight of an athlete. Athletes are people whose bodies require a little bit more energy than that needed by people who are not into sporting activities. This energy plays a crucial role in determining their performance since more energy is directly proportional to more endurance, which is, in turn, directly proportional to better performance in the sporting field. Getting fatigued, especially before achieving the objectives and targets one has set to succeed in the sporting field, is an athlete’s worst nightmare. Don't use plagiarised sources.Get your custom essay just from $11/page
This paper will, therefore, critically analyse and review a range of research findings and recommendations, both the ones that are in support of the low-carb diet and also the ones that are against it, as presented by other researchers. This literature review will aim to establish whether the positives outweigh the negatives, and after that, give recommendations based on the findings.
Critical Review
The keto diet is mainly a weight-loss trend. However, it is by no means a discovery, with the diet first making an entry as far back as th1860s when an individual by the name of William Banting, who was struggling with obesity, was prescribed a low carb diet by his doctor. Banting’s low-carb diet was inclusive of meats, vegetables, and fruits and eliminating sugar and starch. In the 1920s, this diet’s role was as a treatment for children with epilepsy, which inspired further research over the years, providing data, from well-designed studies, on ketogenic diets. The exact mechanism of how this works with epilepsy is yet to be discovered. However, one theory is that many of these neurological disorders are, as a result of, glucose inability to be duly delivered to the cells and that ketones offer an alternative pathway of energy transport (Waltz, 2007. Soenen et al., 2012).
The ketogenic diet has gained popularity because of its associated health and physiological benefits, which include weight loss and more endurance during sporting activities for the athletes. Specifically, a ketogenic diet is a diet that comprises high fat, moderate proteins, and low carbohydrates (Caraballo et al., 2012 and LaGory et al., 2013). A diet high in fats and low in carbs results in the body going into a metabolic phase, termed as ketosis, where it oxides fats rather than carbohydrates for energy. When a person is in ketosis, the liver makes ketones, which are a fuel that produces more energy (LaGory et al., 2013). Ketosis is a state whereby the body has no access to glucose and so relies on breaking down fat in the fat stores to produce energy. Energy can also be referred to as calories. Therefore, in terms of energy balance, if there is not a net calorie deficit, then weight gain will occur. Energy balance, which bases on caloric intake vs. caloric expenditure, is the primary driver in long-term changes in body weight. Therefore, with a minimum of carb intake, in a keto diet, fat is burned as energy rather than stored. If there is a lower energy input (in the form of mostly fats and protein) and higher energy output (exercise), weight loss will occur.
As earlier stated, when in ketosis, the body does not have glucose energy, so it burns fat, which will eventually result in a build-up of acids called ketones in the body (Miljkovic et al., 2007. LaGory et al., 2013). When this occurs, ketones that form in the blood is detectable in urine. To ensure the system flushes ketones, an increase in water consumption will reduce the number of ketones available for the body to burn for energy, and this will help to increase fat and weight loss. It will also protect the body from entering ketosis to the degree that it is dangerous to the body’s functioning.
A keto diet mainly relies on a stasis called ketosis, which is starvation. However, when one consumes enough calories, starvation is only mimicked. When in this state, the body does not have enough sugar to run itself and instead converts fats to ketones, which are an energy-carrying acid, starving two-thirds of the brain of energy. With the rest of the energy production being reliant on glucose, in this case, it will have to be converted from protein or fat as well (Waltz, 2007, Soenen et al., 2012). A standard ketogenic diet will involve consuming 70-80% of the calories from fat and only about 5% from carbohydrates and the other percentage from protein (Brown, 2006).
According to a study by Burke (2017) and Brown (2006), who advocate for a high-carb diet, indicate that a low-carb diet will impair the performance, which means that the Keto diet would not be advisable according to their research. They claim the high-carb diet is adaptable from moderate-carbohydrate meals with performance not being adversely affected by lower glycogen stores. Their argument rests on the fact that for producing ATP energy, glucose stores are paramount. With a keto diet limiting the amount of carbohydrate intake, glucose stores become limited too. The body uses stored glucose in the form of glycogen, which will eventually also deplete.
Figure 1.1 Difference between ketogenic and traditional diet
Fig 1.1 Difference between ketogenic and traditional diet (Hamilton, 2020)
Should Burke and Browns’ recommendations of a high to moderate carb diet be followed, there is the conversion of a substance known as oxaloacetate into glucose in the liver. The initial effect on weight loss is that glycerol is absorbed by the liver, along with some fatty acids. The body breaks down fat into free fatty acids, which metabolize into a substance called acetyl-CoA. Acetyl-CoA is then formed and combines with oxaloacetate to create citric acid. This synthesis launches the citric acid cycle, otherwise known as the Krebs cycle.
The Krebs cycle is a set of chemical reactions in the liver, producing usable energy from fat, protein, and carbohydrates. These mitochondrial activities generate carbon dioxide, water, heat, and energy-carrying molecules used as fuel for cellular activities. This process occurs when the liver breaks down the acetyl-COA into two substances, acetoacetate, and beta-hydroxybutyrate, which are also known as ketone bodies. These two substances are then sent into the bloodstream and are picked up by other cells, which then convert the ketone bodies back into acetyl-CoA, and energy is produced (Chandler et al., 2007, Feinmann, 2019).
Soenen et al. (2012), Burke (2017), and Brown (2006) claim that the brain benefits from the Krebs cycle. Although glucose is relied on by the brain as an energy source, it can also function on ketone bodies, which provide more energy per gram for it than glucose. There have also been studies of the heart carried out by Bough et al. (2007), Noto et al. (2013) and Caraballo et al. (2012) that state that following a low carb diet will improve the health of the heart as well as reverse most heart diseases. This claim, however, has been retorted by Nakamura et al. (2014), who advocates that a ketogenic diet will cause heart arrhythmias, myocardial infarction, and cardiomyopathy in the long-term. There have been studies that have presented an alternative view on the benefits of a high-fat diet, in which they have successfully discovered more negative outcomes than positives.
Some studies claim that the possible side effects of a keto diet may include fatigue, impaired cognition and have a significant impact on concentration and attendance in everyday activities (Waltz, 2007; Soenen et al., 2012; Chandler et al., 2007, Feinmann, 2019). Although there are studies by Burke, 2017, and Brown, 2006 that claim they have found brain health benefits, there are also others that show decreased brain activity and growth, as well as impaired mood present in an experiment involving adolescent rats (Fedorovich et al., 2018). Other significant side effects that have been presented in the studies by Sandin et al. (2007) and Mangels (2019) include gastrointestinal disturbances, including diarrhoea, vomiting, nausea, constipation, and a significant inflammation risk. Thinning hair and hair loss have also arisen as a part of these studies results by Mangels, 2019 and Noto et al., 2013, as well as kidney stones, muscle cramps and weakness, hypoglycaemia which is low blood sugar, low platelet count and even renal tubular acidosis, which is when the kidneys fail to remove all the acid because ketones are very acidic (Fedorovich et al., 2018)
Moreover, Fields et al., 2016 claim that a ketogenic diet also carries the risk of developing many nutrient deficiencies as well as disordered mineral metabolism and can also lead to weak growth in children and skeletal fractures in adults. Osteopenia or osteoporosis is also a significant health risk that can come about in following this diet based on the findings of Burke, 2017, and Brown, 2006. However, on the other hand, there is also evidence that there are individuals who have benefitted from this diet and have had better bone health than before, based on Feinmann (2019) and Chandler et al. (2007). This result is due to their metabolism, and a large variety of foods that they consume that include more macronutrients and micronutrients daily. Another presentation of side-effects in the study by Fields et al. (2016) is that a ketogenic diet may make the skin vulnerable to bruises and cause it to be sensitive. Also, hyperlipidaemia may cause sepsis or infection and even the growth of bacteria on the skin, which is induced by a very high-fat meal.
In terms of the impact of the keto diet on athletes, the ‘racewalker study’ conducted at training camps for competitive race-walking in 2015 and 2016, presented data that showed that race walkers on a keto diet did not improve on their performance in the 10km race. However, this was achieved by those on a high-carb and moderate carbohydrate diet.
The result above is a crucial discovery for competitive endurance athletes as it may affect their competitive performance. Zuntz & Schumburg (1901) and Krogh & Lindhard (1920) claim that increased oxygen cost of ATP production from fat vs. CHO oxidation is self-evident. This should not be overlooked when examining the advantageous or detrimental effect of a keto diet on sports performance. As Joyner & Coyle (2008) emphasise, for sports like jogging, cycling, swimming, or race- walking, the marketplace or efficiency of energy variation to the speed of movement is a crucial determinant of performance. During activities conducted at or around an individual’s lactate threshold, a loss of economy by increasing oxygen uptake is not possible, when following a low-carb, high-fat diet. This is because reduced Adenosine triphosphate (ATP) production from the available oxygen supply will limit exercise capacity. ATP is an organic chemical that gives energy for physical processes to occur in living cells, such as for muscles to contract, nerve impulses, and chemical synthesis.
Phinny et al. (1983) and Volek et al. (2016) undertook research that is unrelated to race pace in competitive endurance athletes. Due to their research focusing on exercise capacity at moderate exercise intensities, at around 60-70% VO2 max, their analysis did not consider the effect of a low-carb high-fat diet on endurance athletes. It, therefore, failed to produce conclusive data proving the positive results that they claimed.
Recommendations
As Mangels (2019) points out, a high-fat diet, mainly based on the consumption of meat, is not healthy, and it is not sustainable, long-term.
The findings of the ‘race walker’ research study stated that the adaptation of endurance athletes to a ketogenic diet showed marked increases in whole-body fat oxidation during exercise over a range of exercise intensities. They also showed that increased rates of fat oxidation resulted in increased oxygen demand at certain speeds that affected the performance of race walkers negatively, thus impairing the performance of elite endurance athletes.
Based on this literature review, a deduced recommendation can be that there should be restricted ketogenic diet for extensive periods as it can lead to adverse health consequences and could be dangerous to the general well-being of an individual (Nakamura et al., 2014, Fields et al. 2016, Noto et al., 2013).
The low carb diet, as this literature review has proved, is not sustainable, and the mortality raises once one starts limiting the amount of carbohydrates in their diet (Caraballo et al., 2012).
Conclusion
In conclusion, the available research on the ketogenic diet concerning its benefits to athletes indicates that, so far, such benefits appear to accrue to endurance athletes more than athletes involved in anaerobic exercise activities. As McKenzie et al., (2017) found out, high-intensity athletes on the ketogenic diet like sprinters experience early onset fatigue with hampered recovery after exercise and, consequently, lower performance. However, the study warns that athletes must allow a long-term adaptation to ketogenic diet or experience adverse effects like hypoglycaemia and muscle glycogen reduction that derail performance. Given the unsustainable ketogenic diet, as this critical review shows, the safest bet for endurance athletes on the ketogenic diet is to include low-glycemic carb sources in their diet. This way, they may avoid the harmful effects of ghosting carbs entirely, such as fatigue.
There is also the realization that a ketogenic diet gives short-term gains in some people, as well as weight loss and alterations in cumulative cholesterol, blood sugar, plus blood pressure. The precise proportion of fats, carbohydrates, as well as proteins that are required to attain health gains, will differ among people as a result of their genetic composition and also body structure. Therefore, endurance athletes should follow a high to moderate carb diet, as the keto diet tends to have an unfavourable influence on their execution, due to a reduction in ATP production from the available oxygen supply. However, for athletes commencing on a Ketogenic diet, they should consult with their clinician as well as a nutritionist. Such consultation monitors closely for any biochemical differences following the regimen commencement, and to generate a meal plan concerning their current health circumstances and to limit or stop nutritional insufficiencies or other health dilemmas (Burke 2017).
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