Weight Loss and Physical Performance with Ketogenic Diet: Overview

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Int J Appl Sports Sci. 2022;34(2):87-94
Publication date (electronic) : 2022 December 31
doi : https://doi.org/10.24985/ijass.2022.34.2.87
M.Sc. student, Department of Food Technology and Nutrition, Lovely Professional University, India
Correspondence: anvirana001@gmail.com
Received 2022 May 20; Revised 2022 June 21; Accepted 2022 August 2.


Several sportsmen are worried about achieving or sustaining their ideal body weight and distribution for their discipline. Players may wish to lose weight to improve effectiveness, enhance visual appeal, or participate in weight class activities. This culminates in attempts to lose body fat while decreasing muscle mass, as well as eating choices that can have serious health effects. A Ketogenic diet is rich in fat, low in carbs, and somewhat high in protein. Various nutrition-exercise combos have been evaluated in an attempt to boost oxidative stress rates while decreasing carbohydrate efficiency levels and improving overall exercise capacity. According to the findings, increasing fat availability leads to higher rates of whole-body and muscular lipid use during regular moderate-intensity aerobic activity. With significant increases in fatty acid oxidation levels, such diets regularly fail to increase stamina results in comparison to a carb diet, and nothing is understood to evaluate the impact of a Ketogenic diet on strength development. Consequently, the Ketogenic diet may be one of the most extensively researched and defined dietary regimes for losing weight. It is also becoming more popular as a long-term treatment for a variety of illnesses, including epilepsy and many others, and is a typical dietary pattern of Regional cultures. Considering these factors, as well as the reality that there are always sportsmen who choose to do, or are compelled to do, just about everything that that may provide even a slight benefit, protocols that provide that are known to be detrimental.


The Ketogenic diet is a dietary plan that consists of a high fat and protein concentration but insufficient carbohydrates for metabolic activity (5 percent of total daily calorie intake), leading fat storage to be the primary source of energy. (Mcardle et al., 2006). Ketosis, the primary metabolic response to an energy shortage, is a life-sustaining mechanism that affects responsive fuel choices, and it is easily ignored for its physiological activities, which are rarely known from outside starvation or diabetic crises. Ketone body metabolism is a survival strategy that has been conserved in higher organisms and permits them to survive longer in times of energy scarcity or metabolic crisis. The advantages of ketone body metabolism during hunger are noticeable: it saves valuable gluconeogenic resources while simultaneously addressing the brain’s particular fuel requirements (Mitchell et al., 1995). Once ketone bodies are present, they act not only as respiration energy to power mitochondrial oxidative processes but also as a signal to control chosen oxidation and fuel substrate translocation. (Poff et al., 2020).

Many athletes are concerned about reaching or maintaining their optimal body weight balance for their sport. Athletes may also want to drop weight to improve their performance, look better, or compete in weight-class sports. This leads to initiatives to reduce extra fat without sacrificing muscle mass, as well as eating selections that may have major health consequences (Keins & Astrup, 2015). Athletes can use the Ketogenic diet to decrease weight while retaining performance, especially endurance. Multiple clinical investigations have shown that the Ketogenic diet effectively reduces body fat while generating considerable lean body cell loss. (Oneill & Ragi, 2020).

It has long been noted that there is a link between strength training responses and food sources. Although this is unclear, it appears that adjusting the foundation supply during exercise can change the training effect (Egan & Zierath, 2013). Skeletal muscle energy status has a substantial influence on resting metabolism and fuel intake during exercise, athletic performance, signal transduction pathways and gene expression regulation, and a variety of training adaptation processes. Numerous recent studies on nutrition and exercise metabolism have intended to evaluate practical evidence for the hypothesis that endurance training with restricted carbohydrate availability generates more adaption modifications than intensive exercise with complicated carbohydrate access (Hawley & Burke, 2010).

Long-distance runners, for example, are always seeking alternative nutritional solutions to improve energy efficiency. High-carbohydrate diets increase glucose stores in the muscles and liver, enhancing muscular endurance but simultaneously speeding up carbohydrate usage during exercise (Billat et al., 1994). Taking all of this into consideration, researchers and athletes have begun experimenting with dietary strategies that would lower glucose usage while boosting fat metabolism during prolonged physical activity. A high-fat, restricted diet appeared to be capable of causing such a change in training metabolism. Very low carbohydrate diets have been suggested for millennia to address obesity and other common and atypical illness conditions. (Zajac et al., 2014).

The Effects of Ketogenic Diet on Body Weight, Body Mass, and Fat Mass Loss

The Ketogenic diet has widespread support for weight loss; however, the specific mechanisms by which it works are still being challenged. Several theories have been advanced, including the notion that “physiological ketosis” is an “intense” situation that results in a “loss of effort” in comparison to other kinds of diets (Paoli et al., 2021). The metabolic processes that occur under a Ketogenic diet can give some support to the “premium” hypothesis for weight loss. The brain requires roughly 10–12g of glucose at the start of the Ketogenic diet; approximately 16–18% of the glucose comes from glycerol, with the remaining coming from proteins via gluconeogenesis (DelMedico & Lov, 2021). According to Jabekk, the use of tissue amino acids as a precursor is critical in the first few days of fasting, its benefit quickly disappears; also, protein consumption on a Ketogenic diet “conserves,” as demonstrated, lean body mass (Jabekk et al., 2010). However, there are few obvious reasons to conclude, and a recent study reveals that there may be no changes in resting energy expenditure after or throughout the Ketogenic diet. Another theory is that increased weight loss is caused by hunger suppression caused by higher protein satisfaction, which may entail changes in appetite hormone levels and/or a direct appetite reduction activity. Moreover, in the long run, the increase in fatty acid oxidation demonstrated by a respiratory system rate may lead to increased fat loss in the Ketogenic diet. (Zinn et al., 2017).

A Ketogenic diet is widely regarded as a useful technique for treating a variety of ailments as well as controlling body and fat mass. Many research suggests that they may be more effective than low-fat diets (Stern et al., 2004). The Ketogenic diet’s effectiveness on body mass and fat mass loss is connected to predisposing variables, and its putative mechanisms include a reduction in calorie intake and hunger, as well as an improvement in energy requirement (Shai et al., 2008). A number of studies have found that baseline insulin dynamics or genetic patterns may play an essential impact on the efficacy of a reduced-fat fat density via a Ketogenic diet on body mass loss (Cornier et al., 2005). Individuals with stronger insulin resistance, for example, maybe be more effective after the Ketogenic diet due to lower reliance on insulin to clear a lesser volume of dietary carbs supplied in the blood circulation (Ebbeling et al., 2007).

Rock et al. discovered that insulin-sensitive women in the Low fat density group shed greater Body mass than those in the Low carbohydrate density group after 12 months (Rock et al., 2016). Conversely, several studies found no difference in body mass loss after a low fat/low carbohydrate diet based on baseline insulin status (Gardner et al., 2018).

A Body mass loss program’s primary goal is to reduce adipose tissue. The ketogenic diet is based on the idea that cutting carbohydrate consumption leads to greater fat oxidation. Mean interstitial glycerol concentrations (lipolysis index) were greater after a short-term high-fat diet than after a low-fat density meal established on the US Department of Agriculture dietary guide pyramid (Howe et al., 2011). Lowering dietary fat consumption when compared to carbohydrate, protein, and mixed meals, low-fat density can be an effective way to minimize calorie consumption and enhance body mass and fat mass reduction (Swaminathan et al., 1985). Additionally, in a non-Ketogenic diet, fat consumption does not instantly boost fat oxidation. The proportion of fatty acids that escape adipose tissue capitation appears to be modest. It is inadequate to account for the reduction in nonesterified fatty acid release via insulin secretion in response to commonly ingested carbs and lipids. The Ketogenic diet, on the other hand, lowers insulin concentrations, which stimulates lipolysis, and fat oxidation, and boosts energy consumption (Czech, 2017).

Moreover, a Ketogenic diet may be advantageous in Body mass loss. Ketogenic diet anti-obesity benefits are mostly due to reduced calorie consumption. Furthermore, limiting hunger (due to nutritional ketosis and greater daily protein intake), restricting meal choices, increasing energy expenditure, increasing lipolysis, and diuresis are all plausible processes that aid body mass reduction in those following a Ketogenic diet. In terms of body fat, the Ketogenic diet may be a viable dietary method for Fat mass loss. Short-term studies show that a Ketogenic diet results in significant fat mass reduction when compared to a non-Ketogenic diet (Kong et al., 2020).

The Influence of a Ketogenic Diet on Endurance and Maximal Intensity Exercise

Since there are still many concerns about using the Ketogenic diet in athletics, certain successful research on the Ketogenic diet and performance illustrates the necessity for a complete examination of its modes of action for sporting purposes (Bowler & Polman, 2020). It appears to have many advantages compared to conventional severe fuel “crash” diets, which, when used for only a few days, can induce undernutrition for necessary nutrients while also attempting to disenfranchise the body of other macro and micronutrients that help control oxidative stress and inflammatory processes. However apart from the very low carb diet levels, an energy-sufficient Ketogenic diet with an adequate protein intake is not a “severe” diet and, as such, doesn’t really consequence in muscle inadequacies that can have adverse implications if nutrient-deficient weight-loss diets are recreated on a regular basis (Wilson et al., 2020).

Impacts on Endurance and Maximal Intensity Exercise

The Ketogenic diet increased maximum lipid oxidation in a large study of long-distance athletes. This result has been connected to improved fat oxidation. In another trial, dietary ketosis enhanced vigorous cyclic stability. This might be a limitation of the research trial, or it could be confirmed by a well-conducted in vivo or in vitro trial. It has been shown that the Ketogenic diet increased the mitochondrial capacity of the tendon over a two-year experiment (Burke, 2021). Other researchers discovered that a 12-week Ketogenic diet combined with weekly aerobic activity boosted gene expression in oxidative stress indicators when contrasted with a diet supplemented with training. An eight-week Ketogenic diet was also found to affect ketolytic and lipolytic metabolism in mice, increasing stamina. These results illustrate some of the methods via which keto-adaption may increase maximum aerobic performance (Mohorko et al., 2019).

According to Kysel, A Ketogenic diet enhances endurance performance and well-being but does not increase aerobic performance (Kysel et al., 2020). Additionally, a low-carbohydrate, high-fat diet reduced physical efficiency and efficacy after hard training in numerous excellent race competitors. Moreover, in an experimental study, two months of a Ketogenic diet significantly increased the aerobic power of mice. There was a link between body weight and duration until tiredness; mice on a higher Ketogenic diet ran faster. This was attributed to calorie restriction. Individuals with substantial metabolic adaptability may choose a Ketogenic diet and indicate the weight change depending on inter variance. In comparison to mice on a regular diet, the optimum weight of Ketogenic diet mice was reduced by 20% following a two-month Ketogenic diet (Mcswiney et al., 2019).

Anaerobic exercise is a sort of high, short-duration activity that lasts less than 2 minutes. Energy requirements are met via the phosphate and lactic acid systems, which depend significantly on skeletal muscle glycogen. During anaerobic action, high mechanical forces develop inside the muscles, causing fibers to be damaged. Besides replenishing glucose throughout the rehabilitation process, enough absorption of essential amino acids is required to sustain protein expression required for muscle repair and regeneration (Medica, 2018). Additionally, due to the reduced carbohydrate diet, the dependence on amino acids for gluconeogenesis, as well as the limits of glycogen-store replenishment, may have a negative impact on anaerobic performance. Additional studies investigated the effect of the Ketogenic diet on anaerobic performance, particularly production or physical metrics, in a number of categories, especially endurance sports (Harvey et al., 2019). Dietary therapy spanned 7 to 14 weeks and included traditional exercise regimens for those studied. In conclusion, the Ketogenic diet (low carbohydrate) did not result in significantly different ability or performance metrics than the comparator group. (Schick, 2016).

According to Kang, Due to the individuals’ decreased body weight, one study discovered a significant improvement in relative capabilities but not supreme power. Several investigations reported reductions in skeletal muscle thickness or lean body mass. Moreover, the Ketogenic diet (low carbohydrate) may repress muscle hypertrophy from resistance training, and all of these statistics indicate that the Ketogenic diet is not an effective technique for increasing anaerobic performance in trained personnel or athletes, and it may disprove the anticipated increases in lean body mass from anaerobic exercise (Kang et al., 2020).

Athletics and Weight Management

Athletes may wish to shed weight for a variety of reasons, such as improving their strength ratio, moving to a more competitive weight class, or, in the instance of bodybuilders, gaining a severe muscle definition that is particularly appealing for aesthetic reasons (Manore, 2015). Many typical weight-loss techniques employed by athletes may have some negative side effects that might have a negative influence on real strength and fitness. This is shown in the mass acceptance of severe weight loss procedures such as drastic calorie consumption reduction, dehydration, and other therapies. These are carried out shortly before the event, with the expected effects such as negative outcomes, weariness, and so on. These approaches are detrimental to mental health since they disturb electrolytes and water balance, glycogen storage, and lean body mass, and may even be illegal in the case of medications (Abbasi, 2018).

Extremely low-calorie calorie dietary approaches are used, and this calorie restriction can lead to lean body mass loss as well as impaired performance, as demonstrated by exhaustion. There are a variety of normally toxic effects on quality as a result of such low energy consumption, as well as negative effects from specific therapies such as sauna dryness or drugs (Merra et al., 2016). Other than the increased risk of long-term health problems, there is also an increased chance of excessive weight gain in young adulthood; also, rapid weight loss can impair muscle function and increase muscle wastage. (Masood et al., 2020). Dehydration can impair aerobic performance by lowering plasma and tissue perfusion, while the exact amount of fluid loss necessary to have a significant influence on endurance sports is unknown. Extreme resource limitations typically result in lower dietary protein, that, given sportsmen’s elevated demands, may result in diminished muscle and, as a result, metabolic derangement of power efficacy. (Goday et al., 2016).


Professionals in sports nutrition teach athletes to attempt to manipulate their eating habits to avoid unnecessary and extreme carbohydrate inlets, and to use educational objectives by modifying the timing, quantity, and classification of carb foods and drinks to regulate durations of low- and high-carbohydrate ease of access, and to embrace proven competitive market techniques that provide appropriate carb accessibility depending on the needs and potentials. Many exercises involve weight control, and some have highly strict weight classes. All athletes compete by nature, but they are also, on aggregate, incredibly young and usually under a lot of pressure to perform. As originally said, the necessity for rapid weight loss is a very common condition that happens on a regular basis in the life of an athlete, and the urge is to try every option available to lose a few kilos in the weeks before the first competition. It is desirable to be at the head of a lower weight category rather than near the bottom of a higher division.

Consequently, competing in a given weight group provides benefits; although, if improper fast weight loss is used to get there, most of those benefits are lost. Moreover, many failed weight loss attempts may result in long-term weight management issues. Most of the other approaches used have proven to be unproductive for a variety of reasons. This includes “crash” diets with drastic food changes, attempts at dehydration, and the use of drugs. The Ketogenic diet differs significantly from many other types of weight-loss diets because it induces particular physiological changes and makes use of natural mechanisms that have evolved to deal with traditionally prevalent situations of short-duration shortage. It should be emphasized once more that produced ketosis is referred to as “physiologic ketosis,” not a pathological state such as “diabetic ketosis.” It is an eating plan that has been heavily scrutinized, especially in the centuries since the widespread adoption of the Atkins diet, and, aside from its beneficial effects on weight loss, the short-term use of the power Ketogenic diet has not been linked to any long-term health issues; the few signs, such as fatigue and brain fog, fade away after several days.

According to biochemical, pharmacological, and epidemiological research, a genuine Ketogenic diet can result in fat loss with no loss of muscle mass. It is a common misconception that the Ketogenic diet is hazardous because it contains “high-protein, high-saturated fat.” This is not correct. Although consuming very little carbohydrate, the primary characteristic is energy sufficiency, which is entirely compatible with appropriate protein consumption and rich nutrition that offers full balances of micronutrients and important macronutrients. However, the Ketogenic diet is one of the well-researched and specified dietary programs for weight loss. It is also becoming more popular as long-term therapy for a range of ailments, including epilepsy, and is a historical food regimen of Cultural identities.


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