Beyond Keto: A 13-Week Journey with Fasting, Caloric Restriction, and Exercise Revealed

TL;DR

• Case study examined effects of strict keto diet + intermittent fasting + calorie restriction + strength training in 23-year-old man
• Lasted 13 weeks with detailed tracking of extensive biomarkers, body composition, cardiovascular metrics
• Found major increases in testosterone, reductions in insulin resistance and liver enzymes, stable cholesterol despite very high fat intake
• Body weight decreased 13%, BMI dropped 12.5%, fat mass declined 44%, lean mass proportion increased
• Blood pressure and heart rate declined notably
• Results showcase improvements in metabolic, endocrine, hepatic, cardiovascular health
• Mechanisms likely involve ketosis, increased fat burning, better insulin sensitivity, along with weight loss
• Limitations include lack of control diet for comparison and inability to isolate keto effects
• Study supports benefits of complementary lifestyle strategies but more research on long-term impacts needed
• Provides uniquely detailed insights into potential synergies from combining keto, intermittent fasting, caloric deficit and exercise

Introduction

A recently published case study in the journal Foods provides an in-depth examination of the multifaceted health impacts of a strict ketogenic diet combined with intermittent fasting and caloric restriction in a 23-year-old physically active man. The study design and extensive range of biomarkers analyzed make this a uniquely thorough investigation into the effects of a low-carb, high-fat ketogenic diet paired with fasting, exercise, and caloric reduction. The results suggest powerful synergies between these factors that lead to significant improvements in objective measures of metabolic health, body composition, and cardiovascular parameters. This post will analyze the key aspects of the study and place the findings within the context of the current scientific literature on ketogenic diets.

Study Overview and Design

The participant followed a calculated ketogenic diet plan for 13 weeks that entailed a restricted feeding period of 8 hours per day from 1pm to 9pm (16:8 intermittent fasting) and an approximately 500 calorie per day deficit. The composition of the ketogenic diet for the first four weeks was 5-10% carbohydrates, 10-20% protein, and 70-80% fat. For weeks 5-13, carbs increased slightly to up to 10% while protein rose to 15-20% and fat reduced to 70-75% of total calories. The man continued his normal 4-5 days per week strength training routine during the 13 week study period.

Researchers analyzed a comprehensive set of 82 biomarkers before and after the 13-week intervention, including hormone levels, lipid profiles, liver enzymes, kidney function, electrolytes, vitamin levels, and complete blood count. The pre-intervention baseline testing established the participant was healthy with no underlying conditions. Additionally, body composition including fat mass, lean mass, and water percentage along with heart rate and blood pressure were assessed weekly under standardized conditions. During the 13 weeks, the investigators also periodically measured blood ketone levels to ensure ketosis was maintained as well as tracked fasting glucose levels.

The level of detail provided on the personalized ketogenic diet plan, including weighs or volumes of all foods and beverages consumed daily for the entire 13 weeks, is a notable strength of this study’s design. It enhances reproducibility and enables accurate analysis of the nutrients provided by the dietary regimen. Too often, studies assessing ketogenic diets fail to report detailed food intake. This study’s comprehensive reporting reinforces the validity and rigor of the methodology.

Another key aspect is the inclusion of intermittent fasting by restricting feeding to an 8-hour window each day. Most studies on ketogenic diets do not incorporate fasting, which means this study provides insight into potential synergies between time-restricted feeding and keto. Intermittent fasting is known to confer metabolic benefits on its own through mechanisms like lowering insulin levels (2). The multifactorial intervention combining fasting, caloric reduction, exercise, and ketogenic diet makes it impossible to isolate the effects of just keto itself. However, this approach has greater relevance to real-world application since people pair ketogenic eating with other lifestyle strategies. Overall, the thorough study design enables an in-depth appraisal of the health impacts of implementing complementary dietary and lifestyle changes together.

Key Findings on Biomarkers and Body Composition

The study yielded several notable findings that provide insights into the multifaceted effects of strict adherence to a ketogenic eating pattern when combined with fasting, caloric restriction, and training:

• Serum testosterone increased substantially by 98% from 24.2 nmol/L at baseline to 48 nmol/L at week 13. This large relative increase is impressive given testosterone tends to decrease with intermittent fasting and being in a caloric deficit. The authors propose strength training, increased dietary fat, and loss of body fat may have contributed to the rise in testosterone. This aligns with research indicating low-carb diets increase testosterone compared to high-carb diets, likely due to reduced insulin. Higher testosterone has wide-ranging health benefits related to muscle growth, bone strength, mood, libido, and metabolic regulation.
• HOMA-IR, a marker of insulin resistance, declined markedly by 81.5% from a score of 2.54 to 0.47. Reduced insulin paired with lower glucose levels demonstrates significantly improved insulin sensitivity. This effect is likely attributable to several interacting factors including very low carb intake, caloric deficit, exercise adaptation, and loss of body fat. These results agree with controlled diet studies showing keto diets reliably reduce HOMA-IR values and fasting insulin versus high-carb diets. Enhancing insulin sensitivity has major implications for mitigating diabetes and metabolic disease risk.
• Liver enzymes alanine transaminase (ALT) and aspartate transaminase (AST) decreased substantially by 79.6% and 48.1%, respectively. Lower ALT and AST levels indicate reduced liver inflammation and improved liver function. The significant decline was likely mediated largely by the 13% reduction in body weight and 44% decrease in visceral adipose tissue as excessive fat accumulation in the liver drives dysregulation of these markers. Some previous research demonstrates ketogenic diets can lower ALT and AST, while others show no change. This study provides evidence a well-formulated keto diet paired with weight loss positively impacts liver health.
• Total and LDL cholesterol remained relatively stable despite cholesterol intakes consistently exceeding 1,000 milligrams per day from high dietary saturated fat. Many studies show keto diets adversely affect cholesterol in the short-term but changes diminish over time. The findings here contradict concerns about potential negative cardiovascular impacts of high saturated fat intakes when carbs are very low. The increase in HDL paired with decrease in triglyceride to HDL ratio also point to possible cardiovascular benefits.
• Body mass index decreased from 26.5 kg/m^2 at baseline to 23.2 kg/m^2 at week 13, representing a 12.5% drop. Total body weight decreased by 10.9 kilograms corresponding to a 12.6% reduction. Fat mass declined by 6.5 kg equating to a substantial 43.9% decrease. Lean mass as a proportion of total weight increased from 82.9% to 89% even though absolute lean mass in kg decreased slightly. These changes reflect significant improvements in body composition and fat loss. However, comparisons of keto to high-carb diets show no major difference when protein is equated. This suggests restricted feeding, caloric deficit, and exercise primarily drove changes, rather than keto itself.
• Blood pressure and resting heart rate showed gradual declining trends across the 13 weeks. Mean arterial pressure in both systolic and diastolic measures dropped approximately 5 mmHg from baseline to end of study. Heart rate declined from an average of 80.9 beats per minute (BPM) in the first 4 weeks to 76.2 BPM in the final 4 weeks. Few studies examine keto diet effects on cardiovascular health metrics, but these outcomes suggest potential benefits for blood pressure and heart rate.

In summary, this broad range of biomarkers provides unique insights into the complex adaptive responses and synergies elicited by simultaneously implementing intermittent fasting, caloric restriction, strength training, and a well-formulated ketogenic diet. The specificity of the personalized planned menu is a major methodological strength. The results showcase marked improvements in endocrine, metabolic, hepatic, cardiovascular, and body composition parameters. Taken together, the findings indicate substantial benefits for promoting optimal health.

Ketogenic Diet Mechanisms and Weight Loss Effects

The significant positive changes observed raise the question—what mechanisms prompted these outcomes? Ketogenic diets are characterized by minimal carbohydrate intake, just 20 to 50 grams per day or 5 to 10% of total calories. This state of carb restriction causes the liver to produce ketone bodies, primarily β-hydroxybutyrate and acetoacetate, from incomplete breakdown of fatty acids through ketogenesis. Ketone bodies can serve as an alternative fuel source for the brain and other tissues in place of glucose from dietary carbs or protein.

Achieving nutritional ketosis induces widespread metabolic adaptations including increased fat oxidation and reduced lipogenesis, increased gluconeogenesis, enhanced insulin sensitivity, and modulation of inflammation and oxidative stress pathways. The distinctive shift in fuel utilization and metabolism underpins the therapeutic potential of the ketogenic diet for conditions like epilepsy, diabetes, and neurological disorders. However, potential benefits for wider health and longevity outcomes remain an active area of research.

In this study, metabolic advantages of keto eating were complemented by incorporating intermittent fasting, caloric restriction, and strength training. Time-restricted feeding within an 8-hour window lowers insulin, increases adiponectin, and modulates circadian rhythms to confer beneficial metabolic effects. The approximately 500 calorie per day deficit created an energy shortfall that compelled increased fat utilization. Strength training maintains lean mass during weight loss while enhancing insulin sensitivity and metabolic rate.

The participant’s body weight decreased by close to 13% over the 13 weeks, reflecting a large caloric deficit. However, comparisons of isocaloric keto and high-carb diets show similar weight loss when protein intake remains constant. This implies total calories expended primarily drove the substantial weight reduction rather than any specific effects of the ketogenic diet itself. Additional randomized controlled trials are needed to isolate the unique effects of keto on weight loss and body composition. Nonetheless, this case study supports the efficacy of pairing keto with intermittent fasting and caloric restriction to achieve meaningful fat loss.

Dietary Fat Type and Cholesterol Response

One noteworthy aspect of this study is the relatively neutral impact on cholesterol levels despite very high fat and saturated fat intake. Baseline total cholesterol was only 173 mg/dL and remained within normal range at 175 mg/dL after 13 weeks. LDL and HDL cholesterol exhibited a slight improvement in ratio. Trimethylamine N-oxide (TMAO), a gut microbe-generated metabolite that promotes atherosclerosis, also did not increase substantially based on the data reported.

These results challenge assumptions that dietary cholesterol and saturated fats inherently elevate cardiovascular risk. Importantly, the types of fats included in the keto diet plan were primarily monounsaturated and omega 3 polyunsaturated fats from plant sources like olive oil, avocado, nuts, seeds and fatty fish. Multiple meta-analyses conclude consuming these unsaturated fats improves lipid profiles compared to carbohydrates and reduces cardiovascular events.

The specific composition of fats likely explains the neutral cholesterol response observed here. Saturated fats from coconut oil, butter, and red meat were also prominent calorie sources. However, some emerging evidence indicates dairy saturated fats are neutral while coconut oil uniquely raises LDL compared to unsaturated plant oils. This study’s findings add to literature demonstrating dietary saturated fat per se does not reliably cause dyslipidemia when substituted for carbs in low-carb diets. Focusing on total fat quantity in the diet may matter more than quality with respect to cholesterol outcomes.

Future Directions for Research on Ketogenic Diets

This case report features a level of methodology rigor lacking in most studies on ketogenic diets. The detailed two-phase keto diet plan, extensive panel of biomarkers, anthropometric tracking, and cardiovascular measures enable a multifaceted assessment of physiological impacts. However, limitations include the lack of a control diet for comparison and applying interventions simultaneously prevents determining the isolated effect of keto. Significant evidence gaps remain regarding the distinctive ramifications of carbohydrate restriction.

Large scale randomized controlled trials that directly compare ketogenic diets to other healthy diet patterns like Mediterranean, DASH, and plant-based while carefully controlling food intake are needed. Studies spanning at least several months to years are necessary to ascertain long-term effects on weight, metabolic factors, cardiovascular health, and chronic disease endpoints. Application in diverse populations should also be a priority. People with insulin resistance, diabetes, obesity, heart disease, and other conditions that influence metabolism may respond differently.

Research on implementation strategies is also important because adherence to very low carb diets poses challenges for many people. Identifying optimal approaches to transitioning into and sustaining ketogenic eating habits long-term through education, support, and behavior change strategies will enable greater real-world impact. Technology like continuous glucose monitors can provide feedback during the keto-adaptation process. Finally, elucidating the complex interplay between ketogenic diets, intermittent fasting, exercise, gut microbiome, and genetics will lead to more personalized and effective application.

Conclusion

In summary, this highly controlled 13-week case study provides uniquely valuable insights into the multifaceted health impacts of complementing a customized ketogenic diet with daily intermittent fasting, caloric restriction, and strength training in a young active man. Improvements in metabolic, endocrine, hepatic, cardiovascular, and body composition parameters using this integrative dietary and lifestyle approach were broad in scope. The detailed reporting of biomarkers and objective measures enables a comprehensive assessment of physiological effects.

However, lack of a comparative control diet makes isolating the specific influence of the ketogenic eating pattern itself impossible. Future randomized controlled trials are needed to elucidate the distinctive mechanistic and clinical implications of carbohydrate restriction. Additional research should examine long-term impacts in diverse populations using multi-modal strategies to implement ketogenic diets in conjunction with fasting, exercise, and behavioral support. With the growing popularity of low-carb high-fat diets, this rigorously executed case study provides intriguing supportive evidence that warrants expanded investigation.