A Ketogenic Low-Carbohydrate High-Fat Diet Increases LDL Cholesterol in Healthy, Young, Normal-Weight Women: A Randomized Controlled Feeding Trial

Self-reported menses physiology is positively modulated by a well-formulated, energy-controlled ketogenic diet vs. low fat diet in women of reproductive age with overweight/obesity

Weight loss can positively alter female physiology; however, whether dietary carbohydrate- or fat- restriction confer unique effects is less studied. Precisely designed, hypocaloric well-formulated ketogenic diets (KD; ~75% energy for weight maintenance) were compared to isocaloric/isonitrogenous low-fat diet (LFD) on self-reported menses in pre-menopausal overweight and obese women (mean ± SD: 34 ± 10 years, BMI: 32.3 ± 2.7 kg/m2). Women received a precisely-weighed and formulated KD with either twice-daily with ketone salts (KS; n = 6) or a flavor-matched placebo (PL; n = 7) daily for six-weeks. An age and BMI-matched cohort (n = 6) was later assigned to the LFD and underwent the same testing procedures as the KD. Self-reported menses fluctuations were assessed bi-weekly along with measures of body weight, body composition, and fasting serum clinical chemistries using repeated measures ANOVA with Bonferroni post-hoc corrections. Both diets elicited clinically-significant weight-loss (Δ: -7.0 ± 0.5 kg; p < 0.001), primarily from fat-mass (Δ: -4.6 ± 0.3 kg; p < 0.001), and improved insulin-sensitivity and serum lipids (all p < 0.05). Fasting plasma glucose and inflammatory markers were not different between diets. Fasting capillary beta-hydroxybutyrate (R-βHB) increased significantly during the KD, independent of supplementation (Δ: 1.2 ± 0.3 mM R-βHB; p < 0.001). Women randomized to the KD+KS (30%) and KD+PL (43%) reported subjective increases in menses frequency and intensity after 14 days, whereas another third reported a regain of menses (>1 year since the last period) after 28 days. No LFD participants reported menses changes. Nutrient-dense, whole-food KDs and LFD improved weight, BMI, body composition, and blood parameters in pre-menopausal women after six-weeks. Changes in self-reported menses were described by most of the KD participants, but none of the LFD women suggesting there may be unique effects of nutritional ketosis, independent of weight loss.

Low-Carbohydrate Diet is More Helpful for Weight Loss Than Low-Fat Diet in Adolescents with Overweight and Obesity: A Systematic Review and Meta-Analysis

Purpose

This manuscript performed a meta-analysis to compare the effects of a low-fat diet (LFD) and a low-carbohydrate diet (LCD) on body weight and lipid levels in adolescents with overweight and obesity.

Patients and Methods

PubMed and other databases were searched for the full-text literature comparing LFD and LCD up to November 2023 using a subject plus free word strategy, with search terms such as "low-fat diet", "low-carbohydrate diet", "obesity", "weight", "adolescents", "RCT", and so on. Two independent reviewers selected promising candidate trials, collected the data, and assessed the quality of the trials. RevMan 5.3 software was utilized to conduct a meta-analysis of the randomized controlled trials (RCTs) that were included.

Results

5 RCTs with 192 participants were included in this meta-analysis. Weight (mean difference -2.81; 95% CI -5.38 to -0.25), Body Mass Index (BMI) (-1.13; 95% CI -2.14 to -0.11) and Triglyceride (TG) (-0.36; 95% CI -0.46 to -0.27) of the LCD were significantly lower than that of the LFD. At the same time, the high-density lipoprotein cholesterol (HDL) levels of the LCD were significantly higher than those of the LFD (0.08; 95% CI 0.04 to 0.12) (P < 0.05). However, there was no significant difference in the Homeostasis Model Assessment of Insulin Resistance (HOMA-IR), percent body fat, total cholesterol (TC), and low-density lipoprotein cholesterol (LDL) between the two groups (P>0.05).

Conclusion

According to this study, LCD is more helpful in improving weight loss, HDL and TG. Thus, LCD may serve as an effective intervention for weight management in adolescents with overweight and obesity, although further research is needed to determine its long-term effects.

Extracellular Vesicles Modulate Liver Cells Viability and Reactive Oxygen Species in Patients Following a Very Low-Calorie Ketogenic Diet

The VLCKD is a diet recognized to promote rapid fat mobilization and reduce inflammation, hepatic steatosis, and liver fibrosis. Extracellular vesicles (EVs) mediate cell-to-cell communication. The aim of the study is to investigate the role of circulating EVs in cell proliferation, ketone bodies, and ROS production in patients on an 8-week VLCKD regimen. Participants were classified as responders (R) or non-responders (NR) to VLCKD treatment based on their fibroscan results. In vitro experiments with the hepatic cell lines HEPA-RG (normal hepatocytes) and LX-2 (stellate cells) were conducted to investigate the effects of circulating EVs on cell viability, ROS production, and ketone body presence. The findings reveal a notable reduction in cell viability in both cell lines when treated with exosomes (EXOs). In contrast, treatment with microvesicles (MVs) did not appear to affect cell viability, which remained unchanged. Additionally, the levels of ketone bodies measured in urine were not consistently correlated with the reduction of fibrosis in responders (R). Similarly, an increase in ketone bodies was observed in non-responders (NR), which was also not aligned with the expected reduction in fibrosis. This inconsistency stands in stark contrast to the levels of Reactive Oxygen Species (ROS), which exhibited a clear and consistent pattern in accordance with the dietary intervention. Finally, in this preliminary study, ROS has been identified as a potential diet adherence marker for VLCKD patients; the ROS levels reliably follow the progression of the fibrosis response, providing a more accurate reflection of the therapeutic effects.

Effects of a Ketogenic Diet on Body Composition in Healthy, Young, Normal-Weight Women: A Randomized Controlled Feeding Trial

This study investigates the effects of a ketogenic low-carbohydrate high-fat (LCHF) diet on body composition in healthy, young, normal-weight women. With the increasing interest in ketogenic diets for their various health benefits, this research aims to understand their impact on body composition, focusing on women who are often underrepresented in such studies. Conducting a randomized controlled feeding trial with a crossover design, this study compares a ketogenic LCHF diet to a Swedish National Food Agency (NFA)-recommended control diet over four weeks. Seventeen healthy, young, normal-weight women adhered strictly to the provided diets, with ketosis confirmed through blood β-hydroxybutyrate concentrations. Dual-energy X-ray absorptiometry (DXA) was utilized for precise body composition measurements. To avoid bias, all statistical analyses were performed blind. The findings reveal that the ketogenic LCHF diet led to a significant reduction in both lean mass (-1.45 kg 95% CI: [-1.90;-1.00]; p < 0.001) and fat mass (-0.66 kg 95% CI: [-1.00;-0.32]; p < 0.001) compared to the control diet, despite similar energy intake and physical activity levels. This study concludes that while the ketogenic LCHF diet is effective for weight loss, it disproportionately reduces lean mass over fat mass, suggesting the need for concurrent strength training to mitigate muscle loss in women following this diet.

Dietary, macronutrient, micronutrient, and nutrigenetic factors impacting cardiovascular risk markers apolipoprotein B and apolipoprotein A1: a narrative review

Genetic predisposition and dietary factors can impact cardiovascular disease (CVD) risk. Two important markers in assessing CVD risk are apolipoprotein (apo) B and apolipoprotein A1 plasma levels. These markers are measured as a ratio, with a high apoB:apoA1 ratio associated with increased CVD risk. Dietary and lifestyle recommendations are the cornerstone of managing primary and secondary CVD risk-mitigation strategies. One way to assess the impact of various dietary and lifestyle interventions on CVD risk is to evaluate the changes in CVD risk markers, such as apoB, apoA1, and apoB:apoA1 ratio. Various human studies have demonstrated the impact of dietary, macronutrient, and micronutrient interventions on apoB and apoA1 status. This review aims to elucidate dietary, macronutrient, micronutrient, and nutrigenetic considerations for impacting apoB and apoA1 levels. A low-carbohydrate, high-saturated-fat diet, low fiber intake, low vitamin and mineral intake, and zinc and iron deficiency are associated with an elevated apoB:apoA1 ratio. The Mediterranean diet, vegan diet, fermented dairy products, lower sugar intake, higher protein intake, higher polyunsaturated fat intake, and an omega-3-rich diet are associated with a decreased apoB:apoA1 ratio. Micronutrients associated with a decreased apoB:apoA1 ratio include vitamin D sufficiency, increased serum vitamin C, and magnesium. Variants in the APOE, APOA1, and FADS2 genes may alter the apoB:apoA1 ratio in response to various dietary interventions. When accounting for factors that may favorably alter the apoB:apoA1 ratio, researchers should consider a healthy diet sufficient in polyunsaturated fats, vitamins, minerals, trace minerals, and lower excess sugars.

Association of a Low-Carbohydrate High-Fat Diet With Plasma Lipid Levels and Cardiovascular Risk

Background

Low-carbohydrate high-fat (LCHF) diets have attracted interest for a variety of conditions. In some individuals, these diets trigger hypercholesterolemia. There are limited data on their effects on cardiovascular disease risk.

Objectives

The purpose of this study was to investigate the association between LCHF dietary patterns, lipid levels, and incident major adverse cardiovascular events (MACE).

Methods

In a cohort from the UK Biobank, participants with ≥1 24-hour dietary questionnaire were identified. A LCHF diet was defined as <100 g/day and/or <25% total daily energy from carbohydrates/day and >45% total daily energy from fat, with participants on a standard diet (SD) not meeting these criteria. Each LCHF case was age- and sex-matched 1:4 to SD individuals.

Results

Of the 2034 LCHF and 8136 SD identified participants, 305 LCHF and 1220 SD individuals completed an enrollment assessment concurrently with lipid collection. In this cohort, low-density lipoprotein-cholesterol (LDL-C) and apolipoprotein B levels were significantly increased in the LCHF vs SD group (P < 0.001). 11.1% of LCHF and 6.2% of SD individuals demonstrated severe hypercholesterolemia (LDL-C >5 mmol/L, P < 0.001). After 11.8 years, 9.8% of LCHF vs 4.3% of SD participants experienced a MACE (P < 0.001). This difference remained significant after adjustment for cardiovascular risk factors (HR: 2.18, 95% CI: 1.39-3.43, P < 0.001). Individuals with an elevated LDL-C polygenic risk score had the highest concentrations of LDL-C on a LCHF diet. Similar significant changes in lipid levels and MACE associations were confirmed in the entire cohort and in ≥2 dietary surveys.

Conclusions

Consumption of a LCHF diet was associated with increased LDL-C and apolipoprotein B levels, and an increased risk of incident MACE.

Dietary Influence on Drug Efficacy: A Comprehensive Review of Ketogenic Diet-Pharmacotherapy Interactions

It is widely acknowledged that the ketogenic diet (KD) has positive physiological effects as well as therapeutic benefits, particularly in the treatment of chronic diseases. Maintaining nutritional ketosis is of utmost importance in the KD, as it provides numerous health advantages such as an enhanced lipid profile, heightened insulin sensitivity, decreased blood glucose levels, and the modulation of diverse neurotransmitters. Nevertheless, the integration of the KD with pharmacotherapeutic regimens necessitates careful consideration. Due to changes in their absorption, distribution, metabolism, or elimination, the KD can impact the pharmacokinetics of various medications, including anti-diabetic, anti-epileptic, and cardiovascular drugs. Furthermore, the KD, which is characterised by the intake of meals rich in fats, has the potential to impact the pharmacokinetics of specific medications with high lipophilicity, hence enhancing their absorption and bioavailability. However, the pharmacodynamic aspects of the KD, in conjunction with various pharmaceutical interventions, can provide either advantageous or detrimental synergistic outcomes. Therefore, it is important to consider the pharmacokinetic and pharmacodynamic interactions that may arise between the KD and various drugs. This assessment is essential not only for ensuring patients' compliance with treatment but also for optimising the overall therapeutic outcome, particularly by mitigating adverse reactions. This highlights the significance and necessity of tailoring pharmacological and dietetic therapies in order to enhance the effectiveness and safety of this comprehensive approach to managing chronic diseases.

Effects of dietary intervention on human diseases: molecular mechanisms and therapeutic potential

Diet, serving as a vital source of nutrients, exerts a profound influence on human health and disease progression. Recently, dietary interventions have emerged as promising adjunctive treatment strategies not only for cancer but also for neurodegenerative diseases, autoimmune diseases, cardiovascular diseases, and metabolic disorders. These interventions have demonstrated substantial potential in modulating metabolism, disease trajectory, and therapeutic responses. Metabolic reprogramming is a hallmark of malignant progression, and a deeper understanding of this phenomenon in tumors and its effects on immune regulation is a significant challenge that impedes cancer eradication. Dietary intake, as a key environmental factor, can influence tumor metabolism. Emerging evidence indicates that dietary interventions might affect the nutrient availability in tumors, thereby increasing the efficacy of cancer treatments. However, the intricate interplay between dietary interventions and the pathogenesis of cancer and other diseases is complex. Despite encouraging results, the mechanisms underlying diet-based therapeutic strategies remain largely unexplored, often resulting in underutilization in disease management. In this review, we aim to illuminate the potential effects of various dietary interventions, including calorie restriction, fasting-mimicking diet, ketogenic diet, protein restriction diet, high-salt diet, high-fat diet, and high-fiber diet, on cancer and the aforementioned diseases. We explore the multifaceted impacts of these dietary interventions, encompassing their immunomodulatory effects, other biological impacts, and underlying molecular mechanisms. This review offers valuable insights into the potential application of these dietary interventions as adjunctive therapies in disease management.

A ketogenic diet rich in fish oil is superior to other fats in preventing NNK-induced lung cancer in A/J mice

Given that ketogenic diets (KDs) are extremely high in dietary fat, we compared different fats in KDs to determine which was the best for cancer prevention. Specifically, we compared a Western and a 15% carbohydrate diet to seven different KDs, containing either Western fats or fats enriched in medium chain fatty acids (MCTs), milk fat (MF), palm oil (PO), olive oil (OO), corn oil (CO) or fish oil (FO) for their ability to reduce nicotine-derived nitrosamine ketone (NNK)-induced lung cancer in mice. While all the KDs tested were more effective at reducing lung nodules than the Western or 15% carbohydrate diet, the FO-KD was most effective at reducing lung nodules. Correlating with this, mice on the FO-KD had low blood glucose and the highest β-hydroxybutyrate level, lowest liver fatty acid synthase/carnitine palmitoyl-1a ratio and a dramatic increase in fecal Akkermansia. We found no liver damage induced by the FO-KD, while the ratio of total cholesterol/HDL was unchanged on the different diets. We conclude that a FO-KD is superior to KDs enriched in other fats in reducing NNK-induced lung cancer, perhaps by being the most effective at skewing whole-body metabolism from a dependence on glucose to fats as an energy source.

Increased low-density lipoprotein cholesterol on a low-carbohydrate diet in adults with normal but not high body weight: A meta-analysis

BACKGROUND

Low-density lipoprotein (LDL) cholesterol change with consumption of a low-carbohydrate diet (LCD) is highly variable. Identifying the source of this heterogeneity could guide clinical decision-making.

OBJECTIVES

To evaluate LDL cholesterol change in randomized controlled trials involving LCDs, with a focus on body mass index (BMI) in kg/m2.

METHODS

Three electronic indexes (Pubmed, EBSCO, and Scielo) were searched for studies between 1 January, 2003 and 20 December, 2022. Two independent reviewers identified randomized controlled trials involving adults consuming <130 g/d carbohydrate and reporting BMI and LDL cholesterol change or equivalent data. Two investigators extracted relevant data, which were validated by other investigators. Data were analyzed using a random-effects model and contrasted with results of pooled individual participant data.

RESULTS

Forty-one trials with 1379 participants and a mean intervention duration of 19.4 wk were included. In a meta-regression accounting for 51.4% of the observed variability on LCDs, mean baseline BMI had a strong inverse association with LDL cholesterol change [β = -2.5 mg/dL/BMI unit, 95% confidence interval (CI): -3.7, -1.4], whereas saturated fat amount was not significantly associated with LDL cholesterol change. For trials with mean baseline BMI <25, LDL cholesterol increased by 41 mg/dL (95% CI: 19.6, 63.3) on the LCD. By contrast, for trials with a mean of BMI 25-<35, LDL cholesterol did not change, and for trials with a mean BMI ≥35, LDL cholesterol decreased by 7 mg/dL (95% CI: -12.1, -1.3). Using individual participant data, the relationship between BMI and LDL cholesterol change was not observed on higher-carbohydrate diets.

CONCLUSIONS

A substantial increase in LDL cholesterol is likely for individuals with low but not high BMI with consumption of an LCD, findings that may help guide individualized nutritional management of cardiovascular disease risk. As carbohydrate restriction tends to improve other lipid and nonlipid risk factors, the clinical significance of isolated LDL cholesterol elevation in this context warrants investigation. This trial was registered at PROSPERO as CRD42022299278.

Role of ketogenic diet and its effect on the periodontium. A scoping review

The purpose of this study is to investigate the relationship between the ketogenic diet and periodontitis, as well as the nature of such relationship. Furthermore, emphasis was given to know whether ketogenic diet causes changes in oral health parameters and more specifically on periodontal health. Studies from 2010 to 2023 were reviewed and analyzed. Databases used to search included PubMed, Mednet, Scopus, Cochrane, and Embase. The literature reviewed was limited to randomized clinical trials, observational studies, and case-control studies. Of the eight studies included, three studies found that diets with similarities to the ketone-based diet could have a significant positive impact on periodontal health. One study pointed to the potential positive effect of a diet such as keto, but no definitive conclusion could be made. The current body of evidence concluded that there may be a relationship between keto and periodontitis, although the evidence is not consistent. It can be implied, however, that it is a positive relationship as ketogenic diet has been shown to have an anti-inflammatory effect, reducing inflammatory markers found in many diseases, including periodontitis.

Changes in the chronic and postprandial blood lipid profiles of trained competitive cyclists and triathletes following a ketogenic diet: a randomized crossover trial

BACKGROUND

The ketogenic diet (KD) is the most popular carbohydrate restriction strategy for endurance athletes. However, because the primary goal of employing the KD is to gain a competitive advantage in competition, endurance athletes may be less concerned with the influence of the KD on their cardiometabolic health; particularly their blood lipid profiles. Thus, the purpose of this study was to examine the chronic and postprandial blood lipid alterations following a two-week ad libitum KD compared to an ad libitum high-carbohydrate diet (HCD) and the athletes' habitual diet (HD) in a group of trained competitive cyclists and triathletes.

METHODS

Six trained competitive cyclists and triathletes (female: 4, male: 2; age: 37.2 ± 12.2) completed this randomized crossover trial, which required them to follow a two-week ad libitum KD and HCD in a randomized order after their HD. Fasting blood lipids were collected following their HD and after two-weeks of the KD and HCD conditions. Postprandial blood lipid responses to a test meal reflective of the assigned diet were collected at the end of each diet condition.

RESULTS

Fasting total cholesterol (TC) was significantly higher following the KD compared to the HD (p < 0.001) and HCD (p = 0.006). Postprandial incremental area under the curve for triglycerides (TRG), TRG:HDL ratio, and VLDL-C were significantly higher following the KD test meal compared to the HD (all p < 0.001) and HCD (all p = 0.001) test meals but LDL-C and LDL:HDL ratio were significantly lower following the KD compared to the HD and HCD test meals (all p < 0.001).

CONCLUSIONS

Trained competitive cyclists and triathletes demonstrate increased TC in response to a two-week KD compared to a HCD or HD. Endurance athletes contemplating a KD should consider the potential for these blood lipid alterations, and future research should focus on postprandial blood lipid responses to determine if these changes manifest in chronic blood lipid shifts.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT04097171 (11 October 2019).

Does a Ketogenic Diet Have a Place Within Diabetes Clinical Practice? Review of Current Evidence and Controversies

Carbohydrate restriction has gained increasing popularity as an adjunctive nutritional therapy for diabetes management. However, controversy remains regarding the long-term suitability, safety, efficacy and potential superiority of a very low carbohydrate, ketogenic diet compared to current recommended nutritional approaches for diabetes management. Recommendations with respect to a ketogenic diet in clinical practice are often hindered by the lack of established definition, which prevents its capacity to be most appropriately prescribed as a therapeutic option for diabetes. Furthermore, with conflicted evidence, this has led to uncertainty amongst clinicians on how best to support and advise their patients. This review will explore whether a ketogenic diet has a place within clinical practice by reviewing current evidence and controversies.

Potential Advantages of a Well-balanced Nutrition Regimen for People Living with Human Immunodeficiency Virus Type -1

This review underscores the important role of nutrition in enhancing the management of Human Immunodeficiency Virus type 1 (HIV-1). Highlighting the efficacy of dietary interventions, including, the importance of omega-3 fatty acids, vitamins D and B-12, and the Mediterranean diet, we delineate how these beneficial nutritional strategies can improve the effectiveness of combined antiretroviral therapy (cART), mitigate its side effects, and ameliorate metabolic disorders in people living with HIV-1 (PLWH). Our review advocates for the integration and implementation of personalized nutritional assessments into the care plan for PLWH, proposing actionable strategies for healthcare providers in HIV-1 field. Summarizing the current standing of the relevance of the nutritional and well-planned diet recommended for the PLWH and emphasizing on the future research directions, this review establishes a foundation for nutrition as a cornerstone in comprehensive HIV-1 management. Our review aims to improve patients' health outcomes and overall quality of life for PLWH.

Thyroid markers and body composition predict LDL-cholesterol change in lean healthy women on a ketogenic diet: experimental support for the lipid energy model

Introduction

There is a large heterogeneity in LDL-cholesterol change among individuals adopting ketogenic diets. Interestingly, lean metabolically healthy individuals seem to be particularly susceptible, with an inverse association between body mass index and LDL-cholesterol change. The lipid energy model proposes that, in lean healthy individuals, carbohydrate restriction upregulates systemic lipid trafficking to meet energy demands. To test if anthropometric and energy metabolism markers predict LDL-cholesterol change during carbohydrate restriction.

Methods

Ten lean, healthy, premenopausal women who habitually consumed a ketogenic diet for ≥6 months were engaged in a three-phase crossover study consisting of continued nutritional ketosis, suppression of ketosis with carbohydrate reintroduction, and return to nutritional ketosis. Each phase lasted 21 days. The predictive performance of all available relevant variables was evaluated with the linear mixed-effects models.

Results

All body composition metrics, free T3 and total T4, were significantly associated with LDL-cholesterol change. In an interaction model with BMI and free T3, both markers were significant independent and interacting predictors of LDL-cholesterol change. Neither saturated fat, HOMA-IR, leptin, adiponectin, TSH, nor rT3 was associated with LDL-cholesterol changes.

Discussion

Among lean, healthy women undergoing carbohydrate restriction, body composition and energy metabolism markers are major drivers of LDL-cholesterol change, not saturated fat, consistent with the lipid energy model.

A Review of Healthy Dietary Choices for Cardiovascular Disease: From Individual Nutrients and Foods to Dietary Patterns

Cardiovascular disease (CVD) remains the first cause of mortality globally. Diet plays a fundamental role in cardiovascular health and is closely linked to the development of CVD. Numerous human studies have provided evidence on the relationship between diet and CVD. By discussing the available findings on the dietary components that potentially influence CVD progression and prevention, this review attempted to provide the current state of evidence on healthy dietary choices for CVD. We focus on the effects of individual macronutrients, whole food products, and dietary patterns on the risks of CVD, and the data from population-based trials, observational studies, and meta-analyses are summarized. Unhealthy dietary habits, such as high intake of saturated fatty acids, sugar-sweetened beverages, red meat, and processed meat as well as high salt intake are associated with the increased risk of CVD. Conversely, increased consumption of plant-based components such as dietary fiber, nuts, fruits, and vegetables is shown to be effective in reducing CVD risk factors. The Mediterranean diet appears to be one of the most evidence-based dietary patterns beneficial for CVD prevention. However, there is still great debate regarding whether the supplementation of vitamins and minerals confers cardioprotective benefits. This review provides new insights into the role of dietary factors that are harmful or protective in CVD, which can be adopted for improved cardiovascular health.

Effects of very low-carbohydrate ketogenic diets on lipid profiles in normal-weight (body mass index < 25 kg/m2) adults: a meta-analysis

CONTEXT

Very low-carbohydrate diets or ketogenic diets (KDs) have garnered attention for weight loss in patients with overweight or obesity as well as for normal-weight adults, yet the adverse effects of KDs, such as dyslipidemia in normal-weight adults, have not been studied extensively.

OBJECTIVE

This meta-analysis aimed to identify the effects of KDs on the lipid profile in normal-weight (body mass index [BMI] < 25 kg/m2) adults from randomized controlled trials.

DATA SOURCES

PubMed and Embase databases were searched on November 21, 2021, using search terms representing KDs and lipid profiles. Two researchers independently screened articles according to PICOS inclusion criteria.

DATA EXTRACTION

General study information, dietary data, and lipid profiles were extracted from eligible studies. Risk of bias was assessed using the Cochrane risk of bias 2 tool.

DATA ANALYSIS

Fixed- or random-effects meta-analysis was performed to estimate the effects of KDs on total cholesterol (TC), high-density lipoprotein-cholesterol (HDL-C), low-density lipoprotein-cholesterol (LDL-C), triglycerides, apolipoprotein A (apoA), and apolipoprotein B (apoB), considering heterogeneity across studies. The certainty of evidence was assessed using the GRADE (Grading of Recommendations, Assessment, Development and Evaluation) approach.

RESULTS

Three studies were selected for meta-analysis. A KD significantly increased TC by 1.47 mmol/L (95%CI, 0.72-2.22 mmol/L), LDL-C by 1.08 mmol/L (95%CI, 0.37-1.79 mmol/L), and apoB by 0.35 g/L (95%CI, 0.06-0.65 g/L). In addition, a KD significantly increased HDL-C by 0.35 mmol/L (95%CI, 0.27-0.42 mmol/L) and apoA by 0.34 g/L (95%CI, 0.28-0.41 g/L) compared with control diets. Triglyceride levels were not significantly different between KDs and control diets (P = 0.63).

CONCLUSION

This study suggests unfavorable effects of KDs on TC and LDL-C in normal-weight adults. Although an increase in HDL-C can compensate for unfavorable changes in lipids, normal-weight individuals should consider the risk of hypercholesterolemia when consuming a KD. Results for triglycerides were inconsistent.

High-fat diet impact on intestinal cholesterol conversion by the microbiota and serum cholesterol levels

Cholesterol-to-coprostanol conversion by the intestinal microbiota has been suggested to reduce intestinal and serum cholesterol availability, but the relationship between intestinal cholesterol conversion and the gut microbiota, dietary habits, and serum lipids has not been characterized in detail. We measured conserved proportions of cholesterol high and low-converter types in individuals with and without obesity from two distinct, independent low-carbohydrate high-fat (LCHF) dietary intervention studies. Across both cohorts, cholesterol conversion increased in previous low-converters after LCHF diet and was positively correlated with the fecal relative abundance of Eubacterium coprostanoligenes. Lean cholesterol high-converters had increased serum triacylglycerides and decreased HDL-C levels before LCHF diet and responded to the intervention with increased LDL-C, independently of fat, cholesterol, and saturated fatty acid intake. Our findings identify the cholesterol high-converter type as a microbiome marker, which in metabolically healthy lean individuals is associated with increased LDL-C in response to LCHF.

Keto Menu-Effect of Ketogenic Menu and Intermittent Fasting on the Biochemical Markers and Body Composition in a Physically Active Man-A Controlled Case Study

The combination of ketogenic diet (KD) with intermittent fasting (IF) has, for years, aroused a great interest in the scientific world and among healthy lifestyle enthusiasts. Its importance is even greater when the study subjects are physically active individuals. The aim of the study was a determination of the effect of strict calculated ketogenic menu combined with IF and with caloric deficit on the selected biochemical markers and body composition in a 23-year-old man performing strength training. At the same time, we decided to conduct the first so-deeply investigated and controlled case study in this respect. The study protocol included a 13-week-long ketogenic diet with intermittent fasting (of delayed time-restricted eating 16:8 type) and caloric deficit. A detailed menu was designed and was used by the man throughout the whole study duration. A number of blood tests were performed before and after the implemented dietary intervention. Additionally, body composition was determined weekly and the concentrations of glucose and ketone bodies, as well as pulse rate and arterial pressure, were measured daily. The most important changes noted included a significant increase in testosterone and vitamin D concentrations and significant reduction in the HOMA-IR index and concentrations of hepatic enzymes, insulin, glucose, iron, urea, and free triiodothyronine (FT3). Moreover, a significant improvement of body composition occurred (the ratio of total body mass to the adipose and muscular tissue and water mass improved). Favourable changes were also noted in heart rate and arterial pressure values. In view of that, the KD with IF and caloric deficit exerted favourable effects on most biochemical parameters and on body composition and caused an almost twofold increase in serum testosterone concentration.

The Ketogenic Diet and Cardiovascular Diseases

The most common and increasing causes of death worldwide are cardiovascular diseases (CVD). Taking into account the fact that diet is a key factor, it is worth exploring this aspect of CVD prevention and therapy. The aim of this article is to assess the potential of the ketogenic diet in the prevention and treatment of CVD. The article is a comprehensive, meticulous analysis of the literature in this area, taking into account the most recent studies currently available. The ketogenic diet has been shown to have a multifaceted effect on the prevention and treatment of CVD. Among other aspects, it has a beneficial effect on the blood lipid profile, even compared to other diets. It shows strong anti-inflammatory and cardioprotective potential, which is due, among other factors, to the anti-inflammatory properties of the state of ketosis, the elimination of simple sugars, the restriction of total carbohydrates and the supply of omega-3 fatty acids. In addition, ketone bodies provide "rescue fuel" for the diseased heart by affecting its metabolism. They also have a beneficial effect on the function of the vascular endothelium, including improving its function and inhibiting premature ageing. The ketogenic diet has a beneficial effect on blood pressure and other CVD risk factors through, among other aspects, weight loss. The evidence cited is often superior to that for standard diets, making it likely that the ketogenic diet shows advantages over other dietary models in the prevention and treatment of cardiovascular diseases. There is a legitimate need for further research in this area.

The Effect of a Low-Carbohydrate High-Fat Diet on Laboratory Parameters in Women with Lipedema in Comparison to Overweight/Obese Women

The aim of this study was to evaluate alterations in blood parameters after a low-carbohydrate high-fat (LCHF) diet in women with lipedema in comparison to overweight or obese women. A total of 115 women were classified into two groups: the lipedema group and the overweight/obesity group. Both study groups followed the caloric-restricted LCHF diet for 7 months. A total of 48 women completed the study. A reduction in body weight was observed in both study groups. A significant decrease in triglycerides and an increase in HDL-C concentrations were observed in both study groups. Despite the increase in the concentration of LDL-C observed in the lipedema group, changes in LDL-C differed between individual patients. Improvements in liver parameters, glucose tolerance, and a decrease in fasting insulin levels were observed, although they were less pronounced in the lipedema group than in the overweight/obesity group. Kidney and thyroid functions were similar before and after the LCHF diet in both groups. The LCHF diet may be a valuable nutritional strategy for lipedema and overweight/obese women, with a beneficial effect on weight, glucose profile, liver function, the concentration of triglycerides, and HDL-C and with no effect on kidney and thyroid function.

Could Gut Microbiota Composition Be a Useful Indicator of a Long-Term Dietary Pattern?

Despite the known effects of diet on gut microbiota composition, not many studies have evaluated the relationship between distinct dietary patterns and gut microbiota. The aim of our study was to determine whether gut microbiota composition could be a useful indicator of a long-term dietary pattern. We collected data from 89 subjects adhering to omnivorous, vegetarian, vegan, and low-carbohydrate, high-fat diet that were equally distributed between groups and homogenous by age, gender, and BMI. Gut microbiota composition was analyzed with a metabarcoding approach using V4 hypervariable region of the 16S rRNA gene. K-means clustering of gut microbiota at the genus level was performed and the nearest neighbor classifier was applied to predict microbiota clustering classes. Our results suggest that gut microbiota composition at the genus level is not a useful indicator of a subject's dietary pattern, with the exception of a vegan diet that is represented by a high abundance of Prevotella 9. Based on our model, a combination of 26 variables (anthropometric measurements, serum biomarkers, lifestyle factors, gastrointestinal symptoms, psychological factors, specific nutrients intake) is more important to predict an individual's microbiota composition cluster, with 91% accuracy, than the dietary intake alone. Our findings could serve to develop strategies to educate individuals about changes of some modifiable lifestyle factors, aiming to classify them into clusters with favorable health markers, independent of their dietary pattern.

High-Fat Diet Related Lung Fibrosis-Epigenetic Regulation Matters

Pulmonary fibrosis (PF) is an interstitial lung disease characterized by the destruction of the pulmonary parenchyma caused by excessive extracellular matrix deposition. Despite the well-known etiological factors such as senescence, aberrant epithelial cell and fibroblast activation, and chronic inflammation, PF has recently been recognized as a metabolic disease and abnormal lipid signature was observed both in serum and bronchoalveolar lavage fluid (BALF) of PF patients and mice PF model. Clinically, observational studies suggest a significant link between high-fat diet (HFD) and PF as manifested by high intake of saturated fatty acids (SFAs) and meat increases the risk of PF and mice lung fibrosis. However, the possible mechanisms between HFD and PF remain unclear. In the current review we emphasize the diversity effects of the epigenetic dysregulation induced by HFD on the fibrotic factors such as epithelial cell injury, abnormal fibroblast activation and chronic inflammation. Finally, we discuss the potential ways for patients to improve their conditions and emphasize the prospect of targeted therapy based on epigenetic regulation for scientific researchers or drug developers.

Comparison of Weight Reduction, Change in Parameters and Safety of a Very Low Carbohydrate Diet in Comparison to a Low Carbohydrate Diet in Obese Japanese Subjects with Metabolic Disorders

Recently, low-carbohydrate diets (LCDs) have gained worldwide attention. LCDs are potentially effective for Japanese overweight and obese individuals with metabolic disorders. However, few randomized trials of LCDs have focused on the difference between LCDs and VLCDs. We conducted a randomized, prospective study of 42 Japanese, obese adults aged 28–65 years to evaluate the efficacy and safety of LCD and VLCD. To ensure the accuracy of the study, all test meals were provided, and compliance was checked using a smartphone app. Body composition measurements and blood tests were performed before and after the 2-month dietary intervention. The results showed that both methods significantly reduced body weight and fat, and also improved lipid abnormalities and liver function. In the current study, the reductions in weight and fat were comparable. The results of a questionnaire at the end of the study indicated that the LCD was easier to carry out than the VLCD, suggesting that the LCD was sustainable. The present study was unique in that it was a randomized, prospective study of Japanese subjects and that accurate data were obtained by providing meals.

Low carbohydrate high fat-diet in real life assessed by diet history interviews

BACKGROUND

Low carbohydrate high fat (LCHF) diet has been a popular low carbohydrate diet in Sweden for 15 years. Many people choose LCHF to lose weight or control diabetes, but there are concerns about the effect on long-term cardiovascular risks. There is little data on how a LCHF diet is composed in real-life. The aim of this study was to evaluate the dietary intake in a population with self-reported adherence to a LCHF diet.

METHODS

A cross-sectional study of 100 volunteers that considered themselves eating LCHF was conducted. Diet history interviews (DHIs) and physical activity monitoring for validation of the DHIs were performed.

RESULTS

The validation shows acceptable agreement of measured energy expenditure and reported energy intake. Median carbohydrate intake was 8.7 E% and 63% reported carbohydrate intake at potentially ketogenic levels. Median protein intake was 16.9 E%. The main source of energy was dietary fats (72.0 E%). Intake of saturated fat was 32 E% and cholesterol was 700 mg per day, both of which exceeded the recommended upper limits according to nutritional guidelines. Intake of dietary fiber was very low in our population. The use of dietary supplements was high, and it was more common to exceed the recommended upper limits of micronutrients than to have an intake below the lower limits.

CONCLUSIONS

Our study indicates that in a well-motivated population, a diet with very low carbohydrate intake can be sustained over time and without apparent risk of deficiencies. High intake of saturated fats and cholesterol as well as low intake of dietary fiber remains a concern.

Severe Dyslipidemia Mimicking Familial Hypercholesterolemia Induced by High-Fat, Low-Carbohydrate Diets: A Critical Review

Emerging studies in the literature describe an association between high-fat, low-carbohydrate diets and severe hypercholesterolemia consistent with the levels observed in patients with (homozygous) familial hypercholesterolemia (FH). High levels of low-density lipoprotein cholesterol (LDL-C) may result from the reduced clearance of LDL particles from the circulation, the increased production of their precursor, or a combination of both. The increased intake of (saturated) fat and cholesterol, combined with limited to no intake of carbohydrates and fiber, are the main features of diets linked to hypercholesterolemia. However, several observations in previous studies, together with our observations from our lipid clinic, do not provide a definitive pathophysiological explanation for severe hypercholesterolemia. Therefore, we review these findings and possible pathophysiological explanations as well as opportunities for future research. Altogether, clinicians should rule out high-fat, low-carbohydrate diets as a possible cause for hypercholesterolemia in patients presenting with clinical FH in whom no mutation is found and discuss dietary modifications to durably reduce LDL-C levels and cardiovascular disease risk.

Safety of Sirolimus in Patients with Tuberous Sclerosis Complex under Two Years of Age-A Bicenter Retrospective Study

BACKGROUND

mTOR inhibitors are a novel pharmacotherapy recommended for subependymal giant astrocytomas, refractory epilepsy, and the treatment of the other clinical manifestations of tuberous sclerosis complex (TSC). Clinical trials on everolimus proved it to be effective and safe in children. Despite its common use in clinical practice, the research on sirolimus is limited. This study is the first to determine and assess the severity of the adverse effects (AEs) of sirolimus administered to children with TSC under two years of age.

METHODS

We performed a bicenter retrospective data analysis of medical records of individuals with TSC who initiated therapy with sirolimus under the age of two.

RESULTS

Twenty-one patients were included in the study. At least one AE was reported in all participants. The most prevalent AEs were anemia, thrombocytosis, and hyperlipidemia. Infections and mouth ulcerations, often reported in the studies on older patients, were infrequent and of mild or moderate grade.

CONCLUSIONS

Adverse effects associated with sirolimus use in infants and young children with TSC are frequent yet not life- or health-threatening. Further multicenter prospective clinical trials should determine the long-term safety of sirolimus.

Dietary management of dyslipidemia and the impact of dietary patterns on lipid disorders

Dyslipidemia is a major risk factor for atherosclerotic cardiovascular disease and a healthy lifestyle is the first line of therapy for treatment. A healthy dietary pattern is a cornerstone for treating elevated low-density lipoprotein-cholesterol (LDL-C) and triglycerides (TG), both of which are hallmarks of dyslipidemia. Much research has been conducted evaluating the effect of different dietary patterns on LDL-C and TG, both eucalorically and with weight loss. Herein we review studies that have evaluated the effects of different dietary patterns on LDL-C and TG. Within the context of a healthy dietary pattern, constituent food and nutrient intakes impact LDL-C and TG lowering. Food- and nutrient-based recommendations for lowering both LDL-C and TG, will also be reviewed. Finally, the suitability of popular diets for patients with dyslipidemia will be discussed. Lifestyle interventions, including dietary intervention, should be individualized and customized to patient preferences to achieve clinically relevant lipid/lipoprotein improvements.

Statin therapy is not warranted for a person with high LDL-cholesterol on a low-carbohydrate diet

PURPOSE OF REVIEW

Although there is an extensive literature on the efficacy of the low carbohydrate diet (LCD) for weight loss and in the management of type 2 diabetes, concerns have been raised that the LCD may increase cardiovascular disease (CVD) risk by increasing the level of low-density lipoprotein cholesterol (LDL-C). We have assessed the value of LDL-C as a CVD risk factor, as well as effects of the LCD on other CVD risk factors. We have also reviewed findings that provide guidance as to whether statin therapy would be beneficial for individuals with high LDL-C on an LCD.

RECENT FINDINGS

Multiple longitudinal trials have demonstrated the safety and effectiveness of the LCD, while also providing evidence of improvements in the most reliable CVD risk factors. Recent findings have also confirmed how ineffective LDL-C is in predicting CVD risk.

SUMMARY

Extensive research has demonstrated the efficacy of the LCD to improve the most robust CVD risk factors, such as hyperglycemia, hypertension, and atherogenic dyslipidemia. Our review of the literature indicates that statin therapy for both primary and secondary prevention of CVD is not warranted for individuals on an LCD with elevated LDL-C who have achieved a low triglyceride/HDL ratio.

Short-term hyper-caloric high-fat feeding on a ketogenic diet can lower low-density lipoprotein cholesterol: the cholesterol drop experiment

PURPOSE OF REVIEW

Conventional knowledge holds that saturated fat is the primary dietary driver of increases in low-density lipoprotein-cholesterol (LDL-C), and that high LDL-C seen among some persons consuming low-carbohydrate, high-fat diets is driven by increased saturated fat intake. This simple paradigm cannot account for the lipid patterns, nor for the magnitude of effect, observed in 'lean mass hyper-responders' on low-carbohydrate diets. The Lipid Energy Model (LEM) provides an alternative explanation for LDL-C increases seen in persons without obesity who adopt ketogenic diets and makes testable predictions, including that acute overfeeding, including increased saturated fat consumption, would decrease LDL-C levels.

RECENT FINDINGS

This study reports data from an n  = 1 experiment, performed in duplicate, in which the subject consumed three ketogenic diets for 5 days that varied in caloric content: weight-maintenance (2278 kcal/day), hypo-caloric (1135 kcal/day), and hyper-caloric (4116 kcal/day). Consistent with the LEM, LDL-C and apolipoprotein B increased following caloric restriction and decreased following overfeeding, despite increased saturated fat consumption. Data from a case series of 24 individuals who underwent similar protocols similarly found that overfeeding on a ketogenic diet decreased LDL-C.

SUMMARY

This n = 1 study and associated case series provide data that short-term overfeeding can lower LDL-C in the context of carbohydrate restriction.

Plant-Based and Ketogenic Diets As Diverging Paths to Address Cancer: A Review

Importance

As the incidence of cancer and metabolic disorders, such as obesity, concurrently rise, there has been increasing awareness of the pervasive effect of nutrition. The whole foods plant-based diet (WFPBD) and ketogenic diet (KD) have gained popularity in oncology, and this topic is increasingly permeating clinical dialogue.

Observations

Dietary intake is associated with multiple pathways involved in carcinogenesis and tumor progression. Consumption of a plant-enriched diet is associated with reduced cancer incidence and is recommended by dietary guidelines for cancer prevention. Despite a starkly different nutrient composition, a WFPBD and KD can be associated with weight loss, decreased inflammation, and decreased insulin levels. In addition, a WFPBD is associated with increased fiber, phytochemicals, and butyrate levels and decreased insulin-like growth factor 1 levels, whereas a KD exerts potential anticancer effects by increasing β hydroxybutyrate levels. A KD may be of interest in select, less common settings, such as tumors treated with phosphatidylinositol 3-kinase inhibitors, which induce hyperinsulinemia and hyperglycemia. Completed interventional trials have focused on increasing fruit and vegetable intake or reducing fat intake but have not specifically tested WFPBD or KD for cancer prevention or treatment. Currently available data support plant-based diets as opposed to KD as part of a lifestyle associated with reduced cancer risk. In the postdiagnosis setting, there are currently no rigorously tested approaches that support the recommendation of any diet to treat cancer.

Conclusions and Relevance

The results of this review suggest that the collective evidence supports plant-enriched diets vs KD for the reduction of cancer risk and the improvement of metabolic disorders in survivors. Additional prospective randomized clinical trials are needed to encourage use of dietary modification across the cancer continuum. Rigorous trial designs that adapt classical oncologic end points may identify populations that are likely to benefit from starkly contrasting diets. Current data support prioritization of plant-based diets, and future data could further personalize dietary recommendations in cancer populations.

The Lipid Energy Model: Reimagining Lipoprotein Function in the Context of Carbohydrate-Restricted Diets

When lean people adopt carbohydrate-restricted diets (CRDs), they may develop a lipid profile consisting of elevated LDL-cholesterol (LDL-C) and HDL-cholesterol (HDL-C) with low triglycerides (TGs). The magnitude of this lipid profile correlates with BMI such that those with lower BMI exhibit larger increases in both LDL-C and HDL-C. The inverse association between BMI and LDL-C and HDL-C change on CRD contributed to the discovery of a subset of individuals—termed Lean Mass Hyper-Responders (LMHR)—who, despite normal pre-diet LDL-C, as compared to non-LMHR (mean levels of 148 and 145 mg/dL, respectively), exhibited a pronounced hyperlipidemic response to a CRD, with mean LDL-C and HDL-C levels increasing to 320 and 99 mg/dL, respectively, in the context of mean TG of 47 mg/dL. In some LMHR, LDL-C levels may be in excess of 500 mg/dL, again, with relatively normal pre-diet LDL-C and absent of genetic findings indicative of familial hypercholesterolemia in those who have been tested. The Lipid Energy Model (LEM) attempts to explain this metabolic phenomenon by positing that, with carbohydrate restriction in lean persons, the increased dependence on fat as a metabolic substrate drives increased hepatic secretion and peripheral uptake of TG contained within very low-density lipoproteins (VLDL) by lipoprotein lipase, resulting in marked elevations of LDL-C and HDL-C, and low TG. Herein, we review the core features of the LEM. We review several existing lines of evidence supporting the model and suggest ways to test the model’s predictions.

Modulation of Dyslipidemia Markers Apo B/Apo A and Triglycerides/HDL-Cholesterol Ratios by Low-Carbohydrate High-Fat Diet in a Rat Model of Metabolic Syndrome

Metabolic syndrome (MetS) risks cardiovascular diseases due to its associated Dyslipidemia. It is proposed that a low-carbohydrate, high-fat (LCHF) diet positively ameliorates the MetS and reverses insulin resistance. Therefore, we aimed to investigate the protecting effect of the LCHF diet on MetS-associated Dyslipidemia in an experimental animal model. Forty male Sprague-Dawley rats were divided into four groups (10/group): the control group, dexamethasone-induced MetS (DEX) (250 µg/kg/day), LCHF-fed MetS group (DEX + LCHF), and High-Carbohydrate-Low-Fat-fed MetS group (DEX + HCLF). At the end of the four-week experiment, fasting glucose, insulin, lipid profile (LDL-C, HDL-C, Triglyceride), oxidized-LDL, and small dense-LDL using the ELISA technique were estimated. HOMA-IR, Apo B/Apo A1 ratio, and TG/HDL were calculated. Moreover, histological examination of the liver by H & E and Sudan III stain was carried out. In the DEX group, rats showed a significant (p < 0.05) increase in the HOMA-IR, atherogenic parameters, such as s-LDL, OX-LDL, Apo B/Apo A1 ratio, and TG/HDL. The LCHF diet significantly improved the parameters of Dyslipidemia (p < 0.05) by decreasing the Apo B/Apo A1 and TG/HDL-C ratios. Decreased steatosis in LCHF-fed rats compared to HCLF was also revealed. In conclusion, the LCHF diet ameliorates MetS-associated Dyslipidemia, as noted from biochemical results and histological examination.

The Effects of Carbohydrate versus Fat Restriction on Lipid Profiles in Highly Trained, Recreational Distance Runners: A Randomized, Cross-Over Trial

A growing number of endurance athletes have considered switching from a traditional high-carbohydrate/low-fat (HCLF) to a low-carbohydrate/high-fat (LCHF) eating pattern for health and performance reasons. However, few studies have examined how LCHF diets affect blood lipid profiles in highly-trained runners. In a randomized and counterbalanced, cross-over design, athletes (n = 7 men; VO2max: 61.9 ± 6.1 mL/kg/min) completed six weeks of two, ad libitum, LCHF (6/69/25% en carbohydrate/fat/protein) and HCLF (57/28/15% en carbohydrate/fat/protein) diets, separated by a two-week washout. Plasma was collected on days 4, 14, 28, and 42 during each condition and analyzed for: triglycerides (TG), LDL-C, HDL-C, total cholesterol (TC), VLDL, fasting glucose, and glycated hemoglobin (HbA1c). Capillary blood beta-hydroxybutyrate (BHB) was monitored during LCHF as a measure of ketosis. LCHF lowered plasma TG, VLDL, and TG/HDL-C (all p < 0.01). LCHF increased plasma TC, LDL-C, HDL-C, and TC/HDL-C (all p < 0.05). Plasma glucose and HbA1c were unaffected. Capillary BHB was modestly elevated throughout the LCHF condition (0.5 ± 0.05 mmol/L). Healthy, well-trained, normocholesterolemic runners consuming a LCHF diet demonstrated elevated circulating LDL-C and HDL-C concentrations, while concomitantly decreasing TG, VLDL, and TG/HDL-C ratio. The underlying mechanisms and implications of these adaptive responses in cholesterol should be explored.

Elevated LDL Cholesterol with a Carbohydrate-Restricted Diet: Evidence for a "Lean Mass Hyper-Responder" Phenotype

BACKGROUND

People commencing a carbohydrate-restricted diet (CRD) experience markedly heterogenous responses in LDL cholesterol, ranging from extreme elevations to reductions.

OBJECTIVES

The aim was to elucidate possible sources of heterogeneity in LDL cholesterol response to a CRD and thereby identify individuals who may be at risk for LDL cholesterol elevation.

METHODS

Hypothesis-naive analyses were conducted on web survey data from 548 adults consuming a CRD. Univariate and multivariate regression models and regression trees were built to evaluate the interaction between body mass index (BMI) and baseline lipid markers. Data were also collected from a case series of five clinical patients with extremely high LDL cholesterol consuming a CRD.

RESULTS

BMI was inversely associated with LDL cholesterol change. Low triglyceride (TG) to HDL cholesterol ratio, a marker of good metabolic health, predicted larger LDL cholesterol increases. A subgroup of respondents with LDL cholesterol ≥200 mg/dL, HDL cholesterol ≥80 mg/dL, and TG ≤70 mg/dL were characterized as "lean mass hyper-responders." Respondents with this phenotype (n = 100) had a lower BMI and, remarkably, similar prior LDL cholesterol versus other respondents. In the case series, moderate reintroduction of carbohydrate produced a marked decrease in LDL cholesterol.

CONCLUSIONS

These data suggest that, in contrast to the typical pattern of dyslipidemia, greater LDL cholesterol elevation on a CRD tends to occur in the context of otherwise low cardiometabolic risk.

Effects of a Non-Energy-Restricted Ketogenic Diet on Clinical Oral Parameters. An Exploratory Pilot Trial

Ketogenic diets (KDs) may be a helpful complement in the prevention of and therapy for several diseases. Apart from their non-cariogenic properties, it is still unclear how KDs affect oral parameters. The aim of this study was to investigate the influence of a KD on clinical periodontal parameters. Twenty generally healthy volunteers with an average age of 36.6 years underwent a KD for 6 weeks. Their compliance was monitored by measuring their urinary ketones daily and by keeping 7-day food records. Clinical oral parameters included plaque (PI), gingival inflammation (GI), a complete periodontal status (probing depths, bleeding on probing), and general physical and serologic parameters at baseline and after 6 weeks. The results showed a trend towards lower plaque values, but with no significant changes from baseline to the end of the study with regard to the clinical periodontal parameters. However, their body weight and BMI measurements showed a significant decrease. The regression analyses showed that the fat mass and the BMI were significantly positively correlated to periodontal inflammation, while HDL, fiber, and protein intake were negatively correlated to periodontal inflammation. The KD change did not lead to clinical changes in periodontal parameters in healthy participants under continued oral hygiene, but it did lead to a significant weight loss.

The effects of fat consumption on low-density lipoprotein particle size in healthy individuals: a narrative review

Cardiovascular disease (CVD) is the number one contributor to death in the United States and worldwide. A risk factor for CVD is high serum low-density lipoprotein cholesterol (LDL-C) concentrations; however, LDL particles exist in a variety of sizes that may differentially affect the progression of CVD. The small, dense LDL particles, compared to the large, buoyant LDL subclass, are considered to be more atherogenic. It has been suggested that replacing saturated fatty acids with monounsaturated and polyunsaturated fatty acids decreases the risk for CVD. However, certain studies are not in agreement with this recommendation, as saturated fatty acid intake did not increase the risk for CVD, cardiovascular events, and/or mortality. Furthermore, consumption of saturated fat has been demonstrated to increase large, buoyant LDL particles, which may explain, in part, for the differing outcomes regarding fat consumption on CVD risk. Therefore, the objective was to review intervention trials that explored the effects of fat consumption on LDL particle size in healthy individuals. PubMed and Web of Science were utilized during the search process for journal articles. The results of this review provided evidence that fat consumption increases large, buoyant LDL and/or decreases small, dense LDL particles, and therefore, influences CVD risk.

Metabolism-based therapies for epilepsy: new directions for future cures

OBJECTIVE

Thousands of years after dietary therapy was proposed to treat seizures, how alterations in metabolism relates to epilepsy remains unclear, and metabolism-based therapies are not always effective.

METHODS

We consider the state of the science in metabolism-based therapies for epilepsy across the research lifecycle from basic to translational to clinical studies.

RESULTS

This analysis creates a conceptual framework for creative, rigorous, and transparent research to benefit people with epilepsy through the understanding and modification of metabolism.

INTERPRETATION

Despite intensive past efforts to evaluate metabolism-based therapies for epilepsy, distinct ways of framing a problem offer the chance to engage different mindsets and new (or newly applied) technologies. A comprehensive, creative, and inclusive problem-directed research agenda is needed, with a renewed and stringent adherence to rigor and transparency across all levels of investigation.

Reply to Ravnskov, U. Is High Cholesterol Deleterious? An Alternative Point of View. Comment on "Burén et al. A Ketogenic Low-Carbohydrate High-Fat Diet Increases LDL Cholesterol in Healthy, Young, Normal-Weight Women: A Randomized Controlled Feeding Trial. Nutrients 2021, 13, 814"

We thank Ravnskov [...].

Is High Cholesterol Deleterious? An Alternative Point of View. Comment on Burén et al. A Ketogenic Low-Carbohydrate High-Fat Diet Increases LDL Cholesterol in Healthy, Young, Normal-Weight Women: A Randomized Controlled Feeding Trial. Nutrients 2021, 13, 814

In their study of the effect of an LCHF-diet on blood lipids, Burén et al. [...].

High-Fat Diet Increases Serum HDL, but Not for LDL and HDL/LDL Ratio in MICE

The use of a ketogenic diet with an increased proportion of fat is rampant lately, both as a therapy or even lifestyle. The use of a ketogenic diet is feared to cause dyslipidemia. It will also lead to atherosclerosis and thrombosis. This study aimed to determine the effect of a high-fat diet on HDL, LDL, and HDL/LDL ratio in mice. Thirty male Mus Musculus, 2-3 mo, 15-25 g divided into five groups diet. K1 (12% fat, 20% protein, 62% carb), K2 (30% fat, 60%protein), K3 (45% fat, 45% protein), K4 (60% fat, 30% protein) and K5 (75% fat, 15% protein) for 4 weeks. Feed and water by adlibitum. Blood for serum was taken from the ventricle, while in the measurement of HDL serum level, the LDL used ELISA. Normality of data analyzed by Shapiro Wilk, and homogeneity by Levene test. HDL serum was analyzed using equality test followed by Games Howell, LDL serum and ratio of HDL/LDL was tested by ANOVA followed by LSD with significance 0,05. HDL serum in K1 (62,50±9.94) mg/dL, K2 (78,40±18,76) mg/dL, K3 (79,00±3,81) mg/dL, K4 (80,00±2,16) mg/dL, and K5 (83,50±5,62) mg/dL with p<0,05 in K1, K2 to K3, K4 and K5. LDL serum in K1 (21,67± 4,80) mg/dL, K2 (23,00±12,70) mg/dL, K3 (18,40±4,34) mg/dL, K4 (24,00 ±1,83) mg/dL and K5 (22,00 ± 4,08) mg/dL with p>0,05. Ratio HDL/LDL K1 (3,01±0,91), K2 (4,10±1,86), K3 (4,53±1,5), K4 (3,35±0,34), and K5 (3,96 ± 1,25) with p>0,05.