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 ß-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.

A Multi-Omics Approach to Disclose Metabolic Pathways Impacting Intestinal Permeability in Obese Patients Undergoing Very Low Calorie Ketogenic Diet.

A very low calorie ketogenic diet (VLCKD) impacts host metabolism in people marked by an excess of visceral adiposity, and it affects the microbiota composition in terms of taxa presence and relative abundances. As a matter of fact, there is little available literature dealing with microbiota differences in obese patients marked by altered intestinal permeability. With the aim of inspecting consortium members and their related metabolic pathways, we inspected the microbial community profile, together with the set of volatile organic compounds (VOCs) from untargeted fecal and urine metabolomics, in a cohort made of obese patients, stratified based on both normal and altered intestinal permeability, before and after VLCKD administration. Based on the taxa relative abundances, we predicted microbiota-derived metabolic pathways whose variations were explained in light of our cohort symptom picture. A totally different number of statistically significant pathways marked samples with altered permeability, reflecting an important shift in microbiota taxa. A combined analysis of taxa, metabolic pathways, and metabolomic compounds delineates a set of markers that is useful in describing obesity dysfunctions and comorbidities.

Intermittent fasting, calorie restriction, and a ketogenic diet improve mitochondrial function by reducing lipopolysaccharide signaling in monocytes during obesity: A randomized clinical trial.

BACKGROUND: Mitochondrial dysfunction occurs in monocytes during obesity and contributes to a low-grade inflammatory state; therefore, maintaining good mitochondrial conditions is a key aspect of maintaining health. Dietary interventions are primary strategies for treating obesity, but little is known about their impact on monocyte bioenergetics. Thus, the aim of this study was to evaluate the effects of calorie restriction (CR), intermittent fasting (IF), a ketogenic diet (KD), and an ad libitum habitual diet (AL) on mitochondrial function in monocytes and its modulation by the gut microbiota. METHODS AND FINDINGS: A randomized controlled clinical trial was conducted in which individuals with obesity were assigned to one of the 4 groups for 1 month. Subsequently, the subjects received rifaximin and continued with the assigned diet for another month. The oxygen consumption rate (OCR) was evaluated in isolated monocytes, as was the gut microbiota composition in feces and anthropometric and biochemical parameters. Forty-four subjects completed the study, and those who underwent CR, IF and KD interventions had an increase in the maximal respiration OCR (p = 0.025, n2p = 0.159 [0.05, 0.27] 95% confidence interval) in monocytes compared to that in the AL group. The improvement in mitochondrial function was associated with a decrease in monocyte dependence on glycolysis after the IF and KD interventions. Together, diet and rifaximin increased the gut microbiota diversity in the IF and KD groups (p = 0.0001), enriched the abundance of Phascolarctobacterium faecium (p = 0.019) in the CR group and Ruminococcus bromii (p = 0.020) in the CR and KD groups, and reduced the abundance of lipopolysaccharide (LPS)-producing bacteria after CR, IF and KD interventions compared to the AL group at the end of the study according to ANCOVA with covariate adjustment. Spearman's correlation between the variables measured highlighted LPS as a potential modulator of the observed effects. In line with this findings, serum LPS and intracellular signaling in monocytes decreased with the three interventions (CR, p = 0.002; IF, p = 0.001; and KD, p = 0.001) compared to those in the AL group at the end of the study. CONCLUSIONS: We conclude that these dietary interventions positively regulate mitochondrial bioenergetic health and improve the metabolic profile of monocytes in individuals with obesity via modulation of the gut microbiota. Moreover, the evaluation of mitochondrial function in monocytes could be used as an indicator of metabolic and inflammatory status, with potential applications in future clinical trials. TRIAL REGISTRATION: This trial was registered with ClinicalTrials.gov (NCT05200468).

Ketogenic diet therapy leads to antiseizure medication reduction in children and adults with drug-resistant epilepsy.

AIMS: This study aimed to evaluate the safety of reducing or withdrawing anti-seizure medications (ASMs) in a cohort comprising both adults and children with drug-resistant epilepsy (DRE) undergoing ketogenic diet therapy (KDT). METHODS: We conducted a comprehensive analysis of clinical profiles in adults and children with DRE who had adhered to KDT for at least 6 months. Successful withdrawal or reduction of an ASM was defined as discontinuation or dose reduction without subsequent resumption or increase and without initiation of any new ASM throughout the entire follow-up period. Changes in the ASM load were calculated specifically for adult patients. RESULTS: The study enrolled 56 participants (34 children and 22 adults) with DRE, with 64.3% achieving successful withdrawal of at least one ASM. The probability of ASM withdrawal remained consistent for children (64.7%) versus adults (63.6%), as well as for responders (62.5%) versus non-responders (68.8%), and it was not associated with other clinical factors. Early ASM reduction (including withdrawal) after diet initiation occurred in 15 patients (26.8%), with treatment outcomes comparable to those of the remaining participants. Among the 22 adults, the mean values of ASM load reduced by 24.5%, with a similar magnitude observed for responders (24.2%) versus non-responders (25.1%). In addition, adults tend to have a slower elevation in serum ketone levels compared to children. CONCLUSION: This study demonstrates the safe achievability of ASM withdrawal through KDT in most patients with DRE, irrespective of age or seizure frequency reduction.

Investigating the Effectiveness of a Carb-Free Oloproteic Diet in Fibromyalgia Treatment.

Fibromyalgia (FM), a chronic disease with a high incidence in women, poses a significant challenge for diagnosis and treatment, especially due to the absence of specific biomarkers and the multifaceted nature of its symptoms, which range from neuromuscular pain to mood disorders and intestinal dysbiosis. While diagnosis currently relies on rheumatological clinical evaluations and treatment options mainly focus on symptom management, FM seems to have possible links with systemic metabolic dysfunctions with a common inflammatory root. In this context, a new therapeutic avenue emerges: could a therapeutic nutritional approach be the missing piece of the puzzle? Indeed, diet therapies employed particularly for metabolic syndromes proved recently to be efficacious for correcting systemic dysmetabolism and a high number of chronic inflammation conditions. In particular, the very-low-calorie ketogenic diet (VLCKD) demonstrated therapeutic benefits in many disorders. In the present study, we aimed to investigate the specific effects of two dietary interventions, namely the oloproteic VLCKD and the low-glycemic insulinemic (LOGI) diet, on two groups of female FM patients (FM1 and FM2) over a 45-day period. Utilizing clinical and laboratory tests, as well as non-invasive NMR metabolomic analysis of serum, urine, and saliva samples, we sought to uncover how these dietary regimens impact the metabolic dysfunctions associated with FM.

Simplification of Dietary Treatment in Pharmacoresistant Epilepsy: Impact of C8 and C10 Fatty Acids on Sirtuins of Neuronal Cells In Vitro.

Pharmacotherapy is the therapeutic mainstay in epilepsy; however, in about 30% of patients, epileptic seizures are drug-resistant. A ketogenic diet (KD) is an alternative therapeutic option. The mechanisms underlying the anti-seizure effect of a KD are not fully understood. Epileptic seizures lead to an increased energy demand of neurons. An improvement in energy provisions may have a protective effect. C8 and C10 fatty acids have been previously shown to activate mitochondrial function in vitro. This could involve sirtuins (SIRTs) as regulatory elements of energy metabolism. The aim of the present study was to investigate whether ß-hydroxybutyrate (ßHB), C8 fatty acids, C10 fatty acids, or a combination of C8 and C10 (250/250 µM) fatty acids, which all increase under a KD, could up-regulate SIRT1, -3, -4, and -5 in HT22 hippocampal murine neurons in vitro. Cells were incubated for 1 week in the presence of these metabolites. The sirtuins were measured at the enzyme (fluorometrically), protein (Western blot), and gene expression (PCR) levels. In hippocampal cells, the C8, C10, and C8 and C10 incubations led to increases in the sirtuin levels, which were not inferior to a ßHB incubation as the 'gold standard'. This may indicate that both C8 and C10 fatty acids are important for the antiepileptic effect of a KD. A KD may be replaced by nutritional supplements of C8 and C10 fatty acids, which could facilitate the diet.

The Assessment of the Efficacy, Safety, and Challenges of Ketogenic Diet Therapy in Children with Epilepsy: The First Experience of a Single Center.

Background and Objectives: Ketogenic diet therapy (KDT) has been used as a non-pharmacological treatment for childhood refractory epilepsy. Its efficacy and safety have been described in numerous studies and reviews. However, there have been fewer studies evaluating the challenges experienced by patients and their family members when starting KDT. When implementing a new treatment method, challenges arise for both the healthcare professionals and patients, making it important to summarize the initial results and compare them with the experiences of other centers. To analyze and evaluate the efficacy and safety of KDT in children with epilepsy, as well as to consider the challenges faced by their parents/caregivers. Materials and Methods: A retrospective analysis of patients' data (N = 30) and an analysis of the completed questionnaires of the parents/caregivers (N = 22) occurred. Results: In the study group, 66.7% of the patients had a >50% decrease in seizure frequency, and 2/3 of them had a >90% decrease in seizure frequency or were seizure-free, which enabled reducing the anti-seizure medications in 36.4% of the patients, as well as reducing the hospital visits. Cognitive improvement and better alertness were subjectively reported by 59.1% of the parents/caregivers. No dangerous long-term adverse effects of KDT have been observed in the study group. The patients with generalized epilepsy experienced significantly more adverse events. Most of the adverse effects of KDT were related to the digestive system, but usually they were temporary and controllable. The challenges of the parents/caregivers were mostly related to social life issues and financial difficulties; the medical-related challenges were minimal. Conclusions: KDT is an effective and safe treatment option for children with drug-resistant epilepsy, and the challenges faced by families are resolvable. In order to ensure effective KDT, a multidisciplinary team is required. This would ensure smooth and comprehensive care and the timely resolution of emerging problems. The cooperation of the families undergoing KDT is also important, enabling them to share their experiences.

Efficacy and tolerability of classical and polyunsaturated fatty acids ketogenic diet in controlling paediatric refractory epilepsy - A randomized study.

OBJECTIVES: To measure and compare the efficacy and tolerability of a classical ketogenic diet (CKD) and a polyunsaturated fatty acids ketogenic diet (PUFAKD) in managing childhood refractory epilepsy. Efficacy was assessed by measuring the change in seizure frequency at 3, 6, 9, and 12 months within and between groups. The percentage reduction in seizures at <50 %, 50-90 %, >90 %, and 100 % was also measured. Tolerability was assessed and compared by recording adverse events - vomiting, nausea, lethargy, and constipation. METHODS: 52 children, aged 2-10 years, were randomized, 25 in the CKD group and 27 in the PUFAKD group. Fat: carbohydrate + protein ratio of 2.2:1-4:1 was maintained in both diets; the PUFAKD group only used unsaturated fats with an omega 3: omega 6 ratio of 1:2.8. Ketone levels were measured using keto-dipsticks, with 4+ and 4++ (80-160 mg/dL) being the most optimal values. RESULTS: A significant decrease (p=0.001) in seizures was observed (n=52), with no significant difference (p=0.537) between the two groups. The mean seizure reduction was 71.1 %, with no significant difference (p=0.488) in both groups. The mean compliance rate was 78.3 % (n=52). A statistically significant linear trend existed between a higher compliance rate and a greater reduction in seizures (p = 0.042, Z=4.039) among all children (n=52). Nausea (p=0.033) and vomiting (p=0.014) occurred more in PUFAKD than in CKD. CONCLUSION: No significant difference was seen in seizure reduction between the two groups. Compliance correlates with a greater seizure reduction. Despite similar seizure reduction rates, the novel PUFAKD exhibited poorer compliance and more pronounced adverse effects compared to CKD. CKD remained a superior choice over the novel PUFAKD in the management of paediatric refractory epilepsy. More controlled trials with varying PUFA compositions are recommended for long-term evaluations.

Ketogenic diet administration later in life improves memory by modifying the synaptic cortical proteome via the PKA signaling pathway in aging mice.

Aging compromises brain function leading to cognitive decline. A cyclic ketogenic diet (KD) improves memory in aged mice after long-term administration; however, short-term effects later in life and the molecular mechanisms that govern such changes remain unclear. Here, we explore the impact of a short-term KD treatment starting at elderly stage on brain function of aged mice. Behavioral testing and long-term potentiation (LTP) recordings reveal that KD improves working memory and hippocampal LTP. Furthermore, the synaptosome proteome of aged mice fed a KD long-term evidence changes predominantly at the presynaptic compartment associated to the protein kinase A (PKA) signaling pathway. These findings were corroborated in vivo by western blot analysis, with high BDNF abundance and PKA substrate phosphorylation. Overall, we show that a KD modifies brain function even when it is administered later in life and recapitulates molecular features of long-term administration, including the PKA signaling pathway, thus promoting synaptic plasticity at advanced age.

Mediterranean ketogenic diet accounts for reduced pain frequency and intensity in patients with chronic migraine: A pilot study.

BACKGROUND: An increasing amount of evidence suggests that migraine is a response to cerebral energy deficiencies or oxidative stress levels that exceed antioxidant capacity. Current pharmacological options are inadequate in treating patients with chronic migraine, and a growing interest focuses on nutritional approaches as non-pharmacological treatments. The ketogenic diet, mimicking fasting that leads to an elevation of ketone bodies, is a therapeutic intervention targeting cerebral metabolism that has recently shown great promise in the prevention of migraines. Moreover, Mediterranean elements like vegetables, nuts, herbs, spices, and olive oil that are sources of anti-inflammatory elements (omega-3 fatty acids, polyphenols, vitamins, essential minerals, and probiotics) may create a positive brain environment by reducing imbalance in the gut microbiome. METHODS: On the basis of these indications, a combined Mediterranean-ketogenic diet was administered to chronic migraine patients for 4 (T1) and 8 weeks (T2), and anthropometric estimations were collected at T1 and T2 while biochemical parameters at only T2. RESULTS: A significant reduction (p < 0.01) in migraine frequency and intensity was detected as early as 4 weeks of dietary intervention, which was associated with a reduced fat mass (p < 0.001) as well as Homa index (p < 0.05) and insulin levels (p < 0.01) after 8 weeks. CONCLUSION: Overall, Mediterranean-ketogenic diet may be considered an effective non-pharmacological intervention for migraine, with positive outcomes on body composition.

Potential therapeutic effect of a ketogenic diet for the treatment of lymphoedema: Results of an exploratory study.

BACKGROUND: Lymphoedema is a chronic and progressive disease characterised by excessive accumulation of lymph in the interstitial compartment, leading to tissue swelling and fibroadipose deposition. Lymphangiogenesis is partly regulated by ketone body oxidation, and a ketogenic diet (KD) has shown therapeutic efficacy in a preclinical mouse tail lymphoedema model. Therefore, we aimed to investigate the potential therapeutic effect of a KD in patients with secondary lymphoedema. METHODS: Nine patients with unilateral stage 2 lymphoedema secondary to lymphadenectomy were included in this quasi-experimental exploratory study consisting of a short run-in phase to gradually induce ketosis, followed by a classic KD (CKD) and modified Atkins diet (MAD) phase during which patients consumed a CKD and MAD, respectively. Lymphatic function and oedema volume, the primary outcomes, were assessed at baseline and at the end of both the CKD and MAD phase. Secondary outcomes included health-related and lymphedema-specific quality of life (QoL). RESULTS: Seven out of nine patients completed the study protocol. Lymphatic function was improved upon consumption of both a CKD (dermal backflow score [mean ± SD]: 7.29 ± 2.98 vs. 10.86 ± 2.19 at baseline; p = 0.03) and MAD (6.71 ± 2.06; p = 0.02), whereas oedema volume did not decrease during the course of the study (excess limb volume [mean ± SD]: 20.13 ± 10.25% at end of CKD and 24.07 ± 17.77% at end of MAD vs. 20.79 ± 12.96% at baseline; p > 0.99 and p > 0.30, respectively). No changes were observed in health-related, nor lymphoedema-specific QoL at the end of CKD and MAD. CONCLUSIONS: The consumption of a KD improved lymphatic function and was associated with a clinically meaningful reduction in oedema volume in some patients (3/7 at end of CKD, 2/7 at end of MAD) with unilateral stage 2 secondary lymphoedema. These results highlight the potential of a KD to improve lymphatic function in patients with lymphoedema. However, further studies are required to substantiate our findings.

Effective reduction in seizure severity and prevention of a fatty liver by a novel low ratio ketogenic diet composition in the rapid kindling rat model of epileptogenesis.

Drug-resistant epilepsy patients may benefit from non-pharmacological therapies, such as the ketogenic diet (KD). However, its high fat content poses compliance challenges and metabolic risks. To mitigate this, we developed a novel KD composition with less fat and additional nutrients (citrate, nicotinamide riboside, and omega-3 fatty acids) for ketone-independent neuroprotection. The efficacy, metabolic and neuropathological effects of the novel KD and a classic KD were compared to a control diet in the rapid kindling model of temporal lobe epilepsy. Both KD groups entered ketosis before kindling onset, with higher ketone levels in the classic KD group. Remarkably, rats on the novel KD had slower progression of behavioral seizures as compared to rats on a control diet, while this was not the case for rats on a classic KD. Both KDs reduced electrographic after-discharge duration, preserved neurons in the dorsal hippocampus, and normalized activity in open field tests. The novel KD, despite lower fat and ketone levels, demonstrated effective reduction of behavioral seizure severity while the classic KD did not, suggesting alternative mode(s) of action are involved. Additionally, the novel KD significantly mitigated liver triglyceride and plasma fatty acid levels compared to the classic KD, indicating a reduced risk of long-term liver steatosis. Our findings highlight the potential of the novel KD to enhance therapeutic efficacy and compliance in epilepsy patients.

The use of ketogenic diets in children living with drug-resistant epilepsy, glucose transporter 1 deficiency syndrome and pyruvate dehydrogenase deficiency: A scoping review.

BACKGROUND: The ketogenic diet (KD) is a high fat, moderate protein and very low carbohydrate diet. It can be used as a medical treatment for drug-resistant epilepsy (DRE), glucose transporter 1 deficiency syndrome and pyruvate dehydrogenase deficiency. The aim of this scoping review was to map the KD literature, with a focus on epilepsy and associated metabolic conditions, to summarise the current evidence-base and identify any gaps. METHODS: This review was conducted using JBI scoping review methodological guidance and the PRISMA extension for scoping reviews reporting guidance. A comprehensive literature search was conducted in September 2021 and updated in February 2024 using MEDLINE, CINAHL, AMED, EmBASE, CAB Abstracts, Scopus and Food Science Source databases. RESULTS: The initial search yielded 2721 studies and ultimately, data were extracted from 320 studies that fulfilled inclusion criteria for the review. There were five qualitative studies, and the remainder were quantitative, including 23 randomised controlled trials (RCTs) and seven quasi-experimental studies. The USA published the highest number of KD studies followed by China, South Korea and the UK. Most studies focused on the classical KD and DRE. The studies key findings suggest that the KD is efficacious, safe and tolerable. CONCLUSIONS: There are opportunities available to expand the scope of future KD research, particularly to conduct high-quality RCTs and further qualitative research focused on the child's needs and family support to improve the effectiveness of KDs.

Literature Review: Support for caregivers of children on the ketogenic diet for epilepsy and other neurologic disorders.

Epilepsy affects millions of people and when medications are insufficient to maintain seizure control, individuals are diagnosed with refractory epilepsy (RE). Medical ketogenic diet therapy (KDT), a diet high in fat and low in carbohydrates and sufficient in protein, is a well-established treatment for RE. However, compliance is one of the main reasons for discontinuation of KDT and, with pediatric RE patients, the ability of informal caregivers, typically family members, to maintain diet adherence is vital for successful KDT treatment. The central role that informal caregivers play for effective KDT implementation is recognized, however, there is a need to elucidate the rationale and theoretical underpinnings of effective KDT caregiver support programs to inform best practices. Therefore, this systematic literature review aims to identify the existing fundamental understandings of KDT caregiver support to help build a foundation of theory-based knowledge to promote evidenced practice. After screening 137 publications, three studies that discussed potential underlying components of effective caregiver support were included in this review. These articles followed a similar approach as they 1) employed qualitative methods delving into caregiver needs, 2) findings highlighted the importance of support from family, friends, fellow caregivers and their child's medical team, and 3) the inclusion of caregiver support findings were a supplement to the main purpose of the manuscript. Research focused on KDT caregivers is in its infancy. There is a clear need for the systematic examination of support for KDT caregivers to build a foundation for effective support programs and to increase the access to quality support programming to foster KDT implementation, desirable patient outcomes, and caregiver well being. In this article we discuss opportunities to apply self-determination theory to the KDT caregiver support research and practice.

Exogenous ketone esters as a potential therapeutic for treatment of sarcopenic obesity.

Identifying effective treatment(s) for sarcopenia and sarcopenic obesity is of paramount importance as the global population advances in age and obesity continues to be a worldwide concern. Evidence has shown that a ketogenic diet can be beneficial for the preservation of muscle quality and function in older adults, but long-term adherence is low due in part to the high-fat (≥80%), very low carbohydrate (<5%) composition of the diet. When provided in adequate amounts, exogenous ketone esters (KEs) can increase circulating ketones to concentrations that exceed those observed during prolonged fasting or starvation without significant alterations in the diet. Ketone esters first emerged in the mid-1990s and their use in preclinical and clinical research has escalated within the past 10-15 years. We present findings from a narrative review of the existing literature for a proposed hypothesis on the effects of exogenous ketones as a therapeutic for preservation of skeletal muscle and function within the context of sarcopenic obesity and future directions for exploration. Much of the reviewed literature herein examines the mechanisms of the ketone diester (R,S-1,3-butanediol diacetoacetate) on skeletal muscle mass, muscle protein synthesis, and epigenetic regulation in murine models. Additional studies are needed to further examine the key regulatory factors producing these effects in skeletal muscle, examine convergent and divergent effects among different ketone ester formulations, and establish optimal frequency and dosing regimens to translate these findings into humans.

Ketogenic Diet in the Treatment of Epilepsy.

Epilepsy is one of the most disabling neurological diseases. Despite proper pharmacotherapy and the availability of 2nd and 3rd generation antiepileptic drugs, deep brain stimulation, and surgery, up to 30-40% of epilepsy patients remain drug-resistant. Consequences of this phenomenon include not only decreased a quality of life, and cognitive, behavioral, and personal disorders, but also an increased risk of death, i.e., in the mechanism of sudden unexpected death in epilepsy patients (SUDEP). The main goals of epilepsy treatment include three basic issues: achieving the best possible seizure control, avoiding the undesired effects of treatment, and maintaining/improving the quality of patients' lives. Therefore, numerous attempts are made to offer alternative treatments for drug-resistant seizures, an example of which is the ketogenic diet. It is a long-known but rarely used dietary therapy for intractable seizures. One of the reasons for this is the unpalatability of the classic ketogenic diet, which reduces patient compliance and adherence rates. However, its antiseizure effects are often considered to be worth the effort. Until recently, the diet was considered the last-resort treatment. Currently, it is believed that a ketogenic diet should be used much earlier in patients with well-defined indications. In correctly qualified patients, seizure activity may be reduced by over 90% or even abolished for long periods after the diet is stopped. A ketogenic diet can be used in all age groups, although most of the available literature addresses pediatric epilepsy. In this article, we focus on the mechanisms of action, effectiveness, and adverse effects of different variants of the ketogenic diet, including its classic version, a medium-chain triglyceride diet, a modified Atkins diet, and a low glycemic index treatment.

A novel hepatocyte ketone production assay to help the selection of nutrients for the ketogenic diet treatment of epilepsy.

The classic ketogenic diet is an effective treatment option for drug-resistant epilepsy, but its high fat content challenges patient compliance. Optimizing liver ketone production guided by a method comparing substrates for their ketogenic potential may help to reduce the fat content of the diet without loss in ketosis induction. Here, we present a liver cell assay measuring the ß-hydroxybutyrate (ßHB) yield from fatty acid substrates. Even chain albumin-conjugated fatty acids comprising between 4 and 18 carbon atoms showed a sigmoidal concentration-ßHB response curve (CRC) whereas acetate and omega-3 PUFAs produced no CRC. While CRCs were not distinguished by their half-maximal effective concentration (EC50), they differed by maximum response, which related inversely to the carbon chain length and was highest for butyrate. The assay also suitably assessed the ßHB yield from fatty acid blends detecting shifts in maximum response from exchanging medium chain fatty acids for long chain fatty acids. The assay further detected a dual role for butyrate and hexanoic acid as ketogenic substrate at high concentration and ketogenic enhancer at low concentration, augmenting the ßHB yield from oleic acid and a fatty acid blend. The assay also found propionate to inhibit ketogenesis from oleic acid and a fatty acid blend at low physiological concentration. Although the in vitro assay shows promise as a tool to optimize the ketogenic yield of a fat blend, its predictive value requires human validation.

Gender Differences in Liver Steatosis and Fibrosis in Overweight and Obese Patients with Metabolic Dysfunction-Associated Steatotic Liver Disease before and after 8 Weeks of Very Low-Calorie Ketogenic Diet.

Obesity and metabolic syndrome are linked to steatotic liver disease (SLD), the most common form of chronic liver disease. Lifestyle modifications and dieting are strategies that can prevent metabolic dysfunction-associated steatotic liver disease (MASLD). The very low-calorie ketogenic diet (VLCKD) is a helpful treatment for MASLD and has been recommended for people affected by obesity; we evaluated the effect of gender on steatosis and fibrosis in a cohort of 112 overweight or obese patients undergoing an eight-week treatment with a VLCKD. Differences between the genders in terms of anthropometric measures, body composition, and metabolic indicators were examined before, during, and after the nutritional intervention. At baseline, there were significant differences between men and women in terms of anthropometric parameters, blood pressure, Homeostatic Model Assessment for Insulin Resistance (HOMA-IR), fasting insulin, hepatic markers, and lipid profile. Men had considerably higher levels of liver steatosis (measured by CAP) and liver stiffness (measured by E) under basal conditions than women. After the VLCKD, there were reductions in both genders of controlled attenuation parameter (CAP), body weight, body mass index (BMI), waist circumference, systolic and diastolic blood pressure, insulin resistance, fat mass (FM), free fat mass (FFM), and fasting blood glucose, insulin, glycated hemoglobin (HbA1c), triglycerides, total cholesterol, low-density lipoprotein (LDL) cholesterol, alanine transaminase (ALT), gamma-glutamyl transferase (γGT), and uric acid levels. Only in men, liver stiffness, aspartate aminotransferase (AST), creatinine, and C-reactive protein (CRP) levels significantly decreased. Moreover, men had significantly greater levels of liver steatosis: the male gender featured an increase of 23.96 points of the Fibroscan CAP. Men exhibited higher levels of steatosis and fibrosis than women, and these differences persist despite VLCKD. These gender-specific variations in steatosis and fibrosis levels could be caused by hormonal and metabolic factors, suggesting that different therapeutic strategies might be required depending on the gender.