Implementing a low-carbohydrate, ketogenic diet to manage type 2 diabetes mellitus

Ketogenic diets and protective mechanisms in epilepsy, metabolic disorders, cancer, neuronal loss, and muscle and nerve degeneration

Ketogenic diet (KD), the "High-fat, low-carbohydrate, adequate-protein" diet strategy, replacing glucose with ketone bodies, is effective against several diseases, from intractable epileptic seizures, metabolic disorders, tumors, autosomal dominant polycystic kidney disease, and neurodegeneration to skeletal muscle atrophy and peripheral neuropathy. Key mechanisms include augmented mitochondrial efficiency, reduced oxidative stress, and regulated phospho-AMP-activated protein kinase, gamma-aminobutyric acid-glutamate, Na^+/ K⁺ pump, leptin and adiponectin levels, ghrelin levels, lipogenesis, ketogenesis, lipolysis, and gluconeogenesis. In cancer cells, KD targets glucose metabolism, suppresses insulin-like growth factor-1 and PI3K/AKT/mTOR pathways, and reduces cancer cachexia and muscle waste and fatigue. An associated increased skeletal proliferator-activated receptor-γ coactivator-1α activity alters systemic ketone body homeostasis, contributing toward attenuated diabetic hyperketonemia. Antioxidative and anti-inflammatory properties enable KD enhance endurance and sports performances while preventing exercise-induced muscle and organ debility. KD reduces metabolic syndromes-associated allodynia and promotes peripheral axonal and sensory regeneration. This review enlightens effects of KD on various disease conditions. PRACTICAL APPLICATIONS: It is increasingly being realized that diet plays a very important role in our fight against several diseases. This can range from neurological disorders to diabetes and cancer. In this context, the potential of KD, the "High-fat, low-carbohydrate, adequate-protein" diet strategy, is increasingly being realized. In this article, we provide a comprehensive analysis of the benefits of KD against many diseases and discuss the underlying biochemical mechanisms. We hope that our write-up will stimulate further research on KD and help generate an interest for the populations to adopt this healthy diet. It can help overcome the problems associated with weight and dysregulated metabolism.

A low-carbohydrate ketogenic diet induces the expression of very-low-density lipoprotein receptor in liver and affects its associated metabolic abnormalities

A low-carbohydrate ketogenic diet (LCKD) promotes the progression of hepatic steatosis in C57BL/6 wild-type mice, but improves the condition in leptin-deficient obese (ob/ob) mice. Here, we show a novel effect of LCKD associated with the conflicting effects on these mice. Gene expression microarray analyses showed that expression of the Vldlr gene, which encodes the very-low-density lipoprotein receptor (VLDLR), was induced in LCKD-fed ob/ob mice. Although the VLDLR is not normally expressed in the liver, the LCKD led to VLDLR expression in both ob/ob and wild-type mice. To clarify this effect on VLDL dynamics, we analyzed the lipid content of serum lipoproteins and found a marked decrease in VLDL-triglycerides only in LCKD-fed wild-type mice. Further analyses suggested that transport of triglycerides via VLDL from the liver to extrahepatic tissues was inhibited by LCKD-induced hepatic VLDLR expression, but rescued under conditions of leptin deficiency.

Review of current evidence and clinical recommendations on the effects of low-carbohydrate and very-low-carbohydrate (including ketogenic) diets for the management of body weight and other cardiometabolic risk factors: A scientific statement from the National Lipid Association Nutrition and Lifestyle Task Force

Historically, low-carbohydrate (CHO) and very-low-CHO diets have been used for weight loss. Recently, these diets have been promoted for type 2 diabetes (T2D) management. This scientific statement provides a comprehensive review of the current evidence base available from recent systematic reviews and meta-analyses on the effects of low-CHO and very-low-CHO diets on body weight, lipoprotein lipids, glycemic control, and other cardiometabolic risk factors. In addition, evidence on emerging risk factors and potential safety concerns of low-CHO and very-low-CHO diets, especially for high-risk individuals, such as those with genetic lipid disorders, was reviewed. Based on the evidence reviewed, low-CHO and very-low-CHO diets are not superior to other dietary approaches for weight loss. These diets may have advantages related to appetite control, triglyceride reduction, and reduction in the use of medication in T2D management. The evidence reviewed showed mixed effects on low-density lipoprotein cholesterol levels with some studies showing an increase. There was no clear evidence for advantages regarding effects on other cardiometabolic risk markers. Minimal data are available regarding long-term (>2 years) efficacy and safety. Clinicians are encouraged to consider the evidence discussed in this scientific statement when counseling patients on the use of low-CHO and very-low-CHO diets.

Lessons Learned from the POUNDS Lost Study: Genetic, Metabolic, and Behavioral Factors Affecting Changes in Body Weight, Body Composition, and Cardiometabolic Risk

PURPOSE OF REVIEW

This paper reviews the genetic and non-genetic factors that provided predictions of, or were associated with, weight loss and other metabolic changes in the POUNDS Lost clinical trial of weight loss. This trial randomized 811 individuals who were overweight or obese to one of four diets that contained either 15% or 25% protein and 20% or 40% fat in a 2 × 2 factorial design. A standard behavioral weight loss program was available for all participants who were followed for 2 years with an 80% completion rate.

RECENT FINDINGS

Nineteen genes and five genetic risk scores were used along with demographic, behavioral, endocrine, and metabolic measurements. Genetic variations in most of the genes were associated with weight loss, but this association often varied with the dietary assignment. A number of demographic and behavioral factors, including attendance at behavioral sessions and food cravings were predictive of weight changes. A high baseline level of free triiodothyronine or free thyroxine predicted the magnitude of weight loss. Several perfluoroakyl compounds predicted more rapid weight regain. Genetic evidence from POUNDS Lost provides guidance toward selection of a personalized weight loss diet and improvement in metabolic profile. There is still room for additional research into the predictors of weight loss.

The mystery of the ketogenic diet: benevolent pseudo-diabetes

Designed a century ago to treat epilepsy, the ketogenic diet (KD) is also effective against obesity and diabetes. Paradoxically, some studies in rodents have found that the KD seemingly causes diabetes, contradicting solid clinical data in humans. This paradox can be resolved by applying the concept of starvation pseudo-diabetes, which was discovered in starved animals almost two centuries ago, and has also been observed in some rapamycin-treated rodents. Intriguingly, use of the KD and rapamycin is indicated for a similar spectrum of diseases, including Alzheimer's disease and cancer. Even more intriguingly, benevolent (starvation) pseudo-diabetes may counteract type 2 diabetes or its complications.

Three consecutive weeks of nutritional ketosis has no effect on cognitive function, sleep, and mood compared with a high-carbohydrate, low-fat diet in healthy individuals: a randomized, crossover, controlled trial

BACKGROUND

The high-fat ketogenic diet (KD) has become an increasingly popular diet not only in overweight/obese populations, or those with clinical conditions, but also in healthy non-overweight populations.

OBJECTIVE

Because there are concerns about the association between high-fat diets and cognitive decline, this study aimed to determine the effects of a KD compared with an isocaloric high-carbohydrate, low-fat (HCLF) diet on cognitive function, sleep, and mood in healthy, normal-weight individuals.

METHODS

Eleven healthy, normal-weight participants (mean age: 30 ± 9 y) completed this randomized, controlled, crossover study. Participants followed 2 isocaloric diets-an HCLF diet (55% carbohydrate, 20% fat, and 25% protein) and a KD (15% carbohydrate, 60% fat, and 25% protein)-in a randomized order for a minimum of 3 wk, with a 1-wk washout period between diets. Measures of β-hydroxybutyrate confirmed that all participants were in a state of nutritional ketosis during post-KD assessments (baseline: 0.2 ± 0.2 mmol/L; KD: 1.0 ± 0.5 mmol/L; washout: 0.2 ± 0.1 mmol/L; and HCLF: 0.3 ± 0.2 mmol/L). Cognitive function was assessed using a validated, psychological computer-based test battery before and after each diet. Subjective measures of mood and sleep were also monitored throughout the study using validated scales.

RESULTS

Three weeks of sustained nutritional ketosis, compared with the HCLF diet, had no effect on speed and accuracy responses in tasks designed to measure vigilance (speed: P = 0.39, Cohen's d = 0.26; accuracy: P = 0.99, Cohen's d = 0.04), visual learning and memory (speed: P = 0.99, Cohen's d = 0.04; accuracy: P = 0.99, Cohen's d = 0.03), working memory (speed: P = 0.62, Cohen's d = 0.26; accuracy: P = 0.98, Cohen's d = 0.07), and executive function (speed: P = 0.60, Cohen's d = 0.31; accuracy: P = 0.90, Cohen's d = 0.19). Likewise, mood, sleep quality, and morning vigilance did not differ (P > 0.05) between the dietary interventions.

CONCLUSION

The results of our randomized, crossover, controlled study suggest that 3 wk of sustained nutritional ketosis had no effect on cognitive performance, mood, or subjective sleep quality in a sample of healthy individuals. This trial was registered in the Pan African Clinical Trial Registry as PACTR201707002406306.

Long-Term Effects of a Classic Ketogenic Diet on Ghrelin and Leptin Concentration: A 12-Month Prospective Study in a Cohort of Italian Children and Adults with GLUT1-Deficiency Syndrome and Drug Resistant Epilepsy

The classical ketogenic diet (cKD) is an isocaloric, high fat, very low-carbohydrate diet that induces ketosis, strongly influencing leptin and ghrelin regulation. However, not enough is known about the impact of a long-term cKD. This study evaluated the effects of a 12-month cKD on ghrelin and leptin concentrations in children, adolescents and adults affected by the GLUT1-Deficiency Syndrome or drug resistant epilepsy (DRE). We also investigated the relationship between the nutritional status, body composition and ghrelin and leptin variations. We carried out a longitudinal study on 30 patients: Twenty-five children and adolescents (15 females, 8 ± 4 years), and five adults (two females, 34 ± 16 years). After 12-monoths cKD, there were no significant changes in ghrelin and leptin, or in the nutritional status, body fat, glucose and lipid profiles. However, a slight height z-score reduction (from −0.603 ± 1.178 to −0.953 ± 1.354, p ≤ 0.001) and a drop in fasting insulin occurred. We found no correlations between ghrelin changes and nutritional status and body composition, whereas leptin changes correlated positively with variations in the weight z-score and body fat (ρ = 0.4534, p = 0.0341; ρ = 0.5901, p = 0.0135; respectively). These results suggest that a long-term cKD does not change ghrelin and leptin concentrations independently of age and neurological condition.

Ketogenic diets potentially reverse Type II diabetes and ameliorate clinical depression: A case study

Efficacious adherence to treatment protocol predicts metabolic control among Type 2 diabetics (T2DM) [1-4]; however, few healthcare systems employ individualized strategies to mediate the comorbidity of T2DM with other chronic disease states. A clinically prescribed ketogenic diet, patient-centered nutritional education and high intensity interval training (HIIT), girded by solution-focused psychotherapy, modulate significant improvements in the clinical biomarkers associated with concurring T2DM and clinical depression [5-15]. Relevant metabolic change was noted in the following measures: HOMA-IR, triglyceride/HDL ratio, HgA1c, fasting insulin, fasting glucose, fasting triglycerides, LDL, VLDL, HDL, total cholesterol and C-reactive protein. The Patient Health Questionnaire 9 (PHQ-9) along with clinical interview and the mental status exam showed notable change in the patient's depressive symptoms; likewise, her self-efficacy score normalized, as measured by the General Self-Efficacy Questionnaire (GSE) and the Metabolic Syndrome Compliance Questionnaire (MSC). The case study highlights a 65-year old female who presented with a 26-year history of dually-diagnosed Type 2 diabetes (T2DM) and major depressive disorder (MDD). The patient was prescribed a ketogenic diet (KD), clinically formulated from her resting metabolic rate, body fat percentage and lean body mass, together with weekly nutrition education, high intensity interval training (matched to her cardiovascular conditioning), and eight 45-minute solution-focused psychotherapy sessions. Intervention goals included improved insulin sensitivity evaluated by the HOMA-IR, sustained glycemic control measured via HgA1c, reduced cardiovascular risk via the triglyceride/HDL ratio, and improved depressive symptoms with increased self-efficacy monitored by the PHQ-9 and GSE/MSC. The results of the 12-week intervention were statistically significant. The patient's HgA1c dropped out of diabetic range (8.0%) and normalized at 5.4%. Her average daily glucose measurements declined from 216 mg/dL to 96 mg/dL; the HOMA-IR and triglyceride/HDL ratios improved by 75%. Her marker for clinical depression and measurement of self-efficacy normalized. The 12-week individualized treatment intervention served to functionally reverse 26 years of T2DM, ameliorate two and half decades of chronic depressive disorder and empower/equip the patient with a new experience of hope and success.