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

The Michigan Collaborative for Type 2 Diabetes (MCT2D): Development and implementation of a statewide collaborative quality initiative

BACKGROUND

Type 2 diabetes (T2D) is one of the most prevalent chronic diseases worldwide and a leading cause of cardiorenal disease and mortality. Only one-third of individuals with T2D receive care as recommended by the American Diabetes Association's clinical practice guidelines. Effective strategies are needed to accelerate the implementation of guideline concordant T2D care.

METHODS

The Michigan Collaborative for Type 2 Diabetes (MCT2D) is a statewide population health collaborative quality initiative (CQI) developed to improve the care of all people with T2D in Michigan. MCT2D has developed a learning health system with physician organizations and their constituent practices to support quality improvement initiatives focused on (1) improving use of guideline-directed pharmacotherapy to improve cardiorenal outcomes, (2) increasing evidence-based use of continuous glucose monitoring, and (3) supporting use of lower carbohydrate eating patterns.

RESULTS

Between 2021 and 2022, MCT2D recruited 28 of the 40 Michigan-based physician organizations participating in Blue Cross' Physician Group Incentive Program with 336 constituent practices and 1357 physicians in primary care (304), endocrinology (21) and nephrology (11). In January 2022, baseline data included a sample of 96,140 unique individuals with T2D. The baseline HbA1c was ≤ 7.0% for 66.3% of patients (n = 32,787), while 14.9% of patients had a most recent HbA1c ≥ 8.0% (n = 7,393). The most recent body mass index (BMI) was ≥ 30.0 for 64.8% of patients (n = 38,516).

DISCUSSION

MCT2D has organized a statewide collaborative to recruit and engage a diverse and large set of physician organizations and their constituent practices. This is a promising opportunity to accelerate adoption of guideline-concordant care for people with T2D and may be a model for other state or regional collaboratives. Future directions include specific evidence-based interventions targeted at reducing diabetes-linked comorbidities and associated healthcare costs as well as strategies focused on T2D prevention among at-risk populations.

An unexpected role for the ketogenic diet in triggering tumor metastasis by modulating BACH1-mediated transcription

We have found that the ketogenic (Keto) diet is able to, unexpectedly, promote the metastatic potential of cancer cells in complementary mouse models. Notably, the Keto diet-induced tumor metastasis is dependent on BTB domain and CNC homolog 1 (BACH1) and its up-regulation of pro-metastatic targets, including cell migration-inducing hyaluronidase 1, in response to the Keto diet. By contrast, upon genetic knockout or pharmacological inhibition of endogenous BACH1, the Keto diet-mediated activation of those targets is largely diminished, and the effects on tumor metastasis are completely abolished. Mechanistically, upon administration of the Keto diet, the levels of activating transcription factor 4 (ATF4) are markedly induced. Through direct interaction with BACH1, ATF4 is recruited to those pro-metastatic target promoters and enhances BACH1-mediated transcriptional activation. Together, these data implicate a distinct transcription regulatory program of BACH1 for tumor metastasis induced by the Keto diet. Our study also raises a potential health risk of the Keto diet in human patients with cancer.

Effect of ketogenic diet on blood pressure: A GRADE-Assessed systematic review and meta-analysis of randomized controlled trials

AIMS

Cardiovascular diseases (CVDs) are major causes of mortality around the world. High blood pressure (BP) or hypertension is one of the most significant predisposing factors to CVDs. Ketogenic diets (KDs) have been the center of attention for their possible health benefits. The aim of this analysis is to study the impact of KDs on BP through the existing literature.

DATA SYNTHESIS

We investigated the impact of KDs on systolic and diastolic blood pressures (SBP and DBP) conducted in the format of randomized controlled trials (RCTs). Four online databases (PubMed/Medline, SCOPUS, Cochrane Library, and Google Scholar) were searched from inception up to November 2022. Subgroup analyses were carried out to find the sources of heterogeneities. Twenty-three RCTs with 1664 participants were identified. KDs did not exert any significant impacts on SBP (WMD: -0.87 mmHg, 95% CI: -2.05, 0.31) nor DBP (WMD: -0.11 mmHg, 95% CI -1.14, 0.93). Subgroup analyses did not reveal any further information. Also, non-linear dose-response analysis could not detect any associations between the percentage of calorie intake from fat in the KD format and BP levels.

CONCLUSION

KDs do not seem to be effective in improving BP. Nonetheless, further investigations are recommended to examine the proportion of fat intake needed to induce favorable clinical impacts.

Ketogenic diet and cardiovascular risk - state of the art review

The ketogenic diet is based on extreme carbohydrate intake reduction and replacing the remaining with fat and has become a popular dietary pattern used for weight loss. The relationship between the ketogenic diet and cardiovascular risk is a controversial topic. This publication aimed to present evidence on the ketogenic diet and cardiovascular risk factors and mortality. The ketogenic diet does not fulfill the criteria of a healthy diet. It presents the potential for rapid short-term reduction of body mass, triglycerides level, Hb1Ac, and blood pressure. Its efficacy for weight loss and the above-mentioned metabolic changes is not significant in long-term observations. In terms of cardiovascular mortality, the low-carb pattern is more beneficial than very low-carbohydrate (including the ketogenic diet). There is still scarce evidence comparing ketogenic to the Mediterranean diet. Other safety concerns in cardiovascular patients such as adverse events related to ketosis, fat-free mass loss, or potential pharmacological interactions should be also taken into consideration in future research.

Association between dietary patterns and cardiovascular diseases: A review

Cardiovascular disease (CVD), especially atherosclerosis, is the primary cause of global deaths. It accounts for millions of deaths annually. Even a small reduction in CVD through preventive treatment can have a substantial impact. Dietary patterns and substances are strongly linked to chronic diseases such as atherosclerosis, hypertension, heart failure, and type 2 diabetes. An unhealthy diet could lead to traditional risk factors such as LDL levels, TG levels, diabetes, and high blood pressure while accelerating atherosclerosis progression. Recent research has shown the potential of dietary interventions to prevent and treat cardiovascular disease, particularly through healthy dietary patterns such as the Mediterranean diet or DASH. In 2016, the World Health Organization (WHO) and the US Centers for Disease Control and Prevention (CDC) launched a new initiative aimed at enhancing the prevention and control of cardiovascular disease (CVD) by improving the management of CVD in primary care, including the optimization of dietary patterns. Here, this review summarizes several large cohort researches about the effects of dietary patterns on atherosclerosis, refines dietary components, and outlines some typical anti-atherosclerosis dietary agents. Finally, this review discusses recent mechanisms by which dietary interventions affect atherosclerosis progression.

How Nutritious Are French Beans (Phaseolus vulgaris L.) from the Citizen Science Experiment?

French beans are tender, immature, edible pods that are harvested early in the plant's growth cycle and are usually eaten cooked. The growth habits of French beans were studied for the first time in a Citizen Science experiment, and 19 pod samples were collected for further nutritional analysis. Various macronutrients (e.g., protein, ash, fat, carbohydrates, amino acids) and multi-element profiles were determined. A survey of their growing habits revealed that beans are usually planted once or twice a year in May and June at a length of 5-10 m, with a predominance of dwarf beans cultivation over climbing varieties, and pest resistance and stringless pods are the most important characteristics when deciding on a bean. Homogenised freeze-dried pod samples contained 16.1-23.1% protein, 4.5-8.2% ash, 0.1-1.1% fat, and 62.0-70.6% carbohydrates and had a caloric value of 337-363 kcal/100 g. Of the 17 free amino acids identified, 8 were essential (histidine, threonine, methionine, valine, lysine, isoleucine, leucine, phenylalanine) and 9 were non-essential (cysteine, aspartic acid, serine, glutamic acid, glycine, arginine, alanine, proline, tyrosine); meanwhile, of the 12 elements, 5 were macroelements and 7 were microelements. The predominant free amino acids were aspartic acid, glutamic acid, and serine. In the multiple comparisons (Box and Whisker plot), the parameters caloric value and iron showed the strongest response. A very strong positive significant Pearson correlation (≥0.95) was found for five pairs of variables within the free amino acids. Comparison of the nutrient data obtained in the pods showed near-perfect or high complementarity (85.2-103.4%) with the food composition databases for half of the parameters, suggesting that the home-grown French beans from the Citizen Science experiment are a highly nutritious vegetable.

Methodological Challenges and Confounders in Research on the Effects of Ketogenic Diets: A Literature Review of Meta-Analyses

Several meta-analyses have found a positive association between a popular type of "fad diet", ketogenic diets, and their effect on anthropometric and blood parameters. However, the non-specific inclusion criteria for meta-analyses may lead to incorrect conclusions. The aim of this literature review is to highlight the main confounders and methodological pitfalls of meta-analyses on ketogenic diets by inspecting the presence of key inclusion criteria. The PubMed, Embase, and Web of Science databases and the Cochrane Database of Systematic Reviews were searched for meta-analyses. Most meta-analyses did not define the essential parameters of a ketogenic diet (i.e., calories, macronutrient ratio, types of fatty acids, ketone bodies, etc.) as inclusion criteria. Of the 28 included meta-analyses, few addressed collecting real, re-measured nutritional data from the ketogenic diet and control groups in parallel with the pre-designed nutritional data. Most meta-analyses reported positive results in favor of ketogenic diets, which can result in erroneous conclusions considering the numerous methodological pitfalls and confounders. Well-designed clinical trials with comparable results and their meta-analyses are needed. Until then, medical professionals should not recommend ketogenic diets as a form of weight loss when other well-known dietary options have been shown to be healthy and effective.

Ketogenic Diet Regulates Cardiac Remodeling and Calcium Homeostasis in Diabetic Rat Cardiomyopathy

A ketogenic diet (KD) might alleviate patients with diabetic cardiomyopathy. However, the underlying mechanism remains unclear. Myocardial function and arrhythmogenesis are closely linked to calcium (Ca2+) homeostasis. We investigated the effects of a KD on Ca2+ homeostasis and electrophysiology in diabetic cardiomyopathy. Male Wistar rats were created to have diabetes mellitus (DM) using streptozotocin (65 mg/kg, intraperitoneally), and subsequently treated for 6 weeks with either a normal diet (ND) or a KD. Our electrophysiological and Western blot analyses assessed myocardial Ca2+ homeostasis in ventricular preparations in vivo. Unlike those on the KD, DM rats treated with an ND exhibited a prolonged QTc interval and action potential duration. Compared to the control and DM rats on the KD, DM rats treated with an ND also showed lower intracellular Ca2+ transients, sarcoplasmic reticular Ca2+ content, sodium (Na+)-Ca2+ exchanger currents (reverse mode), L-type Ca2+ contents, sarcoplasmic reticulum ATPase contents, Cav1.2 contents. Furthermore, these rats exhibited elevated ratios of phosphorylated to total proteins across multiple Ca2+ handling proteins, including ryanodine receptor 2 (RyR2) at serine 2808, phospholamban (PLB)-Ser16, and calmodulin-dependent protein kinase II (CaMKII). Additionally, DM rats treated with an ND demonstrated a higher frequency and incidence of Ca2+ leak, cytosolic reactive oxygen species, Na+/hydrogen-exchanger currents, and late Na+ currents than the control and DM rats on the KD. KD treatment may attenuate the effects of DM-dysregulated Na+ and Ca2+ homeostasis, contributing to its cardioprotection in DM.

Adherence to ketogenic diet in lifestyle interventions in adults with overweight or obesity and type 2 diabetes: a scoping review

BACKGROUND/OBJECTIVES

Despite the evidence supporting the efficacy of the ketogenic diet (KD) on weight and type 2 diabetes (T2D) management, adherence to the KD is challenging. Additionally, no studies have reported changes in PA among individuals with overweight/obesity and T2D who have followed KD. We mapped out the methods used to assess adherence to the KD and level of physical activity (PA) in lifestyle interventions for weight and T2D management in individuals with overweight/obesity and T2D and compared levels of KD adherence and PA in these interventions.

METHODS

Articles published between January 2005 and March 2022 were searched in MEDLINE, CINAHL, and Scopus. Studies that included KD in lifestyle interventions for adults with T2D and overweight/obesity and measured ketone levels were included.

RESULTS

The eleven included studies comprised eight randomized controlled trials. They mainly used self-reported measures to evaluate adherence to the KD and level of PA. We found studies reported higher carbohydrate intake and lower fat intake than the KD regimen. Great inconsistencies were found among studies on the measurement and reporting of ketone and PA levels.

CONCLUSION

Our results demonstrated the need to develop intervention strategies to improve adherence to the KD, as well as the necessity of developing standardized diet and PA assessment tools to establish a stronger evidence base for including KD in lifestyle interventions for weight and T2D management among adults with overweight/obesity and T2D.

A very low-carbohydrate diabetes prevention program for veterans with prediabetes: a single-arm mixed methods pilot study

Introduction

All Veterans Affairs (VA) Medical Centers offer the MOVE! Weight Management Program to help patients achieve and maintain a healthy weight through a calorie-restricted, low-fat diet and increased physical activity. Yet, most MOVE! participants do not achieve clinically significant weight loss of ≥5%. A carbohydrate-restricted diet may help more Veterans to achieve ≥5% weight loss.

Methods

This was a single-arm explanatory sequential mixed methods pilot study conducted in one VA health care system. Veterans with prediabetes and body mass index ≥25 kg/m2 were invited to participate in a group-based, virtual, very low-carbohydrate Diabetes Prevention Program (VLC-DPP) consisting of 23 sessions over 12 months. Participants were taught to follow a very low-carbohydrate eating pattern, defined as 20-35 grams of net carbohydrates per day. The primary outcomes were measures of feasibility and acceptability, including program uptake and session attendance. Secondary outcomes included change in weight, hemoglobin A1c, lipids, and patient-reported measures of food cravings, stress eating, perceived health status, and motivation. Interviews were conducted at 6 months to identify factors that facilitated or hindered participants' achievement of ≥5% weight loss.

Results

Among 108 screened Veterans, 21 enrolled in the study (19%), and 18 were included in the analytic cohort. On average, participants attended 12.4/16 weekly sessions and 3.6/8 bimonthly or monthly sessions. At 12 months, mean percent weight loss was 9.4% (SD = 10.7) with 9 participants (50%) achieving ≥5% weight loss. Three factors facilitated achievement of ≥5% weight loss among 10/16 interviewees: (1) enjoyment of low-carbohydrate foods; (2) careful monitoring of carbohydrate intake; and (3) reduced hunger and food cravings. Three factors hindered achievement of ≥5% weight loss among 6/16 interviewees: (1) food cravings, particularly for sweets; (2) challenges with maintaining a food log; and (3) difficulty with meal planning.

Conclusion

A VLC-DPP is feasible and acceptable and shows preliminary efficacy among Veterans with prediabetes. The program's weight loss effectiveness compared to standard MOVE! should be evaluated in a larger-scale trial. Such a program may be offered in addition to the standard MOVE! program to expand the menu of evidence-based lifestyle counseling options for Veterans.

Clinical Trial Registration

https://clinicaltrials.gov/ct2/show/NCT04881890, identifier NCT04881890.

Association of main meal quality index with the odds of metabolic syndrome in Iranian adults: a cross-sectional study

BACKGROUND

Metabolic syndrome (MetS) is a common global issue linked to the quality of one's eating occasions. The current cross-sectional study evaluates the association between a novel index, the Main Meal Quality Index (MMQI), and MetS among Iranian adults.

METHODS

A total of 824 men and women were recruited, and a 24-hour dietary recall assessed the dietary intake of the participants. Lunch was selected as the main meal based on energy density. The MMQI score was calculated based on ten components of dietary intake, with a higher score indicating more adherence to the index, with the final scores ranging from 0 to 100 points. The associations were assessed using binary logistic regression.

RESULTS

The mean age was 42.2 years and the range of the calculated MMQI was 22 to 86 (mean in total participants: 56.62, mean in women: 56.82, mean in men: 55.64). The total prevalence of MetS in the sample was 34%. After adjustments for potential confounders, the participants at the top quartile of MMQI had a lower odds ratio for hypertriglyceridemia and low high-density lipoprotein (HDL) level, and a higher odds ratio for hypertension, hyperglycemia, abdominal obesity, and MetS. The sex-specific analysis also did not show any significant associations between adherence to MMQI and MetS and its components.

CONCLUSION

Overall, MMQI is not associated with MetS and its components in a sample of Iranian men and women. More research is needed to examine MMQI and its possible association with current health-related problems including MetS.

mTORC1 syndrome (TorS): unified paradigm for diabetes/metabolic syndrome

'Glucolipotoxicity' and 'insulin resistance' are claimed to drive type 2 diabetes (T2D) and the non-glycemic diseases of the metabolic syndrome (MetS) (obesity, dyslipidemia, hypertension). In line with that, glycemic and/or insulin control are considered to be primary goal in treating T2D/MetS. However, recent standard-of-care (SOC) treatments of T2D, initially designed to control T2D hyperglycemia, appear now to alleviate the cardio-renal and non-glycemic diseases of T2D/MetS independently of glucose lowering and insulin resistance, and in non-T2D patients altogether, calling for an alternative unifying pathophysiology/treatment paradigm for T2D/MetS. This opinion article proposes to replace the current 'glucolipotoxic/insulin-resistance' paradigm of T2D/MetS with an 'mammalian target of rapamycin complex 1 (mTORC1) syndrome' (TorS) paradigm, implying an exhaustive cohesive disease entity driven by an upstream hyperactive mTORC1, and which includes diabetic hyperglycemia, diabetic dyslipidemia, hypertension, diabetic macrovascular and microvascular disease, non-alcoholic fatty liver disease, some cancers, neurodegeneration, polycystic ovary syndrome (PCOS), psoriasis, and others. The TorS paradigm may account for the insulin-resistant glycemic context of TorS, combined with response to insulin of the non-glycemic diseases of TorS. The TorS paradigm may account for the efficacy of current antidiabetic SOC treatments in diabetic and nondiabetic patients. Most importantly, the TorS paradigm may generate novel treatments for TorS.

Ketogenic diet restores hormonal, apoptotic/proliferative balance and enhances the effect of metformin on a letrozole-induced polycystic ovary model in rats

OBJECTIVE

Polycystic ovaries (PCO) is a hormonal disorder that is a leading cause of infertility. The formation of multiple persistent cysts and hormonal imbalance are hallmarks of PCO. Recent clinical studies reported a beneficial effect of the ketogenic diet (KD; high-fat, low-carbohydrate) on PCO. The aim of this study was to investigate the effect of the KD alone and in combination with metformin on letrozole-induced PCO in female rats.

METHODS

Female rats were grouped into control and PCO (letrozole; 1 mg/kg for 21 days). The PCO group was subdivided into PCO (non-treated), PCO-metformin (300 mg/kg), PCO rats fed with KD only, and PCO rats treated with metformin and fed with KD. All groups continued to receive letrozole during the 21-day treatment period. At the end of the experiment, serum and ovaries were collected for further analysis.

RESULTS

The untreated-PCO rats showed increased testosterone, LH/FSH ratio, and ovary weights. Disturbed apoptosis and proliferation balance were evident as a low caspase-3 activation and proliferating cell nuclear antigen expression and increased TGF-β expression. The KD improved the letrozole-induced effects, which was comparable to the effect of metformin. Combining the KD with metformin treatment additively enhanced the metformin effect.

CONCLUSION

Our results indicate that the KD has a protective role against PCO in rats, especially when combined with metformin. This study reveals a potential therapeutic role of the KD in PCO, which could prompt valuable future clinical applications.

Ketogenic therapies for glioblastoma: Understanding the limitations in transitioning from mice to patients

Glioblastoma Multiforme is an aggressive brain cancer affecting children and adults frequently resulting in a short life expectancy. Current cancer therapies include surgery and radiation followed by chemotherapy, which due to their ineffectiveness, requires repeated exposure to the same therapies. Since the 1990s, researchers and doctors have explored other therapies, such as diet therapies, to aid in combating gliomas. The ketogenic diet has gained popularity due to Otto Warburg's theory that tumor cells prefer "aerobic glycolysis" and cannot metabolize ketones. The inability of gliomas to use ketones provides an excellent opportunity to weaken the tumor while protecting healthy cells during cancer treatments. This review will examine some of the current research using the ketogenic diet as a form of cancer therapy to determine if this intervention is manageable and effective in patients with glioblastoma. Peer-reviewed articles from 2009 to 2019 were used. The primary objective is to distinguish differences between pre-clinical and clinical research to determine if the ketogenic diet is reproducible from mouse models into humans to determine its effectiveness. The analysis revealed several limitations of the ketogenic diet as an intervention. The effectiveness is more robust in mice than in human studies. Furthermore, tolerability is marginally supported in human studies requiring more reproducible research to validate that the intervention is manageable and effective in patients with glioblastoma.

Daily Intake of D-β-Hydroxybutyric Acid (D-BHB) Reduces Body Fat in Japanese Adult Participants: A Randomized, Double-Blind, Placebo-Controlled Study

Currently, there is considerable interest in ketone metabolism owing to the benefits for human health. Conventionally, strict dietary restrictions on carbohydrates are required to increase plasma ketone levels, while supplementation with D-β-hydroxybutyric acid (D-BHB) can easily increase plasma ketone levels. We hypothesized that a daily intake of D-BHB could promote weight loss, especially through fat reduction. Herein, D-BHB (OKETOATM) was produced via a proprietary fermentation process from sugar. In this randomized, double-blind, placebo-controlled study, we assessed the safety and fat-reduction effects after 12 wk of daily ingestion of D-BHB (2.9 g) in 22 healthy Japanese adults and 22 control participants. Blood samples were collected pre- and post-treatment. Blood chemistry, anthropometric variables, and the body composition of the participants were investigated. Data analysis revealed that visceral fat at 12 wk significantly decreased by 9.0 cm2 (p=0.037), as evidenced by analysis of covariance. Blood parameters and body condition showed no significant differences between the two groups, and the participants reported no adverse effects or discomfort. Furthermore, data were analyzed by regrouping the participants. After removing one suspicious diabetes participant, all others showed significant decreases in visceral fat, body weight, BMI, and fat weight. Additionally, those aged under 50 y old had significantly decreased abdominal circumference and body fat percentage, in addition to visceral fat, body weight, BMI, and fat weight. Overall, our findings indicate that daily D-BHB intake may reduce body fat without dieting or exercise intervention. This study was registered with the UMIN Clinical Trials Registry as UMIN000045322.

Toxicity Investigations of (R)-3-Hydroxybutyrate Glycerides In Vitro and in Male and Female Rats

TCN006, a formulation of (R)-3-Hydroxybutyrate glycerides, is a promising ingredient for enhancing ketone intake of humans. Ketones have been shown to have beneficial effects on human health. To be used by humans, TCN006 must be determined safe in appropriately designed safety studies. The results of a bacterial reverse mutation assay, an in vitro mammalian micronucleus study, and 14-and 90-day repeat dose toxicity studies in rats are reported herein. In the 14- and 90-day studies, male and female Wistar rats had free access to drinking water containing 0, 75,000, 125,000 or 200,000 ppm TCN006 for 92 and 93 days, respectively. TCN006 tested negative for genotoxicity and the no observed adverse effect level (NOAEL) for toxicity in the 14- and 90-day studies was 200,000 ppm, the highest dose administered. In the longer term study, the mean overall daily intake of TCN006 in the 200,000 ppm groups was 14,027.9 mg/kg bw/day for males and 20,507.0 mg/kg bw/day for females. At this concentration, palatability of water was likely affected, which led to a decrease in water consumption in both males and females compared to respective controls. This had no effect on the health of the animals. Although the rats were administered very high levels of (R)-3-Hydroxybutyrate glycerides, there were no signs of ketoacidosis.

Mentha: Nutritional and Health Attributes to Treat Various Ailments Including Cardiovascular Diseases

A poor diet, resulting in malnutrition, is a critical challenge that leads to a variety of metabolic disorders, including obesity, diabetes, and cardiovascular diseases. Mentha species are famous as therapeutic herbs and have long served as herbal medicine. Recently, the demand for its products, such as herbal drugs, medicines, and natural herbal formulations, has increased significantly. However, the available literature lacks a thorough overview of Mentha phytochemicals' effects for reducing malnutritional risks against cardiovascular diseases. In this context, we aimed to review the recent advances of Mentha phytochemicals and future challenges for reducing malnutritional risks in cardiovascular patients. Current studies indicated that Mentha species phytochemicals possess unique antimicrobial, antidiabetic, cytotoxic, and antioxidant potential, which can be used as herbal medicine directly or indirectly (such as food ingredients) and are effective in controlling and curing cardiovascular diseases. The presence of aromatic and flavor compounds of Mentha species greatly enhance the nutritional values of the food. Further interdisciplinary investigations are pivotal to explore main volatile compounds, synergistic actions of phytochemicals, organoleptic effects, and stability of Mentha sp. phytochemicals.

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.

Can low-carbohydrate diets be recommended for reducing cardiovascular risk?

PURPOSE OF REVIEW

This review provides a rationale for implementing carbohydrate restriction as a dietary therapy to improve biomarkers of cardiovascular health and suggests that this will require a paradigm shift away from what is currently promulgated as a 'heart-healthy' diet.

RECENT FINDINGS

Type 2 diabetes mellitus (T2DM), metabolic syndrome, and related co-morbidities are major risk factors for cardiovascular disease (CVD). Ideally, then, a diet intended to support cardiovascular health should be one that improves or reverses these underlying risk factors. Carbohydrate restriction is effective for this purpose as well as for favorably impacting atherogenic dyslipidemia. Recent consensus reports from select national organizations have endorsed low-carbohydrate diets for improving glycemia and cardiovascular risk. Reluctance among public health organizations and some clinicians to more widely promote this therapeutic nutritional approach is driven primarily by the increase in serum low-density lipoprotein cholesterol (LDL-C) observed in a proportion of individuals who adopt a low-carbohydrate diet. Here we explore the rationale for using carbohydrate restriction to improve cardiovascular health by way of favorably impacting T2DM and insulin resistance, and why this salutary effect outweighs the potential adverse effects of an increase in serum LDL-C.

SUMMARY

Carbohydrate restriction is a logical foundation for a dietary intervention intended to reduce CVD risk, particularly among individuals with T2DM or metabolic syndrome.

Dietary Risk Factors and Eating Behaviors in Peripheral Arterial Disease (PAD)

Dietary risk factors play a fundamental role in the prevention and progression of atherosclerosis and PAD (Peripheral Arterial Disease). The impact of nutrition, however, defined as the process of taking in food and using it for growth, metabolism and repair, remains undefined with regard to PAD. This article describes the interplay between nutrition and the development/progression of PAD. We reviewed 688 articles, including key articles, narrative and systematic reviews, meta-analyses and clinical studies. We analyzed the interaction between nutrition and PAD predictors, and subsequently created four descriptive tables to summarize the relationship between PAD, dietary risk factors and outcomes. We comprehensively reviewed the role of well-studied diets (Mediterranean, vegetarian/vegan, low-carbohydrate ketogenic and intermittent fasting diet) and prevalent eating behaviors (emotional and binge eating, night eating and sleeping disorders, anorexia, bulimia, skipping meals, home cooking and fast/ultra-processed food consumption) on the traditional risk factors of PAD. Moreover, we analyzed the interplay between PAD and nutritional status, nutrients, dietary patterns and eating habits. Dietary patterns and eating disorders affect the development and progression of PAD, as well as its disabling complications including major adverse cardiovascular events (MACE) and major adverse limb events (MALE). Nutrition and dietary risk factor modification are important targets to reduce the risk of PAD as well as the subsequent development of MACE and MALE.

Effects of a 6-month, low-carbohydrate diet on glycaemic control, body composition, and cardiovascular risk factors in patients with type 2 diabetes: An open-label randomized controlled trial

AIM

To investigate the efficacy and safety of a non-calorie-restricted low-carbohydrate diet (LCD) on glycaemic control, body composition, and cardiovascular risk factors in patients with type 2 diabetes (T2D) instructed to maintain their non-insulin antidiabetic medication and physical activity.

MATERIALS AND METHODS

In an open-label randomized controlled trial, patients with T2D were randomized 2:1 to either a LCD with a maximum of 20 E% (percentage of total energy intake) from carbohydrates (n = 49) or a control diet with 50-60 E% from carbohydrates (n = 22) for 6 months. Examinations at enrolment and after 3 and 6 months included blood sample analyses, anthropometrics, blood pressure, accelerometer-based assessment of physical activity, and food diaries. Total fat mass and lean mass were determined by dual-energy x-ray absorptiometry scan. The mean difference in change between groups from baseline are reported.

RESULTS

The LCD group decreased carbohydrate intake to 13.4 E% and increased fat intake to 63.2 E%, which was -30.5 ± 2.2 E% lower for carbohydrates and 30.6 ± 2.2 E% higher for fat, respectively, compared with the control group (all P < .001). The LCD reduced HbA1c after 3 months (-8.9 ± 1.7 mmol/mol; P < .0001), and this was maintained after 6 months (-7.5 ± 1.8 mmol/mol; P < .0001) compared with the control diet. The LCD also reduced weight (-3.9 ± 1.0 kg), body mass index (-1.4 ± 0.4 kg/m² ), and waist circumference (-4.9 ± 1.3 cm) compared with the control diet (all P < .01), accompanied by reductions in total fat mass (-2.2 ± 1.0 kg; P = .027) and lean mass (-1.3 ± 0.6 kg; P = .017). No changes in blood lipids or blood pressure were seen after 6 months. The level of physical activity was maintained, and there were no episodes of severe hypoglycaemia.

CONCLUSION

A non-calorie-restricted LCD high in fat has significant beneficial effects on glycaemic control and body composition, and does not adversely affect cardiovascular risk factors in patients with T2D. Reducing carbohydrate intake to 10-25 E% appears to be an effective and safe nutritional approach with respect to classical cardiovascular risk factors and hypoglycaemia.

Continuous Glucose Monitoring With Low-Carbohydrate Nutritional Coaching to Improve Type 2 Diabetes Control: Randomized Quality Improvement Program

BACKGROUND

Type 2 diabetes mellitus (T2DM) is a leading cause of morbidity and mortality globally, with adverse health consequences largely related to hyperglycemia. Despite clinical practice guideline recommendations, effective pharmacotherapy, and interventions to support patients and providers, up to 60% of patients diagnosed with T2DM are estimated to have hemoglobin A_1c (HbA_1c) levels above the recommended targets owing to multilevel barriers hindering optimal glycemic control.

OBJECTIVE

The aim of this study is to compare changes in HbA_1c levels among patients with suboptimally controlled T2DM who were offered the opportunity to use an intermittently viewed continuous glucose monitor and receive personalized low-carbohydrate nutrition counseling (<100 g/day) versus those who received usual care (UC).

METHODS

This was a 12-month, pragmatic, randomized quality improvement program. All adult patients with T2DM who received primary care at a university-affiliated primary care clinic (N=1584) were randomized to either the UC or the enhanced care (EC) group. Within each program arm, we identified individuals with HbA_1c >7.5% (58 mmol/mol) who were medically eligible for tighter glycemic control, and we defined these subgroups as UC-high risk (UC-HR) or EC-HR. UC-HR participants (n=197) received routine primary care. EC-HR participants (n=185) were invited to use an intermittently viewed continuous glucose monitor and receive low-carbohydrate nutrition counseling. The primary outcome was mean change in HbA_1c levels from baseline to 12 months using an intention-to-treat difference-in-differences analysis comparing EC-HR with UC-HR groups. We conducted follow-up semistructured interviews to understand EC-HR participant experiences with the intervention.

RESULTS

HbA_1c decreased by 0.41% (4.5 mmol/mol; P=.04) more from baseline to 12 months among participants in the EC-HR group than among those in UC-HR; however, only 61 (32.9%) of 185 EC-HR participants engaged in the program. Among the EC-HR participants who wore continuous glucose monitors (61/185, 32.9%), HbA_1c was 1.1% lower at 12 months compared with baseline (P<.001). Interviews revealed themes related to EC-HR participants' program engagement and continuous glucose monitor use.

CONCLUSIONS

Among patients with suboptimally controlled T2DM, a combined approach that includes continuous glucose monitoring and low-carbohydrate nutrition counseling can improve glycemic control compared with the standard of care.

Ketogenic diet for human diseases: the underlying mechanisms and potential for clinical implementations

The ketogenic diet (KD) is a high-fat, adequate-protein, and very-low-carbohydrate diet regimen that mimics the metabolism of the fasting state to induce the production of ketone bodies. The KD has long been established as a remarkably successful dietary approach for the treatment of intractable epilepsy and has increasingly garnered research attention rapidly in the past decade, subject to emerging evidence of the promising therapeutic potential of the KD for various diseases, besides epilepsy, from obesity to malignancies. In this review, we summarize the experimental and/or clinical evidence of the efficacy and safety of the KD in different diseases, and discuss the possible mechanisms of action based on recent advances in understanding the influence of the KD at the cellular and molecular levels. We emphasize that the KD may function through multiple mechanisms, which remain to be further elucidated. The challenges and future directions for the clinical implementation of the KD in the treatment of a spectrum of diseases have been discussed. We suggest that, with encouraging evidence of therapeutic effects and increasing insights into the mechanisms of action, randomized controlled trials should be conducted to elucidate a foundation for the clinical use of the KD.

The Ketogenic Diet for Refractory Mental Illness: A Retrospective Analysis of 31 Inpatients

BACKGROUND AND HYPOTHESIS

The robust evidence base supporting the therapeutic benefit of ketogenic diets in epilepsy and other neurological conditions suggests this same metabolic approach may also benefit psychiatric conditions.

STUDY DESIGN

In this retrospective analysis of clinical care, 31 adults with severe, persistent mental illness (major depressive disorder, bipolar disorder, and schizoaffective disorder) whose symptoms were poorly controlled despite intensive psychiatric management were admitted to a psychiatric hospital and placed on a ketogenic diet restricted to a maximum of 20 grams of carbohydrate per day as an adjunct to conventional inpatient care. The duration of the intervention ranged from 6 to 248 days.

STUDY RESULTS

Three patients were unable to adhere to the diet for >14 days and were excluded from the final analysis. Among included participants, means and standard deviations (SDs) improved for the Hamilton Depression Rating Scale scores from 25.4 (6.3) to 7.7 (4.2), P < 0.001 and the Montgomery-Åsberg Depression Rating Scale from 29.6 (7.8) to 10.1 (6.5), P < 0.001. Among the 10 patients with schizoaffective illness, mean (SD) of the Positive and Negative Syndrome Scale (PANSS) scores improved from 91.4 (15.3) to 49.3 (6.9), P < 0.001. Significant improvements were also observed in metabolic health measures including weight, blood pressure, blood glucose, and triglycerides.

CONCLUSIONS

The administration of a ketogenic diet in this semi-controlled setting to patients with treatment-refractory mental illness was feasible, well-tolerated, and associated with significant and substantial improvements in depression and psychosis symptoms and multiple markers of metabolic health.

Ketogenic diet aggravates colitis, impairs intestinal barrier and alters gut microbiota and metabolism in DSS-induced mice

Inflammatory bowel disease (IBD) is an idiopathic inflammatory disease with a high incidence. Multiple factors including dietary composition contribute to its occurrence. Recently, ketogenic diet which consists of a high proportion of fat and low carbohydrates has gained great popularity. Our study is aimed to explore the effect of ketogenic diet on IBD and its potential mechanisms. C57BL/6 mice were given a ketogenic diet or a control diet for a month and IBD was induced by 2% DSS in drinking water in the last week. Gut histology, inflammatory cytokines and chemokines, gut microbiota and metabolism were assessed. Ketogenic diet substantially worsened colitis, in terms of higher body weight loss, DAI scores and histological scores as well as colon length shortening. Levels of serum and colon inflammatory cytokines and chemokines (IL-1α, IL-6, TNF-α, IL-17, GM-CSF and IL-10) were significantly up-regulated in mice treated with ketogenic diet and DSS. Increased intestinal permeability and decreased expressions of intestinal epithelial barrier associated genes were observed due to ketogenic diet administration. Pretreatment with ketogenic diet alters the bacterial abundance, increasing pathogenic taxa such as Proteobacteria, Enterobacteriaceae, Helicobacter and Escherichia-Shigella and decreasing potential beneficial taxa such as Erysipelotrichaceae. Ketogenic diet also modified gut metabolism, increasing metabolites in the bile secretion such as ouabain, taurochenodeoxycholic acid, quinine, cholic acid and glycocholic acid, and decreasing metabolites associated with the biosynthesis of unsaturated fatty acids including stearic acid, arachidic acid, erucic acid, and docosanoic acid. These results suggest that ketogenic diet aggravates DSS-induced colitis in mice by increasing intestinal and systemic inflammation, and disrupting the intestinal barrier, which results from modulated gut microbiota and metabolism.

Nutrition, nutritional deficiencies, and schizophrenia: An association worthy of constant reassessment

Schizophrenia is a mental health disorder that occurs worldwide, cutting across cultures, socioeconomic groups, and geographical barriers. Understanding the details of the neurochemical basis of schizophrenia, factors that contribute to it and possible measures for intervention are areas of ongoing research. However, what has become more evident is the fact that in targeting the neurochemical imbalances that may underlie schizophrenia, the type of response seen with currently available phamacotherapeutic agents does not provide all the answers that are needed. Therefore, the possible contribution of non-pharmacological approaches to schizophrenia management is worthy of consideration. In recent times, research is beginning to show nutrition may play a possibly significant role in schizophrenia, affecting its development, progression and management; however, while attempts had been made to examine this possible relationship from different angles, articles addressing it from a holistic point of view are not common. In this review, we examine existing scientific literature dealing with the possible relationship between nutrition and schizophrenia, with a view to elucidating the impact of diet, nutritional deficiencies and excesses on the aetiology, progression, management and outcome of schizophrenia. Secondly, the effect of nutritional supplements in prevention, as sole therapy, or adjuncts in schizophrenia management are examined.

The therapeutic properties of ketogenic diets, slow-wave sleep, and circadian synchrony

PURPOSE OF REVIEW

To summarize emerging connections between sleep, ketogenic diets, and health.

RECENT FINDINGS

Mechanisms involved in the therapeutic benefits of ketogenic diets continue to be elucidated. Concurrently, the importance of sleep quality and circadian rhythms in their effects on metabolic and cognitive health is increasingly appreciated. Advances in the understanding of the actions of adenosine, nicotinamide adenine dinucleotide, and slow-wave sleep underscore connections between these areas of research.

SUMMARY

Many molecular pathways activated during ketogenic diets are known to modulate sleep-wake cycles, circadian rhythms, and sleep stages. Ketogenic diets often have beneficial effects on sleep at the same time as having beneficial effects on particular medical conditions. Enhancement of slow-wave sleep and rejuvenation of circadian programming may be synergistic with or causally involved in the benefits of ketogenic diets.

A randomized controlled trial of pharmacist-led therapeutic carbohydrate and energy restriction in type 2 diabetes

Type 2 diabetes can be treated, and sometimes reversed, with dietary interventions; however, strategies to implement these interventions while addressing medication changes are lacking. We conducted a 12-week pragmatic, community-based parallel-group randomized controlled trial (ClinicalTrials.gov: NCT03181165) evaluating the effect of a low-carbohydrate (<50 g), energy-restricted diet (~850-1100 kcal/day; Pharm-TCR; n = 98) compared to treatment-as-usual (TAU; n = 90), delivered by community pharmacists, on glucose-lowering medication use, cardiometabolic health, and health-related quality of life. The Pharm-TCR intervention was effective in reducing the need for glucose-lowering medications through complete discontinuation of medications (35.7%; n = 35 vs. 0%; n = 0 in TAU; p < 0.0001) and reduced medication effect score compared to TAU. These reductions occurred concurrently with clinically meaningful improvements in hemoglobin A1C, anthropometrics, blood pressure, and triglycerides (all p < 0.0001). These data indicate community pharmacists are a viable and innovative option for implementing short-term nutritional interventions for people with type 2 diabetes, particularly when medication management is a safety concern.

Community pharmacists are accessible healthcare providers with expertise in medication management. Here the authors show that a low-carbohydrate, low-energy diet implemented by community pharmacists reduced diabetes medication use and improved glucose control in people with type 2 diabetes.

A Pragmatic Approach to Translating Low- and Very Low-Carbohydrate Diets Into Clinical Practice for Patients With Obesity and Type 2 Diabetes

Across all eating patterns, individuals demonstrate marked differences in treatment response; some individuals gain weight and others lose weight with the same approach. Policy makers and research institutions now call for the development and use of personalized nutrition counseling strategies rather than one-size-fits-all dietary recommendations. However, challenges persist in translating some evidence-based eating patterns into the clinical practice due to the persistent notion that certain dietary approaches-regardless of individuals' preferences and health outcomes-are less healthy than others. For example, low- and very low-carbohydrate ketogenic diets (VLCKDs)-commonly defined as 10-26% and <10% total daily energy from carbohydrate, respectively-are recognized as viable lifestyle change options to support weight loss, glycemic control, and reduced medication use. Yet, critics contend that such eating patterns are less healthy and encourage general avoidance rather than patient-centered use. As with all medical treatments, the potential benefits and risks must be considered in the context of patient-centered, outcome-driven care; this is the cornerstone of evidence-based medicine. Thus, the critical challenge is to identify and safely support patients who may prefer and benefit from dietary carbohydrate restriction. In this Perspective, we propose a pragmatic, 4-stepped, outcome-driven approach to help health professionals use carbohydrate-restricted diets as one potential tool for supporting individual patients' weight loss and metabolic health.

Low Carbohydrate Dietary Approaches for People With Type 2 Diabetes-A Narrative Review

Although carbohydrate restriction is not a new approach for the management of Type 2 diabetes, interest in its safety and efficacy has increased significantly in recent years. The purpose of the current narrative review is to summarise the key relevant research and practical considerations in this area, as well as to explore some of the common concerns expressed in relation to the use of such approaches. There is a strong physiological rationale supporting the role of carbohydrate restriction for the management of Type 2 diabetes, and available evidence suggests that low carbohydrate dietary approaches (LCDs) are as effective as, or superior to, other dietary approaches for its management. Importantly, LCDs appear to be more effective than other dietary approaches for facilitating a reduction in the requirement for certain medications, which leads to their effects on other health markers being underestimated. LCDs have also been demonstrated to be an effective method for achieving remission of Type 2 diabetes for some people. The available evidence does not support concerns that LCDs increase the risk of cardiovascular disease, that such approaches increase the risk of nutrient deficiencies, or that they are more difficult to adhere to than other dietary approaches. A growing number of organisations support the use of LCDs as a suitable choice for individuals with Type 2 diabetes.

Mechanical, sensory, and consumer evaluation of ketogenic, gluten-free breads

Ketogenic, gluten-free breads comprised of almond flour, oat bran fiber, or combinations of both were compared. The textural properties, sensory attributes, and consumer acceptance were analyzed on each bread containing 100% almond flour (AF), 66.7% almond flour with 33.3% oat bran fiber (AOB), 66.7% oat bran fiber with 33.3% almond flour (OBA), and 100% oat bran fiber (OB). AF and AOB breads had a more open crumb structure composed of cells between 1-4 mm2. OBA and OB had a significantly dense crumb pattern made up of more cells less than one millimeter squared. Quantitative-descriptive analysis (QDA) and consumer acceptance testing was conducted 24 hr after baking and mechanical endpoints were evaluated 24, 72, and 120 hr after baking. AF and AOB breads were preferred over OBA and OB breads in QDA evaluation and consumer acceptance scores. Greater percentages of oat bran fiber resulted in a bread that was less moist, firmer in texture, and chewier with trained panelists. In both sensory evaluations, higher amounts of almond flour resulted in higher values in eggy flavor while increased amounts of oat bran fiber correlated with higher values in earthy flavor. Mechanical testing identified higher percentages of almond flour resulted in bread that was less firm and less chewy. Over time, all variations with almond flour became softer and less chewy, while the OB bread increased in firmness. Sensory cohesiveness did not correlate with the mechanical equivalent, identifying a need to re-evaluate the parameters used to calculate this objective endpoint.

Ketogenic diet alleviates colitis by reduction of colonic group 3 innate lymphoid cells through altering gut microbiome

Accumulating evidence suggests that ketogenic diets (KDs) mediate the rise of circulating ketone bodies and exert a potential anti-inflammatory effect; however, the consequences of this unique diet on colitis remain unknown. We performed a series of systematic studies using a dextran sulfate sodium (DSS) animal model of inflammatory colitis. Animals were fed with a KD, low-carbohydrate diet (LCD), or normal diet (ND). Germ-free mice were utilized in validation experiments. Colon tissues were analyzed by transcriptome sequencing, RT2 profiler PCR array, histopathology, and immunofluorescence. Serum samples were analyzed by metabolic assay kit. Fecal samples were analyzed by 16S rRNA gene sequencing, liquid chromatography-mass spectrometry and gas chromatography-mass spectrometry. We observed that KD alleviated colitis by altering the gut microbiota and metabolites in a manner distinct from LCD. Quantitative diet experiments confirmed the unique impact of KD relative to LCD with a reproducible increase in Akkermansia, whereas the opposite was observed for Escherichia/Shigella. After colitis induction, the KD protected intestinal barrier function, and reduced the production of RORγt+CD3- group 3 innate lymphoid cells (ILC3s) and related inflammatory cytokines (IL-17α, IL-18, IL-22, Ccl4). Finally, fecal microbiota transplantation into germ-free mice revealed that the KD- mediated colitis inhibition and ILC3 regulation were dependent on the modification of gut microbiota. Taken together, our study presents a global view of microbiome-metabolomics changes that occur during KD colitis treatment, and identifies the regulation of gut microbiome and ILC3s as novel targets involving in IBD dietary therapy.

Adherence to Ketogenic and Mediterranean Study Diets in a Crossover Trial: The Keto-Med Randomized Trial

Adherence is a critical factor to consider when interpreting study results from randomized clinical trials (RCTs) comparing one diet to another, but it is frequently not reported by researchers. The purpose of this secondary analysis of the Keto-Med randomized trial was to provide a detailed examination and comparison of the adherence to the two study diets (Well Formulated Ketogenic Diet (WFKD) and Mediterranean Plus (Med-Plus)) under the two conditions: all food being provided (delivered) and all food being obtained by individual participants (self-provided). Diet was assessed at six time points including baseline (×1), week 4 of each phase when participants were receiving food deliveries (×2), week 12 of each phase when participants were preparing and providing food on their own (×2), and 12 weeks after participants completed both diet phases and were free to choose their own diet pattern (×1). The adherence scores for WFKD and Med-Plus were developed specifically for this study. Average adherence to the two diet patterns was very similar during both on-study time points of the intervention. Throughout the study, a wide range of adherence was observed among participants-for both diet types and during both the delivery phase and self-provided phase. Insight from this assessment of adherence may aid other researchers when answering the important question of how to improve behavioral adherence during dietary trials. This study is registered at clinicaltrials.gov NCT03810378.

A Comparison of Feature Selection and Forecasting Machine Learning Algorithms for Predicting Glycaemia in Type 1 Diabetes Mellitus

Type 1 diabetes mellitus (DM1) is a metabolic disease derived from falls in pancreatic insulin production resulting in chronic hyperglycemia. DM1 subjects usually have to undertake a number of assessments of blood glucose levels every day, employing capillary glucometers for the monitoring of blood glucose dynamics. In recent years, advances in technology have allowed for the creation of revolutionary biosensors and continuous glucose monitoring (CGM) techniques. This has enabled the monitoring of a subject’s blood glucose level in real time. On the other hand, few attempts have been made to apply machine learning techniques to predicting glycaemia levels, but dealing with a database containing such a high level of variables is problematic. In this sense, to the best of the authors’ knowledge, the issues of proper feature selection (FS)—the stage before applying predictive algorithms—have not been subject to in-depth discussion and comparison in past research when it comes to forecasting glycaemia. Therefore, in order to assess how a proper FS stage could improve the accuracy of the glycaemia forecasted, this work has developed six FS techniques alongside four predictive algorithms, applying them to a full dataset of biomedical features related to glycaemia. These were harvested through a wide-ranging passive monitoring process involving 25 patients with DM1 in practical real-life scenarios. From the obtained results, we affirm that Random Forest (RF) as both predictive algorithm and FS strategy offers the best average performance (Root Median Square Error, RMSE = 18.54 mg/dL) throughout the 12 considered predictive horizons (up to 60 min in steps of 5 min), showing Support Vector Machines (SVM) to have the best accuracy as a forecasting algorithm when considering, in turn, the average of the six FS techniques applied (RMSE = 20.58 mg/dL).

Fat, Sugar or Gut Microbiota in Reducing Cardiometabolic Risk: Does Diet Type Really Matter?

The incidence of cardiometabolic diseases, such as obesity, diabetes, and cardiovascular diseases, is constantly rising. Successful lifestyle changes may limit their incidence, which is why researchers focus on the role of nutrition in this context. The outcomes of studies carried out in past decades have influenced dietary guidelines, which primarily recommend reducing saturated fat as a therapeutic approach for cardiovascular disease prevention, while limiting the role of sugar due to its harmful effects. On the other hand, a low-carbohydrate diet (LCD) as a method of treatment remains controversial. A number of studies on the effect of LCDs on patients with type 2 diabetes mellitus proved that it is a safe and effective method of dietary management. As for the risk of cardiovascular diseases, the source of carbohydrates and fats corresponds with the mortality rate and protective effect of plant-derived components. Additionally, some recent studies have focused on the gut microbiota in relation to cardiometabolic diseases and diet as one of the leading factors affecting microbiota composition. Unfortunately, there is still no precise answer to the question of which a single nutrient plays the most important role in reducing cardiometabolic risk, and this review article presents the current state of the knowledge in this field.

Reversal of diabetic tractional retinal detachment attributed to keto diet

A 40-year-old woman, known type 2 diabetes mellitus, obese (100 kg), on insulin (80 units), was under treatment for unstable proliferative diabetic retinopathy with extramacular tractional retinal detachment (TRD) in the left eye. At 1-year follow-up, she developed progression of TRD involving the macula in the left eye for which she was advised surgery. She did not follow-up for 6 months during which time she had adopted a coconut oil-rich ketogenic diet. She reported losing 25 kg body weight along with reversal of diabetes (Glycosylated Haemglobin (HbA1C) of 5.3% without insulin) in the interim. During this 2-year follow-up visit, it was found that there was complete resolution of macular detachment due to TRD in the left eye with stable vision. This was attributed to the impactful ketogenic diet.

Effects of the Ketogenic Diet on Glycemic Control in Diabetic Patients: Meta-Analysis of Clinical Trials

Introduction

The ketogenic diet is a diet that relies on reducing carbohydrate intake to a minimum while increasing fat intake. This induces a state of ketosis where it is hypothesized to favor fat metabolism for energy instead of carbohydrates. The diet is used to treat pediatric patients with seizures to control their symptoms. Today, it is used by many to help in weight loss. Extensive research is being conducted on the benefits of the diet, as it gains popularity among patients with diabetes and obesity, to evaluate its effects on glycemic control.

Methods

This review looks at the published literature and summarizes the interventional trials that use the ketogenic diet for glycemic control. Emphasis was on pooling the results of selected variables such as weight, glycemic control, and lipid profile. The meta-analysis was conducted by a trained statistician using the Cochrane software review manager (Revman version 5.4; Cochrane, London, UK). Results were reviewed by an independent reviewer adhering to the Cochrane Collaboration's guidelines.

Results

The findings of this review show a significant effect of the ketogenic diet as compared to controls in terms of weight reduction, glycemic control, and improved lipid profile. A noticeable improvement was seen in glycated hemoglobin (HbA1c) and in high-density lipoprotein (HDL), favoring the ketogenic diet as compared to control.

Conclusion

This review concludes that the ketogenic diet is superior to controls in terms of glycemic control and lipid profile improvements, and the results are significant enough to recommend it as an adjunctive treatment for type two diabetes.

Low carbohydrate diet: are concerns with saturated fat, lipids, and cardiovascular disease risk justified?

PURPOSE OF REVIEW

There is an extensive literature on the efficacy of the low carbohydrate diet (LCD) for weight loss, and in the improvement of markers of the insulin-resistant phenotype, including a reduction in inflammation, atherogenic dyslipidemia, hypertension, and hyperglycemia. However, critics have expressed concerns that the LCD promotes unrestricted consumption of saturated fat, which may increase low-density lipoprotein (LDL-C) levels. In theory, the diet-induced increase in LDL-C increases the risk of cardiovascular disease (CVD). The present review provides an assessment of concerns with the LCD, which have focused almost entirely on LDL-C, a poor marker of CVD risk. We discuss how critics of the LCD have ignored the literature demonstrating that the LCD improves the most reliable CVD risk factors.

RECENT FINDINGS

Multiple longitudinal clinical trials in recent years have extended the duration of observations on the safety and effectiveness of the LCD to 2-3 years, and in one study on epileptics, for 10 years.

SUMMARY

The present review integrates a historical perspective on the LCD with a critical assessment of the persistent concerns that consumption of saturated fat, in the context of an LCD, will increase risk for CVD.

Intervention Enhancement Strategies Among Adults With Type 2 Diabetes in a Very Low-Carbohydrate Web-Based Program: Evaluating the Impact With a Randomized Trial

BACKGROUND

Adults with type 2 diabetes may experience health benefits, including glycemic control and weight loss, from following a very low-carbohydrate, ketogenic (VLC) diet. However, it is unclear which ancillary strategies may enhance these effects.

OBJECTIVE

This pilot study aims to estimate the effect sizes of 3 intervention enhancement strategies (text messages, gifts, and breath vs urine ketone self-monitoring) that may improve outcomes of a 12-month web-based ad libitum VLC diet and lifestyle intervention for adults with type 2 diabetes. The primary intervention also included other components to improve adherence and well-being, including positive affect and mindfulness as well as coaching.

METHODS

Overweight or obese adults (n=44; BMI 25-45 kg/m²) with type 2 diabetes (glycated hemoglobin [HbA_1c] ≥6.5%), who had been prescribed either no glucose-lowering medications or metformin alone, participated in a 12-month web-based intervention. Using a 2×2×2 randomized factorial design, we compared 3 enhancement strategies: (1) near-daily text messages about the intervention's recommended behaviors (texts n=22 vs no texts n=22), (2) mailed gifts of diet-relevant foods and cookbooks (6 rounds of mailed gifts n=21 vs no gifts n=23), and (3) urine- or breath-based ketone self-monitoring (urine n=21 vs breath n=23). We assessed HbA_1c and weight at baseline and at 4, 8, and 12 months. We evaluated whether each strategy exerted a differential impact on HbA_1c and weight at 12 months against an a priori threshold of Cohen d of 0.5 or greater.

RESULTS

We retained 73% (32/44) of the participants at 12 months. The intervention, across all conditions, led to improvements in glucose control and reductions in body weight at the 12-month follow-up. In intent-to-treat (ITT) analyses, the mean HbA_1c reduction was 1.0% (SD 1.6) and the mean weight reduction was 5.3% (SD 6.0), whereas among study completers, these reductions were 1.2% (SD 1.7) and 6.3% (SD 6.4), respectively, all with a P value of less than .001. In ITT analyses, no enhancement strategy met the effect size threshold. Considering only study completers, 2 strategies showed a differential effect size of at least a d value of 0.5 or greater.

CONCLUSIONS

Text messages, gifts of food and cookbooks, and urine-based ketone self-monitoring may potentially enhance the glycemic or weight loss benefits of a web-based VLC diet and lifestyle intervention for individuals with type 2 diabetes. Future research could investigate other enhancement strategies to help create even more effective solutions for the treatment of type 2 diabetes.

TRIAL REGISTRATION

ClinicalTrials.gov NCT02676648; http://clinicaltrials.gov/ct2/show/NCT02676648.

Very-Low-Calorie Ketogenic Diets With Whey, Vegetable, or Animal Protein in Patients With Obesity: A Randomized Pilot Study

CONTEXT

We compared the efficacy, safety, and effect of 45-day isocaloric very-low-calorie ketogenic diets (VLCKDs) incorporating whey, vegetable, or animal protein on the microbiota in patients with obesity and insulin resistance to test the hypothesis that protein source may modulate the response to VLCKD interventions.

SUBJECTS AND METHODS

Forty-eight patients with obesity (19 males and 29 females, homeostatic model assessment (HOMA) index ≥ 2.5, aged 56.2 ± 6.1 years, body mass index [BMI] 35.9 ± 4.1 kg/m2) were randomly assigned to three 45-day isocaloric VLCKD regimens (≤800 kcal/day) containing whey, plant, or animal protein. Anthropometric indexes; blood and urine chemistry, including parameters of kidney, liver, glucose, and lipid metabolism; body composition; muscle strength; and taxonomic composition of the gut microbiome were assessed. Adverse events were also recorded.

RESULTS

Body weight, BMI, blood pressure, waist circumference, HOMA index, insulin, and total and low-density lipoprotein cholesterol decreased in all patients. Patients who consumed whey protein had a more pronounced improvement in muscle strength. The markers of renal function worsened slightly in the animal protein group. A decrease in the relative abundance of Firmicutes and an increase in Bacteroidetes were observed after the consumption of VLCKDs. This pattern was less pronounced in patients consuming animal protein.

CONCLUSIONS

VLCKDs led to significant weight loss and a striking improvement in metabolic parameters over a 45-day period. VLCKDs based on whey or vegetable protein have a safer profile and result in a healthier microbiota composition than those containing animal proteins. VLCKDs incorporating whey protein are more effective in maintaining muscle performance.

High-protein diet: A barrier to the nephroprotective effects of sodium-glucose co-transporter-2 inhibitors?

Glomerular hyperfiltration is a common finding in patients with diabetes and poor glycaemic control; whole-kidney hyperfiltration, with glomerular filtration rate (GFR) values above normal, should be differentiated from single nephron hyperfiltration, consequent to nephron loss and compensatory hyperfiltration of the remnant nephrons. This is the result of an imbalance between the vascular tone of the afferent and efferent arterioles. Hormonal influences and/or an impaired tubuloglomerular feedback (TGF) system, because of excessive sodium (Na⁺ ) and glucose reabsorption in the proximal tubule, contribute to determine hyperfiltration. Sodium-glucose co-transporter-2 inhibitors (SGLT2is), by decreasing Na⁺ reabsorption and increasing the delivery of Na⁺ to the macula densa, lead to normalization of TGF, and, consequently, decrease GFR (both whole and single nephron). High-protein diets are popular among patients with type 1 and type 2 diabetes; importantly, 80% of the amino acids are also reabsorbed in the proximal tubule of the nephron and are transported by symporters that use the electro-chemical gradient of Na⁺ . Indeed, an acute protein load is associated with increased Na⁺ reabsorption and an increase in GFR. Here, we hypothesize that high-protein diets, by increasing Na⁺ reabsorption and GFR, may offset the positive renal effects of SGLT2is.

Comparing the Keyto App and Device with Weight Watchers' WW App for Weight Loss: Protocol for a Randomized Trial

BACKGROUND

Obesity and being overweight are major contributing factors for many diseases. Calorie restricted diets often fail to result in sustained long-term weight loss. Very low-carbohydrate, high-fat ketogenic diets have been suggested to have superior metabolic and weight loss effects. Keyto is a low-cost, highly scalable mobile health (mHealth) app paired with a noninvasive biofeedback tool aimed at facilitating weight loss through a personalized healthy and predominantly plant- and fish-based ketogenic diet.

OBJECTIVE

This protocol describes a randomized trial comparing the efficacy of the Keyto mHealth app and device intervention to that of Weight Watchers' WW app in individuals who are overweight or obese. The primary outcome is weight loss after 12 weeks. Secondary and exploratory outcomes, including metabolic and cardiovascular risk factors, will be assessed at 12, 24, and 48 weeks.

METHODS

A total of 144 participants will be recruited and randomized to either the Keyto program or Weight Watchers program. Study participants will be guided through the study via video conference or phone calls and will undergo a fasting blood analysis performed by a third-party diagnostic lab at weeks 0 and 12 to assess metabolic and cardiovascular risk markers. All participants will be asked to weigh themselves daily on a study-provided Bluetooth-enabled scale. Participants randomized to the Keyto arm will also be asked to measure their breath acetone levels, a measure of ketosis, with the Keyto device 3 times per day.

RESULTS

Recruitment started in December 2019. Rolling recruitment is expected to be completed by July 2020. Data collection and analysis of the primary intervention phase is expected to be completed in October 2020. The 24- and 48-week follow-ups are expected to be completed in January 2021 and July 2021, respectively.

CONCLUSIONS

This trial will provide high-quality evidence regarding the efficacy of the Keyto weight loss program in individuals who are overweight and obese in a free-living condition. This study also fills a gap by examining the impact of a ketogenic diet emphasizing plant- and fish-based fats on blood lipid profile and cardiovascular disease risk.

TRIAL REGISTRATION

ClinicalTrials.gov NCT04165707; https://clinicaltrials.gov/ct2/show/NCT04165707.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

DERR1-10.2196/19053.

The Effects of a Low Calorie Ketogenic Diet on Glycaemic Control Variables in Hyperinsulinemic Overweight/Obese Females

Diet is a factor which can influence both glycaemic variables and body mass. The aim of this study was to compare the influence of a 12-week, well-planned, low-calorie ketogenic diet (LCKD) on hyperglycaemic, hyperinsulinemic and lipid profile in adult, overweight or obese females. Ninety-one females who participated in the study were divided into two groups: a LCKD group who followed a hypocaloric ketogenic diet (8% of carbohydrate, 72% of fat and 20% of proteins) (n = 46), and a control group (CG) (n = 45) who continued their typical diet (50% of carbohydrates, 32% of fat and 18% of proteins). Methods: Baseline and post-intervention glucose (Gl), insulin (I), glycated haemoglobin (HbA1c), Homeostatic model assessment HOMA-IR, triglycerides (TG) and high-density cholesterol (HDL-C) were evaluated. Also, body mass (BM), waist circumference (WC), hip circumference (HC) and thigh circumference (TC) were measured. Results: Compared with the CG, there were significant changes observed in the LCKD group regarding all biochemical variables. Also, BM, TC, WC and AC changed significantly in the LCKD group compared with the CG. Conclusions: The 12-week LCKD intervention changed the glucose control variables, body mass, as well as waist, hip and thigh circumferences. A low-calorie ketogenic diet may be recommended for adult females with glucose control variables disturbance and excess body mass.

Type 2 Diabetes Remission and Lifestyle Medicine: A Position Statement From the American College of Lifestyle Medicine

Objectives. The present review represents the position of the American College of Lifestyle Medicine on type 2 diabetes (T2D) and remission treatment. Background. Research now reveals that sufficiently intensive lifestyle interventions can produce remission of T2D with similar success to bariatric surgery, but with substantially fewer untoward side effects. Methods. A literature review was conducted to examine lifestyle modifications targeting T2D remission, with most studies using a combination of blood glucose markers and treatment history. Results. There were notable differences in the dosing intensity of lifestyle interventions between therapeutic interventions and subtherapeutic interventions. Studies with therapeutic dosing typically used very low energy diets (600-1100 kcal/day) with a weighted mean remission rate of 49.4%, while studies with subtherapeutic dosing typically used more moderate caloric restrictions (reducing energy intake by 500-600 kcal/day) and the weighted mean remission rate was 6.9%. Conclusions. Remission should be the clinical goal in T2D treatment, using properly dosed intensive lifestyle interventions as a primary component of medical care for T2D patients.