Very low calorie ketogenic diets in overweight and obesity treatment: Effects on anthropometric parameters, body composition, satiety, lipid profile and microbiota

Obesity and Obesity-Related Thyroid Dysfunction: Any Potential Role for the Very Low-Calorie Ketogenic Diet (VLCKD)?

PURPOSE OF REVIEW

This review aims to explore in-depth the different aspects of the association between very low-calorie ketogenic diet (VLCKD), obesity and obesity-related thyroid dysfunction.

RECENT FINDINGS

The VLCKD, proposed as a non-pharmacological strategy for the management of certain chronic diseases, is becoming increasingly popular worldwide. Initially used to treat epilepsy, it has been shown to be effective in controlling body weight gain and addressing various pathophysiological conditions. Research has shown that a low-calorie, high-fat diet can affect thyroid hormone levels. Weight loss can also influence thyroid hormone levels. Studies have suggested that long-term use of VLCKD for refractory epilepsy may be related to the development of hypothyroidism, with an effect seen in various populations. In particular, women with obesity following VLCKD tend to have reduced T3 levels. We propose further research to unravel the underlying mechanisms linking VLCKD to obesity and obesity-related thyroid dysfunction.

Nutritional Considerations During Major Weight Loss Therapy: Focus on Optimal Protein and a Low-Carbohydrate Dietary Pattern

PURPOSE OF REVIEW

Considering the high prevalence of obesity and related metabolic impairments in the population, the unique role nutrition has in weight loss, reversing metabolic disorders, and maintaining health cannot be overstated. Normal weight and well-being are compatible with varying dietary patterns, but for the last half century there has been a strong emphasis on low-fat, low-saturated fat, high-carbohydrate based approaches. Whereas low-fat dietary patterns can be effective for a subset of individuals, we now have a population where the vast majority of adults have excess adiposity and some degree of metabolic impairment. We are also entering a new era with greater access to bariatric surgery and approval of anti-obesity medications (glucagon-like peptide-1 analogues) that produce substantial weight loss for many people, but there are concerns about disproportionate loss of lean mass and nutritional deficiencies.

RECENT FINDINGS

No matter the approach used to achieve major weight loss, careful attention to nutritional considerations is necessary. Here, we examine the recent findings regarding the importance of adequate protein to maintain lean mass, the rationale and evidence supporting low-carbohydrate and ketogenic dietary patterns, and the potential benefits of including exercise training in the context of major weight loss. While losing and sustaining weight loss has proven challenging, we are optimistic that application of emerging nutrition science, particularly personalized well-formulated low-carbohydrate dietary patterns that contain adequate protein (1.2 to 2.0 g per kilogram reference weight) and achieve the beneficial metabolic state of euketonemia (circulating ketones 0.5 to 5 mM), is a promising path for many individuals with excess adiposity.

Scoping review of obesity interventions: Research frontiers and publication status

Obesity and overweight are significant global health issues, and numerous obesity intervention studies have been conducted. Summarizing current knowledge of interventions aims to inform researchers and policymakers to keep up-to-date with the latest scientific advancements and trends. In this review, we comprehensively retrieved and screened 4,541 studies on obesity intervention published between 2018 and 2022 in the Web of Science Core Collection, and objectively presented research frontiers using bibliometric analysis. The research frontiers of intervention are mainly focused on dietary, exercise, pharmacological interventions, bariatric surgery, environmental, and cognitive interventions. Time-restricted eating is the hottest research topic, followed by probiotics and Roux-en-Y gastric bypass. Gut microbiota is located in the "Basic and transversal themes" quadrant with a high centrality and low density, which has great development potentiality. Obesity intervention is becoming increasingly common,and we advocate for researchers to undertake more focused research endeavors that consider the specific characteristics of diverse populations or patients.

Does gut microbiota affect the success of weight loss? Evidence and speculation

Obesity is a chronic state of excessive fat accumulation in the body, characterized by significant relapse and complicated by a range of health consequences. In the treatment of obesity, a holistic approach including diet, physical activity, pharmacotherapy, bariatric surgery, and psychological support is recommended. The implications of gut microbiota (GM) as a pathogenic factor in excess body weight have been discussed, and microbial-targeted therapies-including probiotics, prebiotics, and synbiotics-are considered adjuvant in obesity management. Many studies have focused on assessing the effectiveness of probiotics, prebiotics, or synbiotics in weight control, although with inconclusive results, mainly because of the significant heterogeneity of the studies (with different strains, doses, forms, interventional durations, and outcomes). It is also unclear whether using probiotics or synbiotics accompanied by weight loss dietary interventions or as a part of bariatric surgery will be more effective in obesity management, not only in the short-term but also for long-term weight loss maintenance. The aim of this study was to collect and compare the available scientific data on the effectiveness of probiotic or synbiotic supplementation (as a single therapy versus as part of dietary interventions, pharmacotherapy, or bariatric therapy) on weight control in obesity.

Short- and long-term effects of very low- and low-calorie ketogenic diets on metabolism and cardiometabolic risk factors: a narrative review

Worldwide obesity and cardiovascular diseases have encouraged the adoption of new and efficient dietary strategies. Among various proposed diets, ketogenic diets, both the very-low-calorie ketogenic diet (VLCKD) and the low-calorie ketogenic diet (LCKD), have been suggested in recent years as an effective nutritional approach for obesity management. The VLCKD and the LCKD are characterized by a low carbohydrate content (<50 g/day), 1-1.5 g of protein/kg of ideal body weight, less than 20-30 g of lipids, and a daily intake of about 800 calories for VLCKD and about 1200-1400 calories for LCKD. The purpose of our narrative review is to offer an overview of the most impactful studies in the scientific literature regarding VLCKD and LCKD to discuss their short- and long-term effects (less than 12 months and more than 12 months respectively) on weight loss, metabolic and cardiovascular aspects. Articles we focused on were cohort studies, case-control studies, cross-sectional studies, randomized controlled trials, and meta-analyses. Results indicate that VLCKD and LCKD could be helpful to ameliorate metabolic and cardiovascular risk factors such as weight loss, glucose, and cholesterol levels, both in the short and long term. Further research in this area may include more randomized controlled trials to gather more data.

Can the ketogenic diet improve our dreams? Effect of very low-calorie ketogenic diet (VLCKD) on sleep quality

BACKGROUND

Obesity is a condition that is often associated with sleep disorders, including reduced sleep quality (SQ). Very low calorie ketogenic diet (VLCKD) has proven to be effective in the management of obesity and associated metabolic disorders. However, little is still known about the effects of this promising nutritional protocol on SQ. Thus, the purpose of this study was to investigate the short-term effect of VLCKD on SQ in women with overweight/obesity and if any changes, to identify the predictive factor that through VLCKD modified SQ.

METHODS

Were consecutively enrolled a total of 324 subjects, who met the inclusion criteria and accepted to adhere to VLCKD. Assessment of nutritional status, including anthropometric measurements (height, weight, and waist circumference), bioelectrical impedance analysis (phase-sensitive system, 50 kHz BIA 101 RJL, Akern Bioresearch, Florence, Italy Akern), high sensitivity C reactive protein levels (hs-CRP), and SQ were carried out at baseline and after 31 days of active stage of VLCKD. SQ was evaluated using the validated questionnaire Pittsburgh Sleep Quality Index (PSQI).

RESULTS

In addition to the expected general improvement of anthropometric parameters and body composition, VLCKD improved significantly SQ, as demonstrated by the improvement of all parameters included in the PSQI questionnaire (p < 0.001). Both at baseline and after 31 days of active stage of VLCKD, the PSQI score was significantly associated with BMI, waist circumference, fat mass, fat free mass (p < 0.001 for all) and hs-CRP (p = 0.023). PhA was negatively associated with PSQI score only at baseline (p < 0.001). ∆% PSQI positively correlated with ∆% BMI, ∆% fat mass, ∆% hs-CRP (p < 0.001 for all) and negatively correlated with ∆% fat free mass (p < 0.001), and ∆% PhA (p = 0.031). In the multiple regression analysis ∆% fat mass represented the only predictor of changes in SQ after VLCKD. Finally, in the ROC analysis, a threshold value of ∆% fat mass > - 8.4% predicted improvement in SQ (p < 0.001).

CONCLUSION

In conclusion, VLCKD determines an improvement of SQ in women with overweight and obesity, that was mostly mediated by the reduction of fat mass related to this nutritional protocol.

The Impact of a Very-Low-Calorie Ketogenic Diet in the Gut Microbiota Composition in Obesity

The very-low-calorie KD (VLCKD) is characterized by a caloric intake of under 800 kcal/day divided into less than 50 g/day of carbohydrate (13%) and 1 to 1.5 g of protein/kg of body weight (44%) and 43% of fat. This low carbohydrate intake changes the energy source from glucose to ketone bodies. Moreover, clinical trials have consistently shown a beneficial effect of VLCKD in several diseases, such as heart failure, schizophrenia, multiple sclerosis, Parkinson's, and obesity, among others. The gut microbiota has been associated with the metabolic conditions of a person and is regulated by diet interactions; furthermore, it has been shown that the microbiota has a role in body weight homeostasis by regulating metabolism, appetite, and energy. Currently, there is increasing evidence of an association between gut microbiota dysbiosis and the pathophysiology of obesity. In addition, the molecular pathways, the role of metabolites, and how microbiota modulation could be beneficial remain unclear, and more research is needed. The objective of the present article is to contribute with an overview of the impact that VLCKD has on the intestinal microbiota composition of individuals with obesity through a literature review describing the latest research regarding the topic and highlighting which bacteria phyla are associated with obesity and VLCKD.

Effects of Animal and Vegetable Proteins on Gut Microbiota in Subjects with Overweight or Obesity

The gut microbiota plays a pivotal role in the balance between host health and obesity. The composition of the gut microbiota can be influenced by external factors, among which diet plays a key role. As the source of dietary protein is important to achieve weight loss and gut microbiota modulation, in the literature there is increasing evidence to suggest consuming more plant proteins than animal proteins. In this review, a literature search of clinical trials published until February 2023 was conducted to examine the effect of different macronutrients and dietary patterns on the gut microbiota in subjects with overweight and obesity. Several studies have shown that a higher intake of animal protein, as well as the Western diet, can lead to a decrease in beneficial gut bacteria and an increase in harmful ones typical of obesity. On the other hand, diets rich in plant proteins, such as the Mediterranean diet, lead to a significant increase in anti-inflammatory butyrate-producing bacteria, bacterial diversity and a reduction in pro-inflammatory bacteria. Therefore, since diets rich in fiber, plant protein, and an adequate amount of unsaturated fat may help to beneficially modulate the gut microbiota involved in weight loss, further studies are needed.

Ketogenic Diet Applied in Weight Reduction of Overweight and Obese Individuals with Progress Prediction by Use of the Modified Wishnofsky Equation

Ketogenic diet is often used as diet therapy for certain diseases, among other things, its positive effect related to weight loss is highlighted. Precisely because of the suggestion that KD can help with weight loss, visceral obesity, and appetite control, 100 respondents joined the weight loss program (of which 31% were men and 69% were women). The aforementioned respondents were interviewed in order to determine their eating habits, the amount of food consumed, and the time when they consume meals. Basic anthropometric data (body height, body mass, chest, waist, hips, biceps, and thigh circumferences) were also collected, in order to be able to monitor their progress during the different phases of the ketogenic diet. Important information is the expected body mass during the time frame of a certain keto diet phase. This information is important for the nutritionist, medical doctor, as well as for the participant in the reduced diet program; therefore, the model was developed that modified the original equation according to Wishnofsky. The results show that women lost an average of 22.7 kg (average number of days in the program 79.5), and for men the average weight loss was slightly higher, 29.7 kg (with an average of 76.8 days in the program). The prediction of expected body mass by the modified Wishnofsky's equation was extremely well aligned with the experimental values, as shown by the Bland-Altman graph (bias for women 0.021 kg and -0.697 kg for men) and the coefficient of determination of 0.9903. The modification of the Wishnofsky equation further shed light on the importance of controlled energy reduction during the dietetic options of the ketogenic diet.

Plum supplementation and lipid profile: a systematic review and meta-analysis of randomised controlled trials

Plums are abundant in bioactive compounds which have been associated with numerous health benefits. In the present study, we aimed at examining the impact of plum supplementation on lipid profile of individuals. Electronic bibliographical databases were searched for relevant randomised clinical trials. Articles meeting our eligibility criteria were included for data extraction and final analysis. Weighted mean difference (WMD) was estimated using a random-effect model. Of the total articles retrieved in the initial search, nine articles were found to be eligible to be included in the analysis. Our results show that plum supplementation significantly improves total cholesterols levels in the unhealthy individuals. Moreover, plum supplementation reduces the LDL-c levels in the pooled sample (WMD = -11⋅52 mg/dl; 95 % CI -21⋅93, -1⋅11, P = 0⋅03, I ² = 98⋅7 %) and also in some of the subgroups of individuals (dried plum, unhealthy subjects, duration more than 8 weeks). Moreover, it had a significant reducing effect on TC levels just in unhealthy subjects. Although plum supplementation did not have any significant impact on serum levels of TG nor HDL-c. Our results show that supplementation with plums is potentially effective in reducing serum total cholesterol and LDL-c.

Revised Protein Sparing Diet in Obesity and Type 2 Diabetes Mellitus

Effective nutrition therapy is a pressing issue in obesity and type 2 diabetes mellitus (T2DM) management. As such, this research aimed to determine the performance of a revised dietary strategy built on the protein-sparing diet in obesity and type 2 diabetes mellitus with regard to obtaining a rapid and stable improvement in glucometabolic control, body weight, body composition, and energy metabolism when applying the strategy in just twenty-one days. The revised protein-sparing diet differs from the traditional protein-sparing modified fast (PSMF) because it does not include foods. The daily calorie intake of this diet is exclusively derived from Isolate whey protein in addition to a formulation of Isolate whey protein enriched with essential amino acids in free form, with the addition of lipids such as extra virgin olive oil and coconut oil as a source of medium chain fatty acids, where the latter is taken for only the first four days of the diet, together with the use, for the same duration, of extended-release metformin, as the only antihyperglycemic allowed. Anthropometric measurements, bioimpedance analysis, indirect calorimetry, and blood chemistry assessments were conducted at the beginning of the study, time 0 (T0), and at the end, time 1 (T1), i.e., on the 21st day. The main outcomes of the revised protein-sparing diet after only twenty-one days were a reduction in body weight with the predominant loss of visceral atherogenic abdominal fat and, therefore, a possible contextual reduction in ectopic fat deposits together with a simultaneous reduction in insulin resistance and normalization of insulin levels, maintenance of free fat mass and basal metabolism, restoration of metabolic flexibility, and improvement of the glucometabolic and lipidic parameters. These results demonstrate the promising potential of the revised protein-sparing diet as an "etiologic tool" in the integrated nutritional treatment of metabolic diseases such as obesity and type 2 diabetes mellitus.

Mediterranean Diet versus Very Low-Calorie Ketogenic Diet: Effects of Reaching 5% Body Weight Loss on Body Composition in Subjects with Overweight and with Obesity-A Cohort Study

The best nutritional strategy to fight the rise in obesity remains a debated issue. The Mediterranean diet (MD) and the Very Low-Calorie Ketogenic diet (VLCKD) are effective at helping people lose body weight (BW) and fat mass (FM) while preserving fat-free mass (FFM). This study aimed to evaluate the time these two diets took to reach a loss of 5% of the initial BW and how body composition was affected. We randomized 268 subjects with obesity or overweight in two arms, MD and VLCKD, for a maximum of 3 months or until they reached 5% BW loss. This result was achieved after one month of VLCKD and 3 months of MD. Both diets were effective in terms of BW (p < 0.0001) and FM loss (p < 0.0001), but the MD reached a higher reduction in both waist circumference (p = 0.0010) and FM (p = 0.0006) and a greater increase in total body water (p = 0.0017) and FFM (p = 0.0373) than VLCKD. The population was also stratified according to gender, age, and BMI. These two nutritional protocols are both effective in improving anthropometrical parameters and body composition, but they take different time spans to reach the goal. Therefore, professionals should evaluate which is the most suitable according to each patient's health status.

The Anti-Obesity Potential of Superparamagnetic Iron Oxide Nanoparticles against High-Fat Diet-Induced Obesity in Rats: Possible Involvement of Mitochondrial Biogenesis in the Adipose Tissues

BACKGROUND

Obesity is a pandemic disease that is rapidly growing into a serious health problem and has economic impact on healthcare systems. This bleak image has elicited creative responses, and nanotechnology is a promising approach in obesity treatment. This study aimed to investigate the anti-obesity effect of superparamagnetic iron oxide nanoparticles (SPIONs) on a high-fat-diet rat model of obesity and compared their effect to a traditional anti-obesity drug (orlistat).

METHODS

The obese rats were treated daily with orlistat and/or SPIONs once per week for 8 weeks. At the end of the experiment, blood samples were collected for biochemical assays. Then, the animals were sacrificed to obtain white adipose tissues (WAT) and brown adipose tissues (BAT) for assessment of the expression of thermogenic genes and mitochondrial DNA copy number (mtDNA-CN).

RESULTS

For the first time, we reported promising ameliorating effects of SPIONs treatments against weight gain, hyperglycemia, adiponectin, leptin, and dyslipidemia in obese rats. At the molecular level, surprisingly, SPIONs treatments markedly corrected the disturbed expression and protein content of inflammatory markers and parameters controlling mitochondrial biogenesis and functions in BAT and WAT.

CONCLUSIONS

SPIONs have a powerful anti-obesity effect by acting as an inducer of WAT browning and activator of BAT functions.

The gut microbiome as possible mediator of the beneficial effects of very low calorie ketogenic diet on type 2 diabetes and obesity: a narrative review

Several studies have shown a strong correlation between the different types of diets and gut microbiota composition on glycemia and weight loss. In this direction, low-carbohydrate and ketogenic diets have gained popularity, despite studies published so far leading to controversial results on subjects with diabetes. In this narrative review, firstly, we aimed to analyze the role of very-low-calorie ketogenic diets (VLCKDs) in type 2 diabetes (T2DM) and obesity management. Secondly, in this context, we focused attention on gut microbiota as a function of VLCKD, particularly in T2DM and obesity treatment. Finally, we reported all this evidence to underline the importance of gut microbiota to exalt new nutritional strategies for "tailor-made" management, treatment, and rehabilitation in subjects with T2DM and obesity, even with diabetic complications. In conclusion, this narrative review outlined the beneficial impact of VLCKD on gut microbiota even in subjects with T2DM and obesity, and, despite inner VLCKD short-duration feature allowing no sound-enough provisions for long-term outcomes, witnessed in favor of the short-term safety of VLCKD in those patients.Level of evidence Level V: Opinions of authorities, based on descriptive studies, narrative reviews, clinical experience, or reports of expert committees.

The Effect of Ketogenic Diet on Shared Risk Factors of Cardiovascular Disease and Cancer

Cardiovascular disease (CVD) and cancer are the first and second leading causes of death worldwide, respectively. Epidemiological evidence has demonstrated that the incidence of cancer is elevated in patients with CVD and vice versa. However, these conditions are usually regarded as separate events despite the presence of shared risk factors between both conditions, such as metabolic abnormalities and lifestyle. Cohort studies suggested that controlling for CVD risk factors may have an impact on cancer incidence. Therefore, it could be concluded that interventions that improve CVD and cancer shared risk factors may potentially be effective in preventing and treating both diseases. The ketogenic diet (KD), a low-carbohydrate and high-fat diet, has been widely prescribed in weight loss programs for metabolic abnormalities. Furthermore, recent research has investigated the effects of KD on the treatment of numerous diseases, including CVD and cancer, due to its role in promoting ketolysis, ketogenesis, and modifying many other metabolic pathways with potential favorable health effects. However, there is still great debate regarding prescribing KD in patients either with CVD or cancer. Considering the number of studies on this topic, there is a clear need to summarize potential mechanisms through which KD can improve cardiovascular health and control cell proliferation. In this review, we explained the history of KD, its types, and physiological effects and discussed how it could play a role in CVD and cancer treatment and prevention.

Satiety of Edible Insect-Based Food Products as a Component of Body Weight Control

Among the many aspects determining the nutritional potential of insect-based foods, research into the satiating potential of foods is an important starting point in the design of new functional foods, including those based on edible insects. The aim of this study was to assess the satiating value of products with the addition of freeze-dried insect flour. The test material included wheat pancakes in which corresponding proportions of wheat flour were substituted with 10% Mw, 0% Mw, and 30% Mw of flour from freeze-dried Tenebrio molitor, 10% Bw, 20% Bw, and 30% Bw of flour from Alphitobius diaperinus, and 10% Cr, 20% Cr, and 30% Cr of flour from Acheta domesticus. The study included the characterisation of physico-chemical properties and their effect on the satiating potential of the analysed pancakes. A total of 71 healthy volunteers (n = 39 women, n = 32 men) with no food phobias were qualified for the study. Each subject rated the level of hunger and satiety before and after ingestion at 30 min intervals over the subsequent 180 min on two separate graphical scales. The rating was done on an unstructured 100 mm visual analogue scale (VAS). A portion intended for testing had a value of 240 kcal. The highest average satiety values were noted for the pancakes with an addition of 30% Alphitobius diaperinus (Bw) and with the addition of 20% and 30% addition of Acheta domesticus flour (Cr). The Tenebrio molitor-based products were the least satiating. However, the largest addition of 30% of an insect flour for each variant considerably increased the satiating potential as compared to the control sample. Satiety was influenced the most by the protein content in the test wheat pancakes. The results support the idea of a possible usage of insect-based food products in the composition of obesity treatment diets, carbohydrate-limiting diets, and as alternative sources of protein.

Impact of Food-Based Weight Loss Interventions on Gut Microbiome in Individuals with Obesity: A Systematic Review

The observation that the gut microbiota is different in healthy weight as compared with the obese state has sparked interest in the possible modulation of the microbiota in response to weight change. This systematic review investigates the effect of food-based weight loss diets on microbiota outcomes (α-diversity, β-diversity, relative bacterial abundance, and faecal short-chain fatty acids, SCFAs) in individuals without medical comorbidities who have successfully lost weight. Nineteen studies were included using the keywords ‘obesity’, ‘weight loss’, ‘microbiota’, and related terms. Across all 28 diet intervention arms, there were minimal changes in α- and β-diversity and faecal SCFA concentrations following weight loss. Changes in relative bacterial abundance at the phylum and genus level were inconsistent across studies. Further research with larger sample sizes, detailed dietary reporting, and consistent microbiota analysis techniques are needed to further our understanding of the effect of diet-induced weight loss on the gut microbiota.

Examining the Efficacy of a Very-Low-Carbohydrate Ketogenic Diet on Cardiovascular Health in Adults with Mildly Elevated Low-Density Lipoprotein Cholesterol in an Open-Label Pilot Study

Background:

The objective of this open-label pilot study was to investigate the efficacy of a very-low-carbohydrate ketogenic diet (VLCKD), known as Nic's Ketogenic Diet, for 140 days on cardiometabolic markers in healthy adults with mildly elevated low-density lipoprotein cholesterol (LDL-C).

Methods:

Study assessments were conducted at Day 0, 28, 56, 70, 84, 112, and 140, and weight and blood pressure (BP) were measured and fasting blood was collected for analysis of plasma lipids. A DEXA scan was performed and body mass index recorded on Day 0, 70, and 140. Blood glucose, inflammatory, and thyroid markers were measured on Day 0 and 140. Compliance was assessed using weekly 3-day food records and daily blood glucose and ketone monitoring.

Results:

The results showed that body fat percentage decreased by 2.25% and 4.41% at Day 70 and 140, respectively (P ≤ 0.012). Significant reductions in android, gynoid, and android/gynoid fat ratio and increases in muscle mass occurred by Day 70 and 140. Total cholesterol, LDL-C, and high-density lipoprotein cholesterol were increased and systolic BP and glycated hemoglobin (HbA1c) were decreased at Day 140 (P < 0.05). Following this VLCKD for 140 days was found to be safe and was well tolerated.

Conclusion:

The VLCKD showed beneficial changes in body composition and cardiometabolic markers in eutrophic and overweight participants in a 140-day study suggesting a future role for this diet in populations at cardiovascular disease risk. Future research with larger sample size in a randomized double blind clinical trial is warranted to confirm these results.

Clinical Trial Registration number: NCT04195594.

A protein-supplemented very-low-calorie diet does not mitigate reductions in lean mass and resting metabolic rate in subjects with overweight or obesity: A randomized controlled trial

BACKGROUND & AIMS

The European Food Safety Authority recently recommended an increase in the protein content of total diet replacement (TDR) products from 50 to 75 g/day. The rationale was to minimize reductions in lean mass (LM) and resting metabolic rate (RMR) that occur with weight loss, and thereby facilitate maintenance of lost weight. We sought to directly compare the efficacy of TDR regimens with the new vs the current protein requirement.

METHODS

We randomized 108 adults with overweight or obesity (body mass index 28-40 kg/m²) to very-low-calorie diets (VLCD) with either 52 or 77 g/day protein for 8 weeks (total energy intake of 600 or 700 kcal/day, respectively). LM was determined by dual energy X-ray absorptiometry and RMR by indirect calorimetry.

RESULTS

Attrition rate was 22% in both groups. Both VLCDs decreased body weight, fat mass, LM, and RMR (all P < 0.05). Significant time-by-group interactions were detected for weight and fat mass (both P < 0.05), with corresponding reductions being smaller in the higher-protein than the standard-protein VLCD, likely because of the added calories. On the other hand, reductions in LM (6% from baseline) and RMR (9-10% from baseline) did not differ between groups (P = 0.155 and P = 0.389, respectively), and the contribution of LM to total weight loss was identical (27 ± 2% of lost weight, P = 0.973).

CONCLUSIONS

Our results indicate that the proposed increase in the protein content of TDR products does not attenuate reductions in LM and RMR in individuals with overweight and obesity who are treated with <800 kcal/day VLCDs for 2 months.

CLINICAL TRIAL REGISTRY

ClinicalTrials.gov # NCT04156165.

Alternative Dietary Patterns for Americans: Low-Carbohydrate Diets

The decades-long dietary experiment embodied in the Dietary Guidelines for Americans (DGA) focused on limiting fat, especially saturated fat, and higher carbohydrate intake has coincided with rapidly escalating epidemics of obesity and type 2 diabetes (T2D) that are contributing to the progression of cardiovascular disease (CVD) and other diet-related chronic diseases. Moreover, the lack of flexibility in the DGA as it pertains to low carbohydrate approaches does not align with the contemporary trend toward precision nutrition. We argue that personalizing the level of dietary carbohydrate should be a high priority based on evidence that Americans have a wide spectrum of metabolic variability in their tolerance to high carbohydrate loads. Obesity, metabolic syndrome, and T2D are conditions strongly associated with insulin resistance, a condition exacerbated by increased dietary carbohydrate and improved by restricting carbohydrate. Low-carbohydrate diets are grounded across the time-span of human evolution, have well-established biochemical principles, and are now supported by multiple clinical trials in humans that demonstrate consistent improvements in multiple established risk factors associated with insulin resistance and cardiovascular disease. The American Diabetes Association (ADA) recently recognized a low carbohydrate eating pattern as an effective approach for patients with diabetes. Despite this evidence base, low-carbohydrate diets are not reflected in the DGA. As the DGA Dietary Patterns have not been demonstrated to be universally effective in addressing the needs of many Americans and recognizing the lack of widely available treatments for obesity, metabolic syndrome, and T2D that are safe, effective, and sustainable, the argument for an alternative, low-carbohydrate Dietary Pattern is all the more compelling.

Effect of a Ketogenic Diet on the Nutritional Parameters of Obese Patients: A Systematic Review and Meta-Analysis

The effect of a ketogenic diet (KD) on biochemical parameters and nutritional status has been the subject of debate over the years, as several randomized clinical trials (RCTs) obtained different results.

METHOD

A systematic review and random-effects meta-analysis of RCTs comparing KD with a balanced diet was performed by means of a search of PubMed, Cochrane Library, Scopus, and Web of Science. Trials where the method for measuring the response variables was unclear, those that considered pathologies other than chronic non-communicable diseases and those with participants receiving pharmacological treatment for obesity were excluded from the comparison.

RESULTS

Of the studies included in the meta-analysis, no statistically significant standardized mean differences were observed for body mass index (BMI) (d = -0.457, p = 0.359), total cholesterol, COL-T (d = 0.230, p = 0.591), high-density lipoprotein, HDL (d = -0.028, p = 0.934), low-density lipoprotein, LDL (d = 0.528, p = 0.173), or triglycerides, TG (d = -0.283, p = 0.222), with high values of heterogeneity. The percentage of women included in the studies is a significant moderating variable in terms of BMI ratio (z = -6.68, p < 0.001) and TG (z = -2.27, p = 0.023).

CONCLUSION

A KD shows no more benefits on nutritional parameters than a balanced diet, and adverse effects of being on the diet are sometimes reported.

Metabolic Derangement in Pediatric Patient with Obesity: The Role of Ketogenic Diet as Therapeutic Tool

Obesity is defined as a condition characterized by an excessive fat accumulation that has negative health consequences. Pediatric obesity is associated with an increased risk for many diseases, including impaired glycemic and lipidic control that may lead to the development of chronic, and potentially disabling, pathologies, such as type 2 diabetes mellitus (T2DM) and cardiovascular events, in adult life. The therapeutic strategy initially starts with interventions that are aimed at changing lifestyle and eating behavior, to prevent, manage, and potentially reverse metabolic disorders. Recently, the ketogenic diet (KD) has been proposed as a promising dietary intervention for the treatment of metabolic and cardiovascular risk factors related to obesity in adults, and a possible beneficial role has also been proposed in children. KD is very low in carbohydrate, high in fat, and moderate to high in protein that may have the potential to promote weight loss and improve lipidic derangement, glycemic control, and insulin sensitivity. In this review, we present metabolic disorders on glycemic and lipidic control in children and adolescents with obesity and indication of KD in pediatrics, discussing the role of KD as a therapeutic tool for metabolic derangement. The results of this review may suggest the validity of KD and the need to further research its potential to address metabolic risk factors in pediatric obesity.

A multiphase dietetic protocol incorporating an improved ketogenic diet enhances weight loss and alters the gut microbiome of obese people

The prevalence of obesity and its associated diseases is increasing. In the current study, 15 obese subjects took part in a 12-week multiphase dietetic protocol incorporating an improved ketogenic diet (MDP-i-KD) (KYLLKS 201806). We investigated the effects of the MDP-i-KD on the anthropometric parameters and the gut microbiota of obese subjects. Our results showed that the MDP-i-KD led to significant reductions in body mass index in obese subjects. The MDP-i-KD significantly decreased the relative abundance of the Lachnospiraceae_ND3007_group, the Eubacterium_hallii_group, and Pseudomonas and Blautia. In addition, gut microbiota co-occurrence networks in obese subjects were restructured to a more healthy condition after weight loss. These results show that the MDP-i-KD enhanced weight loss, which may be associated with dietary-induced changes in the gut microbiome. Our results emphasise the importance of determining the interaction between the host and microbial cells to comprehensively understand the mechanism by which diet affects host physiology and the microbiota.

Ketogenic diets and appetite regulation

PURPOSE OF REVIEW

The popularity of ketogenic diets in the treatment of obesity has increased dramatically over the last years, namely due to their potential appetite suppressant effect. The purpose of this review was to examine the latest evidence regarding the impact of ketogenic diets on appetite.

RECENT FINDINGS

The majority of the studies published over the last 2 years adds to previous evidence and shows that ketogenic diets suppress the increase in the secretion of the hunger hormone ghrelin and in feelings of hunger, otherwise see when weight loss is induced by non-ketogenic diets. Research done using exogenous ketones point out in the same direction. Even though the exact mechanisms by which ketogenic diets suppress appetite remain to be fully determined, studies show that the more ketotic participants are (measured as β-hydroxybutyrate plasma concentration), the smaller is the increase in ghrelin and hunger and the larger is the increase in the release of satiety peptides. Further evidence for a direct effect of ketones on appetite comes from studies using exogenous ketones.

SUMMARY

The appetite suppressant effect of ketogenic diets may be an important asset for improving adherence to energy restricted diets and weight loss outcomes.

Exploring the Genetic Conception of Obesity via the Dual Role of FoxO

Obesity or overweight are not superficial problems, constituting a pressing issue. The obesity index has almost tripled since 1975, which is an alarming state. Most of the individuals are currently becoming overweight or have inappropriate body mass index (BMI) conditions. Obesity is characterized by increased fat accumulation and thus poses a higher health risk. There is increased size and volume of fat cells in the body, which usually accounts for obesity. Many investigations have been carried out in this area, such as behavioral improvements, dietary changes, chemical involvements, etc., but presently no such goals are established to manage these health concerns. Based on previous literature reports and our interpretation, the current review indicates the involvement of various transcriptional and transporter functions in modifying the above-mentioned health conditions. Various transcriptional factors such as Forkhead box O1 (FoxO1) impart a significant effect on the physiology and pathology of metabolic dysfunction such as obesity. FoxO1 plays a dual role whether in the progression or suppression of metabolic processes depending on its targets. Thus, in the current study, will be discussed the dual role of FoxO1 in metabolic conditions (such as obesity), also summarizing the role of various other transcriptional factors involved in obesity.

Exploring the Genetic Conception of Obesity via the Dual Role of FoxO

Obesity or overweight are not superficial problems, constituting a pressing issue. The obesity index has almost tripled since 1975, which is an alarming state. Most of the individuals are currently becoming overweight or have inappropriate body mass index (BMI) conditions. Obesity is characterized by increased fat accumulation and thus poses a higher health risk. There is increased size and volume of fat cells in the body, which usually accounts for obesity. Many investigations have been carried out in this area, such as behavioral improvements, dietary changes, chemical involvements, etc., but presently no such goals are established to manage these health concerns. Based on previous literature reports and our interpretation, the current review indicates the involvement of various transcriptional and transporter functions in modifying the above-mentioned health conditions. Various transcriptional factors such as Forkhead box O1 (FoxO1) impart a significant effect on the physiology and pathology of metabolic dysfunction such as obesity. FoxO1 plays a dual role whether in the progression or suppression of metabolic processes depending on its targets. Thus, in the current study, will be discussed the dual role of FoxO1 in metabolic conditions (such as obesity), also summarizing the role of various other transcriptional factors involved in obesity.

Implicating the effect of ketogenic diet as a preventive measure to obesity and diabetes mellitus

Obesity and diabetes are the two major metabolic complications linked with bad eating habits and the sedentary (lazy) lifestyle. In the worst-case situation, metabolic problems are a causative factor for numerous other conditions. There is also an increased demand to control the emergence of such diseases. Dietary and lifestyle improvements contribute to their leadership at an elevated level. The present review, therefore, recommends the use of the ketogenic diet (KD) in obesity and diabetes treatment. The KD involves a diet that replaces glucose sugar with ketone bodies and is effective in numerous diseases, such as metabolic disorders, epileptic seizures, autosomal dominant polycystic disease of the kidney, cancers, peripheral neuropathy, and skeletal muscle atrophy. A lot of high profile pathways are available for KD action, including sustaining the metabolic actions on glucose sugar, suppressing insulin-like growth factor-1 (IGF1) and phosphoinositide 3-kinase (PI3K)/protein kinase B (AKT)/mammalian target of rapamycin (mTOR) pathways, altering homeostasis of the systemic ketone bodies, contributing to lowering diabetic hyperketonemia, and others. The KD regulates the level of glucose sugar and insulin and can thus claim to be an effective diabetes approach. Thus, a stopgap between obesity and diabetes treatment can also be evidenced by KD.