Effects of weight loss during a very low carbohydrate diet on specific adipose tissue depots and insulin sensitivity in older adults with obesity: a randomized clinical trial

Effects of low-carbohydrate diets, with and without caloric restriction, on inflammatory markers in adults: a systematic review and meta-analysis of randomized clinical trials

Low-carbohydrate diets (LCDs) have gained interest due to their favorable effects on health outcomes, such as inflammation. However, further research is needed to ascertain the overall effects of LCDs on inflammatory parameters, but at the same time considering weight loss and calorie intake. Thus, a systematic review and meta-analysis of randomized clinical trials was performed to investigate the effects of LCDs compared with low-fat diets (LFDs), with and without caloric restriction, on inflammatory markers in adults. PubMed, Scopus, and Web of Science were searched through March 2022 to select intervention studies addressing LCDs vs. LFDs, in which the following circulating inflammatory markers were used: C-reactive protein (CRP), tumor necrosis factor alpha (TNF-α), and interleukin (IL-6). Analyses were conducted comparing LCDs vs. LFDs through weighted mean differences (WMD) or standardized mean differences (SMD) and 95% confidence intervals (95% CIs) using random effects models. The systematic review and meta-analysis included a total of 51 studies with a total sample of 4,164 adults, with or without other chronic diseases. Intervention durations ranged from 2-144 weeks. LCDs, compared with LFDs, significantly decreased body weight [WMD = -1.35%, p = 0.001], CRP [SMD = -0.1, p = 0.03], and IL-6 [SMD = -0.15, p = 0.09]. However, LCDs did not significantly decrease TNF-α [SMD = -0.02, p = 0.7] compared to LFDs. In conclusion, LCDs have a beneficial effect on markers of inflammation by decreasing CRP and IL-6; this effect has an association with weight loss. However, LCDs were not more effective than LFDs in decreasing TNF-α.

A very-low-calorie diet (VLCD) intervention for the management of prediabetes and early Type 2 diabetes mellitus in a multi-ethnic cohort in Aotearoa New Zealand: The PROGRESS NZ feasibility study

BACKGROUND AND OBJECTIVES

Very-low calorie diets (VLCD) achieve weight loss and remission of Type 2 diabetes (T2DM), but efficacy and acceptability in non-European populations is less clear. This feasibility study examines the impact of 10% weight loss through VLCD on metabolic and body composition outcomes in a multi-ethnic cohort of Aotearoa New Zealand (AoNZ) men with prediabetes/early T2DM, and VLCD tolerability/cultural acceptability.

METHODS AND STUDY DESIGN

Participants followed a VLCD intervention (mean energy 3033kJ/day) until achievement of 10% weight loss. An oral glucose tolerance test (OGTT), hyperinsulinaemic isoglycaemic clamp with stable isotopes, hood calorimetry and dual-energy Xray absorptiometry (DXA) were undertaken before and after intervention. Qualitative data on VLCD tolerability/cultural acceptability were collected.

RESULTS

Fifteen participants were enrolled; nine achieved 10% weight loss. In this group, mean HbA1c reduced by 4.8mmol/mol (2.4-7.1) and reverted to normoglycaemia in n=5/9; mean body weight reduced by 12.0 kg (11.0-13.1) and whole-body glucose disposal improved by 1.5 mg kgFFM-1 min-1 (0.7-2.2). Blood pressure and fasting triglycerides improved significantly. No changes in hepatic glu-cose metabolism were found. In all participants who attended completion testing, HbA1c reduced by 3.4mmol/mol (SD 3.5) and total weight by 9.0kg (SD 5.7). The intervention was highly tolerable/culturally acceptable however challenges with fulfilment of cultural obligations were described.

CONCLUSIONS

Results support VLCD use in AoNZ however further work to investigate ethnic differences in physiological response to VLCDs and to optimise protocols for multi-ethnic populations are required.

Association of daily carbohydrate intake with intermuscular adipose tissue in Korean individuals with obesity: a cross-sectional study

BACKGROUND/OBJECTIVES

The prevalence of obesity, a worldwide pandemic, has been increasing steadily in Korea. Reports have shown that increased intermuscular adipose tissue (IMAT) is associated with an increased risk of cardiovascular disease, independent of body mass index. However, the relationship between dietary intake and IMAT accumulation in the Korean population remains undetermined. The objective of this study was to evaluate regional fat compartments using advanced magnetic resonance imaging (MRI) techniques. We also aimed to investigate the association between IMAT amounts and dietary intake, including carbohydrate intake, among Korean individuals with obesity.

SUBJECTS/METHODS

This cross-sectional study, performed at a medical center in South Korea, recruited 35 individuals with obesity (15 men and 20 women) and classified them into 2 groups according to sex. Anthropometry was performed, and body fat distribution was measured using MRI. Blood parameters, including glucose and lipid profiles, were analyzed using commercial kits. Linear regression analysis was used to test whether the IMAT was associated with daily carbohydrate intake.

RESULTS

Carbohydrate intake was positively associated with IMAT in all individuals, with adjustments for age, sex, height, and weight. No significant differences in blood indicators were found between the sexes.

CONCLUSIONS

Regardless of sex and age, higher carbohydrate intake was strongly correlated with greater IMAT accumulation. This suggests the need to better understand sex differences and high carbohydrate diet patterns in relation to the association between obesity and metabolic risk, which may help reduce obesity prevalence.

The effect of a ketogenic diet on inflammation-related markers: a systematic review and meta-analysis of randomized controlled trials

CONTEXT

Despite the important role of inflammation-related factors on the occurrence of chronic diseases, there is still conflicting evidence about the effects of the ketogenic diet (KD) on these factors.

OBJECTIVE

In order to obtain a better viewpoint, this study aimed to comprehensively investigate the effects of a KD on inflammation-related markers.

DATA SOURCES

To find pertinent randomized controlled trials up to August 2023, databases including PubMed/Medline, Web of Science, Scopus, Cochrane Library, and Embase were searched.

DATA EXTRACTION

This study included all randomized controlled trials investigating the effects of a KD on C-reactive protein (CRP), tumor necrosis factor-alpha (TNF-α), interleukin (IL)-6, IL-8, and IL-10 levels. Pooled weighted mean difference (WMD) and 95% confidence intervals (CIs) were achieved by random-effects model analysis for the best estimation of outcomes.

DATA ANALYSIS

Forty-four studies were included in this article. The pooled findings showed that a KD has an effect on lowering TNF-α (WMD: -0.32 pg/mL; 95% CI: -0.55, -0.09; P = 0.007) and IL-6 (WMD: -0.27 pg/mL; 95% CI: -0.52, -0.02; P = 0.036) compared with control groups. However, no significant effect was reported for others inflammation marker-related levels. The results of the subgroup analysis showed that, in trials following the KD for ≤8 weeks and in people aged ≤50 years, the reduction in TNF-α levels was significantly higher than in other groups. In addition, in people with a body mass index greater than 30 kg/m2 compared to a body mass index ≤30 kg/m2, IL-6 levels decreased to a greater extent after receiving the KD.

CONCLUSIONS

Consequently, adherence to a KD appears to improve some markers associated with inflammation, including TNF-α and IL-6.

Obesity and malnutrition in children and adults: A clinical review

Background

In the U.S., children and adults are consuming more low-nutrient foods with added sugar and excess fats as compared to healthy, high-quality calories and micronutrients. This diet is increasing the prevalence of malnutrition and nutritional deficiencies, despite high calorie intake. This is a review of the common micronutrient deficiencies, the risk factors for malnutrition, dietary plans, and the health consequences in children and adults with obesity in the U.S.

Methods

This clinical review of literature was performed on the MEDLINE (PubMed) search engine. A total of 1391 articles were identified and after review, a total of 130 were found to be most pertinent.

Discussion

The most common micronutrient deficiencies found in patients with obesity were vitamin A, thiamine (B1), folate (B9), cobalamin (B12), vitamin D, iron, calcium, and magnesium, especially prior and after bariatric surgery. Diets that produced the most weight reduction also further puts these individuals at risk for worsening malnutrition. Malnutrition and micronutrient deficiencies can worsen health outcomes if not properly managed.

Conclusion

Adequate screening and awareness of malnutrition can improve the health outcomes in patients with obesity. Physiologic changes in response to increased adiposity and inadequate intake increase this population's risk of adverse health effects. Malnutrition affects the individual and contributes to worse public health outcomes. The recommendations for screening for malnutrition are not exclusive to individuals undergoing bariatric procedures and can improve the health outcomes of any patient with obesity. However, clearly, improved nutritional status can assist with metabolism and prevent adverse nutritional outcomes post-bariatric surgery. Clinicians should advise on proper nutrition and be aware of diets that worsen deficiencies.

Impact of the ketogenic diet on body fat, muscle mass, and exercise performance: a review

PURPOSE

The purpose of this review was to investigate the effects of the ketogenic diet (KD), on body fat, muscle mass, and exercise performance. As the KD is a subject of ongoing debate, we also present the existing evidence regarding its potential benefits in the aforementioned areas of body fat, muscle mass, and exercise performance.

METHODS

A literature search was conducted using the keywords "ketogenic diet, low-carbohydrate diet, high-fat diet, body fat, muscle mass, and exercise performance" in PubMed, Web of Science, and Google Scholar.

RESULTS

The KD effectively reduced body fat in the short term and, preserved muscle mass during weight loss, however, its impact on exercise performance remains inconclusive owing to various factors.

CONCLUSION

While controversial, it is undeniable that the KD has the potential to affect body fat, muscle mass, and exercise performance. Consequently, additional research is required to elucidate the underlying mechanisms across various populations, optimize their implementation, and understand their long-term effects.

[Beneficial effects of ketogenic diet for Alzheimer's disease management]

Alzheimer's disease (AD) is a neurodegenerative disease that affects almost 1 million people in France and 55 million in the world. This pathology is a global health preoccupation because of the lack of efficient curative treatment and the increase of its prevalence. During the last decade, the comprehension of pathophysiological mechanisms involved in AD have been improved. Amyloid plaques and neurofibrillary tangles accumulation are characteristic of Alzheimer's brain patients, accompanied by increased brain inflammation and oxidative stress, impaired cerebral metabolism of glucose and mitochondrial function. Treatment of AD includes different approaches, as pharmacology, psychology support, physiotherapy, and speech therapy. However, these interventions do not have a curative effect, but only compensatory on the disease. Ketogenic diet (KD), a low-carbohydrates and high-fat diet, associated with a medium-chain triglycerides intake (MCTs) might induce benefices for Alzheimer disease patients. Carbohydrate restriction and MCTs promotes the production of ketone bodies from fatty acid degradation. These metabolites replacing glucose, serve the brain as energetic substrates, and induce neuroprotective effects. Such a nutritional support might slow down the disease progression and improve cognitive abilities of patients. This review aims to examine the neuroprotective mechanisms of KD in AD progression and describes the advantages and limitations of KD as a therapeutic strategy.

A low-carb diet increases fecal short-chain fatty acids in feces of obese women following a weight-loss program: randomized feeding trial

To compare fecal level of short-chain fatty acid (SCFA) and some serum inflammatory markers between the low-carbohydrate (LCD) and the habitual (HD) diet, subjects were enrolled from our previous study on the effect of LCD vs. HD on gut microbiota in obese women following an energy-restricted diet. Serum interleukin-6 (IL-6) significantly increased in the HD group (p < 0.001). Adjusted for the baseline parameters, fecal level of butyric, propionic, and acetic acid were significantly different between the LCD and HD groups (p < 0.001, p = 0.02, and p < 0.001, respectively). Increase in serum insulin level correlated with decrease in fecal propionic acid by 5.3-folds (95% CI =  - 2.7,  - 0.15, p = 0.04). Increase in serum high sensitive C-reactive protein (hs-CRP) correlated with decrease in the percentage of fecal butyric acid by 25% (p = 0.04). Serum fasting blood sugar (FBS) and insulin showed a significant effect on fecal acetic acid (p = 0.009 and p = 0.01, respectively). Elevated serum FBS and insulin correlated with increase in fecal acetic acid by 2.8 and 8.9-folds (95%CI = 0.34, 1.9 and 1.2, 9.2), respectively. The LCD increased fecal SCFAs and a significant correlation was seen between serum IL-6 and fecal propionic acid level. More studies are needed to reach a concise correlation. Trial registration number: The trial was registered in Iranian ClinicalTrials.gov IRCT20200929048876N3.

Nutrition and exercise interventions to improve body composition for persons with overweight or obesity near retirement age: A systematic review and network meta-analysis of randomised controlled trials

The retirement phase is an opportunity to integrate healthy (nutrition/exercise) habits into daily life. We conducted this systematic review to assess which nutrition and exercise interventions most effectively improve body composition (fat/muscle mass), body mass index (BMI) and waist circumference (WC) in persons with obesity/overweight near retirement age (ages 55-70). We conducted a systematic review and network-meta-analysis (NMA) of randomised controlled trials, searching four databases from their inception up to 12 July 2022. The NMA was based on a random effects model, pooled mean differences, standardised mean differences, their 95% confidence intervals, and correlations with multi-arm studies. Subgroup and sensitivity analyses were also conducted. 92 studies were included, 66 of which with 4957 participants could be used for the NMA. Identified interventions were clustered into 12 groups: no intervention, energy restriction (i.e. 500-1000 kcal), energy restriction plus high protein (HP) intake (1.1-1.7 g/kg/body weight), intermittent fasting, mixed exercise (aerobic and resistance), resistance training (RT), aerobic training (AT), HP plus RT, energy restriction plus HP plus exercise, energy restriction plus RT, energy restriction plus AT, and energy restriction plus mixed exercise (ME). Intervention durations ranged from 8 weeks to 6 months. Body fat was reduced with energy restriction plus any exercise or plus HP intake. Energy restriction alone was less effective and tended to decrease muscle mass. Muscle mass was only significantly increased with ME. All other interventions including exercise effectively preserved muscle mass. A BMI and/or WC decrease was achieved with all interventions except AT/RT alone or RT plus HP. Overall, the most effective strategy for nearly all outcomes was combining energy restriction with RT or ME and HP. Healthcare professionals involved in the management of persons with obesity need to be aware that an energy-restricted diet alone may contribute to sarcopenic obesity in persons near retirement age. This network meta-analysis is registered at https://www.crd.york.ac.uk/prospero/as CRD42021276465.

The Effect of a Moderately Restricted Carbohydrate Diet on Cardiometabolic Risk Factors in Overweight and Obese Women With Metabolic Syndrome: A Randomized Controlled Trial

PURPOSE

Metabolic syndrome (MetS) is a major public health concern that increases the risk of cardiovascular disease and mortality. In previous studies of MetS management, low-carbohydrate diets have been strongly emphasized, despite the fact that many apparently healthy individuals have difficulties adhering to these diets on a long-term basis. The purpose of the present study was to elucidate the effects of a moderately restricted carbohydrate diet (MRCD) on cardiometabolic risk factors in women with MetS.

METHODS

This parallel 3-month, single-blind randomized controlled trial was conducted in Tehran, Iran, among 70 women with overweight or obesity aged 20 to 50 years with MetS. Patients were randomly allocated to receive either MRCD (42%-45% carbohydrates and 35%-40% fats) (n = 35) or a normal weight loss diet (NWLD) (52%-55% carbohydrates and 25%-30% fats) (n = 35). Both diets contained the same quantity of protein, which accounted for 15% to 17% of total energy. Anthropometric measurements, blood pressure, lipid profile, and glycemic indices were all assessed before and after the intervention.

FINDINGS

Compared with the NWLD group, following an MRCD significantly decreased weight (-4.82 vs -2.40 kg; P = 0.01), body mass index (-1.88 vs -0.94 kg/m²; P = 0.01), waist circumference (-5.34 vs -2.75 cm; P = 0.01), hip circumference (-2.58 vs -1.11 cm; P = 0.01), serum triglyceride (-26.8 vs -7.19 mg/dL; P = 0.01), and increased serum HDL-C levels (1.89 vs. 0.24 mg/dL; P = 0.01). There was no significant difference between the 2 diets in waist-to-hip ratio, serum total cholesterol, serum LDL-C, systolic and diastolic blood pressure, fasting blood glucose, insulin levels, or the homeostasis model assessment for insulin resistance.

IMPLICATIONS

Moderate carbohydrate replacement with dietary fats significantly improved weight, body mass index, waist circumference, hip circumference, serum triglyceride, and HDL-C levels among women with MetS. Iranian Registry of Clinical Trials identifier: IRCT20210307050621N1.

Intermuscular adipose tissue in metabolic disease

Intermuscular adipose tissue (IMAT) is a distinct adipose depot described in early reports as a 'fatty replacement' or 'muscle fat infiltration' that was linked to ageing and neuromuscular disease. Later studies quantifying IMAT with modern in vivo imaging methods (computed tomography and magnetic resonance imaging) revealed that IMAT is proportionately higher in men and women with type 2 diabetes mellitus and the metabolic syndrome than in people without these conditions and is associated with insulin resistance and poor physical function with ageing. In parallel, agricultural research has provided extensive insight into the role of IMAT and other muscle lipids in muscle (that is, meat) quality. In addition, studies using rodent models have shown that IMAT is a bona fide white adipose tissue depot capable of robust triglyceride storage and turnover. Insight into the importance of IMAT in human biology has been limited by the dearth of studies on its biological properties, that is, the quality of IMAT. However, in the past few years, investigations have begun to determine that IMAT has molecular and metabolic features that distinguish it from other adipose tissue depots. These studies will be critical to further decipher the role of IMAT in health and disease and to better understand its potential as a therapeutic target.

The role of the dietary patterns in the cardiovascular disease risk prevention

Cardiovascular diseases (CVD) are a part of a wide group of diseases, which became main threat to the life and health of the population in highly developed countries. To prevent and treat CVD, in addition to implementation of pharmacological methods, there are a number of lifestyle components, including eating habits, that significantly influence the development of these diseases. The dietary patterns strongly correlate with the risk of cardiovascular disease. Modifications of the dietary habits allow to control many parameters such as: body weight, cholesterol/triglyceride levels or blood pressure. Alternative diets are frequently used to reduce the risk of developing a CVD. The main recommended dietary patterns includes Mediterranean diet (MD), the DASH diet (Dietary Approach to Stop Hypertension) and mild variants of vegetarianism. The more controversial nutritional styles includes the ketogenic or vegan diets. Due to various assumptions as well as the mechanisms of action of each diets, an attempt of its evaluation have been made. The aim of our study is to review and analyze the available data on the impact of various nutrition models regarding to cardiovascular diseases risk prevention.

Diets differing in carbohydrate cellularity and amount similarly reduced visceral fat in people with obesity - a randomized controlled trial (CARBFUNC)

BACKGROUND & AIMS

Visceral adipose tissue (VAT) volume is associated with common lifestyle diseases. Dietary quality, including food matrix and degree of carbohydrate cellularity, as well as the carbohydrate/fat ratio, may influence VAT volume. We aimed to determine the effects of isocaloric diets differing in either "cellularity", a novel marker of dietary carbohydrate quality, or carbohydrate amount on visceral fat volume and anthropometric measures in adults with obesity.

METHODS

In a randomized controlled trial of 193 people with obesity/central adiposity, we compared changes in VAT volume after 6 and 12 months, measured by abdominal computed tomography, on three isocaloric eating patterns based on "acellular" carbohydrate sources (e.g., flour-based whole-grain products; comparator arm), "cellular" carbohydrate sources (minimally processed foods with intact cellular structures such as fruits, potatoes/tubers, and rice), or low-carbohydrate high-fat (LCHF) principles. Outcomes were compared by an intention-to-treat (ITT) analysis using constrained linear mixed-effects modelling (cLMM) providing baseline-adjusted change scores and proper missing data handling without imputation.

RESULTS

78 and 57 participants completed 6 and 12 months, respectively, with similar intakes of energy (females: 1820-2060 kcal, males: 2480-2550 kcal) and protein (16-17 energy percent, E%) throughout the intervention, and only modest reductions in energy from baseline. Reported dietary intakes were 42-44, 41-42, and 11-15 E% carbohydrate and 36-38, 37-38, and 66-70 E% fat in the acellular, cellular and LCHF groups, respectively. There were no significant between-group differences in VAT volume after 6 months (cellular vs. acellular [95% CI]: -55 cm³ [-545, 436]; LCHF vs. acellular [95% CI]: -225 cm³ [-703, 253]) or after 12 months (cellular vs. acellular [95% CI]: -122 cm³ [-757, 514]; LCHF vs. acellular [95% CI]: -317 cm³ [-943, 309]). VAT volume decreased significantly within all groups by 14-18% and 12-17% after 6 and 12 months, respectively. Waist circumference was reduced to a significantly greater degree in the LCHF vs. acellular group at 6 months (LCHF vs. acellular [95% CI]: -2.78 cm [-5.54, -0.017]).

CONCLUSIONS

Despite modest energy restriction, the three isocaloric eating patterns, differing in carbohydrate cellularity and amount, decreased visceral fat volume significantly and to a similar clinically relevant degree.

CLINICAL TRIALS IDENTIFIER

NCT03401970. https://clinicaltrials.gov/ct2/show/NCT03401970.

Dietary carbohydrates: Pathogenesis and potential therapeutic targets to obesity-associated metabolic syndrome

Metabolic syndrome (MetS) is a common feature in obesity, comprising a cluster of abnormalities including abdominal fat accumulation, hyperglycemia, hyperinsulinemia, dyslipidemia, and hypertension, leading to diabetes and cardiovascular diseases (CVD). Intake of carbohydrates (CHO), particularly a sugary diet that rapidly increases blood glucose, triglycerides, and blood pressure levels is the predominant determining factor of MetS. Complex CHO, on the other hand, are a stable source of energy taking a longer time to digest. In particular, resistant starch (RS) or soluble fiber is an excellent source of prebiotics, which alter the gut microbial composition, which in turn improves metabolic control. Altering maternal CHO intake during pregnancy may result in the child developing MetS. Furthermore, lifestyle factors such as physical inactivity in combination with dietary habits may synergistically influence gene expression by modulating genetic and epigenetic regulators transforming childhood obesity into adolescent metabolic disorders. This review summarizes the common pathophysiology of MetS in connection with the nature of CHO, intrauterine nutrition, genetic predisposition, lifestyle factors, and advanced treatment approaches; it also emphasizes how dietary CHO may act as a key element in the pathogenesis and future therapeutic targets of obesity and MetS.

Short Term Isocaloric Ketogenic Diet Modulates NLRP3 Inflammasome Via B-hydroxybutyrate and Fibroblast Growth Factor 21

A ketogenic diet (KD) is known to have beneficial health effects. Various types of KD interventions have been applied to manage metabolic syndrome based on modification of diet parameters such as duration of intervention, macronutrient components, and total calories. Nevertheless, the beneficial health impact of isocaloric KD is largely unknown, especially in healthy subjects. The present study investigated the acute effects of a 3-day isocaloric KD. In this non-randomized intervention study, we recruited 15 healthy volunteers aged 24-38 years (7 men and 8 women) and placed them on an isocaloric KD restricting intake of carbohydrates but not energy (75% fat, 20% protein, 5% carbohydrate) for 3 days. Biochemical profiles and laboratory measurements were performed. Peripheral blood monocular cells were cultured, and measured cell stimulated cytokines. After short-term isocaloric KD, subjects lost body weight and serum free fatty acid levels were increased. These results accompanied elevated serum β-hydroxybutyrate (BHB) concentration and fibroblast growth factor 21 (FGF21) levels and improved insulin sensitivity. Regarding the direct effect of BHB on inflammasome activation, interleukin-1β (IL-1β) and tumor necrosis factor-α secretion in response to adenosine triphosphate or palmitate stimulation in human macrophages decreased significantly after isocaloric KD. In ex-vivo experiments with macrophages, both FGF21 and BHB further reduced IL-1β secretion compared to either BHB or FGF21 alone. The inhibitory effect of FGF21 on IL-1β secretion was blunted with bafilomycin treatment, which blocked autophagy flux. In conclusion, isocaloric KD for 3 days is a promising approach to improve metabolic and inflammatory status.

Rethinking COVID-19 and Beyond: Prevention, Remedies, and Recovery

In a relatively short timeframe, millions of deaths and illnesses associated with COVID-19 have been reported, accompanied by substantial economic losses, and overall, negatively impacting society. This experience should serve as a wakeup call to those in public health and healthcare, along with politicians and citizens: COVID-19 is considered a predictable and preventable disaster. While various reactive responses to address the pandemic were implemented, some with adverse effects, proactive measures in the years before COVID-19 were neglected. Predominately this involved the development of a preventable overfat pandemic, which played a key role in both rising rates of chronic disease, the comorbidities that increase the risk for COVID-19, along with associated inflammation and malnutrition. This increased the risk of infection in billions of people worldwide, which, in essence, primed society for high rates of COVID-19 infection. Excess body fat evolves primarily from poor nutrition, particularly the overconsumption of sugar and other refined carbohydrates, which replace the vital nutrients needed for optimal immune function. Sugar and refined carbohydrates must be considered the new tobacco, as these foods are also devoid of nutrients, and underly inflammatory chronic diseases. A balanced diet of nutrient-dense wholefood must be emphasized to combat infectious and inflammatory diseases. Implementing proactive preventive lifestyle changes must begin now, starting with simple, safe, and inexpensive dietary modifications that can quickly lead to a healthier population.

Weight loss and cystic disease progression in autosomal dominant polycystic kidney disease

Progression of autosomal dominant polycystic kidney disease (ADPKD) is modified by metabolic defects and obesity. Indeed, reduced food intake slows cyst growth in preclinical rodent studies. Here, we demonstrate the feasibility of daily caloric restriction (DCR) and intermittent fasting (IMF) in a cohort of overweight or obese patients with ADPKD. Clinically significant weight loss occurred with both DCR and IMF; however, weight loss was greater and adherence and tolerability were better with DCR. Further, slowed kidney growth correlated with body weight and visceral adiposity loss independent of dietary regimen. Similarly, we compared the therapeutic efficacy of DCR, IMF, and time restricted feeding (TRF) using an orthologous ADPKD mouse model. Only ADPKD animals on DCR lost significant weight and showed slowed cyst growth compared to ad libitum, IMF, or TRF feeding. Collectively, this supports therapeutic feasibility of caloric restriction in ADPKD, with potential efficacy benefits driven by weight loss.

Effects of a Very Low-Carbohydrate High-Fat Diet and High-Intensity Interval Training on Visceral Fat Deposition and Cardiorespiratory Fitness in Overfat Individuals: A Randomized Controlled Clinical Trial

Purpose: This randomized controlled parallel-group study examined the effects of a very low-carbohydrate high-fat (VLCHF) diet and high-intensity interval training (HIIT) program over 12 weeks on visceral adipose tissue (VAT) and cardiorespiratory fitness (CRF) level in overfat individuals. Methods: Ninety-one participants were randomly allocated to the HIIT (N = 22), VLCHF (N = 25), VLCHF+HIIT (N = 25), or control (N = 19) groups for 12 weeks. Body composition and CRF were analyzed before the experimental period and after 4, 8, and 12 weeks. Dual-energy X-ray absorptiometry (DXA) and graded exercise test (GXT) to volitional exhaustion were used for the body composition and CRF assessments, respectively. Results: There were significant between-group differences in the VAT mass and body composition outcome changes. VAT mass decreased after 12 weeks only in the VLCHF and VLCHF+HIIT groups (p < 0.001, median [95% CI]: VLCHF: -142.0 [-187.0; -109.5] g; VLCHF+HIIT: -104.0 [-135.0; -71.0] g). Similarly, changes in body mass, total body fat, trunk fat mass, waist and hip circumferences were distinctly decreased in the VLCHF and VLCHF+HIIT groups, when compared to HIIT and Control groups. Total lean mass significantly decreased in the VLCHF and VLCHF+HIIT groups (-2.1 [-3.0; -1.6] kg and -2.5 [-3.6; -1.8] kg, respectively) after 12 weeks. While the HIIT program significantly increased total time to exhaustion in the GXT, peak oxygen uptake was unchanged. Conclusions: A VLCHF diet, either in isolation or in combination with HIIT, was shown to induce a significant reduction in VAT mass and body composition variables. HIIT alone did not cause such effects on body composition, but improved exercise capacity. Our findings indicate that the VLCHF diet and exercise training provoked different and isolated effects on body composition and CRF. Clinical Trial Registration: https://clinicaltrials.gov/ct2/show/NCT03934476, identifier: NCT03934476.

Association of the low-carbohydrate dietary pattern with postpartum weight retention in women

Low-carbohydrate diets (LCD) have been considered a popular dietary strategy for weight loss. However, the association of the low-carbohydrate dietary pattern with postpartum weight retention (PPWR) in women remains unknown. The present study involved 426 women from a prospective mother-infant cohort study. Overall, animal or plant LCD scores, which represent adherence to different low-carbohydrate dietary patterns, were calculated using diet intake information assessed by three consecutive 24 h dietary surveys. PPWR was assessed by the difference of weight at 1 year postpartum minus the pre-pregnancy weight. After adjusting for potential confounding variables, women in higher quartiles of total and animal-based LCD scores had a significantly lower body weight and weight retention at 1 year postpartum (P < 0.05). The multivariable-adjusted ORs of substantial PPWR (≥5 kg), comparing the highest with the lowest quartile, were 0.47 (95% confidence interval 0.23-0.96) for the total LCD score (P = 0.021 for trend) and 0.38 (95% confidence interval 0.19-0.77) for the animal-based LCD score (P = 0.019 for trend), while this association was significantly attenuated by rice, glycemic load, fish, poultry, animal fat and animal protein (P for trend <0.05). A high score for plant-based LCD was not significantly associated with the risk of PPWR (P > 0.05). The findings suggested that a low-carbohydrate dietary pattern, particularly with high protein and fat intake from animal-source foods, is associated with a decreased risk of weight retention at 1 year postpartum. This association was mainly due to low intake of glycemic load and high intake of fish and poultry.

[Obesity, inflammation and COVID-19: preventive interest of ketogenic diet?]

Obesity is considered a pandemic responsible for millions of deaths worldwide for many years. At the end of 2019, the Coronavirus disease 2019 (COVID-19) appeared, causing the death of more than a million people in less than a year. Numerous studies suggest that obesity could be defined as key to the onset of severe forms of this emerging disease. Indeed, SARS-CoV2 infects the host by binding to ACE2 receptors present on the surface of the cells and causes excessive secretion of pro-inflammatory cytokines including IL-1, IL-6 and TNF-α, which lead to developing acute respiratory distress syndrome (ARDS). It therefore seems essential to make up effective preventive strategies to protect this part of the population from the risk of developing a severe form of COVID-19. The ketogenic diet, which is low in sugars and high in fat, has interesting properties, both in the fight against obesity but also against severe infections. This article focuses on the latest scientific advances that make it possible to consider the ketogenic diet as a preventive strategy that simultaneously reduces the development of obesity while strengthening the immune system, two key actions in the fight against SARS-CoV2 infections and severe forms of COVID-19.

A Pilot Study of Associations Between Visceral Fat, IL-6, and Urinary F2-Isoprostanes in Older Adults Exposed to a Diet Intervention

BACKGROUND

Short-term markers of successful visceral adipose tissue (VAT) loss are needed. Urinary F2-isoprostanes might serve as a marker for intensified lipid metabolism, whereas circulating IL-6 might stimulate fat oxidation and enhance mobilization of VAT.

OBJECTIVES

This pilot study was designed to explore the hypotheses that 1) reduction in VAT is associated with increase in IL-6, and 2) that increases in urinary F2-isoprostanes are associated with increases in IL-6 and reduction in VAT.

METHODS

Eighteen participants (aged 60-75 y, BMI 30-40 kg/m2) were randomly assigned to either a very-low-carbohydrate diet (VLCD; <10:25:>65% energy from carbohydrate:protein:fat) or a low-fat diet (LFD; 55:25:20%) for 8 wk. Changes in fat distribution were assessed by MRI. Four urinary F2-isoprostane isomers were quantified in 24-h urine collection using LC-MS/MS analyses. Changes in 4 F2-isoprostane isomers were summarized using factor analysis (Δ-F2-isoprostane factor). Statistical significance was set at P < 0.1.

RESULTS

Within the VLCD group, change in VAT was inversely associated with change in IL-6 (r = -0.778, P = 0.069) and Δ-F2-isoprostane factor (r = -0.690, P = 0.086), demonstrating that participants who maintained higher concentrations of F2-isoprostane factor across the intervention showed greater decreases in VAT. A positive relation between Δ-F2-isoprostane factor and change in IL-6 was observed (r = 0.642, P = 0.062). In the LFD group, no significant associations between changes in VAT, F2-isoprostane factor, or IL-6 were observed.

CONCLUSIONS

Results from this exploratory study in older adults with obesity suggest that, in the context of a VLCD, IL-6 could be involved in VAT mobilization, and urinary F2-isoprostanes could reflect intensified oxidation of mobilized fatty acids.Trial registration: This study is registered at clinicaltrials.gov as NCT02760641.

The Potential Health Benefits of the Ketogenic Diet: A Narrative Review

Considering the lack of a comprehensive, multi-faceted overview of the ketogenic diet (KD) in relation to health issues, we compiled the evidence related to the use of the ketogenic diet in relation to its impact on the microbiome, the epigenome, diabetes, weight loss, cardiovascular health, and cancer. The KD diet could potentially increase genetic diversity of the microbiome and increase the ratio of Bacteroidetes to Firmicutes. The epigenome might be positively affected by the KD since it creates a signaling molecule known as β-hydroxybutyrate (BHB). KD has helped patients with diabetes reduce their HbA1c and reduce the need for insulin. There is evidence to suggest that a KD can help with weight loss, visceral adiposity, and appetite control. The evidence also suggests that eating a high-fat diet improves lipid profiles by lowering low-density lipoprotein (LDL), increasing high-density lipoprotein (HDL), and lowering triglycerides (TG). Due to the Warburg effect, the KD is used as an adjuvant treatment to starve cancer cells, making them more vulnerable to chemotherapy and radiation. The potential positive impacts of a KD on each of these areas warrant further analysis, improved studies, and well-designed randomized controlled trials to further illuminate the therapeutic possibilities provided by this dietary intervention.

Nutrition in Gynecological Diseases: Current Perspectives

Diet and nutrition are fundamental in maintaining the general health of populations, including women's health. Health status can be affected by nutrient deficiency and vice versa. Gene-nutrient interactions are important contributors to health management and disease prevention. Nutrition can alter gene expression, as well as the susceptibility to diseases, including cancer, through several mechanisms. Gynecological diseases in general are diseases involving the female reproductive system and include benign and malignant tumors, infections, and endocrine diseases. Benign diseases such as uterine fibroids and endometriosis are common, with a negative impact on women's quality of life, while malignant tumors are among the most common cause of death in the recent years. In this comprehensive review article, a bibliographic search was performed for retrieving information about nutrients and how their deficiencies can be associated with gynecological diseases, namely polycystic ovary syndrome, infertility, uterine fibroids, endometriosis, dysmenorrhea, and infections, as well as cervical, endometrial, and ovarian cancers. Moreover, we discussed the potential beneficial impact of promising natural compounds and dietary supplements on alleviating these significant diseases.

Greater Loss of Central Adiposity from Low-Carbohydrate versus Low-Fat Diet in Middle-Aged Adults with Overweight and Obesity

The objective of this study is to determine whether middle-aged adults prescribed a low carbohydrate-high fat (LCHF) or low fat (LF) diet would have greater loss of central fat and to determine whether the insulin resistance (IR) affects intervention response. A total of 50 participants (52.3 ± 10.7 years old; 36.6 ± 7.4 kg/m2 BMI; 82% female) were prescribed either a LCHF diet (n = 32, carbohydrate: protein: fat of 5%:30%:65% without calorie restriction), or LF diet (n = 18, 63%:13–23%: 10–25% with calorie restriction of total energy expenditure—500 kcal) for 15 weeks. Central and regional body composition changes from dual-x-ray absorptiometry and serum measures were compared using paired t-tests and ANCOVA with paired contrasts. IR was defined as homeostatic model assessment (HOMA-IR) > 2.6. Compared to the LF group, the LCHF group lost more android (15.6 ± 11.2% vs. 8.3 ± 8.1%, p < 0.01) and visceral fat (18.5 ± 22.2% vs. 5.1 ± 15.8%, p < 0.05). Those with IR lost more android and visceral fat on the LCHF verses LF group (p < 0.05). Therefore, the clinical prescription to a LCHF diet may be an optimal strategy to reduce disease risk in middle-aged adults, particularly those with IR.

Efficacy and Safety of Combined Extracts of Cornus officinalis and Ribes fasciculatum for Body Fat Reduction in Overweight Women

Obesity is a medical condition that presents excessive fat accumulation with high risk of serious chronic diseases. The aim of this clinical trial is to investigate the anti-obesity effects of Cornus officinalis (CO) and Ribes fasciculatum (RF) on body fat reduction in Korean overweight women. A total of 147 overweight female participants enrolled in double-blinded clinical trial for 12 weeks and 76 participants completed the clinical study. Participants were treated with four CO and RF mixture (COEC; 400 mg per tablet) or four placebo tablets once a day. Obesity associated parameters (body weight, body mass index (BMI), waist circumference, waist-to-hip ratio, body fat percentage and body fat mass) and safety assessment were analyzed. After 12 weeks of COEC treatment, primary outcomes such as body fat percentage (0.76% vs. 0.01%; p = 0.022) and mass (1.1 kg vs. 0.5 kg; p = 0.049) were significantly decreased. In addition, the results were statistically significant between the COEC and placebo groups, strongly indicated that COEC had anti-obesity effects on overweight women. Secondary outcomes—including body weight, waist and hip circumference, waist-to-hip ratio, body mass index and computed tomography measurement of visceral fat area, subcutaneous fat area, total abdominal fat area and visceral-to-subcutaneous fat ratio—were reduced in COEC-treated group, but no statistical differences were found between the COEC and placebo groups. The safety assessment did not differ between the two groups. These results suggest that treatment of COEC extract reduces body fat percentage and mass in Korean overweight women, indicating it as a protective functional agent for obesity.

Islet Health, Hormone Secretion, and Insulin Responsivity with Low-Carbohydrate Feeding in Diabetes

Exploring new avenues to control daily fluctuations in glycemia has been a central theme for diabetes research since the Diabetes Control and Complications Trial (DCCT). Carbohydrate restriction has re-emerged as a means to control type 2 diabetes mellitus (T2DM), becoming increasingly popular and supported by national diabetes associations in Canada, Australia, the USA, and Europe. This approval comes from many positive outcomes on HbA1c in human studies; yet mechanisms underlying their success have not been fully elucidated. In this review, we discuss the preclinical and clinical studies investigating the role of carbohydrate restriction and physiological elevations in ketone bodies directly on pancreatic islet health, islet hormone secretion, and insulin sensitivity. Included studies have clearly outlined diet compositions, including a diet with 30% or less of calories from carbohydrates.

Efficacy of Low-Carbohydrate Ketogenic Diet in the Treatment of Type 2 Diabetes

Low-carbohydrate ketogenic diet (LCKD), originally used as a treatment for childhood epilepsy is currently gaining acceptance as a nutritional therapy for obesity and type 2 diabetes. In addition, this diet has a positive effect on body weight, blood glucose level, glycosylated hemoglobin, plasma lipid profile, and neurological disorders. This review focuses on the therapeutic effectiveness, negative effects, and the rationale of using LCKD for the treatment of type 2 diabetes. It is shown that LCKD contributes to the reduction in the intake of insulin and oral antidiabetic drugs in patients with type 2 diabetes. Furthermore, the data presented in this review reveal the efficacy and cost-effectiveness of LCKD in the management of type 2 diabetes.