The association of dietary energy density and the risk of obesity, type 2 diabetes and metabolic syndrome: A systematic review and meta-analysis of observational studies

The effects of prebiotic, probiotic or synbiotic supplementation on overweight/obesity indicators: an umbrella review of the trials' meta-analyses

Background

There is controversial data on the effects of prebiotic, probiotic, or synbiotic supplementations on overweight/obesity indicators. Thus, we aimed to clarify this role of biotics through an umbrella review of the trials' meta-analyses.

Methods

All meta-analyses of the clinical trials conducted on the impact of biotics on overweight/obesity indicators in general populations, pregnant women, and infants published until June 2023 in PubMed, Web of Sciences, Scopus, Embase, and Cochrane Library web databases included. The meta-analysis of observational and systematic review studies without meta-analysis were excluded. We reported the results by implementing the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) flowchart. The Assessment of Multiple Systematic Reviews-2 (AMSTAR2) and Grading of Recommendations Assessment, Development, and Evaluation (GRADE) systems were used to assess the methodological quality and quality of evidence.

Results

Overall, 97 meta-analysis studies were included. Most studies were conducted on the effect of probiotics in both genders. Consumption of prebiotic: 8-66 g/day, probiotic: 104 -1.35×1015 colony-forming unit (CFU)/day, and synbiotic: 106-1.5×1011 CFU/day and 0.5-300 g/day for 2 to 104 weeks showed a favorable effect on the overweight/obesity indicators. Moreover, an inverse association was observed between biotics consumption and overweight/obesity risk in adults in most of the studies. Biotics did not show any beneficial effect on weight and body mass index (BMI) in pregnant women by 6.6×105-1010 CFU/day of probiotics during 1-25 weeks and 1×109-112.5×109 CFU/capsule of synbiotics during 4-8 weeks. The effect of biotics on weight and BMI in infants is predominantly non-significant. Prebiotics and probiotics used in infancy were from 0.15 to 0.8 g/dL and 2×106-6×109 CFU/day for 2-24 weeks, respectively.

Conclusion

It seems biotics consumption can result in favorable impacts on some anthropometric indices of overweight/obesity (body weight, BMI, waist circumference) in the general population, without any significant effects on birth weight or weight gain during pregnancy and infancy. So, it is recommended to intake the biotics as complementary medications for reducing anthropometric indices of overweight/obese adults. However, more well-designed trials are needed to elucidate the anti-obesity effects of specific strains of probiotics.

Giving fruits and vegetables a tax break: lessons from a Dutch attempt

OBJECTIVE

Food taxation can improve diets by making unhealthy foods more expensive and by making healthy foods cheaper. In the Netherlands, a political window of opportunity arose in December 2021 to reduce the value-added tax (VAT) on fruits and vegetables to zero percent. The policy is now facing institutional friction along several fronts, however, delaying and potentially averting its implementation. We analysed this institutional friction to inform future food tax policies.

DESIGN

We qualitatively analysed open-access fiscal and health experts' position papers about benefits and downsides of the zero-rate that were discussed with members of parliament in June 2023.

SETTING

The Netherlands.

PARTICIPANTS

Not applicable.

RESULTS

Health and fiscal experts expressed noticeably different viewpoints towards the utility of the zero-rate. One important argument fiscal experts based their negative advice upon pertained to the legal restrictions for distinguishing between healthier and unhealthier forms of fruits and vegetables (i.e. the principle of neutrality). A zero-rate VAT on unhealthier forms of fruits and vegetables, e.g. processed cucumber, mixed with salt and sugar, would be undesirable, but differentiating between raw and processed cucumber would offend the neutrality principle.

CONCLUSIONS

The Dutch attempt to give fruits and vegetables a tax break highlights the need for crystal-clear food classifications when designing food tax policies. Public health nutritionists should combine classifications based on caloric density, palatability, degree of processing and nutrient content to provide a database for evidence-informed tax differentiation according to food item healthfulness.

Effects of boron citrate supplementation on cardiometabolic factors, inflammatory biomarkers and anthropometric measures in obese patients: study protocol for a randomised, double-blind clinical trial

INTRODUCTION

Obesity is a chronic disease with serious health consequences, but weight loss is difficult to maintain through lifestyle intervention alone. The efficacy and safety of boron citrate (BC), a novel therapeutic approach, in patients with obesity are not known. The current trial will take place to determine the effects of BC supplementation on cardiometabolic factors, inflammatory biomarkers, anthropometric measures and body composition in obese patients.

METHODS AND ANALYSIS

This double-blind, placebo-controlled, randomised clinical trial will involve 60 eligible obese participants aged 18-60 years. Participants will randomly be allocated to receive either BC capsules (containing 10 mg of boron) in the intervention group or placebo capsules (containing 10 mg of maltodextrin) in the placebo group for 12 weeks. Moreover, physical activity and dietary recommendations will be provided for both groups. To assess the dietary intakes of participants, a 3-day food record (2 days of the week and 1 day of the weekend) will be filled. Cardiometabolic factors, inflammatory biomarkers including tumour necrosis factor α, C reactive protein, interleukin-6 and interleukin-10 levels, anthropometric measures and body composition will be assessed at the baseline and end of the intervention. The findings of this study will provide evidence for the effectiveness of BC in the management of obesity.

ETHICS AND DISSEMINATION

There are so far no reported adverse effects associated with the use of boron. This trial was approved by the Ethics Committee of Tabriz University of Medical Sciences (approval number: IR.TBZMED.REC.1401.350). Positive as well as negative findings will be published in peer-reviewed journals.

TRIAL REGISTRATION NUMBER

IRCT20220806055624N1.

Structural diversity, hypothetical biosynthesis, chemical synthesis, and biological activity of Ganoderma meroterpenoids

Covering: 2018 to 2022Meroterpenoids found in fungal species of the genus Ganoderma and known as Ganoderma meroterpenoids (GMs) are substances composed of a 1,2,4-trisubstituted benzene and a polyunsaturated side chain. These substances have attracted the attention of chemists and pharmacologists due to their diverse structures and significant bioactivity. In this review, we present the structures and possible biosynthesis of representative GMs newly found from 2018 to 2022, as well as chemical synthesis and biological activity of some interesting GMs. We propose for the first time a plausible biosynthetic pathway for GMs, which will certainly motivate further research on the biosynthetic pathway in Ganoderma species, as well as on chemical synthesis of GMs as important bioactive compounds for the purpose of drug development.

Ultraprocessed Foods and Obesity Risk: A Critical Review of Reported Mechanisms

Epidemiologic evidence supports a positive association between ultraprocessed food (UPF) consumption and body mass index. This has led to recommendations to avoid UPFs despite very limited evidence establishing causality. Many mechanisms have been proposed, and this review critically aimed to evaluate selected possibilities for specificity, clarity, and consistency related to food choice (i.e., low cost, shelf-life, food packaging, hyperpalatability, and stimulation of hunger/suppression of fullness); food composition (i.e., macronutrients, food texture, added sugar, fat and salt, energy density, low-calorie sweeteners, and additives); and digestive processes (i.e., oral processing/eating rate, gastric emptying time, gastrointestinal transit time, and microbiome). For some purported mechanisms (e.g., fiber content, texture, gastric emptying, and intestinal transit time), data directly contrasting the effects of UPF and non-UPF intake on the indices of appetite, food intake, and adiposity are available and do not support a unique contribution of UPFs. In other instances, data are not available (e.g., microbiome and food additives) or are insufficient (e.g., packaging, food cost, shelf-life, macronutrient intake, and appetite stimulation) to judge the benefits versus the risks of UPF avoidance. There are yet other evoked mechanisms in which the preponderance of evidence indicates ingredients in UPFs actually moderate body weight (e.g., low-calorie sweetener use for weight management; beverage consumption as it dilutes energy density; and higher fat content because it reduces glycemic responses). Because avoidance of UPFs holds potential adverse effects (e.g., reduced diet quality, increased risk of food poisoning, and food wastage), it is imprudent to make recommendations regarding their role in diets before causality and plausible mechanisms have been verified.

Analysis of the association between glomerular filtration rate, proteinuria and metabolic syndrome in chronic kidney patients based on longitudinal data

Chronic kidney disease (CKD) is a group of chronic diseases caused by kidney damage from multiple causes. Metabolic syndrome (MS) manifests as dysfunction of endothelial cells and chronic functional inflammatory states, and may be involved in pathological changes related to renal impairment. Based on longitudinal data analysis of the association between estimated glomerular filtration rate (eGFR), proteinuria and MS in patients with CKD, this study aims to provide new ideas for the pathophysiological mechanism of CKD and a theoretical basis for the early prevention and effective intervention of MS-related kidney damage. A total of 126 patients with CKD were divided into non-MS group and MS group. According to the eGFR level, 126 patients with CKD were divided into G1 group, G2 group, G3a group, G3b group, G4 group and G5 group. Serum markers such as eGFR, urine protein, and triglycerides (TG) were collected. The correlation between eGFR, urine protein and MS-related indexes was analysed, and the risk factors affecting CKD complicated by MS were analysed. In patients with CKD, the levels of urine protein, abdominal circumference, TG, systolic blood pressure (SBP), diastolic blood pressure (DBP), and fasting blood glucose (FPG) were increased with the course of the disease, but the levels of eGFR and high density lipoprotein (HDL-C) were decreased (p < 0.05). Abdominal circumference, TG, SBP, DBP, FP were significantly negatively correlated with eGFR, but HDL-C was positively correlated with eGFR (p < 0.05). Diabetes, hyperlipidemia, UA, and SBP were independent risk factors affecting CKD complicated MS, and eGFR were independent protective factors (p < 0.05). The combination of diabetes, hyperlipidemia, UA, SBP, and eGFR exhibited higher prediction value for the CKD patients complicated by MS. There was a certain correlation between between MS components with eGFR and urinary protein in patients with CKD. The early intervention treatment of MS was helpful in delaying the development of CKD and reducing proteinuria.

Effects of a Web-Based Lifestyle Intervention on Weight Loss and Cardiometabolic Risk Factors in Adults With Overweight and Obesity: Randomized Controlled Clinical Trial

BACKGROUND

The high proportion of people with overweight and obesity has become a worldwide problem in recent decades, mainly due to health consequences, such as cardiovascular diseases, neoplasia, and type 2 diabetes mellitus. Regarding effective countermeasures, the digitization of health services offers numerous potentials, which, however, have not yet been sufficiently evaluated. Web-based health programs are becoming increasingly interactive and can provide individuals with effective long-term weight management support.

OBJECTIVE

The purpose of this randomized controlled clinical trial was to evaluate the effectiveness of an interactive web-based weight loss program on anthropometric, cardiometabolic, and behavioral variables and to compare it with a noninteractive web-based weight loss program.

METHODS

The randomized controlled trial included people who were aged between 18 and 65 years (mean 48.92, SD 11.17 years) and had a BMI of 27.5 to 34.9 kg/m² (mean 30.71, SD 2.13 kg/m²). Participants (n=153) were assigned to either (1) an interactive and fully automated web-based health program (intervention) or (2) a noninteractive web-based health program (control). The intervention program focused on dietary energy density and allowed for dietary documentation with appropriate feedback on energy density and nutrients. The control group only received information on weight loss and energy density, but the website did not contain interactive content. Examinations were performed at baseline (t0), at the end of the 12-week intervention (t1), and at 6 months (t2) and 12 months (t3) thereafter. The primary outcome was body weight. The secondary outcomes were cardiometabolic variables as well as dietary and physical activity behaviors. Robust linear mixed models were used to evaluate the primary and secondary outcomes.

RESULTS

The intervention group showed significant improvements in anthropometric variables, such as body weight (P=.004), waist circumference (P=.002), and fat mass (P=.02), compared with the control group over the course of the study. The mean weight loss after the 12-month follow-up was 4.18 kg (4.7%) in the intervention group versus 1.29 kg (1.5%) in the control group compared with the initial weight. The results of the nutritional analysis showed that the energy density concept was significantly better implemented in the intervention group. Significant differences in cardiometabolic variables were not detected between the 2 groups.

CONCLUSIONS

The interactive web-based health program was effective in reducing body weight and improving body composition in adults with overweight and obesity. However, these improvements were not associated with relevant changes in cardiometabolic variables, although it should be noted that the study population was predominantly metabolically healthy.

TRIAL REGISTRATION

German Clinical Trials Register DRKS00020249; https://drks.de/search/en/trial/DRKS00020249.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

RR2-10.3390/ijerph19031393.

Effects of probiotic/synbiotic supplementation on body weight in patients with diabetes: a systematic review and meta-analyses of randomized-controlled trials

OBJECTIVE

The aim of the present study was to assess the effect of probiotic/synbiotic supplementation on anthropometric measures in adults with diabetes, independent of body weight.

METHODS

PubMed, Scopus, Web of Sciences and the Cochrane Library were searched for randomized controlled trials (RCTs) up until December 14, 2022. The effect sizes were pooled using an inverse-variance random-effects model. The methodological quality of studies as well as the quality of evidence was assessed using standard tools.

RESULTS

Thirty-two RCTs met the established inclusion criteria. Overall, compared with the respective control groups, probiotic/synbiotic supplementation resulted in a significant reduction in body weight (weighted mean difference [WMD]: -0.50 kg; 95% CI: -0.83, -0.17; I² = 79.8%, n = 27 studies]), body mass index (WMD: -0.24 kg/m²; 95% CI: -0.39, -0.09; I² = 85.7%, n = 30 studies), and waist circumference (WMD: -0.90 cm; 95% CI: -1.13, -0.52; I² = 0%, n = 11 studies). However, hip circumference and waist to hip ratio were not significantly improved.

CONCLUSIONS

Our analysis revealed that probiotic/synbiotic supplementation may assist with weight management in patients with diabetes, especially when consumed at higher doses, in younger adults, and in participants with obesity. However, more studies are needed to elucidate the anti-obesity effects of specific strains of probiotics/synbiotics.

Effect of nuts on components of metabolic syndrome in healthy adults with overweight/obesity: A systematic review and meta-analysis

AIMS

Randomized controlled trials evaluating the effects of nut consumption on the metabolic profile of healthy adults with overweight/obesity have yielded conflicting results. This systematic review and meta-analysis aimed to summarize the effects of incorporating nuts into the diet on serum lipid profile, glycemic markers, and blood pressure in healthy adults with overweight/obesity.

DATA SYNTHESIS

PubMed, Embase, Scopus, Web of Science, and Cochrane Library were searched up to April 2021. The random-effects model was used to determine the pooled effect sizes expressed as weighted mean difference (WMD) with % 95 confidence intervals (CIs). Ten eligible RCTs (with 12 arms) were included in the meta-analysis. The meta-analysis revealed that nut intake significantly decreased serum triglycerides (TG) (WMD: -13.19 mg/dL, 95% CI: - 25.90, - 0.48). Furthermore, subgroup analysis showed a significant reduction in serum LDL-cholesterol (LDL-C) following adherence to normocaloric, nut-enriched diets (WMD: - 4.56 mg/dL, 95% CI: - 8.24, - 0.88). However, nuts did not affect serum total cholesterol, high-density lipoprotein cholesterol, glycemic markers, and blood pressure.

CONCLUSIONS

Overall, incorporating nuts into the diet of healthy adults with overweight/obesity have favorable effects on serum TG and LDL-C. Thus, nuts might exert protective effects against dyslipidemia in this population.

REGISTRY NUMBER

PROPSPERO CRD42021250662.

Effectiveness of a personal health coaching intervention (diabetescoach) in patients with type 2 diabetes: protocol for an open-label, pragmatic randomised controlled trial

INTRODUCTION

The widespread prevalence of type 2 diabetes (T2D) not only influences patients' daily lives but also has an economic impact on society. Increasing physical activity and a healthy diet can delay the progression of T2D. Although there are evidence-based recommendations on diet and physical activity, patients with T2D have difficulties implementing them. An appropriate lifestyle intervention can address this problem.

METHODS AND ANALYSIS

This study is based on the need to develop an intervention that helps patients to establish behavioural changes in order to achieve glycaemic control. The intervention will be evaluated in a monocentric, open-label, pragmatic, two-arm randomised controlled trial with a sample ratio of 1:1 and a parallel design. This superiority study will be conducted in Switzerland. All enrolled patients (n=90) will receive the standard medical treatment for T2D. The intervention group will receive personal health coaching by telephone and access to a smartphone and web application for 1 year. The control group will receive access to the application for 1 year and a one-time written diet and exercise recommendation. The primary outcomes are objectively measured physical activity and glycated haemoglobin. Secondary outcomes are self-reported physical activity, nutrition, cognitive mediators of changes in sport-related behaviour, blood values, medication and nutritional supplements, anthropometric data, quality of life, neuropathy and cost-effectiveness. All outcomes will be measured at baseline, at 27 weeks after inclusion and at 54 weeks after inclusion. The recruitment of participants and the measurements will be completed after 2 years. Linear mixed-effects models will be applied for each outcome variable to analyse the intervention effects.

ETHICS AND DISSEMINATION

This study was approved by the Ethics Committee North-western and Central Switzerland in February 2021 (ref: 2020-02755). All participants will be required to provide written informed consent. The results will be published in international peer-reviewed journals.

TRIAL REGISTRATION NUMBER

ISRCTN79457541.

Comparison of Dietary Behaviors and the Prevalence of Metabolic Syndrome in Single- and Multi-Person Households among Korean Adults

Changes in household dynamics in Korea, such as the transition from multi- to single-person households, have led to changes in individuals' dietary behavior patterns and health status. Thus, this study aimed to compare dietary behaviors and determine the prevalence of metabolic syndrome (MetS) as well as explore factors associated with MetS according to household type among Korean adults. Using data from the Korea National Health and Nutrition Examination Survey 2014-2018, we included 21,944 Korean adults with available health examination and dietary recall data. Based on self-reported information, individuals were divided into two household types: single- and multi-person households. We used multivariable logistic regression to estimate the adjusted odds ratios (AORs) and 95% confidence intervals (CIs) for MetS and its components after adjusting for potential covariates. Among the study population, 9.19% and 90.81% lived in single-person and multi-person households, respectively. Individuals in single-person households had a higher energy intake overall and a greater percentage of energy from animal protein; total, saturated, and monounsaturated fats; and animal source foods and a lower percentage of energy from carbohydrates, plant protein, and plant source foods than those from multi-person households (all, p < 0.05). Individuals living in single-person rather than multi-person households were more likely to consume milk/dairy products, alcoholic and non-alcoholic beverages, oils/fats, and others but were less likely to consume vegetables/mushrooms, fruits, seaweeds, and fish/shellfish (all, p < 0.05). Living alone was associated with higher energy intake from main meals and foods prepared away from home but a lower dietary variety score and fewer total main meals consumed (all, p < 0.05). Skipping breakfast, frequent eating out, food insecurity, and MetS combination phenotypes significantly differed by household type. Individuals living alone had higher odds of MetS (AOR: 1.14, 95% CI: 1.02-1.29), abdominal obesity (AOR: 1.14, 95% CI: 1.01-1.28), elevated blood pressure (AOR: 1.28, 95% CI: 1.12-1.47), and elevated fasting blood glucose (AOR: 1.18, 95% CI: 1.05-1.33) than those living with others. Compared with those in multi-person households, individuals in single-person households tend to have health and dietary behaviors that increase vulnerability to MetS; therefore, establishing health care strategies and nutrition policies according to household type is necessary.