Effect of Fibre Supplementation on Body Weight and Composition, Frequency of Eating and Dietary Choice in Overweight Individuals

Effects of Soluble Dextrin Fiber from Potato Starch on Body Weight and Associated Gut Dysbiosis Are Evident in Western Diet-Fed Mice but Not in Overweight/Obese Children

BACKGROUND

The study investigated the impact of starch degradation products (SDexF) as prebiotics on obesity management in mice and overweight/obese children.

METHODS

A total of 48 mice on a normal diet (ND) and 48 on a Western diet (WD) were divided into subgroups with or without 5% SDexF supplementation for 28 weeks. In a human study, 100 overweight/obese children were randomly assigned to prebiotic and control groups, consuming fruit and vegetable mousse with or without 10 g of SDexF for 24 weeks. Stool samples were analyzed for microbiota using 16S rRNA gene sequencing, and short-chain fatty acids (SCFA) and amino acids (AA) were assessed.

RESULTS

Results showed SDexF slowed weight gain in female mice on both diets but only temporarily in males. It altered bacterial diversity and specific taxa abundances in mouse feces. In humans, SDexF did not influence weight loss or gut microbiota composition, showing minimal changes in individual taxa. The anti-obesity effect observed in mice with WD-induced obesity was not replicated in children undergoing a weight-loss program.

CONCLUSIONS

SDexF exhibited sex-specific effects in mice but did not impact weight loss or microbiota composition in overweight/obese children.

Green Onion (Allium fistulosum): An Aromatic Vegetable Crop Esteemed for Food, Nutritional and Therapeutic Significance

In recent years, there has been a shift towards a greater demand for more nutritious and healthier foods, emphasizing the role of diets in human well-being. Edible Alliums, including common onions, garlic, chives and green onions, are staples in diverse cuisines worldwide and are valued specifically for their culinary versatility, distinct flavors and nutritional and medicinal properties. Green onions are widely cultivated and traded as a spicy vegetable. The mild, onion-like flavor makes the crop a pleasant addition to various dishes, serving as a staple ingredient in many world cuisines, particularly in Eastern Asian countries such as China, Japan and the Republic of Korea. The green pseudostems, leaves and non-developed bulbs of green onions are utilized in salads, stir-fries, garnishes and a myriad of culinary preparations. Additionally, green onions have a rich historical background in traditional medicine and diets, capturing the attention of chefs and the general public. The status of the crop as an important food, its culinary diversity and its nutraceutical and therapeutic value make it a subject of great interest in research. Therefore, the present review has examined the distribution, culinary, nutritional and therapeutic significance of green onions, highlighting the health benefits derived from the consumption of diets with this aromatic vegetable crop as a constituent.

Nourishing the Cognition with Millets: A Comprehensive Review of Their Nutritional Impact and Potential as Cognitive Enhancers

Cognition is the mental processes and abilities involved in acquiring, storing, retrieving and using it for decision making. Cognitive decline due to aging, lifestyle factor, chronic health conditions, genetic, and environmental factors are rising global concern and propose a potential threat to the cognitive health. The nutritional imbalance has led to increase in cognitive disorders around the world. Millets can be a nutritional intervention for promoting cognitive health and preventing cognitive decline. Millets has abundant phenolic compounds, flavonoids, and antioxidants to protect against oxidative stress-induced cognitive impairment. Millets exert neuroprotective effects by modulating pathways involved in neuronal-survival, synaptic-plasticity, and release of brain-derived neurotrophic factor. Millets demonstrates anti-inflammatory properties by regulating inflammatory-pathways and suppressing cytokines associated with cognitive impairment. Millets maintain healthy gut microbiota by producing metabolites such as short-chain fatty acids, which influence brain function and cognition. However, further research is needed to elucidate the underlying mechanisms and on optimizing the proportion do exploit its potential. Implementing millet-based dietary strategies through public health initiatives and educational programs can be a practical approach to support cognitive health across populations. Harnessing the potential of millets as a nutritional intervention offers a promising avenue for promoting cognitive health and improving the quality of life.

Starch-entrapped microspheres enhance gut microbiome-mediated anti-obesity effects of resistant starch in high-fat diet induced obese C57BL/6J mice

The prevalence of obesity is growing worldwide and has been extensively linked to gut microbiota dysbiosis. In addition to exercise and physical activity, fiber-rich foods may be a first-line prophylactic to manage obesity. This study investigated in vivo dietary intervention with high-amylose maize starch (HAMS) and starch-entrapped microspheres (MS) to treat high-fat diet induced metabolic disorder and gut microbiome dysbiosis in mice. MS more efficiently controlled body weight as well as adipose tissue mass compared to HAMS. Furthermore, MS significantly reduced blood glucose, insulin, lipid and pro-inflammatory cytokine levels compared to the high-fat diet, while the effects of HAMS were less pronounced. The MS-altered gut microbiota composition favoring Streptococcaceae, Bacilli, Firmicutes and unclassified Clostridiales was predicted to promote fatty acid, pantothenate and Coenzyme A biosynthesis. In line with this, elevated fecal short chain fatty acid (SCFA), in particular, propionate concentration was observed in MS-fed mice. Our study provides novel insights into the mechanistic action of MS on intestinal homeostasis, providing a basis for future dietary therapeutic applications.

Dietary Fiber Intake and Related Factors in Community-Based Iranian's Elderly

Background

There are considerable documents suggesting that inadequate fiber intake (FI) is a key risk factor for various chronic diseases. The aim of this study was to investigate Dietary FI in the Persian elderly.

Methods

This descriptive-analytic study was performed to investigate FI in a sample of the elderly who received free services from healthcare centers in Karaj, Iran. For sampling method: at first, the names of 36 centers were written on small pieces of paper and poured into a container, then another person was asked to randomly select the names of 10 centers, then referring to each of the centers and preparing a list of elderly people, the study subjects were selected, The study was conducted between September 2018, and April 2019Several questionnaires were used to collect data regarding DF: characteristics, daily FI , knowledge, SE (self-efficacy), perceived benefits, and barriers towards FI as well as stage of readiness of FI. t-test and ANOVA were used to compare independent mean values. Data were checked for normality before analysis by using Kolmogorov-Smirnov (K-S) test to check data normality.

Results

Totally of 400 elderly individuals entered the study with the average amount of fiber per day. The data analysis indicated they did not know the recommended intake of at least 25 gr each day. feeling less hungry and fiber's price was the most frequent perceived benefits and barriers towards FI , respectively. Gastrointestinal diseases ( P < 0.001), smoking (P < 0.001), and perceived barriers (P < 0.001), were statistically significant independent positive predictors of FI.

Conclusion

The findings of the current study indicated that FI among elderly people in Iran was very low and varied a great by gender, education, marital status, income level, employment status, smoking, stage of change, and gastrointestinal disease.

The Association between Plant-Based Diet Indices and Metabolic Syndrome in Chinese Adults: Longitudinal Analyses from the China Health and Nutrition Survey

Objectives: To investigate the association between a plant-based diet and metabolic syndrome (MetS) among Chinese adults. Methods: Based on the data from the 2004–2015 China Health and Nutrition Survey and the corresponding edition of China Food Composition, we calculated the healthy plant-based diet indices (hPDI) and unhealthy plant-based diet indices (uPDI). The Cox proportional hazards regression model was used to estimate the hazard ratios (HRs) with 95% confidence intervals (CIs) for MetS. Mediation analysis was further conducted to explore the mediator role of Body Mass Index (BMI) in the association between hPDI and MetS. Results: We included 10,013 participants, and over a median follow-up of 5 years, 961 patients (9.60%) developed MetS. Compared to those in the lowest quintile of hPDI score, we found that those in the highest quintile of hPDI score had a 28% lower ([HR]: 0.72, 95% CI 0.56–0.93, Ptrend = 0.021) risk of developing MetS and had a 20% lower (hazard ratio [HR]: 0.80, 95% CI 0.70–0.92, Ptrend = 0.004) risk of developing abdominal obesity. No significant associations were observed between uPDI and the MetS, but those in the highest quintile of uPDI score had a 36% higher (hazard ratio [HR]: 1.36, 95% CI 1.20–1.64, Ptrend < 0.001) risk of developing abdominal obesity, compared to those in the lowest quintile of uPDI score. In exploratory analysis, we observed that BMI at baseline mediated 27.8% of the association between hPDI and incident MetS, and BMI at baseline mediated 29.7% of the association between hPDI and abdominal obesity. Conclusion: The current findings reveal a possible causal relationship between a healthy plant-based diet and a reduced risk of MetS, especially abdominal obesity. It is observed that BMI may mediate the relationship between hPDI score and MetS. Controlling early dietary patterns and BMI may help reduce the risk of MetS.

Healthy plant-based diets improve dyslipidemias, insulin resistance, and inflammation in metabolic syndrome. A narrative review

Plant-based diets (PBDs) have become very popular in recent years and have been identified as a dietary strategy associated with protection against chronic disease. However, the classifications of PBDs vary depending on the type of diet. Some PBDs have been recognized as healthful for their high content of vitamins, minerals, antioxidants, and fiber, or unhealthful if they are high in simple sugars and saturated fat. Depending on this classification, the type of PBD impacts its protective effects against disease dramatically. Metabolic syndrome (MetS), characterized by the presence of high plasma triglycerides and low HDL cholesterol, impaired glucose metabolism, elevated blood pressure, and increased concentrations of inflammatory biomarkers, also increases the risk for heart disease and diabetes. Thus, healthful plant-based diets could be considered favorable for individuals having MetS. The different types of plant-based diets (vegan, lacto-vegetarian, lacto-ovo-vegetarian, or pescatarian) are discussed with a focus on specific effects of dietary components in maintaining a healthy weight, protecting against dyslipidemias, insulin resistance, hypertension, and low-grade inflammation.

Inverse Association of Fruit and Vegetable Consumption with Nonalcoholic Fatty Liver Disease in Chinese Patients with Type 2 Diabetes Mellitus

We aimed to investigate the association of fruit and vegetable consumption with nonalcoholic fatty liver disease (NAFLD) in Chinese patients with type 2 diabetes mellitus (T2DM). This cross-sectional study included 2667 Chinese patients with T2DM aged 18 to 76 years from March 2017 to October 2021. Dietary intake was assessed using a food frequency questionnaire, and prevalent NAFLD was diagnosed with abdominal ultrasonography. High fruit−vegetable consumption was determined using ≥500 g/day consumption of both fruit and vegetable, and both fruit and vegetable consumption were divided into three categories of <200 g/day (low), 200−400 g/day (median) and >400 g (high). The primary outcome measurement was multivariate-adjusted odds ratios (ORs) with 95% confidence intervals (CIs) for the prevalence of NAFLD in relation to the highest fruit and (or) vegetable intake compared with the lowest. Secondary analyses were conducted to assess the effects of either fruit or vegetable intake on the fatty liver index (FLI) using multivariable linear regressions. There were 1694 men and 973 women in this study, and 1445 (54.06%) participants had prevalent NAFLD. Patients with high fruit−vegetable intake had a lower prevalence of NAFLD than those with low fruit−vegetable intake (52.04% vs. 56.48%), but this difference was not statistically significant (p = 0.065). Vegetable intake had a significantly inverse association with NAFLD (OR: 0.68, 95% CI: 0.52−0.90), but this association was not pronounced with fruit intake (OR: 1.23, 95% CI: 0.89−1.69) or fruit−vegetable intake (OR: 0.90, 95% CI: 0.73−1.10). Additional analyses showed that an increase in vegetable intake was linearly associated with a significant reduction in FLI (β: −1.028, 95% CI: −1.836, −0.219). In conclusion, higher vegetable consumption was associated with lower odds of NAFLD in Chinese patients with T2DM, which suggested that increased vegetable intake might protect patients with diabetes against NAFLD.

Impacts of food consumption on biochemical markers and anthropometric variables of women with metabolic syndrome

BACKGROUND

Metabolic syndrome (MetS) is a group of diseases characterized by insulin resistance. MetS has high prevalence among women, which is impacted by food intake. MetS is related to high level of inflammation; however, the impacts of whole diets on biochemical and anthropometrical markers and the effects on MetS need to be further elucidated. In this case, the objective of this study was to assess the relationship between food intake, biochemical and anthropometrical markers in women with MetS.

METHODS

This is a cross-sectional study, in which 1 hundred and 22 women participated in the assessment of biochemical (glycated hemoglobin, glycaemia, insulin, uric acid, total cholesterol, HDL-c, LDL-c, triglycerides, C-reactive protein) and anthropometrical (body mass, height, waist circumference - WC) variables. Participants also performed blood pressure and 24-hour dietary recall assessments. Out of the 122 participants, 44 (36%, age: 59 ± 11 years) had MetS and were included in the analysis.

RESULTS

The consumption of monounsaturated fats had direct relationship with glycaemia (b = 7.48), whereas the consumption of fibers had inverse relationship with body mass (b = - 0.71) and WC (b = - 0.56).

CONCLUSION

The intake of monounsaturated fats and fiber was related to higher blood sugar levels and lower body mass and WC, respectively. These relationships elucidate and highlight the significance and importance of adequate diet in women with MetS.

Prolonged Isolated Soluble Dietary Fibre Supplementation in Overweight and Obese Patients: A Systematic Review with Meta-Analysis of Randomised Controlled Trials

The prevalence of overweight and obesity is rising rapidly, currently affecting 1.9 billion adults worldwide. Prebiotic dietary fibre supplementation is a promising approach to improve weight loss and reduce metabolic complications in overweight and obese subjects due to modifications of the microbiota composition and function. Previous systematic reviews and meta-analyses addressing similar questions revealed discordant evidence and/or are outdated. We searched MEDLINE, Embase, Google Scholar, and forward and backward citations for randomised controlled trials (RCTs) with isolated soluble dietary fibre supplementation for at least 12 weeks in overweight and obese patients measuring body weight, published through April 2022. We expressed the results as mean differences (MDs) using the random-effects model of the metafor package in R and assessed risk of bias using the Cochrane RoB2 tool. We conducted the study according to the PRISMA guidelines and registered the protocol on PROSPERO (CRD42022295246). The participants with dietary fibre supplementation showed a significantly higher reduction in body weight (MD −1.25 kg, 95% CI −2.24, −0.25; 27 RCTs; 1428 participants) accompanied by a significant decrease in BMI, waist circumference, fasting blood insulin, and HOMA-IR compared to the control group. Certainty of evidence was high, paving the way for the implementation of isolated soluble dietary fibre supplementation into clinical practice.

Effect of Dietary and Lifestyle Interventions on the Amelioration of NAFLD in Patients with Metabolic Syndrome: The FLIPAN Study

Background: Adults with fatty liver present unusual glycaemia and lipid metabolism; as a result, non-alcoholic fatty liver disease (NAFLD) is now considered as part of the metabolic syndrome (MetS). Objective: To assess the 6- and 12-month effects of customized hypocaloric dietary and enhanced physical activity intervention on intrahepatic fat contents and progression of NAFLD, in patients with MetS. Design: Cross-sectional study in 155 participants (40–60 years old) from Balearic Islands and Navarra (Spain) with a diagnosis of NAFLD and MetS, and BMI (body mass index) between 27 and 40 kg/m²; patients were randomized in a 1:1:1 ratio to either Conventional Diet, Mediterranean diet (MD)–high meal frequency, and MD–physical activity groups. Methods: Dietary intake was assessed using a validated food frequency questionnaire. Adherence to Mediterranean diet, anthropometrics, physical activity, and biochemical parameters (fasting glucose, glycated hemoglobin, bilirubin, aspartate aminotransferase, alanine aminotransferase—ALT–, gamma-glutamyl transferase, uric acid, urea, creatinine, albumin, total cholesterol, high-density lipoprotein cholesterol—HDL-cholesterol–, and triglycerides) were also assessed. Results: Subjects with NAFLD and MetS had reduced intrahepatic fat contents, and liver stiffness, despite the intervention the participants went through. All participants ameliorated BMI, insulin, Hb1Ac, diastolic blood pressure, HDL-cholesterol, and ALT, and improved consumption of total energy, fish, and legumes. Participants in the MD–HMF group improved waist circumference. Conclusions: Customized hypocaloric dietary and enhanced physical activity interventions may be useful to ameliorate NAFLD.

Micronutrient status of individuals with overweight and obesity following 3 months' supplementation with PolyGlycopleX (PGX®) or psyllium: a randomized controlled trial

Background

Safe and effective weight control strategies are needed to curtail the current obesity epidemic worldwide. Increasing dietary fibre has shown positive results with weight loss as well as in the reduction of metabolic syndrome risk factors. However, fibre can act as an inhibitor to the bioavailability of micronutrients in the gastrointestinal tract. While there is a substantial amount of scientific research into psyllium fibre, PolyGlycopleX (PGX®) is a novel fibre and as yet the effects of PGX® on micronutrient status is not well researched.

Aim

To determine whether 3-months’ supplementation with 15 g of psyllium or PGX® fibre daily affects micronutrient status of overweight and obese adults.

Methods

Overweight and obese individuals with a BMI between 25–40 kg/m² and aged between 18 and 65 years, but otherwise healthy, were instructed to consume a 5 g sachet of psyllium, PGX® fibre or a rice flour placebo three times a day for 52 weeks as part of a larger long-term study. Blood sample data for the first 3 months were analysed for associations between serum micronutrient levels and psyllium fibre and/or PGX® supplements.

Results

No significant differences between fibre supplement groups and micronutrient status were found after 3 months at p > 0.05. Dietary intake of vitamin C was significantly lower for PGX® at 3 months compared to baseline and compared to control (p < 0.05). Folate was significantly lower in the control group after 3 months (p < 0.05). In the psyllium group, folate, sodium, zinc and magnesium intake decreased after 3 months (p < 0.05). A limitation of dietary intake data (tertiary measure) is the potential for inaccurate self-reporting, although reduced nutrient intake could be due to the satiating effect of dietary fibre.

Conclusions

There were no significant between group differences in serum micronutrient concentrations after a 3-month psyllium fibre or PGX® supplementation intervention of 15 g per day. Fibre supplementation is unlikely to compromise the nutritional status of overweight and obese individuals in the short term. Further research is recommended to monitor micronutrient status over a longer period or with a higher fibre dosage.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40795-022-00534-7.

Dietary Fiber and All-Cause and Cardiovascular Mortality in Older Adults with Hypertension: A Cohort Study Of NHANES

OBJECTIVES

Several studies have documented that dietary fiber was inversely associated with a variety of diseases, but the association of dietary fiber with the prognosis of older adults with hypertension is unknown. The aim was to assess the association of dietary fiber with all-cause and cardiovascular mortality in older adults with hypertension.

METHODS

This study enrolled 4906 participants (51.6% were female) aged 65 years or older with hypertension in the National Health and Nutrition Examination Survey (NHANES) 2003-2014 and ascertained mortality through December 31, 2015. Dietary fiber intake data were assessed by using a 24-h recall survey. Participants were grouped by dietary fiber intake quartiles: Q1(fiber < 10.20, g/day), Q2 (10.20 ≤ fiber < 14.45, g/day), Q3 (14.45 ≤ fiber < 19.85, g/day), and Q4 (19.85 ≤ fiber, g/day). Multivariate Cox proportional hazard models were used to evaluate the associations of dietary fiber intake with all-cause and cardiovascular mortality. Kaplan-Meier survival curves and restricted cubic spline models were applied to reveal the relationship between dietary fiber intake and mortality.

RESULTS

Over the median follow-up duration of 70 months (interquartile range: 38-100 months), 1369 participants were determined as all-cause mortality (27.9%) and 270 participants were identified as cardiovascular mortality (5.5%). In the fully adjusted model, the higher dietary fiber intake group was associated with relatively lower all-cause (Q4 vs Q1: 0.68 (0.58, 0.80); P for trend <0.001) and cardiovascular mortality (Q4 vs Q1: 0.64 (0.45, 0.92); P for trend =0.010). The non-linear relationship was not observed between dietary fiber intake and all-cause or cardiovascular mortality.

CONCLUSIONS

Higher dietary fiber intake was significantly associated with decreased all-cause and cardiovascular mortality in older adults with hypertension. Increasing dietary fiber intake may improve the prognosis of older adults with hypertension.

Complementary and Alternative Therapies for Weight Loss: A Narrative Review

Despite various strategies, overweight and obesity problems are still increasingly prevalent worldwide with serious health outcomes. Consequently, the continuous demand for more effective, safe and acceptable therapies for reducing body weight is also escalating—including complementary and alternative therapies (CATs). The aim of this review is to provide a summary of the most commonly- and recently-used CATs, with evaluation of their safety and efficacy for weight loss. Electronic scientific databases such as Scopus, PubMed and EBSCO Host were explored for articles that reported CATs for overweight and obesity treatment from 2015 to December 2019. Only systematic reviews, meta-analysis and randomized controlled trials (RCTs) published in English were included. Studies whereby CATs were not utilized for reducing body weight were excluded. Eight systematic reviews and meta-analyses and 11 additional RCTs with 765 participants (50.2% overweight and 49.8% obese) related to hypnotherapy, acupuncture and dietary supplements met the inclusion criteria. Their results suggested that spirulina, chitosan, probiotic, EPA + DHA, vitamin D, fiber, and herbal extract supplementation may all provide small reductions in body weight (ranging from 1-10 kg). Interestingly, hypnotherapy and acupuncture reported significantly greater reduction in body weight compared with placebo (p < 0.001 and p < 0.0001, respectively). Nonetheless, the evidence is still relatively limited and not encouraging to provide a definitive conclusion due to the methodological shortcomings and the presence of adverse events in chitosan and fiber supplementation. Hence, studies of this nature need to be further replicated and improved to corroborate the efficacy and safety of the CATs to combat weight issues.

Effects of β-glucan and inulin consumption on postprandial appetite, energy intake and food consumption in healthy females: A randomized controlled trial

BACKGROUND

To date, several researchers have investigated the association between dietary fibre consumption and satiety. However, there is no study that includes both inulin and β-glucan to compare energy intake (EI) and satiety ratings.

AIM

The current study investigated the effects of two dietary fibres, β-glucan and inulin, on satiety and food intake.

METHODS

The study was carried out among 24 woman over 18 years of age. The dietary fibres β-glucan (6 g/day) or inulin (6 g/day) were consumed by participants for five weeks. On the first and fifth week visits, the participants consumed a standard breakfast followed by an ad libitum test meal. Appetite was assessed using visual analogue scales (VAS) before and after breakfast. EI was measured at the test meal using plate waste.

RESULTS

Both dietary fibres significantly reduced the VAS scores of hunger, prospective food consumption and desire to eat, and increased satiety compared with the control group. However, the area under curve data for the VAS scores did not exhibit a significant difference. Significant reductions in EI and anthropometric values between the first and fifth week measures were observed in both dietary fibre groups. Statistically significant changes occurred in the body weight [-1.25 (1.27) kg], body mass index [-0.41 (0.42) kg/m²], waist circumference [-1.25 (1.04) cm] and waist/hip ratio [-0.01(0.01)] in the β-glucan group, whereas a statistically significant change occurred in body fat percentage in the inulin group [-2.16% (7.49)].

CONCLUSIONS

Overall, these findings demonstrate that the participants consuming β-glucan over the course of the five weeks had less EI, felt less hunger and had more satiety.

The effects of nondigestible fermentable carbohydrates on adults with overweight or obesity: a meta-analysis of randomized controlled trials

CONTEXT

Nondigestible fermentable carbohydrates (NDFCs) can be fermented by microbiota, thereby yielding metabolites that have a beneficial role in the prevention and treatment of obesity and its complications. However, to our knowledge, no meta-analysis has been conducted to evaluate the effects of NDFCs on obesity.

OBJECTIVE

To conduct a meta-analysis of randomized controlled trials (RCTs) to summarize existing evidence on the effects of numerous NDFCs on adiposity and cardiovascular risk factors in adults with overweight or obesity with ≥2 weeks of follow-up.

DATA SOURCES

The following databases were searched: MEDLINE, Embase, and CINAHL.

DATA EXTRACTION

Seventy-seven RCTs with 4535 participants were identified for meta-analysis from the 3 databases.

DATA ANALYSIS

The findings suggest that increased intake of NDFCs is significantly effective in reducing body mass index by 0.280 kg/m2, weight by 0.501 kg, hip circumference by 0.554 cm, waist circumference by 0.649 cm, systolic blood pressure by 1.725 mmHg, total cholesterol by 0.36 mmol/L, and low-density lipoprotein by 0.385 mmol/L, with evidence of moderate-to-high quality.

CONCLUSION

Convincing evidence from meta-analyses of RCTs indicates that increased NDFC intake improves adiposity, blood lipid levels, and systolic blood pressure in people with overweight and obesity.

The Health Benefits of Dietary Fibre

Background: Dietary fibre consists of non-digestible forms of carbohydrate, usually as polysaccharides that originate from plant-based foods. Over recent decades, our diet within Westernised societies has changed radically from that of our hominid ancestors, with implications for our co-evolved gut microbiota. This includes increased ingestion of ultra-processed foods that are typically impoverished of dietary fibre, and associated reduction in the intake of fibre-replete plant-based foods. Over recent decades, there has been a transformation in our understanding of the health benefits of dietary fibre. Objective: To explore the current medical literature on the health benefits of dietary fibre, with a focus on overall metabolic health. Data Sources: We performed a narrative review, based on relevant articles written in English from a PubMed search, using the terms ‘dietary fibre and metabolic health’. Results: In the Western world, our diets are impoverished of fibre. Dietary fibre intake associates with overall metabolic health (through key pathways that include insulin sensitivity) and a variety of other pathologies that include cardiovascular disease, colonic health, gut motility and risk for colorectal carcinoma. Dietary fibre intake also correlates with mortality. The gut microflora functions as an important mediator of the beneficial effects of dietary fibre, including the regulation of appetite, metabolic processes and chronic inflammatory pathways. Conclusions: Multiple factors contribute to our fibre-impoverished modern diet. Given the plethora of scientific evidence that corroborate the multiple and varied health benefits of dietary fibre, and the risks associated with a diet that lacks fibre, the optimization of fibre within our diets represents an important public health strategy to improve both metabolic and overall health. If implemented successfully, this strategy would likely result in substantial future health benefits for the population.

Microbiota, Fiber, and NAFLD: Is There Any Connection?

Gut microbiota can contribute to the development and progression of non-alcoholic fatty liver disease (NAFLD). In fact, some specific changes of gut microbiota are observed in patients in what is called dysbiota. There has been a lot of investigation by using a variety of interventions, including diet, showing the possibility to modify components of gastrointestinal dysbiota towards healthy and multivariate microbiota to restore physiologic status. One of the main focuses has been dietary fiber (DF), in which most of its variants are prebiotics. The highest effective treatment for NAFLD is, so far, weight loss achieved by caloric restriction. DF supplementation with oligofructose facilitates weight loss, enhances the production of beneficial metabolites, decreases some pathogenic bacteria population by increasing Bifidobacteria, and has effects on intestinal barrier permeability. DF use has been associated with improvement in diverse metabolic diseases, including NAFLD, by modifying gut microbiota. Additionally, it has been shown that a higher insoluble fiber consumption (≥7.5 g/day) revealed improvements in 3 different scores of liver fibrosis. Further research is needed, but given the evidence available, it is reasonable to prescribe its consumption in early stages of NAFLD in order to prevent disease progression.

Can dietary viscous fiber affect body weight independently of an energy-restrictive diet? A systematic review and meta-analysis of randomized controlled trials

BACKGROUND

The role of dietary fiber in obesity management remains debatable. Evidence suggests that intake of viscous fiber may have the potential to facilitate weight loss.

OBJECTIVE

We aimed to summarize and quantify the effects of viscous fiber on body weight, BMI, waist circumference, and body fat, independent of calorie restriction, through a systematic review and meta-analysis of randomized controlled trials.

METHODS

Trials ≥4 wk in duration that assessed the effect of viscous fiber supplemented to an ad libitum diet along with comparator diets were included. MEDLINE, EMBASE, and the Cochrane library were searched through 24 July, 2019. Two independent reviewers extracted relevant data. Data were pooled using the generic inverse variance method and random-effects models and expressed as mean differences with 95% CIs. Interstudy heterogeneity was assessed (Cochran Q statistic) and quantified (I2 statistic). The overall certainty of evidence was explored using the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) approach.

RESULTS

Findings from 62 trials (n = 3877) showed that viscous fiber reduced mean body weight (-0.33 kg; 95% CI: -0.51, -0.14 kg; P = 0.004), BMI (in kg/m2) (-0.28; 95% CI: -0.42, -0.14; P = 0.0001), and waist circumference (-0.63 cm; 95% CI: -1.11, -0.16 cm; P = 0.008), with no change in body fat (-0.78%; 95% CI: -1.56%, 0.00%; P = 0.05) when consumed with an ad libitum diet. Greater reductions in body weight were observed in overweight individuals and those with diabetes and metabolic syndrome. The certainty of evidence was graded moderate for body weight, high for waist circumference and body fat, and low for BMI.

CONCLUSIONS

Dietary viscous fiber modestly yet significantly improved body weight and other parameters of adiposity independently of calorie restriction. Future trials are warranted to address the inconsistency and imprecision identified through GRADE and to determine long-term weight-loss sustainability.This systematic review and meta-analysis was registered at clinicaltrials.gov as NCT03257449.

The effect of inulin and resistant maltodextrin on weight loss during energy restriction: a randomised, placebo-controlled, double-blinded intervention

PURPOSE

The objective of this study was to investigate the additive effects of combining energy restriction with dietary fibres on change in body weight and gut microbiota composition.

METHODS

The study was a 12-week randomised, placebo-controlled, double-blinded, parallel intervention trial. A total of 116 overweight or obese participants were assigned randomly either to 10 g inulin plus 10 g resistant maltodextrin or to 20 g of placebo supplementation through 400 mL of milk a day, while on a - 500 kcal/day energy restricted diet.

RESULTS

Altogether, 86 participants completed the intervention. There were no significant differences in weight loss or body composition between the groups. The fibre supplement reduced systolic (5.35 ± 2.4 mmHg, p = 0.043) and diastolic (2.82 ± 1.3 mmHg, p = 0.047) blood pressure to a larger extent than placebo. Furthermore, a larger decrease in serum insulin was observed in the placebo group compared to the fibre group (- 26.0 ± 9.2 pmol/L, p = 0.006). The intake of fibre induced changes in the composition of gut microbiota resulting in higher abundances of Parabacteroides and Bifidobacteria, compared to placebo. The effects on blood pressure and glucose metabolism were mainly observed in women, and could be attributed to a higher gut microbiota diversity after intervention. Finally, the fibre group experienced a higher degree of gastrointestinal symptoms, which attenuated over time.

CONCLUSIONS

Supplementation of inulin and resistant maltodextrin did not provide an additional weight loss during an energy-restricted diet, but reduced both systolic and diastolic blood pressure. Furthermore, the fibre supplement did stimulate the growth of potentially beneficial bacteria genera.

CLINICAL TRIAL REGISTRY

The study was registered at http://www.clinicaltrials.gov , NCT03135041.

Effect of PolyGlycopleX (PGX) Consumption on Blood Lipid Profiles in Healthy, Low CVD Risk Overweight Adults

Raised blood lipid levels are associated with a risk of a cardiovascular disease (CVD). Moderate reductions in several CVD factors such as total, low-density lipoprotein (LDL) cholesterol and non-high-density lipoprotein (non-HDL) cholesterol concentrations may be more effective in reducing overall risk than a major reduction in just one. A blind, randomised controlled trial was conducted with 120 healthy overweight (BMI 25⁻30) adults aged 25⁻70 years who were non-smokers, not diabetic and of low risk of cardiovascular disease, as assessed by the Framingham risk equation. Participants consumed 4.5 g PolyGlycopleX (PGX) as softgel capsules (PGXS) or 5 g PGX granules (PGXG) or 5 g rice flour (RF) with meals three times a day for 12 weeks. Total, LDL and non-HDL cholesterol were all significantly reduced (-6%, -5% and -3.5%, respectively) post the PGX granule treatment; however, PGX in softgel capsule form did not affect blood lipid profiles. Daily consumption of PGX granules in overweight low CVD risk adults produced lipid changes indicating a CVD preventative benefit.

Response to Comments by Vuksan V. et al., Nutrients 2017, 9, 398, Regarding an Article by Solah V.A. et al., Nutrients 2017, 9, 149

n/a.

BMI is Associated with the Willingness to Record Diet with a Mobile Food Record among Adults Participating in Dietary Interventions

Image-based dietary assessment methods have the potential to address respondent burden and improve engagement in the task of recording for dietary interventions. The aim of this study was to assess factors associated with the willingness of adults to take images of food and beverages using a mobile food record (mFR) application. A combined sample of 212 young adults and 73 overweight and obese adults completed a 4-day mobile food record on two occasions and a follow-up usability questionnaire. About 74% of participants stated they would record using the mFR for a longer period compared with a written record (29.4 ± 69.3 vs. 16.1 ± 42.6 days respectively; p < 0.0005). Multivariable logistic regression was used to identify those who were more likely to record mFR in the top tertile (≥14 days). After adjusting for age and gender, those with a BMI ≥ 25 were 1.68 times more likely (Odds Ratio 95% Confidence Interval: 1.02-2.77) than those with BMI < 25 to state a willingness to record with the mFR for ≥ 14 days. The greater willingness of overweight and obese individuals to record dietary intake using an mFR needs further examination to determine if this translates to more accurate estimates of energy intake.