Mid- and long-term changes in satiety-related hormones, lipid and glucose metabolism, and inflammation after a Mediterranean diet intervention with the goal of losing weight: A randomized, clinical trial

Effects of plant-based diets combined with exercise training on leptin and adiponectin levels in adults with or without chronic diseases: a systematic review and meta-analysis of clinical studies

Background

The effects of exercise training combined with plant-based diets (PBD) on leptin and adiponectin levels have been studied. However, little is known regarding the impact of exercise training combined with PBD on leptin and adiponectin levels in adults with or without chronic diseases.

Methods

PubMed, Web of Science, and Scopus were searched to identify original articles, published until May 2024, to assess the effects of exercise training combined with PBD on leptin and adiponectin levels in adults with or without chronic diseases. Standardized mean differences (SMD) and 95% confidence intervals were calculated using random models.

Results

Nine studies comprising 960 participants with overweight and obesity were included in the current meta-analysis. Exercise training combined with PBD reduced leptin [SMD = -0.33 (95% CI: -0.62 to -0.04); p = 0.025] while increasing adiponectin [SMD = 0.93 (95% CI: 0.12 to 1.74); p = 0.024] levels.

Conclusion

Exercise training combined with PBD is suggested as a non-invasive intervention for reducing leptin while increasing adiponectin levels to control body mass and other disorders related to obesity in adults.

Enteropancreatic hormone changes in caloric-restricted diet interventions associate with post-intervention weight maintenance

BACKGROUND & AIMS

To explore enteropancreatic hormone changes during isocaloric-restricted dietary interventions and their impact on post-intervention weight maintenance.

METHODS

253 individuals with overweight/obesity and prediabetes were randomly assigned to 25% isocaloric-restricted diets: Control diet, Traditional Jiangnan diet or Mediterranean diet. Serum hormones and clinical indices were evaluated at 0, 3 and 6 months. Body weight values were collected again 6 months after completing interventions.

RESULTS

We observed decreased fasting and post-glucose load levels of glucagon, amylin, peptide YY, and glucagon-like peptide-1 (GLP-1) while increased ghrelin at three months after 25% calorie restriction (CR) of three dietary interventions, and most of these changes were sustained through the six month-treatment period. Interestingly, changes in appetite-inhibitory hormones glucagon, amylin and GLP-1 showed positive associations with body weight change while appetite-promoting hormone ghrelin showed an inverse association during intervention. Furthermore, subjects with more reduction in amylin and GLP-1, or more increase in ghrelin during intervention showed a greater increase in body weight after completing intervention.

CONCLUSIONS

CR intervention results in consistent hormone signatures regardless of dietary patterns. More changes in amylin, GLP-1 or ghrelin levels during CR are associated with poor weight maintenance after intervention, supporting that CR-induced hormone changes as biomarkers for predicting weight maintenance after intervention.

TRIAL REGISTRATION

Clinicaltrials.gov NCT03856762.

Dietary impact on fasting and stimulated GLP-1 secretion in different metabolic conditions - a narrative review

Glucagon-like peptide 1 (GLP-1), a gastrointestinal peptide and central mediator of glucose metabolism, is secreted by L cells in the intestine in response to food intake. Postprandial secretion of GLP-1 is triggered by nutrient-sensing via transporters and G-protein-coupled receptors (GPCRs). GLP-1 secretion may be lower in adults with obesity/overweight (OW) or type 2 diabetes mellitus (T2DM) than in those with normal glucose tolerance (NGT), but these findings are inconsistent. Because of the actions of GLP-1 on stimulating insulin secretion and promoting weight loss, GLP-1 and its analogs are used in pharmacologic preparations for the treatment of T2DM. However, physiologically stimulated GLP-1 secretion through the diet might be a preventive or synergistic method for improving glucose metabolism in individuals who are OW, or have impaired glucose tolerance (IGT) or T2DM. This narrative review focuses on fasting and postprandial GLP-1 secretion in individuals with different metabolic conditions and degrees of glucose intolerance. Further, the influence of relevant diet-related factors (e.g., specific diets, meal composition, and size, phytochemical content, and gut microbiome) that could affect fasting and postprandial GLP-1 secretion are discussed. Some studies showed diminished glucose- or meal-stimulated GLP-1 response in participants with T2DM, IGT, or OW compared with those with NGT, whereas other studies have reported an elevated or unchanged GLP-1 response in T2DM or IGT. Meal composition, especially the relationship between macronutrients and interventions targeting the microbiome can impact postprandial GLP-1 secretion, although it is not clear which macronutrients are strong stimulants of GLP-1. Moreover, glucose tolerance, antidiabetic treatment, grade of overweight/obesity, and sex were important factors influencing GLP-1 secretion. The results presented in this review highlight the potential of nutritional and physiologic stimulation of GLP-1 secretion. Further research on fasting and postprandial GLP-1 concentrations and the resulting metabolic consequences under different metabolic conditions is needed.

Positive Impacts of Aphanizomenon Flos Aquae Extract on Obesity-Related Dysmetabolism in Mice with Diet-Induced Obesity

The present study evaluated the ability of KlamExtra®, an Aphanizomenon flos aquae (AFA) extract, to counteract metabolic dysfunctions due to a high fat diet (HFD) or to accelerate their reversion induced by switching an HFD to a normocaloric diet in mice with diet-induced obesity. A group of HFD mice was fed with an HFD supplemented with AFA (HFD-AFA) and another one was fed with regular chow (standard diet-STD) alone or supplemented with AFA (STD-AFA). AFA was able to significantly reduce body weight, hypertriglyceridemia, liver fat accumulation and adipocyte size in HFD mice. AFA also reduced hyperglycaemia, insulinaemia, HOMA-IR and ameliorated the glucose tolerance and the insulin response of obese mice. Furthermore, in obese mice AFA normalised the gene and the protein expression of factors involved in lipid metabolism (FAS, PPAR-γ, SREBP-1c and FAT-P mRNA), inflammation (TNF-α and IL-6 mRNA, NFkB and IL-10 proteins) and oxidative stress (ROS levels and SOD activity). Interestingly, AFA accelerated the STD-induced reversion of glucose dysmetabolism, hepatic and VAT inflammation and oxidative stress. In conclusion, AFA supplementation prevents HFD-induced dysmetabolism and accelerates the STD-dependent recovery of glucose dysmetabolism by positively modulating oxidative stress, inflammation and the expression of the genes linked to lipid metabolism.

Impact of 4-week of a restricted Mediterranean diet on taste perception, anthropometric, and blood parameters in subjects with severe obesity

Introduction

The study of taste functionality and its relation to human health is receiving growing attention. Obesity has been reported to cause alterations in sensory perception regarding system functionality and preferences. However, a small body of research addresses tastes perception and its modification with the achievement of body mass reduction through surgical intervention. Much fewer efforts have been made to evaluate the impact of mild restrictive nutritional intervention on gustatory functions. Thus, the objectives of this study were to determine if a dietary intervention of 4 weeks following a restricted balanced Mediterranean diet would affect the sweet and salty taste thresholds of subjects with severe obesity and could influence their anthropometric and blood parameters.

Methods

Fifty-one patients with severe obesity (F: 31; age: 43.7 ± 12.5; BMI = 47.6 ± 1.0) were enrolled in the study. The recognition threshold for sweet and salty taste and anthropometric and blood parameters were assessed before and after the 4-week weight loss program.

Results and Discussion

The Mediterranean diet has proven to be an effective treatment, significantly improving all anthropometric and blood parameters (p < 0.05) after 4 weeks of intervention. Moreover, the hypo-sodium treatment associated with the diet significantly improved the salty threshold (p < 0.001). No changes were detected for the sweet threshold. Collectively, these data highlight that dietary treatment might impact taste perception differently. Therefore, a taste-oriented nutritional intervention could represent a novel approach to developing more individualized, taste-oriented follow-up interventions to maintain sustainable and long-term weight loss.

Evidence-Based Dietary Practices to Improve Osteoarthritis Symptoms: An Umbrella Review

While there is some research investigating whole foods or diets that are easily understood and accessible to patients with osteoarthritis, specific nutrients or nutraceuticals are more commonly identified. Unfortunately, guidelines and evidence surrounding individual nutrients, extracts, and nutraceuticals are conflicting and are more difficult to interpret and implement for patients with osteoarthritis. The purpose of this umbrella review is to provide a comprehensive understanding of the existing evidence of whole foods and dietary patterns effects on osteoarthritis-related outcomes to inform evidence-based recommendations for healthcare professionals and identify areas where more research is warranted. A literature search identified relevant systematic reviews/meta-analyses using five databases from inception to May 2022. Five systematic reviews/meta-analyses were included in the current umbrella review. Most evidence supported the Mediterranean diet improving osteoarthritis-related outcomes (e.g., pain, stiffness, inflammation, biomarkers of cartilage degeneration). There was little to no evidence supporting the effects of fruits and herbs on osteoarthritis-related outcomes; however, there was some suggestion that specific foods could potentiate symptom improvement through antioxidative mechanisms. The overall lack of homogeneity between the studies limits the conclusions that can be made and highlights the need for quality research that can identify consumer-accessible foods to improve osteoarthritis-related symptoms.