The Effect of a Low GI Diet on Truncal Fat Mass and Glycated Hemoglobin in South Indians with Type 2 Diabetes-A Single Centre Randomized Prospective Study

Global regional, and national burden of type 2 diabetes attributable to dietary factors from 1990 to 2021

The study comprehensively assesses the global burden of type 2 diabetes (T2D) linked to dietary factors from 1990 to 2021. Data from the Global Burden of Disease Study 2021 (GBD 2021) was analyzed for T2D dietary risk factors across 204 countries, using age-standardized metrics and SDI quintiles, with joinpoint regression and other analytical methods. The results revealed a significant increase in the global burden of T2D, with a 1.92-fold rise in DALYs and a 1.28-fold rise in total mortality cases due to dietary risks. High intake of processed meat and sugar-sweetened beverages were identified as major contributors to the increasing burden, whereas the age-standardized mortality rates attributable to low vegetable intake declined over time. The study also emphasized the impact of age, period, and cohort effects on the incidence of T2D, along with the growing health disparity gaps between high and low SDI countries. The study emphasizes the importance of dietary interventions to reduce T2D burden, suggesting a decrease in processed meat and sugary drink consumption and an increase in vegetable intake. It calls for global strategies to address health disparities and improve equitable access to health resources.

The effectiveness of a community-based online low-glycaemic index diet and lifestyle recommendations intervention for people with type 2 diabetes: a randomized controlled trial

BACKGROUND

The community health workers (CHWs)-led model is an important strategy for managing type 2 diabetes mellitus (T2DM) in China. However, existing community-based dietary and health education interventions in diabetes management are insufficient. Meanwhile, emerging mobile health (mHealth) has emerged as a promising tool for improving disease management. Current evidence on the combined efficacy of mHealth technologies and CHWs strategies remains limited.

OBJECTIVE

This study evaluates the effectiveness of an online dietary and health education intervention delivered through a tertiary hospital's WeChat official account (WOA) for T2DM patients, examining its influence on glycated hemoglobin (HbA1c) levels, body mass index (BMI), serum lipid profiles, and diabetes-specific quality of life (DSQL).

METHODS

This randomized clinical trial was conducted in two community health centers in China, enrolling adults diagnosed with T2DM. Participants were randomly assigned to two groups over 3 months. The control group received standard care, while the intervention group accessed online low glycaemic index (GI) dietary and lifestyle recommendations via the WOA. This group was instructed to monitor blood glucose levels, upload daily dietary photos, review health education notifications, and participate in real-time communication with the diabetes management team via the WOA.

RESULTS

A total of 178 participants were randomized to the control group (mean [SD] age, 57.07 [10.96] years, n = 89) and the intervention group (mean [SD] age, 57.18 [10.61] years, n = 89). After 3 months, significant improvements were observed in the intervention group compared to the control group, with lower HbA1c levels (mean 7.82%, SD 0.43%; p = 0.001), BMI (mean 24.35, SD 1.25 kg/m2; p < 0.001), low-density lipoprotein cholesterol (mean 2.38, SD 0.21 mmol/L; p < 0.001), and DSQL scores (mean 43.24, SD 7.23; P < 0.001), whereas high-density lipoprotein cholesterol (mean 1.35, SD 0.37 mmol/L; p = 0.001) was significantly higher. Subgroup analysis at 3 months showed that age, education, disease duration, comorbidity, and BMI influenced the effectiveness of HbA1c reduction.

CONCLUSION

Overall, the WOA-based intervention effectively engages patients in community diabetes management, leading to improved glycemic control, weight reduction, lipid metabolism optimization, and better quality of life.

TRIAL REGISTRATION

ChiCTR2400081045.

The role of low glycemic index and load diets in medical nutrition therapy for type 2 diabetes: an update

The increasing prevalence of type 2 diabetes mellitus (T2DM) and its microvascular and macrovascular complications necessitate an optimal approach to prevention and management. Medical nutrition therapy serves as the cornerstone of diabetes care, reducing reliance on diabetic medications for glycemic control and mitigating cardiovascular risk. The broadening field of research in the effect of low glycemic index (GI) and/or glycemic load (GL) diets on individuals with T2DM has yielded promising results in the existing literature. Adopting low-GI and GL dietary patterns contributes to minimizing fluctuations in blood glucose levels, thus presenting a good strategy for achieving enhanced glycemic control. Furthermore, the above dietary practices may offer a viable alternative and practical approach to weight management in individuals with T2DM. However, clinical practice guidelines for diabetes dietary management show inconsistency regarding the certainty of evidence supporting the implementation of low-GI/GL nutritional patterns. This review aims to thoroughly evaluate the available data on the effectiveness of low-GI and low-GL diets in managing glycemic control and reducing cardiovascular risk factors.

The Health Effects of Low Glycemic Index and Low Glycemic Load Interventions on Prediabetes and Type 2 Diabetes Mellitus: A Literature Review of RCTs

Diets with a low glycemic index (GI) and a low glycemic load (GL) can improve glycemic control, blood lipids, blood pressure and BMI in prediabetes and type 2 diabetes (T2DM), but evidence regarding other aspects of cardiometabolic health is limited. We searched the literature for RCTs published from 2013 to 2023 and reviewed the evidence on low-GI/GL diets and their effects on different aspects of health in prediabetes and T2DM, aiming to build a report on all relevant outcomes included in the studies. We included 14 RCTs with 1055 participants, who were mostly middle-aged individuals with T2DM. Interventions were mostly low GI and lasted 1-36 months. Low-GI/GL foods and diets showed benefits in terms of short-term glycemic control, weight and adiposity. Longer-term trials would be necessary to determine whether these benefits persist over time and/or lead to lower CVD risk and mortality. Effects on lipid profile were inconsistent. Some studies also reported positive effects of low-GI/GL interventions on blood pressure, inflammatory biomarkers, renal function and gut microbiota composition. Future trials should focus on some of these novel outcome measures, which may provide important insights into the metabolic effects of low-GI diets on individuals with diabetes.

Effect of Dietary Approaches on Glycemic Control in Patients with Type 2 Diabetes: A Systematic Review with Network Meta-Analysis of Randomized Trials

BACKGROUND

Dietary patterns play a critical role in diabetes management, while the best dietary pattern for Type 2 diabetes (T2DM) patients is still unclear. The aim of this network meta-analysis was to compare the impacts of various dietary approaches on the glycemic control of T2DM patients.

METHODS

Relevant studies were retrieved from PubMed, Embase, Web of Knowledge, Cochrane Central Register of Controlled Trials (CENTRAL), and other additional records (1949 to 31 July 2022). Eligible RCTs were those comparing different dietary approaches against each other or a control diet in individuals with T2DM for at least 6 months. We assessed the risk of bias of included studies with the Cochrane risk of bias tool and confidence of estimates with the Grading of Recommendations Assessment, Development, and Evaluation approach for network meta-analyses. In order to determine the pooled effect of each dietary approach relative to each other, we performed a network meta-analysis (NMA) for interventions for both HbA1c and fasting glucose, which enabled us to estimate the relative intervention effects by combing both direct and indirect trial evidence.

RESULTS

Forty-two RCTs comprising 4809 patients with T2DM were included in the NMA, comparing 10 dietary approaches (low-carbohydrate, moderate-carbohydrate, ketogenic, low-fat, high-protein, Mediterranean, Vegetarian/Vegan, low glycemic index, recommended, and control diets). In total, 83.3% of the studies were at a lower risk of bias or had some concerns. Findings of the NMA revealed that the ketogenic, low-carbohydrate, and low-fat diets were significantly effective in reducing HbA1c (viz., -0.73 (-1.19, -0.28), -0.69 (-1.32, -0.06), and -1.82 (-2.93, -0.71)), while moderate-carbohydrate, low glycemic index, Mediterranean, high-protein, and low-fat diets were significantly effective in reducing fasting glucose (viz., -1.30 (-1.92, -0.67), -1.26 (-2.26, -0.27), -0.95 (-1.51, -0.38), -0.89 (-1.60, -0.18) and -0.75 (-1.24, -0.27)) compared to a control diet. The clustered ranking plot for combined outcomes indicated the ketogenic, Mediterranean, moderate-carbohydrate, and low glycemic index diets had promising effects for controlling HbA1c and fasting glucose. The univariate meta-regressions showed that the mean reductions of HbA1c and fasting glucose were only significantly related to the mean weight change of the subjects.

CONCLUSIONS

For glycemic control in T2DM patients, the ketogenic diet, Mediterranean diet, moderate-carbohydrate diet, and low glycemic index diet were effective options. Although this study found the ketogenic diet superior, further high-quality and long-term studies are needed to strengthen its credibility.

Culturally Tailored Dietary Interventions for Improving Glycaemic Control and Preventing Complications in South Asians with Type 2 Diabetes: Success and Future Implications

Glycaemic control is the basis of type 2 diabetes mellitus (T2DM) management and is crucial for preventing diabetes microvascular and macrovascular complications. The South Asian population is at higher risk of T2DM and resultant cardiovascular disease, peripheral vascular disease and death compared to Caucasians. Effective diabetes care has been deemed challenging in this population, but little is known about the usefulness of lifestyle interventions in improving glycaemic control and reducing complications. This narrative review aims to explore the efficacy of lifestyle interventions targeted to South Asians with T2DM in inducing clinically relevant improvements in HbA1c levels at such levels that reduce the risk of diabetes complications. A search of the literature using six databases (MEDLINE (EBSCOhost), PubMed, CINAHL, PsycINFO, Cochrane Central Register of Controlled Trials and Scopus) identified dietary-based, physical-activity-based and education-based interventions that aimed to manage T2DM in South Asians. Results showed that dietary and physical activity interventions (duration 3-12 months) have been effective in generating a clinically relevant decrease in HbA1c levels (≥0.5%) in South Asians with T2DM and could potentially assist in reducing diabetes complications. Education-based interventions produced small effects on glycaemic control. These outcomes support the development of comparable longer-term randomised clinical trials combining dietary and physical activity interventions with the aim to provide further evidence on specific interventions that can lower complications and ensure effective diabetes care in a high-risk population.

Dietary Interventions for Type 2 Diabetes in South Asian Populations-A Systematic Review

PURPOSE

South Asians face a high burden of type 2 diabetes (T2D). We systematically summarized current research on the efficacy, cultural relevance, and research gaps of nutrition interventions that could be used for treatment in this population.

FINDINGS

We identified 18 articles published since 2010. Dietary pattern interventions have focused on low-glycemic index (GI) solutions and consistently reported improvement in glycemic management. Trials of nutrition education and counselling had diverse approaches, with those utilizing more intensive interventions generally eliciting better glycemic outcomes. Many studies developed interventions with cultural relevance by including traditional foods, providing materials in the local language, and acknowledging important food-related customs. These adaptations were seen in South Asian countries as well as Western countries hosting immigrants. Data from South Asian countries support low-GI and intensive counselling approaches for the treatment of T2D. Given the high prevalence of T2D in these populous countries, approaches that can reach large numbers of people are needed. In Western countries, more emphasis on providing culturally relevant nutrition therapy is needed.

Comparative efficacy of different eating patterns in the management of type 2 diabetes and prediabetes: An arm-based Bayesian network meta-analysis

AIMS/INTRODUCTION

Diet therapy is a vital approach to manage type 2 diabetes and prediabetes. However, the comparative efficacy of different eating patterns is not clear enough. We aimed to compare the efficacy of various eating patterns for glycemic control, anthropometrics, and serum lipid profiles in the management of type 2 diabetes and prediabetes.

MATERIALS AND METHODS

We conducted a network meta-analysis using arm-based Bayesian methods and random effect models, and drew the conclusions using the partially contextualized framework. We searched twelve databases and yielded 9,534 related references, where 107 studies were eligible, comprising 8,909 participants.

RESULTS

Eleven diets were evaluated for 14 outcomes. Caloric restriction was ranked as the best pattern for weight loss (SUCRA 86.8%) and waist circumference (82.2%), low-carbohydrate diets for body mass index (81.6%), and high-density lipoprotein (84.0%), and low-glycemic-index diets for total cholesterol (87.5%) and low-density lipoprotein (86.6%). Other interventions showed some superiorities, but were imprecise due to insufficient participants and needed further investigation. The attrition rates of interventions were similar. Meta-regression suggested that macronutrients, energy intake, and weight may modify outcomes differently. The evidence was of moderate-to-low quality, and 38.2% of the evidence items met the minimal clinically important differences.

CONCLUSIONS

The selection and development of dietary strategies for diabetic/prediabetic patients should depend on their holistic conditions, i.e., serum lipid profiles, glucometabolic patterns, weight, and blood pressure. It is recommended to identify the most critical and urgent metabolic indicator to control for one specific patient, and then choose the most appropriate eating pattern accordingly.

Effects of lifestyle interventions on cardiovascular risk factors in South Asians: a systematic review and meta-analysis

BACKGROUND

The cardiovascular disease (CVD) burden among South Asians is high. Lifestyle interventions have been effective in the primary prevention of CVD, but this has not been replicated, through a synthesis of randomised trials, in South Asians.

METHODS

Four electronic databases (MEDLINE, Embase, CENTRAL and CINAHL), two clinical trial registries and references of included articles were searched through June 2022 (featuring ≥90% South Asian participants). Random-effects pairwise meta-analyses were performed, and heterogeneity was quantified with the I2 statistic. The Grades of Recommendation, Assessment, Development, and Evaluation (GRADE) framework was used to report on the quality of evidence (International Prospective Register of Systematic Reviews registration (PROSPERO).

RESULTS

Thirty-five studies were included. Twelve tested diet and physical activity interventions; 18 tested diet alone; and 5 tested physical activity alone. All reported effects of the intervention(s) on at least one established risk factor for CVD, including blood pressure (systolic blood pressure (SBP), diastolic blood pressure (DBP) and blood lipids (high-density lipoprotein cholesterol (HDLc), low-density lipoprotein cholesterol (LDLc) or triglycerides). No trials reported clinical CVD. There is moderate-quality evidence that diet and physical activity interventions improve SBP (mean difference (MD) -2.72 mm Hg, 95% CI -4.11 to -1.33) and DBP (MD -1.53 mm Hg, 95% CI -2.57 to -0.48); high-quality to moderate-quality evidence that diet-only interventions improve DBP (MD -2.05 mm Hg, 95% CI -2.93 to -1.16) and blood lipids (triglycerides (MD -0.10 mmol/L, 95% CI -0.14 to -0.06) and LDLc (MD -0.19 mmol/L, 95% CI -0.32 to -0.06)); and moderate-quality evidence that physical activity-only interventions improve SBP (MD -9.7 mm Hg, 95% CI -11.05 to -8.35), DBP (MD -7.29 mm Hg, 95% CI -8.42 to -6.16) and HDLc (MD 0.08 mmol/L, 95% CI 0.04 to 0.11) compared with usual care.

CONCLUSIONS

Lifestyle interventions improve blood pressure and blood lipid profiles in adult South Asians at risk of CVD. Tailored interventions should be used to modify cardiovascular risk factors in this at-risk group.

PROSPERO REGISTRATION NUMBER

CRD42018090419.

Low-Glycemic Index Diets as an Intervention in Metabolic Diseases: A Systematic Review and Meta-Analysis

We aimed to investigate the effects of a low-glycemic index (GI) diet on the body mass and blood glucose of patients with four common metabolic diseases by conducting a systematic review and meta-analysis of studies comparing a low-GI diet (LGID) and other types of diet. Search terms relating to population, intervention, comparator, outcomes, and study design were used to search three databases: PubMed, Embase, and the Cochrane Library. We identified 24 studies involving 2002 participants. Random-effects models were used for 16 studies in the meta-analysis and stratified analyses were performed according to the duration of the intervention. The systematic review showed that LGIDs slightly reduced body mass and body mass index (BMI) (p < 0.05). BMI improved more substantially after interventions of >24 weeks and there was no inter-study heterogeneity (I² = 0%, p = 0.48; mean difference (MD) = -2.02, 95% confidence interval (CI): -3.05, -0.98). Overall, an LGID had superior effects to a control diet on fasting blood glucose (FBG) and glycosylated hemoglobin. When the intervention exceeded 30 days, an LGID reduced FBG more substantially (MD = -0.34, 95% CI: -0.55, -0.12). Thus, for patients with metabolic diseases, an LGID is more effective at controlling body mass and blood glucose than a high-GI or other diet.

Effect of low glycaemic index or load dietary patterns on glycaemic control and cardiometabolic risk factors in diabetes: systematic review and meta-analysis of randomised controlled trials

OBJECTIVE

To inform the update of the European Association for the Study of Diabetes clinical practice guidelines for nutrition therapy.

DESIGN

Systematic review and meta-analysis of randomised controlled trials.

DATA SOURCES

Medline, Embase, and the Cochrane Library searched up to 13 May 2021.

ELIGIBILITY CRITERIA FOR SELECTING STUDIES

Randomised controlled trials of three or more weeks investigating the effect of diets with low glycaemic index (GI)/glycaemic load (GL) in diabetes.

OUTCOME AND MEASURES

The primary outcome was glycated haemoglobin (HbA1c). Secondary outcomes included other markers of glycaemic control (fasting glucose, fasting insulin); blood lipids (low density lipoprotein cholesterol (LDL-C), high density lipoprotein cholesterol (HDL-C), non-HDL-C, apo B, triglycerides); adiposity (body weight, BMI (body mass index), waist circumference), blood pressure (systolic blood pressure (SBP) and diastolic blood pressure (DBP)), and inflammation (C reactive protein (CRP)).

DATA EXTRACTION AND SYNTHESIS

Two independent reviewers extracted data and assessed risk of bias. Data were pooled by random effects models. GRADE (grading of recommendations assessment, development, and evaluation) was used to assess the certainty of evidence.

RESULTS

29 trial comparisons were identified in 1617 participants with type 1 and 2 diabetes who were predominantly middle aged, overweight, or obese with moderately controlled type 2 diabetes treated by hyperglycaemia drugs or insulin. Low GI/GL dietary patterns reduced HbA1c in comparison with higher GI/GL control diets (mean difference −0.31% (95% confidence interval −0.42 to −0.19%), P<0.001; substantial heterogeneity, I2=75%, P<0.001). Reductions occurred also in fasting glucose, LDL-C, non-HDL-C, apo B, triglycerides, body weight, BMI, systolic blood pressure (dose-response), and CRP (P<0.05), but not blood insulin, HDL-C, waist circumference, or diastolic blood pressure. A positive dose-response gradient was seen for the difference in GL and HbA1c and for absolute dietary GI and SBP (P<0.05). The certainty of evidence was high for the reduction in HbA1c and moderate for most secondary outcomes, with downgrades due mainly to imprecision.

CONCLUSIONS

This synthesis suggests that low GI/GL dietary patterns result in small important improvements in established targets of glycaemic control, blood lipids, adiposity, blood pressure, and inflammation beyond concurrent treatment with hyperglycaemia drugs or insulin, predominantly in adults with moderately controlled type 1 and type 2 diabetes. The available evidence provides a good indication of the likely benefit in this population.

STUDY REGISTRATION

ClinicalTrials.gov NCT04045938.

Determining the glycaemic responses of foods: conventional and emerging approaches

A low-glycaemic diet is crucial for those with diabetes and cardiovascular diseases. Information on the glycaemic index (GI) of different ingredients can help in designing novel food products for such target groups. This is because of the intricate dependency of material source, composition, food structure and processing conditions, among other factors, on the glycaemic responses. Different approaches have been used to predict the GI of foods, and certain discrepancies exist because of factors such as inter-individual variation among human subjects. Besides other aspects, it is important to understand the mechanism of food digestion because an approach to predict GI must essentially mimic the complex processes in the human gastrointestinal tract. The focus of this work is to review the advances in various approaches for predicting the glycaemic responses to foods. This has been carried out by detailing conventional approaches, their merits and limitations, and the need to focus on emerging approaches. Given that no single approach can be generalised to all applications, the review emphasises the scope of deriving insights for improvements in methodologies. Reviewing the conventional and emerging approaches for the determination of GI in foods, this detailed work is intended to serve as a state-of-the-art resource for nutritionists who work on developing low-GI foods.

South Indian Cuisine with Low Glycemic Index Ingredients Reduces Cardiovascular Risk Factors in Subjects with Type 2 Diabetes

Background: Inflammation is considered as a predictor of cardiovascular diseases in type 2 diabetes mellitus. No previous studies have investigated the effect of low glycemic index (LGI) recipes of South Indian cuisine on the risk factors of cardiovascular disease in patients with diabetes. Aim: The aim of this randomized controlled trial was to evaluate the improvement in cardiovascular risk factors and blood glucose control, in patients with type 2 diabetes, after intervention with recipes of Kerala cuisine, from locally available whole grain cereals, low in glycemic index. Method: This was a prospective and randomized controlled study that was conducted over a period of 24 weeks. A total of 80 participants were recruited from the Department of Endocrinology and Diabetes Outpatient in Kerala, South India. All 80 patients had type 2 diabetes, and were aged between 35 and 65 years. Participants were randomly assigned and advised to follow either a LGI diet plan (n = 40) or their usual diet, which served as a control group (n = 40). The advice was reinforced throughout the study period. Anthropometric, biochemical parameters which included glycemic and cardio-metabolic parameters were measured according to standard procedures. T-tests were conducted to compare the differences between intervention and control groups, and the Pearson correlation coefficient was used to evaluate associations between the variables. Results: There were significant differences (p < 0.05) between the intervention and control groups with respect to weight, HbA1c, insulin, triglycerides, Homeostatic Model Assessment of Insulin Resistance (HOMA-IR), high sensitivity C-reactive protein (hs-CRP) and apolipoprotein B (ApoB). There was also a positive correlation between weight and blood glucose variables. ApoB was positively correlated with lipid profile and insulin levels. Conclusions: The long-term implementation of LGI diet of Kerala cuisine has been found to promote weight loss, enhance insulin sensitivity and reduce the cardiovascular risk.

Destigmatizing Carbohydrate with Food Labeling: The Use of Non-Mandatory Labelling to Highlight Quality Carbohydrate Foods

Dietary carbohydrates are components of healthy foods, but many carbohydrate foods have recently been stigmatized as primary causes of diet-related risk factors for chronic disease. There is an opportunity to enhance efforts within the food landscape to encourage the consumption of higher quality carbohydrate foods. The use of labelling is one strategy that permits consumers to identify healthy carbohydrate foods at the point-of-purchase. This review discusses the regulatory frameworks and examples of associated non-mandatory food labelling claims that are currently employed to highlight healthy carbohydrate foods to consumers. The existing labelling frameworks discussed here align with established measures of carbohydrate quality, such as 1. dietary fibre nutrient content claims and associated dietary fibre-based health claims; 2. the presence of whole carbohydrate foods and ingredients that are intact or reconstituted, such as whole grains; and 3. low glycemic index and glycemic response claims. Standards from Codex Alimentarius, and regulations from Australia and New Zealand, Canada, Europe, and the United States will be used to illustrate the means by which food labelling can be used by consumers to identify quality carbohydrate foods.