A behavioural intervention incorporating specific glycaemic index goals improves dietary quality, weight control and glycaemic control in adults with type 2 diabetes

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.

An evaluation of goal setting in the NHS England diabetes prevention programme

OBJECTIVE

We know little about how goal setting is actually delivered in routine practice. The National Health Service Diabetes Prevention Programme (NHS-DPP) is a behavioural intervention aiming to prevent progression to Type 2 diabetes in those at risk. It has been delivered across England by four commercial providers. This study aimed to establish whether goal setting in the NHS-DPP was delivered in line with the current evidence base. Design: Observational study and document review. One-hundred-and-eighteen NHS-DPP sessions with 419 people were observed at eight sites (two sites per provider). Main outcome measures: Multiple characteristics of goal setting were reliably coded from each providers' programme plans (intended goal setting) and from audio-recorded NHS-DPP sessions (actual goal setting). Results: Providers intended to deliver goal setting in 88.3% of sessions, though goal setting was delivered in only 52.5% of sessions. During delivery, the observed goals set across providers were generally specific (62.5%), set privately (53.1%), with goal difficulty rarely mentioned (3.1%). Conclusions: Goal setting in the NHS-DPP is being under-delivered, and not in line with the evidence base for promoting behavioural change. Goal setting in national behaviour change programmes should be optimised and training provided specifically for goal setting.

The Effect of Dietary Glycaemic Index on Glycaemia in Patients with Type 2 Diabetes: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Background: The increasing prevalence of diabetes in the United Kingdom and worldwide calls for new approaches to its management, and diets with low glycaemic index have been proposed as a useful means for managing glucose response. However, there are conflicting reports and differences in the results of studies in terms of their effectiveness. Furthermore, the impact of low-glycaemic index diets and their long-term use in patients with type 2 diabetes remains unclear. Objectives: The objective of this study was to conduct a systematic review and meta-analysis of the effect of low-glycaemic index diets in patients with type 2 diabetes. Methods: Search methods: Randomised controlled studies were selected from a number of databases (EBSCOHost with links to Health Research databases, PubMed, and grey literature) based on the Population, Intervention, Comparator, Outcomes and Study designs (PICOS) framework. The search terms included synonyms and Medical Subject Headings (MeSH) and involved the use of Boolean operators (AND/OR) which allowed the combination of words and search terms. Selection criteria: As per the selection criteria, the following types of articles were selected: studies on randomised controlled trials, with year of publication between 2008 and 2018, including patients with type 2 diabetes. Thus, studies involving patients with gestational and type 1 diabetes were excluded, as were observational studies. Nine articles which met the inclusion criteria were selected for the systematic review, whereas only six articles which met the criteria were included in the meta-analysis. Data collection and analysis: Studies were evaluated for quality and risk of bias. In addition, heterogeneity, meta-analysis, and sensitivity tests of the extracted data were carried out using Review Manager 5.3 (Review Manager, 2014). Results: The findings of the systematic review showed that the low-glycaemic index (low-GI) diet resulted in a significant improvement (<0.05) in glycated haemoglobin (HbA1c) in two studies: low-GI diet Δ = −0.5% (95% CI, −0.61% to −0.39%) vs. high-cereal fibre diet Δ = −0.18% (95% CI, −0.29% to −0.07%); and low-GI legume diet Δ = −0.5% (95%, −0.6% to −0.4%) vs. high-wheat fibre diet Δ = −0.3% (95% Cl, −0.4 to −0.2%). There was a slight improvement in one study (low glycaemic response = 6.5% (6.3–7.1) vs. control = 6.6% (6.3–7.0) and no significant difference (p > 0.05) in four studies compared with the control diet. Four studies showed improvements in fasting blood glucose in low-GI diets compared to higher-GI diets or control: low-GI diet = 150.8 ± 8.7 vs. higher-GI diet = 157.8 ± 10.4 mg/dL, mean ± SD p = 0.43; low-GI diet = 127.7 vs. high-cereal fibre diet = 136.8 mg/dL, p = 0.02; low-GI diet = 6.5 (5.6–8.4) vs. standard diabetic diet = 6.7 (6.1–7.5) mmol/L, median and interquartile range p > 0.05; and low-GI diet = 7.3 ± 0.3 vs. conventional carbohydrate exchange diet = 7.7 ± 0.4 mmol/L, mean ± SEM (Standard Error of Mean) p < 0.05. The results of the meta-analysis and sensitivity tests demonstrated significant differences (p < 0.001 and p < 0.001, respectively) between the low-GI diet and the higher-GI diet or control diet in relation to glycated haemoglobin. Differences between the low-GI diet and higher-GI diet or control were significant (p < 0.05) with respect to the fasting blood glucose following meta-analysis. Conclusion: The low-GI diet is more effective in controlling glycated haemoglobin and fasting blood glucose compared with a higher-GI diet or control in patients with type 2 diabetes.

Effects comparison between low glycemic index diets and high glycemic index diets on HbA1c and fructosamine for patients with diabetes: A systematic review and meta-analysis

AIMS

The purpose of this study is to evaluate the effect of low glycemic index (GI) through the comparison of low-GI foods group and high-GI foods group on glycemic control (the measurements were HbA1c and fructosamine) for patients with diabetes.

METHODS

The studies were retrieved from databases including PubMed, MEDLINE, Springer, Elsevier Science Direct, Cochrane Library and Google scholar from their inception to August 2014. Review Manager 5.1 and STATA package v.11.0 software were applied for the meta-analysis. Standard mean difference (SWD) and its corresponding 95% confidence interval (CI) for HbA1c and fructosamine of patients with diabetes were collected and calculated in a fixed or random effects model when appropriate. Subgroup analysis stratified by study design, geographic area of participants and types of diabetes were also conducted.

RESULTS

There were significant differences of overall effects on HbA1c between low-GI foods group and high-GI foods group (SWD=-0.42, 95%CI=-0.69 to -0.16, P<0.01) in patients with diabetes, and the subgroup analysis indicated that significant differences of HbA1c were also found between the two groups in crossover study, in Australian population and American population, as well as in type 2 diabetes. The overall fructosamine was also significantly different in patients with diabetes between low-GI foods and high-GI foods group (SMD=-0.44, 95%CI=-0.82 to -0.06, P=0.02).

CONCLUSIONS

Our results suggest that low-GI diets achieve a more beneficial effect on glycemic control than that of high-GI foods diets.

Goal setting: an integral component of effective diabetes care

Goal setting is a widely used behavior change tool in diabetes education and training. Prior research found specific relatively difficult but attainable goals set within a specific timeframe improved performance in sports and at the workplace. However, the impact of goal setting in diabetes self-care has not received extensive attention. This review examined the mechanisms underlying behavioral change according to goal setting theory and evaluated the impact of goal setting in diabetes intervention studies. Eight studies were identified, which incorporated goal setting as the primary strategy to promote behavioral change in individual, group-based, and primary care settings among patients with type 2 diabetes. Improvements in diabetes-related self-efficacy, dietary intake, physical activity, and A1c were observed in some but not all studies. More systematic research is needed to determine the conditions and behaviors for which goal setting is most effective. Initial recommendations for using goal setting in diabetes patient encounters are offered.

Carbohydrates, glycemic index, and pregnancy outcomes in gestational diabetes

This review critically evaluates the current evidence regarding the effect of the dietary glycemic index (GI) on pregnancy outcomes in gestational diabetes mellitus (GDM). Current evidence, although limited, consistently supports the advantages of, and has demonstrated no disadvantages of, a low-GI diet. We conclude that pregnant women with GDM are likely to benefit from following a low-GI meal pattern, with no significant side effects, and consideration of the GI should be given when formulating a diet for GDM. However, until larger scale intervention trials are completed, an exclusive low-GI diet should not replace the current recommended diets for GDM from relevant government and health agencies. Further studies that intervene at an earlier stage of pregnancy are required.

Making healthy food choices using nutrition facts panels. The roles of knowledge, motivation, dietary modifications goals, and age

Nutrition facts panels (NFPs) contain a rich assortment of nutrition information and are available on most food packages. The importance of this information is potentially even greater among older adults due to their increased risk for diet-related diseases, as well as those with goals for dietary modifications that may impact food choice. Despite past work suggesting that knowledge and motivation impact attitudes surrounding and self-reported use of NFPs, we know little about how (i.e., strategies used) and how well (i.e., level of accuracy) younger and older individuals process NFP information when evaluating healthful qualities of foods. We manipulated the content of NFPs and, using eye tracking methodology, examined strategies associated with deciding which of two NFPs, presented side-by-side, was healthier. We examined associations among strategy use and accuracy as well as age, dietary modification status, knowledge, and motivation. Results showed that, across age groups, those with dietary modification goals made relatively more comparisons between NFPs with increasing knowledge and motivation; but that strategy effectiveness (relationship to accuracy) depended on age and motivation. Results also showed that knowledge and motivation may protect against declines in accuracy in later life and that, across age and dietary modification status, knowledge mediates the relationship between motivation and decision accuracy.