Dietary instructions focusing on meal-sequence and nutritional balance for prediabetes subjects: An exploratory, cluster-randomized, prospective, open-label, clinical trial

Influence of Meal Sequence and Number of Teeth Present on Nutrient Intake Status: A Cross-Sectional Study

Intake of fiber, as well as protein, and lipid preloading help to control postprandial glycemic elevation in people with type 2 diabetes and in healthy individuals. However, there are few studies on the awareness of meal sequence and nutrient intake status that consider oral conditions. This cross-sectional study aimed to determine the effects of meal sequences on nutrient intake status and whether these relationships were related to the number of teeth present. The subjects were recruited from the Medical and Dental Collaboration Center of Kanagawa Dental University Hospital between 2018 and 2021. Medical and dental examinations were performed, and a questionnaire was used to determine whether the diet consisted of vegetables, meat or fish, and carbohydrates in that order. Nutrient intake status was assessed using the brief-type self-administered diet history questionnaire. Data were collected from 238 participants. The group with awareness of meal sequence ingested increased nutrients such as n-3 fatty acids, total dietary fiber, calcium, and vitamin C. Saturated fatty acid intake increased in those with fewer teeth, while it was not significantly related to meal sequence. In conclusion, our results showed that meal sequence was associated with nutrient intake status. In addition, the intake of saturated fatty acids increased when many teeth were lost, regardless of meal sequence.

Impact on Glycemic Variation Caused by a Change in the Dietary Intake Sequence

This work presents an analysis of the effect on glycemic variation caused by modifying the macronutrient intake sequence in a person without a diagnosis of diabetes. In this work, three types of nutritional studies were developed: (1) glucose variation under conditions of daily intake (food mixture); (2) glucose variation under conditions of daily intake modifying the macronutrient intake sequence; (3) glucose variation after a modification in the diet and macronutrient intake sequence. The focus of this research is to obtain preliminary results on the effectiveness of a nutritional intervention based on the modification of the sequence of macronutrient intake in a healthy person during 14-day periods. The results obtained corroborate the positive effect on the glucose of consuming vegetables, fiber, or proteins before carbohydrates, decreasing the peaks in the postprandial glucose curves (vegetables: 113-117 mg/dL; proteins: 107-112 mg/dL; carbohydrates: 115-125 mg/dL) and reducing the average levels of blood glucose concentrations (vegetables: 87-95 mg/dL; proteins: 82-99 mg/dL; carbohydrates: 90-98 mg/dL). The present work demonstrates the preliminary potential of the sequence in the macronutrient intake for the generation of alternatives of prevention and solution of chronic degenerative diseases, improving the management of glucose in the organism and permeating in the reduction of weight and the state of health of the individuals.

Eating Vegetables First Regardless of Eating Speed Has a Significant Reducing Effect on Postprandial Blood Glucose and Insulin in Young Healthy Women: Randomized Controlled Cross-Over Study

People with fast eating habits have been reported to have an increased risk of diabetes and obesity. To explore whether the speed of eating a test meal (tomato, broccoli, fried fish, and boiled white rice) influences postprandial blood glucose, insulin, triglyceride, and free fatty acid levels, 18 young, healthy women consumed a 671 kcal breakfast at fast speed (10 min) and slow speed (20 min) with vegetables first and slow speed (20 min) with carbohydrate first on three separate days. This study was conducted using a within-participants cross-over design in which all participants consumed identical meals of three different eating speeds and food orders. Significant ameliorations of both fast and slow eating with vegetables first regimen on postprandial blood glucose and insulin levels at 30 and 60 min were observed compared with those of slow eating with carbohydrates first. In addition, the standard deviation, large amplitude of excursion, and incremental area under the curve for blood glucose and insulin in both fast and slow eating with vegetables first were all significantly lower than those of slow eating with carbohydrate first. Interestingly, there was no significant difference between fast and slow eating on postprandial blood glucose and insulin levels as long as vegetables were consumed first, although postprandial blood glucose at 30 min was significantly lower in slow eating with vegetables first than that of fast eating with the same food order. These results suggest that food order with vegetables first and carbohydrate last ameliorates postprandial blood glucose and insulin concentrations even if the meal was consumed at fast speed.

Impact of Dietitian-Led Nutrition Therapy of Food Order on 5-Year Glycemic Control in Outpatients with Type 2 Diabetes at Primary Care Clinic: Retrospective Cohort Study

The aim of this retrospective cohort study was to evaluate the effect of 5-year follow-up of dietitian-led medical nutrition therapy (eating vegetables before carbohydrates) on glycemic control in outpatients with type 2 diabetes (T2DM) at a primary care clinic. A total of 138 patients with dietitian-led medical nutrition therapy (intervention group) and 104 patients without dietitian-led nutrition therapy (control group) were compared for glycemic control, serum lipid, blood pressure, and diabetic complications for 5 years. Each patient in the intervention group received dietary education focused on food order (eating vegetables before carbohydrates) by dietitians. A significant improvement in HbA1c after 5 years in the intervention group [8.5 ± 1.7% (69 mmol/mol) to 7.6 ± 1.1% (59 mmol/mol), p < 0.001] was observed, whereas no change was observed in the control group [7.9 ± 1.2% (62 mmol/mol) to 8.0 ± 1.2% (63 mmol/mol)]. Dietary intake of protein, fat, carbohydrates, cholesterol, and salt in the intervention group demonstrated significant reduction, while the intake of dietary fiber significantly increased after the dietary education. Simple dietary education of ‘eating vegetables before carbohydrates’ presented by dietitians achieved good glycemic control after a 5-year period in outpatients with T2DM at primary care clinic.

Efficacy of a meal sequence in patients with type 2 diabetes: a systematic review and meta-analysis

INTRODUCTION

This systematic review investigated the efficacy of a meal sequence, the carbohydrate-later meal pattern (CL), on type 2 diabetes mellitus (T2DM).

RESEARCH DESIGN AND METHODS

We searched the Cochrane Central Register of Controlled Trials, MEDLINE, Embase, WHO International Clinical Trials Registry Platform, and ClinicalTrials.gov until April 2020 to perform meta-analyses using random-effects models. Primary outcomes were hemoglobin A1c (HbA1c) and quality of life. Secondary outcomes were plasma concentrations of glucose, insulin and incretin 120 min after a meal, and any adverse outcomes. The revised Cochrane risk-of-bias tool and Grading of Recommendations, Assessment, Development, and Evaluation approach were used to assess the quality of individual studies and the body of evidence, respectively. The present study was registered in the UMIN Clinical Trials Registry.

RESULTS

We included 230 participants in eight trials, including both trials that examined long-term changes (more than 2 months and less than 2 years) and short-term changes (in 2-hour postprandial values). CL resulted in a slight to no difference in HbA1c (mean difference (MD), -0.21% in the intervention group; 95% CI -0.44% to+0.03%), plasma glucose (MD,+4.94 mg/dL; 95% CI -8.34 mg/dL to +18.22 mg/dL), plasma insulin (MD, -3.63 μIU/mL; 95% CI -11.88 μIU/mL to +4.61 μIU/mL), plasma GLP-1 (MD, +0.43 pmol/L; 95% CI -0.69 pmol/L to +1.56 pmol/L), and plasma GIP (MD, -2.02 pmol/L; 95% CI -12.34 pmol/L to +8.31 pmol/L). All of these outcomes were of low-certainty evidence or very low-certainty evidence. None of the trials evaluated quality of life or adverse events.

CONCLUSIONS

There was no evidence for the potential efficacy of recommending CL beyond standard dietary advice on T2DM.

TRIAL REGISTRATION NUMBER

UMIN000039979.

Nutritional management of type 2 diabetes in subjects with obesity: an international guideline for clinical practice

Type 2 diabetes mellitus (T2DM) and obesity represent a global public health problem. Current nutritional recommendations focused on weight loss and overall dietary quality. However, there is no consensus on the optimal macronutrient composition of the diet, particularly for the long-term management of T2DM in subjects with obesity. An international panel of experts reviewed and critically appraised the updated literature published on the topic. This review primarily examines the evidence for areas of consensus and uncertainty about nutritional therapy in patients with T2DM and obesity. The aim of this article is to provide nutritional advice to manage these patients in clinical practice.

A Review of Recent Findings on Meal Sequence: An Attractive Dietary Approach to Prevention and Management of Type 2 Diabetes

While adjustment of total energy and nutritional balance is critically important, meal sequence, a relatively simple method of correcting postprandial hyperglycemia, is becoming established as a practical dietary approach for prevention and management of diabetes and obesity. Meal sequence, i.e., consumption of protein and/or fat before carbohydrate, promotes secretion of glucagon-like peptide-1 (GLP-1) from the gut and ameliorates secretions of insulin and glucagon and delays gastric emptying, thereby improving postprandial glucose excursion. GLP-1 is known to suppress appetite by acting on the hypothalamus via the afferent vagus nerve. Thus, enhancement of GLP-1 secretion by meal sequence is expected to reduce body weight. Importantly, consumption of a diet rich in saturated fatty acids such as meat dishes before carbohydrate increases secretions of not only GLP-1 but also glucose-dependent insulinotropic polypeptide (GIP), which promotes energy storage in adipose tissue and may lead to weight gain in the long term. Dietary fiber intake before carbohydrate intake significantly reduces postprandial glucose elevation and may have a weight loss effect, but this dietary strategy does not enhance the secretion of GLP-1. Thus, it is suggested that their combination may have additive effects on postprandial glucose excursion and body weight. Indeed, results of some clinical research supports the idea that ingesting dietary fiber together with meal sequence of protein and/or fat before carbohydrate benefits metabolic conditions of individuals with diabetes and obesity.