Effect of carbohydrate distribution on postprandial glucose peaks with the use of continuous glucose monitoring in type 2 diabetes

Association of largest meal timing and eating frequency with body mass index and obesity

BACKGROUND AND AIMS

The circadian pattern of eating behaviors has garnered increasing interest as a strategy for obesity prevention and weight loss. It is believed that the benefits stem from aligning food intake with the body's natural daily rhythms. However, the existing body of evidence is limited in scale and scope and there has been insufficient evaluation of temporal eating behaviors, such as the specific time of day in which the highest calorie consumption occurs, meal frequency, and distribution. This research aims to explore the association between the timing of the largest meal of the day and eating frequency with Body Mass Index (BMI) and obesity.

METHODS

Participants (n = 2050, 18-65y) were part of an exploratory cross-sectional and population-based research, with data collection in a virtual environment. Linear regression analyses and restricted cubic splines evaluated differences in BMI associated with independent eating variables [timing of the largest meal, number of meals/day (as continuous and categorical: ≤3 or >3/day), and each largest meal of the day (breakfast/lunch/dinner)]. Logistic regression models were fitted to assess Odds Ratios (OR) and 95 % Confidence Intervals (CI) of obesity associated with the same independent variables.

RESULTS

Our main findings were that the timing of the largest meal and reporting dinner as the largest meal were associated with higher values of BMI (respectively, 0.07 kg/m2 and 0.85 kg/m2) and increased odds of obesity [respectively OR(95%CI):1.04(1.01,1.08), and OR(95%CI):1.67(1.18,2.38)]. Those who realized more than 3 meals/day presented lower values of BMI (-0.14 kg/m2) and 32 % lower odds of having obesity [OR(95%CI):0.68(0.52,0.89)]. Reporting lunch as the largest meal also protected against obesity [OR(95%CI):0.71(0.54,0.93)]. These associations were statistically significant and independent of sex, age, marital status, education level, diet quality, sleep duration, and weekly frequency of physical exercise.

CONCLUSION

Having the largest meal earlier in the day, concentrating the majority of caloric intake during lunch, and consuming more than three meals a day, may present a promising intervention for preventing and treating obesity/overweight.

Graded Replacement of Carbohydrate-Rich Breakfast Products with Dairy Products: Effects on Postprandial Aminoacidemia, Glycemic Control, Bone Metabolism, and Satiety

BACKGROUND

Postprandial metabolic responses following dairy consumption have mostly been studied using stand-alone dairy products or milk-derived nutrients.

OBJECTIVE

Assessing the impact of ingesting dairy products as part of a common breakfast on postprandial aminoacidemia, glycemic control, markers of bone metabolism, and satiety.

METHODS

In this randomized, crossover study, 20 healthy young males and females consumed on 3 separate occasions an iso-energetic breakfast containing no dairy (NO-D), 1 dairy (ONE-D), or 2 dairy (TWO-D) products. Postprandial concentrations of amino acids, glucose, insulin, glucagon-like peptide-1 (GLP-1), calcium, parathyroid hormone (PTH), and markers of bone formation (P1NP) and resorption (CTX-I) were measured before and up to 300 min after initiating the breakfast, along with VAS-scales to assess satiety.

RESULTS

Plasma essential and branched-chained amino acids availability (expressed as total area under the curve (tAUC)) increased in a dose-dependent manner (P<0.05 for all comparisons). Plasma glucose tAUCs were lower in ONE-D and TWO-D compared with NO-D (P<0.05 for both comparisons). Plasma GLP-1 tAUC increased in a dose-dependent manner (P<0.05 for all comparisons), whereas no differences were observed in plasma insulin tAUC between conditions (P>0.05 for all comparisons). Serum calcium tAUCs were higher in ONE-D and TWO-D compared with NO-D (P<0.05 for both comparisons), along with lower PTH tAUCs in ONE-D and TWO-D compared with NO-D (P=0.001 for both comparisons). In accordance, serum CTX-I concentrations were lower in the late postprandial period in ONE-D and TWO-D compared with NO-D (P<0.01 for both comparisons). No differences were observed in P1NP tAUCs between conditions (P>0.05). The tAUC for satiety was higher in TWO-D compared with NO-D and ONE-D (P<0.05 for both comparisons).

CONCLUSIONS

Iso-energetic replacement of a carbohydrate-rich breakfast component with one serving of dairy improves postprandial amino acid availability, glycemic control, and bone metabolism. Adding a second serving of dairy in lieu of carbohydrates augments postprandial amino acid and GLP-1 concentrations while further promoting satiety. This study was registered at https://doi.org/10.1186/ISRCTN13531586 with Clinical Trial Registry number ISRCTN13531586.

Early time-restricted carbohydrate consumption vs conventional dieting in type 2 diabetes: a randomised controlled trial

AIMS/HYPOTHESIS

Early time-restricted carbohydrate consumption (eTRC) is a novel dietary strategy that involves restricting carbohydrate-rich food intake to the morning and early afternoon to align with circadian variations in glucose tolerance. We examined the efficacy, feasibility and safety of eTRC in individuals with type 2 diabetes under free-living conditions.

METHODS

In this randomised, parallel-arm, open label, controlled trial, participants with type 2 diabetes and overweight/obesity (age 67.2±7.9 years, 47.8% women, BMI 29.4±3.7 kg/m2, HbA1c 49±5 mmol/mol [6.6±0.5%]) were randomised, using computer-generated random numbers, to a 12 week eTRC diet or a Mediterranean-style control diet with matched energy restriction and macronutrient distribution (50% carbohydrate, 30% fat and 20% protein). The primary outcome was the between-group difference in HbA1c at 12 weeks. Body composition, 14 day flash glucose monitoring and food diary analysis were performed every 4 weeks. Mixed meal tolerance tests with mathematical beta cell function modelling were performed at baseline and after 12 weeks.

RESULTS

Twelve (85.7%) participants in the eTRC arm and 11 (84.6%) participants in the control arm completed the study, achieving similar reductions in body weight and fat mass. The two groups experienced comparable improvements in HbA1c (-3 [-6, -0.3] mmol/mol vs -4 [-6, -2] mmol/mol, corresponding to -0.2 [-0.5, 0]% and -0.3 [-0.5, -0.1]%, respectively, p=0.386), fasting plasma glucose, flash glucose monitoring-derived glucose variability and mixed meal tolerance test-derived glucose tolerance, insulin resistance, insulin clearance and plasma glucagon levels, without changes in model-derived beta cell function parameters, glucagon-like peptide-1, glucose-dependent insulinotropic polypeptide and non-esterified fatty acid levels. The two diets similarly reduced liver function markers and triglyceride levels, being neutral on other cardiometabolic and safety variables. In exploratory analyses, diet-induced changes in body weight and glucometabolic variables were not related to the timing of carbohydrate intake.

CONCLUSIONS/INTERPRETATION

The proposed eTRC diet provides a feasible and effective alternative option for glucose and body weight management in individuals with type 2 diabetes, with no additional metabolic benefits compared with conventional dieting.

TRIAL REGISTRATION

ClinicalTrials.gov NCT05713058 FUNDING: This study was supported by the European Society for Clinical Nutrition and Metabolism (ESPEN) and the Italian Society of Diabetology (SID).

Impact of a low-carbohydrate versus low-fat breakfast on blood glucose control in type 2 diabetes: a randomized trial

BACKGROUND

In type 2 diabetes (T2D), consuming carbohydrates results in a rapid and large increase in blood glucose, particularly in the morning when glucose intolerance is highest.

OBJECTIVE

We investigated if a low-carbohydrate (LC) breakfast (∼465kcal: 25g protein, 8g carbohydrates, 37g fat) could improve glucose control in people with type 2 diabetes when compared to a low-fat control (CTL) breakfast (∼450kcal:20g protein, 56g carbohydrates, 15g fat).

METHODS

Participants with T2D (N=121, 53% female, mean age 64 years) completed a remote 3-month parallel-group randomized controlled trial comparing a LC versus standard low-fat guideline CTL breakfast. Change in hemoglobin A1c (HbA1c) was the pre-specified primary outcome. Continuous glucose monitoring, self-reported anthropometrics and dietary information were collected for an intention-to-treat analysis.

RESULTS

HbA_1c was reduced (-0.3%, 95% CI: -0.4% to -0.1%) after 12 weeks of a LC breakfast, but the between group difference in HbA_1c was of borderline statistical significance (-0.2, 95% CI: -0.4 to 0.0; P=0.06). Self-reported total daily energy (-242 kcal, 95% CI -460 to -24 kcal; P=0.03) and carbohydrate (-73g, 95% CI: -101 to -44 g; P<0.01) intake were lower in the LC group but the significance of this difference is unclear. Mean and maximum glucose, area under the curve, glycemic variability, standard deviation, and time above range were all significantly lower, and time in range was significantly higher, in the LC group compared to CTL (all P<0.05).

CONCLUSIONS

Advice and guidance to consume a LC breakfast appears to be a simple dietary strategy to reduce overall energy and carbohydrate intake and improve several CGM variables when compared to a CTL breakfast in persons living with T2D.

TRIAL REGISTRATION

https://clinicaltrials.gov/ct2/show/NCT04550468.

The crucial role and mechanism of insulin resistance in metabolic disease

Insulin resistance (IR) plays a crucial role in the development and progression of metabolism-related diseases such as diabetes, hypertension, tumors, and nonalcoholic fatty liver disease, and provides the basis for a common understanding of these chronic diseases. In this study, we provide a systematic review of the causes, mechanisms, and treatments of IR. The pathogenesis of IR depends on genetics, obesity, age, disease, and drug effects. Mechanistically, any factor leading to abnormalities in the insulin signaling pathway leads to the development of IR in the host, including insulin receptor abnormalities, disturbances in the internal environment (regarding inflammation, hypoxia, lipotoxicity, and immunity), metabolic function of the liver and organelles, and other abnormalities. The available therapeutic strategies for IR are mainly exercise and dietary habit improvement, and chemotherapy based on biguanides and glucagon-like peptide-1, and traditional Chinese medicine treatments (e.g., herbs and acupuncture) can also be helpful. Based on the current understanding of IR mechanisms, there are still some vacancies to follow up and consider, and there is also a need to define more precise biomarkers for different chronic diseases and lifestyle interventions, and to explore natural or synthetic drugs targeting IR treatment. This could enable the treatment of patients with multiple combined metabolic diseases, with the aim of treating the disease holistically to reduce healthcare expenditures and to improve the quality of life of patients to some extent.

Circadian rhythms in cardiac metabolic flexibility

Numerous aspects of cardiovascular physiology (e.g., heart rate, blood pressure) and pathology (e.g., myocardial infarction and sudden cardiac death) exhibit time-of-day-dependency. In association with day-night differences in energetic demand and substrate availability, the healthy heart displays remarkable metabolic flexibility through temporal partitioning of the metabolic fate of common substrates (glucose, lipid, amino acids). The purpose of this review is to highlight the contribution that circadian clocks provide toward 24-hr fluctuations in cardiac metabolism and to discuss whether attenuation and/or augmentation of these metabolic rhythms through adjustment of nutrient intake timing impacts cardiovascular disease development.

American Association of Clinical Endocrinology Clinical Practice Guideline: Developing a Diabetes Mellitus Comprehensive Care Plan-2022 Update

OBJECTIVE

The objective of this clinical practice guideline is to provide updated and new evidence-based recommendations for the comprehensive care of persons with diabetes mellitus to clinicians, diabetes-care teams, other health care professionals and stakeholders, and individuals with diabetes and their caregivers.

METHODS

The American Association of Clinical Endocrinology selected a task force of medical experts and staff who updated and assessed clinical questions and recommendations from the prior 2015 version of this guideline and conducted literature searches for relevant scientific papers published from January 1, 2015, through May 15, 2022. Selected studies from results of literature searches composed the evidence base to update 2015 recommendations as well as to develop new recommendations based on review of clinical evidence, current practice, expertise, and consensus, according to established American Association of Clinical Endocrinology protocol for guideline development.

RESULTS

This guideline includes 170 updated and new evidence-based clinical practice recommendations for the comprehensive care of persons with diabetes. Recommendations are divided into four sections: (1) screening, diagnosis, glycemic targets, and glycemic monitoring; (2) comorbidities and complications, including obesity and management with lifestyle, nutrition, and bariatric surgery, hypertension, dyslipidemia, retinopathy, neuropathy, diabetic kidney disease, and cardiovascular disease; (3) management of prediabetes, type 2 diabetes with antihyperglycemic pharmacotherapy and glycemic targets, type 1 diabetes with insulin therapy, hypoglycemia, hospitalized persons, and women with diabetes in pregnancy; (4) education and new topics regarding diabetes and infertility, nutritional supplements, secondary diabetes, social determinants of health, and virtual care, as well as updated recommendations on cancer risk, nonpharmacologic components of pediatric care plans, depression, education and team approach, occupational risk, role of sleep medicine, and vaccinations in persons with diabetes.

CONCLUSIONS

This updated clinical practice guideline provides evidence-based recommendations to assist with person-centered, team-based clinical decision-making to improve the care of persons with diabetes mellitus.

Effects of Diet, Lifestyle, Chrononutrition and Alternative Dietary Interventions on Postprandial Glycemia and Insulin Resistance

As years progress, we are found more often in a postprandial than a postabsorptive state. Chrononutrition is an integral part of metabolism, pancreatic function, and hormone secretion. Eating most calories and carbohydrates at lunch time and early afternoon, avoiding late evening dinner, and keeping consistent number of daily meals and relative times of eating occasions seem to play a pivotal role for postprandial glycemia and insulin sensitivity. Sequence of meals and nutrients also play a significant role, as foods of low density such as vegetables, salads, or soups consumed first, followed by protein and then by starchy foods lead to ameliorated glycemic and insulin responses. There are several dietary schemes available, such as intermittent fasting regimes, which may improve glycemic and insulin responses. Weight loss is important for the treatment of insulin resistance, and it can be achieved by many approaches, such as low-fat, low-carbohydrate, Mediterranean-style diets, etc. Lifestyle interventions with small weight loss (7-10%), 150 min of weekly moderate intensity exercise and behavioral therapy approach can be highly effective in preventing and treating type 2 diabetes. Similarly, decreasing carbohydrates in meals also improves significantly glycemic and insulin responses, but the extent of this reduction should be individualized, patient-centered, and monitored. Alternative foods or ingredients, such as vinegar, yogurt, whey protein, peanuts and tree nuts should also be considered in ameliorating postprandial hyperglycemia and insulin resistance. This review aims to describe the available evidence about the effects of diet, chrononutrition, alternative dietary interventions and exercise on postprandial glycemia and insulin resistance.

Novel trends and concepts in the nutritional management of glycemia in type 2 diabetes mellitus-beyond dietary patterns: a narrative review

A variety of eating patterns are recommended by international guidelines to help people with type 2 diabetes mellitus (T2DM) achieve general health and glycemia goals. Apart from eating patterns, there is evidence that other approaches related to the everyday application of dietary advice, such as meal frequency, breakfast consumption, daily carbohydrate distribution, and order of food consumption during meals, have significant effects on glycemia management. The aims of this review were to examine published diabetes nutrition guidelines concerning specific recommendations with regard to the above approaches, as well as to review evidence from studies that have investigated their effect on glycemia in T2DM. The data suggest that eating breakfast regularly, consuming most carbohydrates at lunch, avoiding large dinners late at night, and applying the carbohydrate-last meal pattern are effective practices towards better nutritional management of T2DM.

Meal Timing and Glycemic Control during Pregnancy-Is There a Link?

Hyperglycemia during pregnancy and gestational diabetes mellitus (GDM) constitute an important public health problem due to their prevalence and long-term health consequences both for the mother and offspring. Results from studies in rodents and some clinical investigations suggest that meal time manipulation may be a potential lifestyle approach against conditions involving perturbations in glucose homeostasis (e.g., hyperglycemia, insulin resistance, diabetes, etc.). The purpose of this review is to summarize and critically evaluate the current literature on the role of meal timing and daily nutrient distribution on glycemic control during pregnancy. Only a small number of mostly observational studies have assessed the role of meal timing in glucose homeostasis during pregnancy. Food consumption earlier in the day and short-term fasting with adequate nutrient intake may improve glycemic control during the second and third trimester of gestation. Considering that the field of chrononutrition is still in its infancy and many questions remain unanswered, future prospective and carefully designed studies are needed to better understand the role of meal timing in metabolic homeostasis and maternal and fetal health outcomes during pregnancy.

Both macronutrient food composition and fasting insulin resistance affect postprandial glycemic responses in senior subjects

INTRODUCTION

Postprandial hyperglycemia is a risk factor for type 2 diabetes. Insulin resistance (IR) might affect metabolic responses in non-fasting states. Dietary intake and food composition influence postprandial glucose homeostasis. The aims of this study were to evaluate the effects of different test foods varying in the macronutrient composition on postprandial glycemic responses and whether these outcomes are conditioned by the basal glycemic status in senior subjects.

METHODS

In a randomized, controlled crossover design, thirty-four adults consumed a test food, a high protein product (n = 19) or a high carbohydrate (CHO) product (n = 15), using the oral glucose tolerance test (OGTT) as a reference. Blood glucose and insulin were measured at fasting and at 15, 30, 45, 60, 90, and 120 min after starting the food intake. For each type of food, the incremental area under the curve (iAUC) for glucose and insulin was calculated. IR was measured using the Homeostatic Model Assessment of IR (HOMA-IR).

RESULTS

Consumption of a high protein product significantly lowered the peak and Δ blood glucose concentrations compared to the high CHO product (p < 0.001). Concerning the insulin response, no significant differences between both foods were observed. Fasting glucose was positively correlated with the glucose iAUC only for the high protein product. Positive associations of both fasting insulin and HOMA-IR with the insulin iAUC for all the cases were observed. Linear regression models showed significant positive associations between the glucose iAUC and fasting glucose after adjusting for age and sex. Regarding the insulin iAUC, positive associations were found with fasting insulin and HOMA-IR. Regression models also evidenced that both food test consumptions were able to decrease the glucose and insulin iAUC values when compared with the OGTT product.

CONCLUSION

Our research found that not only is the nutritional composition of foods important, but also the baseline glycemic state of individuals when assessing glycemic index estimations and addressing precision nutritional strategies to prevent and treat IR-associated disturbances.

Exercise-nutrient interactions for improved postprandial glycemic control and insulin sensitivity

Type 2 diabetes (T2D) is a rapidly growing yet largely preventable chronic disease. Exaggerated increases in blood glucose concentration following meals is a primary contributor to many long-term complications of the disease that decrease quality of life and reduce lifespan. Adverse health consequences also manifest years prior to the development of T2D due to underlying insulin resistance and exaggerated postprandial concentrations of the glucose-lowering hormone insulin. Postprandial hyperglycemic and hyperinsulinemic excursions can be improved by exercise, which contributes to the well-established benefits of physical activity for the prevention and treatment of T2D. The aim of this review is to describe the postprandial dysmetabolism that occurs in individuals at risk for and with T2D, and highlight how acute and chronic exercise can lower postprandial glucose and insulin excursions. In addition to describing the effects of traditional moderate-intensity continuous exercise on glycemic control, we highlight other forms of activity including low-intensity walking, high-intensity interval exercise, and resistance training. In an effort to improve knowledge translation and implementation of exercise for maximal glycemic benefits, we also describe how timing of exercise around meals and post-exercise nutrition can modify acute and chronic effects of exercise on glycemic control and insulin sensitivity. Novelty: Exaggerated postprandial blood glucose and insulin excursions are associated with disease risk. Both a single session and repeated sessions of exercise improve postprandial glycemic control in individuals with and without T2D. The glycemic benefits of exercise can be enhanced by considering the timing and macronutrient composition of meals around exercise.

Protein and carbohydrate distribution among the meals: effect on metabolic parameters of patients with type 2 diabetes: a single-blinded randomised controlled trial

Studies have revealed that the timing of macronutrient ingestion may influence body weight and glucose tolerance. We aimed to examine the effect of high protein v. high carbohydrate intake at the evening meal on metabolic parameters of patients with type 2 diabetes. This is a single-blinded, parallel, randomised controlled trial. Ninety-six patients with type 2 diabetes, aged 32-65 years with a mean BMI of 28·5 (sd 3·4) kg/m2, were randomly assigned into one of these three groups: standard evening meal (ST), high-carbohydrate evening meal (HC) and high-protein evening meal (HP). Then, the patients were followed for 10 weeks. HbA1c, fasting blood glucose, fasting insulin, insulin resistance, TAG, LDL-cholesterol, VLDL-cholesterol, diastolic blood pressure, body weight, body fat percentage and waist circumference decreased significantly in all three groups (P < 0·05). HbA1c showed more improvement in the ST compared with the HP group (-0·45 (sd 0·36) v. -0·26 (sd 0·36)). Reductions in BMI and body weight were significantly higher in the ST compared with the HP group (P < 0·05). Reductions in total cholesterol, non-HDL-cholesterol and systolic blood pressure were significant in all groups, except for the HP group. Non-HDL-cholesterol:HDL-cholesterol remained unchanged in all groups. The results of the present study revealed that even distribution of carbohydrates and protein among meals compared with reducing carbohydrates and increasing protein at dinner may have a more beneficial effect on glycaemic control of patients with type 2 diabetes.

Chrono-nutrition: From molecular and neuronal mechanisms to human epidemiology and timed feeding patterns

The circadian timing system governs daily biological rhythms, synchronising physiology and behaviour to the temporal world. External time cues, including the light-dark cycle and timing of food intake, provide daily signals for entrainment of the central, master circadian clock in the hypothalamic suprachiasmatic nuclei (SCN), and of metabolic rhythms in peripheral tissues, respectively. Chrono-nutrition is an emerging field building on the relationship between temporal eating patterns, circadian rhythms, and metabolic health. Evidence from both animal and human research demonstrates adverse metabolic consequences of circadian disruption. Conversely, a growing body of evidence indicates that aligning food intake to periods of the day when circadian rhythms in metabolic processes are optimised for nutrition may be effective for improving metabolic health. Circadian rhythms in glucose and lipid homeostasis, insulin responsiveness and sensitivity, energy expenditure, and postprandial metabolism, may favour eating patterns characterised by earlier temporal distribution of energy. This review details the molecular basis for metabolic clocks, the regulation of feeding behaviour, and the evidence for meal timing as an entraining signal for the circadian system in animal models. The epidemiology of temporal eating patterns in humans is examined, together with evidence from human intervention studies investigating the metabolic effects of morning compared to evening energy intake, and emerging chrono-nutrition interventions such as time-restricted feeding. Chrono-nutrition may have therapeutic application for individuals with and at-risk of metabolic disease and convey health benefits within the general population.

Glycemic Index (GI) or Glycemic Load (GL) and Dietary Interventions for Optimizing Postprandial Hyperglycemia in Patients with T2 Diabetes: A Review

The increasing prevalence of type 2 diabetes (T2D) worldwide calls for effective approaches to its management. Strategies for diabetes have generally focused on optimizing overall glycemic control as assessed by glycated hemoglobin (HbA1c) and fasting plasma glucose (FPG) values. However, since 2001, the American Diabetes Association has established postprandial glucose (PPG) as an independent contributor to both HbA1c and diabetes complications, and increasing evidence suggests that all three glycemic parameters of HbA1c, FPG, and postprandial glucose (PPG) are independently important. Objectives: The objective of this review was to comprehensively summarize the literature on the effects of nutritional strategies incorporating glycemic index (GI)/glycemic load (GL) on the postprandial hyperglycemia in people with T2D, as well as to provide recommendations for effective dietary strategies addressing both the dietary glycemic index and load in clinical practice. Design: An advanced Pubmed search was conducted. A total of 10 randomized controlled studies met the inclusion criteria. Six studies compared low-GI with higher GI meals, three included studies that compared reduced carbohydrate content with higher carbohydrate content, and one study compared meals of low-GI (with high or low fiber) with meals of higher GI (with high or low fiber). Results: Most of the clinical trials resulted in significant improvement (p < 0.05) of postprandial hyperglycemia. Conclusions: Either reducing the amount of carbohydrate in a meal or increasing consumption of soluble fiber has a favorable effect on postprandial glucose excursions.

Association between breakfast skipping and postprandial hyperglycaemia after lunch in healthy young individuals

Breakfast skipping has become an increasing trend in the modern lifestyle and may play a role in obesity and type 2 diabetes. In our previous studies in healthy young individuals, a single incident of breakfast skipping increased the overall 24-h blood glucose and elevated the postprandial glycaemic response after lunch; however, it was difficult to determine whether this response was due to breakfast omission or the extra energy (i.e. lunch plus breakfast contents). The present study aimed to assess the postprandial glycaemic response and to measure their hormone levels when healthy young individuals had identical lunch and dinner, and the 24-h average blood glucose as a secondary outcome. Nine healthy young men (19−24 years) participated in two-meal trials: with breakfast (three-meal condition) or without breakfast (breakfast skipping condition). During the meals, each individual’s blood glucose was continuously monitored. Skipping breakfast resulted in a significantly higher (P &lt; 0·001) glycaemic response after lunch as compared with the glycaemic response after an identical lunch when breakfast was consumed. Despite the difference in the total energy intake, the 24-h average blood glucose was similar between the two-meal conditions (P = 0·179). Plasma NEFA level was significantly higher (P &lt; 0·05) after lunch when breakfast was omitted, and NEFA level positively correlated with the postprandial glycaemic response (r 0·631, P &lt; 0·01). In conclusion, a single incident of breakfast skipping increases postprandial hyperglycaemia, and associated impaired insulin response, after lunch. The present study showed that skipping breakfast influences glucose regulation even in healthy young individuals.

Critical and emerging topics in dietary carbohydrates and health

Multiple factors may affect the metabolic fate of carbohydrates. Today, well-standardised and accepted methods may allow for the definitions of the changes in the glucose and insulin curves following the ingestion of either carbohydrate-based and other foods. More debate is still raised on the clinical meaning of these classifications when used at a population level, while emphasis is raised on the approach to carbohydrate metabolism on an individual basis. Within these ranges of applications, other compounds, such as plant polyphenols, may favourably add synergic effects through the modulation of carbohydrate digestion and glucose metabolic steps, resulting in lowering postprandial glucose and insulin levels. Finally, a growing knowledge suggests that the balance of dietary fructose and individual physical activity represent the key point to address the compound towards either positive, energy sparing effects, or a degenerative metabolic burden. The carbohydrate quality within a whole dietary and lifestyle pattern may therefore challenge the individual balance towards health or disease.

Restricting carbohydrates at breakfast is sufficient to reduce 24-hour exposure to postprandial hyperglycemia and improve glycemic variability

BACKGROUND

The breakfast meal often results in the largest postprandial hyperglycemic excursion in people with type 2 diabetes.

OBJECTIVE

Our purpose was to investigate whether restricting carbohydrates at breakfast would be a simple and feasible strategy to reduce daily exposure to postprandial hyperglycemia.

DESIGN

Adults with physician-diagnosed type 2 diabetes [n = 23; mean ± SD age: 59 ± 11 y; glycated hemoglobin: 6.7% ± 0.6%; body mass index (kg/m2): 31 ± 7] completed two 24-h isocaloric intervention periods in a random order. Participants consumed one of the following breakfasts: 1) a very-low-carbohydrate high-fat breakfast (LCBF; <10% of energy from carbohydrate, 85% of energy from fat, 15% of energy from protein) or 2) a breakfast with dietary guidelines-recommended nutrient profile (GLBF; 55% of energy from carbohydrate, 30% of energy from fat, 15% of energy from protein), with the same lunch and dinner provided. Continuous glucose monitoring was used to assess postprandial glucose responses over 24 h, and visual analog scales were used to assess ratings of hunger and fullness.

RESULTS

The LCBF significantly reduced postprandial hyperglycemia after breakfast (P < 0.01) and did not adversely affect glycemia after lunch or dinner. As such, overall postprandial hyperglycemia (24-h incremental area under the glucose curve) and glycemic variability (mean amplitude of glycemic excursions) were reduced with the LCBF (24-h incremental area under the glucose curve: -173 ± 361 mmol/L; P = 0.03; mean amplitude of glycemic excursions: -0.4 ± 0.8 mmol/L · 24 h; P = 0.03) compared with the GLBF. Premeal hunger was lower before dinner with the LCBF than with the GLBF (P-interaction = 0.03).

CONCLUSIONS

A very-low-carbohydrate high-fat breakfast lowers postbreakfast glucose excursions. The effects of this simple strategy appear to be sufficient to lower overall exposure to postprandial hyperglycemia and improve glycemic variability. Longer-term interventions are warranted. This trial was registered at clinicaltrials.gov as NCT02982330.

A carbohydrate-reduced high-protein diet acutely decreases postprandial and diurnal glucose excursions in type 2 diabetes patients

The aim of the study was to assess whether a simple substitution of carbohydrate in the conventionally recommended diet with protein and fat would result in a clinically meaningful reduction in postprandial hyperglycaemia in subjects with type 2 diabetes mellitus (T2DM). In all, sixteen subjects with T2DM treated with metformin only, fourteen male, with a median age of 65 (43-70) years, HbA1c of 6·5 % (47 mmol/l) (5·5-8·3 % (37-67 mmol/l)) and a BMI of 30 (sd 4·4) kg/m2 participated in the randomised, cross-over study. A carbohydrate-reduced high-protein (CRHP) diet was compared with an iso-energetic conventional diabetes (CD) diet. Macronutrient contents of the CRHP/CD diets consisted of 31/54 % energy from carbohydrate, 29/16 % energy from protein and 40/30 % energy from fat, respectively. Each diet was consumed on 2 consecutive days in a randomised order. Postprandial glycaemia, pancreatic and gut hormones, as well as satiety, were evaluated at breakfast and lunch. Compared with the CD diet, the CRHP diet reduced postprandial AUC of glucose by 14 %, insulin by 22 % and glucose-dependent insulinotropic polypeptide by 17 % (all P<0·001), respectively. Correspondingly, glucagon AUC increased by 33 % (P<0·001), cholecystokinin by 24 % (P=0·004) and satiety scores by 7 % (P=0·035), respectively. A moderate reduction in carbohydrate with an increase in fat and protein in the diet, compared with an energy-matched CD diet, greatly reduced postprandial glucose excursions and resulted in increased satiety in patients with well-controlled T2DM.

Insulin in Type 1 and Type 2 Diabetes-Should the Dose of Insulin Before a Meal be Based on Glycemia or Meal Content?

The aim of this review was to investigate existing guidelines and scientific evidence on determining insulin dosage in people with type 1 and type 2 diabetes, and in particular to check whether the prandial insulin dose should be calculated based on glycemia or the meal composition, including the carbohydrates, protein and fat content in a meal. By exploring the effect of the meal composition on postprandial glycemia we demonstrated that several factors may influence the increase in glycemia after the meal, which creates significant practical difficulties in determining the appropriate prandial insulin dose. Then we reviewed effects of the existing insulin therapy regimens on glycemic control. We demonstrated that in most existing algorithms aimed at calculating prandial insulin doses in type 1 diabetes only carbohydrates are counted, whereas in type 2 diabetes the meal content is often not taken into consideration. We conclude that prandial insulin doses in treatment of people with diabetes should take into account the pre-meal glycemia as well as the size and composition of meals. However, there are still open questions regarding the optimal way to adjust a prandial insulin dose to a meal and the possible benefits for people with type 1 and type 2 diabetes if particular parameters of the meal are taken into account while calculating the prandial insulin dose. The answers to these questions may vary depending on the type of diabetes.

Variable Glycemic Responses to Intact and Hydrolyzed Milk Proteins in Overweight and Obese Adults Reveal the Need for Precision Nutrition

Background

Dietary modifications can contribute to improved pancreatic β cell function and enhance glycemic control.

Objectives

The objectives of this study were as follows: 1) to investigate the potential of milk protein hydrolysates to modulate postprandial glucose response; 2) to assess individual responses; and 3) to explore the inter- and intraindividual reproducibility of the response.

Methods

A 14-d randomized crossover study investigated interstitial glucose levels of participants in response to 12% w/v milk protein drinks (intact caseinate and casein hydrolysate A and B) consumed in random order with a 2-d washout between treatments. Milk protein drinks were consumed immediately prior to study breakfast and evening meals. Twenty participants (11 men, 9 women) aged 50 ± 8 y with a body mass index (in kg/m2) of 30.2 ± 3.1 were recruited. Primary outcome was glucose levels assessed at 15-min intervals with the use of glucose monitors.

Results

Repeated-measures ANOVA revealed that for breakfast there was a significant difference across the 3 treatment groups (P = 0.037). The ability to reduce postprandial glucose was specific to casein hydrolysate B in comparison with intact caseinate (P = 0.039). However, despite this significant difference, further examination revealed that only 3 out of 18 individuals were classified as responders (P < 0.05). High intraclass correlation coefficients were obtained for glucose response to study meals (intraclass correlation coefficient: 0.892 for breakfast with intact caseinate). The interindividual CVs were higher than the intraindividual CVs. Mean inter- and intraindividual CVs were 19.4% and 5.7%, respectively, for breakfast with intact caseinate.

Conclusion

Ingestion of a specific casein hydrolysate successfully reduced the postprandial glucose response; however, at an individual level only 3 participants were classified as responders, highlighting the need for precision nutrition. Exploration of high interindividual responses to nutrition interventions is needed, in combination with the development of precision nutrition, potentially through an n-of-1 approach. This clinical trial was registered as ISRCTN61079365 (https://www.isrctn.com/).

Glucose Variability and Coronary Artery Disease

Fasting blood glucose, postprandial blood glucose and glycated haemoglobin are considered three important indicators for diabetes treatment. There is increasing evidence that glucose variability has more detrimental effects on the coronary arteries than does chronic sustained hyperglycaemia. This overview summarises recent findings in the field of glucose variability and its possible relationship with coronary artery disease. Glucose variability may be a marker of increased progression of coronary disease and plaque vulnerability. It might be a potential new therapeutic target for secondary prevention of coronary artery disease. Future studies will focus on the early detection and control of glucose variability to improve the clinical outcomes in patients with coronary artery disease.

Acute Effects of Dietary Carbohydrate Restriction on Glycemia, Lipemia and Appetite Regulating Hormones in Normal-Weight to Obese Subjects

Postprandial responses to food are highly dependent on the macronutrient composition of the diet. We investigated the acute effects of transition from the recommended moderately high carbohydrate (HC) diet towards a carbohydrate-reduced high-protein (CRHP) diet on postprandial glycemia, insulinemia, lipemia, and appetite-regulating hormones in non-diabetic adults. Fourteen subjects, including five males (Mean ± SD: age 62 ± 6.5; BMI 32 ± 7.6 kg/m²; hemoglobin A_1c (HbA_1c) 40 ± 3.0 mmol/mol; HOMA2-IR 2.1 ± 0.9) were included in this randomized, cross-over study. Iso-caloric diets were consumed for two consecutive days with a median wash-out period of 21 days (range 2–8 weeks) between diets (macronutrient energy composition: CRHP/HC; 31%/54% carbohydrate, 29%/16% protein, 40%/30% fat). Postprandial glucose, insulin secretion rate (ISR), triglycerides (TGs), non-esterified fatty acids (NEFAs), and satiety ratings were assessed after ingestion of breakfast (Br) and lunch (Lu), and gut hormones and glucagon were assessed after ingestion of Br. Compared with the HC diet, the CRHP diet reduced peak glucose concentrations (Br 11%, p = 0.024; Lu 11%, p < 0.001), glucose excursions (Br 80%, p = 0.20; Lu 85%, p < 0.001), and ISR (Br 31%; Lu 64%, both p < 0.001) whereas CRHP, as compared with HC, increased glucagon-like peptide-1 (Br 27%, p = 0.015) and glucagon values (Br 249%, p < 0.001). NEFA and TG levels increased in the CRHP diet as compared with the HC diet after Br, but no difference was found after Lu (NEFA Br 22%, p < 0.01; TG Br 42%, p = 0.012). Beta-cell glucose sensitivity, insulin clearance, cholecystokinin values, and subjective satiety ratings were unaffected. It is possible to achieve a reduction in postprandial glycemia and insulin without a deleterious effect on beta-cell glucose sensitivity by substituting part of dietary carbohydrate with iso-caloric protein and fat in subjects without type 2 diabetes mellitus (T2DM). The metabolic effects are more pronounced after the second meal.

Effect of diurnal variations in the carbohydrate and fat composition of meals on postprandial glycemic response in healthy adults: a novel insight for the second-meal phenomenon

Background

Meals, particularly carbohydrate intake, determine diurnal blood glucose (BG) excursions. However, the effect of meals with variable carbohydrate content on diurnal BG excursions remains poorly understood, despite routine consumption of meals that vary daily.

Objective

The aim of this study was to verify our hypothesis that glycemic response is elevated when a meal with a higher carbohydrate content follows a meal with a lower carbohydrate content.

Design

This was a secondary analysis of a study whose primary endpoint was energy metabolism (e.g., energy expenditure and substrate oxidation). This crossover study was designed to test BG responses to 3 types of meals with different macronutrient contents [regular meals (R), meals with a high-carbohydrate breakfast (CB), and meals with a high-fat breakfast (FB)] using a continuous glucose monitoring system. The R test included 3 meals/d with the same macronutrient composition; the CB test, a high-carbohydrate meal at breakfast, a high-fat meal at lunch, and a high-carbohydrate meal at dinner; and the FB test, a high-fat meal at breakfast, a high-carbohydrate meal at lunch, and a high-carbohydrate meal at dinner. Each test had similar daily macronutrient compositions, except CB and FB had larger variations in carbohydrate content than R. Fourteen healthy young men were tested in random order and underwent whole-body indirect calorimetry.

Results

Daily peak BG concentrations were higher for the CB (mean ± SD: 143.9 ± 25.3 mg/dL) and FB (140.2 ± 24.8 mg/dL) conditions than for the R condition (127.5 ± 15.7 mg/dL). Postprandial BG peaks after a high-carbohydrate meal were ∼20 mg/dL higher when a previous meal was relatively high-fat than when not high-fat (P < 0.05 for all). A multiple regression analysis indicated that the postprandial glycemic response was negatively associated with the preprandial respiratory quotient.

Conclusions

Our findings indicate that switching from high-fat to high-carbohydrate meals contributes to larger postprandial BG excursions, along with alterations in prioritization of carbohydrate utilization. This study was registered at the UMIN Clinical Trials Registry as UMIN000028895.

Effects of 6 vs 3 eucaloric meal patterns on glycaemic control and satiety in people with impaired glucose tolerance or overt type 2 diabetes: A randomized trial

BACKGROUND/OBJECTIVES

The study aimed to compare the effects of two eucaloric meal patterns (3 vs 6 meals/day) on glycaemic control and satiety in subjects with impaired glucose tolerance and plasma glucose (PG) levels 140-199mg/dL at 120min (IGT-A) or PG levels 140-199mg/dL at 120min and >200mg/dL at 30/60/90min post-oral glucose load on 75-g OGTT (IGT-B), or overt treatment-naïve type 2 diabetes (T2D).

SUBJECTS/METHODS

In this randomized crossover study, subjects with IGT-A (n=15, BMI: 32.4±5.2kg/m²), IGT-B (n=20, BMI: 32.5±5kg/m²) or T2D (n=12, BMI: 32.2±5.2kg/m²) followed a weight-maintenance diet (45% carbohydrates, 20% proteins, 35% fats) in 3 or 6 meals/day (each intervention lasting 12 weeks). Anthropometrics, diet compliance and subjective appetite were assessed every 2 weeks. OGTT and measurements of HbA1c and plasma lipids were performed at the beginning and end of each intervention period.

RESULTS

Body weight and physical activity levels remained stable throughout the study. In T2D, HbA1c and PG at 120min post-OGTT decreased with 6 vs 3 meals (P<0.001 vs P=0.02, respectively). The 6-meal intervention also improved post-OGTT hyperinsulinaemia in IGT-A subjects and hyperglycaemia in IGT-B subjects. In all three groups, subjective hunger and desire to eat were reduced with 6 vs 3 meals/day (P<0.05). There were no differences in HOMA-IR or plasma lipids between interventions.

CONCLUSION

Although weight loss remains the key strategy in hyperglycaemia management, dietary measures such as more frequent and smaller meals may be helpful for those not sufficiently motivated to adhere to calorie-restricted diets. Our study shows that 6 vs 3 meals a day can increase glycaemic control in obese patients with early-stage T2D, and may perhaps improve and/or stabilize postprandial glucose regulation in prediabetes subjects.

Semaglutide improves postprandial glucose and lipid metabolism, and delays first-hour gastric emptying in subjects with obesity

AIM

To investigate the effects of semaglutide on fasting and postprandial glucose and lipid responses, and on gastric emptying.

MATERIALS AND METHODS

This was a randomized, double-blind, placebo-controlled, 2-period, crossover trial. Subjects with obesity (N = 30) received once-weekly subcutaneous semaglutide, dose-escalated to 1.0 mg, or placebo. After each 12-week treatment period, glucose and lipid metabolism were assessed before and after standardized meals. Gastric emptying (paracetamol absorption test) and peptide YY (PYY) response were also assessed.

RESULTS

Semaglutide treatment significantly lowered fasting concentrations of glucose and glucagon, and increased insulin vs placebo (estimated treatment ratio: 0.95 [95% confidence interval: 0.91, 0.98]; 0.86 [0.75, 0.98]; 1.45 [1.20, 1.75], respectively). Postprandial glucose metabolism significantly improved with semaglutide vs placebo (incremental area under the curve 0 to 5 hours [iAUC0-5h ]; estimated treatment difference: glucose -1.34 mmol h/L [-2.42, -0.27]; insulin -921 pmol h/L [-1461, -381]; C-peptide -1.42 nmol h/L [-2.33, -0.51]). Fasting and postprandial lipid metabolism improved with semaglutide vs placebo. First-hour gastric emptying after the meal was delayed with semaglutide vs placebo (AUC0-1h ; estimated treatment ratio: 0.73 [0.61, 0.87]); this may have contributed to the lower postprandial glucose increase in semaglutide-treated subjects. Overall gastric emptying (AUC0-5h ) was not statistically different between treatments. Fasting and postprandial PYY responses were significantly lower with semaglutide vs placebo (P = .0397 and P = .0097, respectively).

CONCLUSION

Semaglutide improved fasting and postprandial glucose and lipid metabolism. Overall gastric emptying was similar to that with placebo; however, the observed first-hour delay with semaglutide may contribute to a slower entry of glucose into the circulation.

Sodium-glucose co-transporter-2 inhibitor use and dietary carbohydrate intake in Japanese individuals with type 2 diabetes: A randomized, open-label, 3-arm parallel comparative, exploratory study

This study investigated the safety and efficacy of the sodium-glucose co-transporter-2 (SGLT2) inhibitor luseogliflozin with differing carbohydrate intakes in Japanese individuals with type 2 diabetes (T2D). Participants were randomly assigned to 3 carbohydrate-adjusted meals for 14 days (days 1-14; a high carbohydrate [HC; 55% total energy carbohydrate] and high glycaemic index [HGI] meal; an HC [55% total energy carbohydrate] and low glycaemic index [LGI] meal; or a low carbohydrate [LC; 40% total energy carbohydrate] and HGI meal). All participants received luseogliflozin for the last 7 days (days 8-14), continuous glucose monitoring (CGM) before and after luseogliflozin treatment (days 5-8 and days 12-15) and blood tests on days 1, 8 and 15. Luseogliflozin significantly decreased the area under the curve and mean of CGM values in all 3 groups similarly. Fasting plasma glucose, insulin and glucagon were similar at all time points. Ketone bodies on day 15 were significantly higher in the LC-HGI group compared with the HC-HGI and HC-LGI groups. In conclusion, luseogliflozin has similar efficacy and safety in Japanese people with T2D when meals contain 40% to 55% total energy carbohydrate, but a strict LC diet on this class of drug should be avoided to prevent SGLT2 inhibitor-associated diabetic ketoacidosis.

Effect of carbohydrate restriction in the first meal after an overnight fast on glycemic control in people with type 2 diabetes: a randomized trial

BACKGROUND

People with type 2 diabetes are advised to consume an even meal distribution of carbohydrate. Whether this distribution is optimal is unknown.

OBJECTIVE

Our objective was to show that omitting carbohydrate in the first meal after a fast would lead to an augmented lunch response.

DESIGN

Two diets of 1-d duration that differed only in the breakfast-meal composition (carbohydrate or no carbohydrate) were consumed on sequential days in a randomized crossover study. The procedure was repeated in the alternate order 1 wk later. Blood glucose concentrations were tested with the use of continuous glucose monitoring. The primary endpoints were the percentage of time spent with a blood glucose concentration >10 mmol/L (%T >10) and peak blood glucose (G_max). The following 45 adults with type 2 diabetes were recruited: subjects with glycated hemoglobin (HbA1c) ≤7% and subjects with HbA1c ≥8%. Twenty-eight adults completed the study.

RESULTS

The daily G_max was significantly lower after the no-carbohydrate breakfast than after the carbohydrate breakfast (11.0 ± 0.4 and 12.1 ± 0.4 mmol/L, respectively; P = 0.003) whereas the %T >10 throughout the day was a nonsignificant 22% less after the no-carbohydrate breakfast than after the carbohydrate breakfast (13% ± 10% compared with 10% ± 8%; P = 0.09). G_max over 5 h after breakfast was significantly lower after the no-carbohydrate meal (by 1.9 ± 0.4 mmol/L; P < 0.001), and the %T >10 was lower after the no-carbohydrate meal than after the carbohydrate meal (11% ± 3% compared with 26% ± 4%, respectively; P < 0.001).

CONCLUSIONS

The withholding of carbohydrate in the first meal results in significantly decreased G_max after the meal, but the lunch response is not affected. Overall daily control is not significantly improved. This trial was registered at the Australian New Zealand Clinical Trials Registry as ACTRN12609000331235.

Effect of meal frequency on glucose and insulin levels in women with polycystic ovary syndrome: a randomised trial

BACKGROUND/OBJECTIVES

The aim of the study was to compare the effect of two-meal patterns (three vs six meals per day) on glucose and insulin levels in women with polycystic ovary syndrome (PCOS).

SUBJECTS/METHODS

In a randomised, crossover, 24-week study, 40 women with PCOS, aged 27±6 years, body mass index 27±6 kg/m(2), followed a weight maintenance diet (% carbohydrates:protein:fat, 40:25:35), consumed either as a three- or a six-meal pattern, with each intervention lasting for 12 weeks. Anthropometric measurements, diet compliance and subjective hunger, satiety and desire to eat were assessed biweekly. All women underwent an oral glucose tolerance test (OGTT) with 75 g glucose for measurement of plasma glucose and insulin at the beginning and end of each intervention. HaemoglobinA1c (HbA1c), blood lipids and hepatic enzymes were measured at the beginning and end of each intervention.

RESULTS

Body weight remained stable throughout the study. Six meals decreased significantly fasting insulin (P=0.014) and post-OGTT insulin sensitivity (Matsuda index, P=0.039) vs three meals. After incorporation of individual changes over time, with adjustment for potential confounders, the only variable that remained significant was the Matsuda index, which was then used in multivariate analysis and general linear models. Six meals improved post-OGTT insulin sensitivity independently of age and body weight vs three meals (P=0.012). No significant differences were found between six and three meals for glucose, HbA1c, blood lipids, hepatic enzymes, subjective desire to eat and satiety.

CONCLUSIONS

Six meals had a more favourable effect on post-OGTT insulin sensitivity in women with PCOS compared with isocaloric three meals.

Nocturnal eating disturbs phosphorus excretion in young subjects: a randomized crossover trial

BACKGROUND

Nocturnal eating have recently increased. Serum phosphorus levels and regulators of phosphorus have circadian variations, so it is suggested that the timing of eating may be important in controlling serum phosphorus levels. However, there have been no reports on the effects of nocturnal eating on phosphorus metabolism. The objective was to evaluate the effects of nocturnal eating on phosphorus metabolism.

METHODS

Fourteen healthy men participated in two experimental protocols with differing dinner times. The design of this study was a crossover study. The subjects were served test meals three times (breakfast; 07:30 h, lunch; 12:30 h, dinner; 17:30 or 22:30 h) a day. Blood and urine samples were collected to assess diurnal variation until the following morning.

RESULTS

The following morning, fasting serum phosphorus levels in the late dinner group were markedly higher than those in the early dinner group (p < 0.001), although serum calcium levels were maintained at approximately constant levels throughout the day in both groups. Fluctuations in urinary calcium excretion were synchronized with the timing of dinner eating, however, fluctuations in urinary phosphorus excretion were not synchronized. Urinary phosphorus excretions at night were inhibited in the late dinner group. In the late dinner group, intact parathyroid hormone levels didn't decrease, and they were significantly higher in this group compared with the early dinner group at 20:00 h (p = 0.004). The following morning, fasting serum fibroblast growth factor 23 levels in the late dinner group had not changed, but those in the early dinner group were significantly increased (p = 0.003). Serum free fatty acid levels before dinner were significantly higher in the late dinner group compared with the early dinner group.

CONCLUSIONS

Our results indicate that nocturnal eating inhibits phosphorus excretion. It is suggested that nocturnal eating should be abstained from to manage serum phosphorus levels to within an adequate range.

The effects of muffins enriched with sour cherry pomace on acceptability, glycemic response, satiety and energy intake: a randomized crossover trial

BACKGROUND

Sour cherry pomace (CP), a by-product obtained during fruit processing, was used to replace wheat flour in a muffin formula. The influence of the most sensory acceptable muffins on glycemic response, appetite sensation, and energy intake during subsequent meal in a randomized crossover trial was studied.

RESULTS

It is acceptable to incorporate up to 30% CP into muffin formulas. With CP-treated muffins glucose responses were significantly lower at 30, 45, and 60 min intervals, and the incremental peak glucose was 0.40 and 0.60 mmol L(-1) lower than for plain muffins (PM). The CP-enriched muffins showed an incremental area under the blood glucose response curve values lower than that of PM. 20% CP and 30% CP resulted in improved satiety and induced a lower energy intake at a test meal ingested 3 h later (-13.7%; -15.1%) as compared to PM, respectively.

CONCLUSION

CP may be a good functional ingredient for bakery products that assists in managing glucose levels, satiety, and subsequent energy intake in healthy individuals. © 2015 Society of Chemical Industry.

Glycemic Variability: Assessing Glycemia Differently and the Implications for Dietary Management of Diabetes

The primary therapeutic target for diabetes management is the achievement of good glycemic control, of which glycated hemoglobin (HbA1c) remains the standard clinical marker. However, glycemic variability (GV; the amplitude, frequency, and duration of glycemic fluctuations around mean blood glucose) is an emerging target for blood glucose control. A growing body of evidence supports GV as an independent risk factor for diabetes complications. Several techniques have been developed to assess and quantify intraday and interday GV. Additionally, GV can be influenced by several nutritional factors, including carbohydrate quality, quantity; and distribution; protein intake; and fiber intake. These factors have important implications for clinical nutrition practice and for optimizing blood glucose control for diabetes management. This review discusses the available evidence for GV as a marker of glycemic control and risk factor for diabetes complications. GV quantification techniques and the influence of nutritional considerations for diabetes management are also discussed.

Efficacy and safety of lixisenatide in Japanese patients with type 2 diabetes mellitus inadequately controlled by sulfonylurea with or without metformin: Subanalysis of GetGoal-S

Aims/Introduction

This was a subanalysis of Japanese patients included in the glucagon-like peptide-1 receptor agonist AVE0010 in patients with type 2 diabetes mellitus for glycemic control and safety evaluation (GetGoal-S) study – a 24-week, randomized, placebo-controlled study of lixisenatide in patients with type 2 diabetes mellitus inadequately controlled by sulfonylurea with or without metformin.

Materials and Methods

In GetGoal-S, 127 Japanese patients received the once-daily prandial glucagon-like peptide-1 receptor agonist lixisenatide 20 μg/day or a matching placebo. The primary outcome was change in glycated hemoglobin.

Results

At week 24, lixisenatide significantly reduced mean glycated hemoglobin (least squares mean difference vs the placebo −1.1% [12 mmol/mol, P < 0.0001]), and significantly more lixisenatide patients reached glycated hemoglobin targets of <7% (53 mmol/mol) and ≤6.5% (48 mmol/mol) vs the placebo. Lixisenatide produced statistically significant reductions in 2-h postprandial plasma glucose (least squares mean difference vs the placebo −8.51 mmol/L, P < 0.0001) and glucose excursion vs the placebo, and significantly reduced fasting plasma glucose (least squares mean difference vs the placebo −0.65 mmol/L, P = 0.0454). Bodyweight decreased with both lixisenatide and the placebo (least squares mean change −1.12 kg for lixisenatide, −1.02 kg for placebo). The overall incidence of adverse events was similar for lixisenatide and the placebo (84.2 and 82.4%, respectively), the most frequent being gastrointestinal disorders (52.6% for lixisenatide vs 29.4% for placebo). The incidence of symptomatic hypoglycemia was higher with lixisenatide vs the placebo (17.1 and 9.8%, respectively), with no cases of severe symptomatic hypoglycemia in either group.

Conclusions

In the Japanese subpopulation of the GetGoal-S study, lixisenatide produced a significant and clinically relevant improvement in glycated hemoglobin, with a pronounced improvement in postprandial plasma glucose, and a good safety and tolerability profile.

The effect of nopal (Opuntia ficus indica) on postprandial blood glucose, incretins, and antioxidant activity in Mexican patients with type 2 diabetes after consumption of two different composition breakfasts

Nopal is a plant used in traditional Mexican medicine to treat diabetes. However, there is insufficient scientific evidence to demonstrate whether nopal can regulate postprandial glucose. The purpose for conducting this study was to evaluate the glycemic index, insulinemic index, glucose-dependent insulinotropic peptide (GIP) index, and the glucagon-like peptide 1 (GLP-1) index, and the effect of nopal on patients with type 2 diabetes after consumption of a high-carbohydrate breakfast (HCB) or high-soy-protein breakfast (HSPB) on the postprandial response of glucose, insulin, GIP, GLP-1, and antioxidant activity. In study 1, the glycemic index, insulinemic index, GIP index, and GLP-1 index were calculated for seven healthy participants who consumed 50 g of available carbohydrates from glucose or dehydrated nopal. In study 2, 14 patients with type 2 diabetes consumed nopal in HCB or HSPB with or without 300 g steamed nopal. The glycemic index of nopal was 32.5±4, insulinemic index was 36.1±6, GIP index was 6.5±3.0, and GLP-1 index was 25.9±18. For those patients with type 2 diabetes who consumed the HCB+nopal, there was significantly lower area under the curve for glucose (287±30) than for those who consumed the HCB only (443±49), and lower incremental area under the curve for insulin (5,952±833 vs 7,313±1,090), and those patients with type 2 diabetes who consumed the HSPB avoided postprandial blood glucose peaks. Consumption of the HSPB+nopal significantly reduced the postprandial peaks of GIP concentration at 30 and 45 minutes and increased the antioxidant activity after 2 hours measured by the 2,2-diphenyl-1-picrilhidracyl method. These findings suggest that nopal could reduce postprandial blood glucose, serum insulin, and plasma GIP peaks, as well as increase antioxidant activity in healthy people and patients with type 2 diabetes.

24-hour glucose profiles on diets varying in protein content and glycemic index

Evidence is increasing that the postprandial state is an important factor contributing to the risk of chronic diseases. Not only mean glycemia, but also glycemic variability has been implicated in this effect. In this exploratory study, we measured 24-h glucose profiles in 25 overweight participants in a long-term diet intervention study (DIOGENES study on Diet, Obesity and Genes), which had been randomized to four different diet groups consuming diets varying in protein content and glycemic index. In addition, we compared 24-h glucose profiles in a more controlled fashion, where nine other subjects followed in random order the same four diets differing in carbohydrate content by 10 energy% and glycemic index by 20 units during three days. Meals were provided in the lab and had to be eaten at fixed times during the day. No differences in mean glucose concentration or glucose variability (SD) were found between diet groups in the DIOGENES study. In the more controlled lab study, mean 24-h glucose concentrations were also not different. Glucose variability (SD and CONGA1), however, was lower on the diet combining a lower carbohydrate content and GI compared to the diet combining a higher carbohydrate content and GI. These data suggest that diets with moderate differences in carbohydrate content and GI do not affect mean 24-h or daytime glucose concentrations, but may result in differences in the variability of the glucose level in healthy normal weight and overweight individuals.

Assessment guidance of carbohydrate counting method in patients with type 2 diabetes mellitus

AIMS

We evaluated the application of the method of carbohydrate counting performed by 21 patients with type 2 diabetes, 1 year later attending a guidance course.

METHODS

Participants answered a questionnaire to assess patients' adhesion to carbohydrate counting as well as to identify habit changes and the method's applicability, and values of glycated hemoglobin were also analyzed.

RESULTS

Most participants (76%) were females, and 25% of them had obesity degree III. There was a statistically significant decrease in glycated hemoglobin from 8.42±0.02% to 7.66±0.01% comparing values before and after counseling. We observed that although patients stated that the method was difficult they understood that carbohydrate counting could allow them make choices and have more freedom in their meals; we also verified if they understood accurately how to replace some foods used regularly in their diets and most patients correctly chose replacements for the groups of bread (76%), beans (67%) and noodles (67%).

CONCLUSIONS

We concluded that participation in the course led to improved blood glucose control with a significant reduction of glycated hemoglobin, better understanding of food groups and the adoption of healthier eating habits.

Diurnal eating rhythms: association with long-term development of diabetes in the 1946 British birth cohort

BACKGROUND AND AIMS

Few studies have described the association between time-of-day of macronutrient intake and diabetes. This study examined the prospective association between time-of-day and nutrient composition of eating occasions in relation to diabetes incidence in the 1946 British birth cohort.

METHODS AND RESULTS

The study included 1618 survey members who completed dietary assessment at age 43 (1989) and for whom data on glycosylated haemoglobin at age 53 years (1999) were available. Diet was assessed using 5d estimated diaries, divided into seven meal slots: breakfast, mid-morning, lunch, mid-afternoon, dinner, late evening and extras. Diabetes was defined by glycosylated haemoglobin (HbA1c) ≥ 6.5% or diabetes medication use. The association between time-of-day of macronutrient intake at age 43 years and diabetes at age 53 years was assessed using logistic multivariate nutrient density models after adjustment for potential confounders. There were 66 cases of diabetes at age 53 years. Survey members with diabetes obtained 50.4% of their energy from carbohydrate at breakfast compared to 55.9% in survey members without diabetes (P = 0.001). Increasing carbohydrate intake at breakfast at the expense of fat was related to lower odds ratio (OR) of diabetes (OR = 0.86; 95%CI = 0.79-0.93; P < 0.001). This relationship was attenuated after adjustment for body mass index and waist circumference.

CONCLUSION

Increasing energy intake from carbohydrate at the expense of fat at breakfast is inversely associated with 10-year diabetes incidence. However, further studies are required to elucidate whether the type or source of carbohydrates or fat influences the above association.

Association of high carbohydrate versus high fat diet with glycated hemoglobin in high calorie consuming type 2 diabetics

Background

Since both dietary carbohydrate and fatty acids separately affect carbohydrate metabolism, how dietary macronutrients distribution may have different effects on carbohydrate metabolism pathways and regulation of blood glucose especially in diabetic patients.

Methods

In this cross-sectional study 750 type 2 diabetic patients (261 men and 489 women, aged 35–65 years),who at least two years were followed in Diabetes and Metabolic disease Clinic of Tehran University of Medical Sciences, were recruited according to inclusion and exclusion criteria by simple sampling. Dietary data were collected by a validated food frequency questionnaire. Other variables were anthropometric measurements, Stress, physical activity level, Biochemical analyses including fasting and postprandial plasma glucose, Glycated hemoglobin, total cholesterol, low and high density lipoproteins, triglycerides and 25-hydoxy D₃. Linear regression models were used to assess the association of covariates with the mean concentrations of HbA_1C in quintiles and multivariate linear regression model was used to distinguish the impacts of dietary macronutrient composition of the diet.

Results

Carbohydrate and dietary fiber intakes were inversely (P: < 0.0001 and 0.003 respectively) and dietary amount and proportion of saturated, mono-unsaturated and poly-unsaturated fatty were positively (P: < 0.0001, 0.03, 0.01 and 0.01 respectively) associated with HbA_1C concentrations.

Multivariate linear regression macronutrient density model that controlled for age, sex, diabetes duration and calorie intake showed that carbohydrate was inversely associated with HbA_1C (P < 0.0001, R² = 15%). Results were also the same in the other three models adjusted for stress and exercise levels in model 2, waist circumference and sum of meals in model 3 and serum triglyceride and 25-hydroxy vitamin D in model 4(P < .0001, <.0001 and 0.0003 respectively). Calorie intake of 25 Kcal/body weight was identified as a cut of point of the negative effect of dietary carbohydrate and 30 for the positive effect of fat on HbA1c respectively (P = 0.04 and 0.03). Moreover, carbohydrate intake was positively (β = 0.08, P = 0.01) and protein (β = −0.04, P < 0.0001), SAFA (β = −0.04, P < 0.0001) and MUFA (β = −0.02, 0.07) proportion were negatively associated with increment in calorie intake.

Conclusion

This study showed that the substitution of fat for carbohydrate is associated with low concentrations of HbA1c in high calorie consuming type 2 diabetic patients.

Continuous glucose monitoring and cognitive performance in type 2 diabetes

BACKGROUND

Type 2 diabetes is associated with reductions in cognitive function that are associated with glycated hemoglobin (HbA1c) levels, but there is no information on whether cognition is related to postmeal glucose spikes. We explored the relationship of cognition to glucose levels measured by a continuous glucose monitoring system (CGMS) both before and after a weight loss diet.

SUBJECTS AND METHODS

Forty-four white subjects with type 2 diabetes (59.0 ± 6.2 years old; body mass index, 32.8 ± 4.2 kg/m(2); HbA1c, 6.9 ± 1.0%) completed an 8-week energy-restricted (approximately 6-7 MJ, 30% deficit) diet. Cognitive functioning (short-term memory, working memory, speed of processing [inspection time], psychomotor speed, and executive function) was assessed during four practice sessions, baseline, and Week 8. Parallel glucose levels were attained using the CGMS in 27 subjects. Outcomes were assessed by fasting blood glucose (FBG), postprandial peak glucose (G(max)), time spent >12 mmol/L (T > 12), and 24-h area under the glucose curve (AUC(24)).

RESULTS

Despite a fall in FBG of 0.65 mmol/L after 8 weeks, digits backward results correlated with FBG at both Week 0 and Week 8 (r = -0.43, P < 0.01 and r = -0.32, P < 0.01, respectively). Digits forward results correlated with FBG (r = -0.39, P < 0.01), G(max) (r = -0.46, P < 0.05), and AUC(24) (r = -0.50, P < 0.01) at Week 0 and FBG (r = -0.59, P < 0.001), G(max) (r = 0.37, P = 0.01), AUC(24) (r = -0.41, P < 0.01), and percentage weight loss (r = 0.31, P < 0.01) at Week 8. Cognitive function was not altered by weight loss, gender, baseline lipid levels, or premorbid intelligence levels (National Adult Reading Test).

CONCLUSIONS

FBG, G(max,) and AUC(24) were related to cognitive function and an energy-restricted diet for 8 weeks did not alter this relationship.

Postprandial hyperglycemia is highly prevalent throughout the day in type 2 diabetes patients

AIM

Although postprandial hyperglycemia is recognized as an important target in type 2 diabetes treatment, information on the prevalence of postprandial hyperglycemia throughout the day is limited. Therefore, we assessed the prevalence of hyperglycemia throughout the day in type 2 diabetes patients and healthy controls under standardized dietary, but otherwise free-living conditions.

METHODS

60 male type 2 diabetes patients (HbA(1c) 7.5±0.1% [58±1 mmol/mol]) and 24 age- and BMI-matched normal glucose tolerant controls were recruited to participate in a comparative study of daily glycemic control. During a 3-day experimental period, blood glucose concentrations throughout the day were assessed by continuous glucose monitoring.

RESULTS

Type 2 diabetes patients experienced hyperglycemia (glucose concentrations >10 mmol/L) 38±4% of the day. Even diabetes patients with an HbA(1c) level below 7.0% (53 mmol/mol) experienced hyperglycemia for as much as 24±5% throughout the day. Hyperglycemia was negligible in the control group (3±1%).

CONCLUSION

Hyperglycemia is highly prevalent throughout the day in type 2 diabetes patients, even in those patients with a HbA(1c) level well below 7.0% (53 mmol/mol). Standard medical care with prescription of oral blood glucose lowering medication does not provide ample protection against postprandial hyperglycemia.

The evidence for medical nutrition therapy for type 1 and type 2 diabetes in adults

This article reviews the evidence and nutrition practice recommendations from the American Dietetic Association's nutrition practice guidelines for type 1 and type 2 diabetes in adults. The research literature was reviewed to answer nutrition practice questions and resulted in 29 recommendations. Here, we present the recommendations and provide a comprehensive and systematic review of the evidence associated with their development. Major nutrition therapy factors reviewed are carbohydrate (intake, sucrose, non-nutritive sweeteners, glycemic index, and fiber), protein intake, cardiovascular disease, and weight management. Contributing factors to nutrition therapy reviewed are physical activity and glucose monitoring. Based on individualized nutrition therapy client/patient goals and lifestyle changes the client/patient is willing and able to make, registered dietitians can select appropriate interventions based on key recommendations that include consistency in day-to-day carbohydrate intake, adjusting insulin doses to match carbohydrate intake, substitution of sucrose-containing foods, usual protein intake, cardioprotective nutrition interventions, weight management strategies, regular physical activity, and use of self-monitored blood glucose data. The evidence is strong that medical nutrition therapy provided by registered dietitians is an effective and essential therapy in the management of diabetes.

Contribution of postprandial glucose to excess hyperglycaemia in Asian type 2 diabetic patients using continuous glucose monitoring

BACKGROUND

previous studies examining the contributions of fasting glucose (FG) and postprandial glucose (PPG) to glycated haemoglobin (HbA(1c)) have yielded conflicting results. We aimed to clarify the contributions of PPG to hyperglycaemia in Asian type 2 diabetic patients using continuous glucose monitoring.

METHODS

continuous glucose monitoring was conducted in 121 non-insulin-using type 2 diabetic outpatients, who were divided into five groups according to quintiles of HbA(1c) (ranging from 5.7 to 12.7%). Glucose area under the curve (AUC) above a glucose value of 5.5 mmol/L 24 or 4 h after meals was defined as AUC(total). Glucose AUC above FG or preprandial glucose levels was defined as AUC(PPG). The contribution of PPG to hyperglycaemia was calculated as (AUC(PPG)/AUC(total) × 100%. The contribution of FG or preprandial glucose was calculated as [(AUC(total) - AUC(PPG))/AUC(total)] × 100%.

RESULTS

the contribution of PPG to either 24-h hyperglycaemia or 4-h hyperglycaemia after meals was significantly higher than FG and preprandial glucose in the lowest quintile of HbA(1c) (both p < 0.001). However, no difference was observed in the other four quintiles. Peak PPG and glucose excursions were higher after breakfast than those after lunch and dinner (p < 0.01 for all comparisons).

CONCLUSIONS

in Asian patients with type 2 diabetes, PPG 24 and 4 h after meals was a predominant contributor to excess hyperglycaemia in well-controlled patients and was equally important as FG or preprandial glucose in moderately to poorly controlled patients with mean HbA(1c) up to 10%.

Diabetic gastroparesis and its impact on glycemia

Diabetes is the most common cause of gastroparesis and it is now recognized that the relationship between gastric emptying and glycemia is complex and intertwined. Postprandial blood glucose levels influence, and are influenced by, the rate of gastric emptying, highlighting the difficulty in determining which is the cause and which is the effect. Novel diagnostic techniques and therapeutic strategies have been developed for the management of diabetic gastroparesis. This article highlights recent advances in knowledge about diabetic gastroparesis, with an emphasis on the inter-relationships between disordered gastric motor function on glycemia and vice versa, as well as therapeutic strategies for optimizing glycemic control using modulation of gastric emptying.

Can postprandial blood glucose excursion be predicted in type 2 diabetes?

OBJECTIVE

We investigated the relationship between carbohydrate intake and postprandial blood glucose (BG) levels to determine the most influential meal for type 2 diabetic subjects treated with basal insulin and needing prandial insulin.

RESEARCH DESIGN AND METHODS

Three-day BG profiles for 37 type 2 diabetic subjects, with A1C levels of 7.7%, treated with sulfonylurea and metformin, and well titrated on insulin glargine, were analyzed using a continuous glucose monitoring system. Food intake from 680 meals was recorded and quantified during continuous glucose monitoring.

RESULTS

The median BG excursion (DeltaBG) was higher at breakfast than at lunch or dinner (111 [81; 160] vs. 69.5 [41.5; 106] and 82.5 mg/dl [53; 119] mg/dl, P < 0.0001). There was a weak overall correlation between DeltaBG and carbohydrate intake. Correlation improved when mealtime was taken into account. Simple relationships were established: DeltaBG (mg/dl) = 65 x carbohydrate/body weight + 73 for breakfast (R(2) = 0.20, P < 0.0001); the slope was reduced by half at lunch and by one-third at dinner. Twelve relevant variables likely to affect DeltaBG were integrated into a polynomial equation. This model accounted for 49% of DeltaBG variability. Two groups of patients were identified: responders, in whom DeltaBG was well correlated with carbohydrate intake (R(2) >or= 0.30, n = 8), and nonresponders (R(2) < 0.30, n = 29). Responders exhibited a greater insulinopenic profile than nonresponders.

CONCLUSIONS

The carbohydrate intake in responders clearly drives DeltaBG, whereas, in nonresponders, other factors predominate. This sort of characterization should be used to guide therapeutic choices toward more targeted care with improved type 2 diabetes management.

Influence of oral antidiabetic drugs on hyperglycemic response to foods in persons with type 2 diabetes mellitus as assessed by continuous glucose monitoring system: a pilot study

BACKGROUND

The purpose of this prospective open-label trial was (1) to assess the influence of oral antidiabetic drugs (OAD) on the glycemic index (GI), glucose response curves (GRCs), daily mean plasma glucose (MPG) and (2) to compare the GI of foods in persons with OAD-treated type 2 diabetes mellitus (T2DM) with the respective GI in healthy persons (HP).

METHODS

Tested foods containing 50 g of carbohydrates were eaten for breakfast and dinner after 10 and 4 h of fasting, respectively. Glycemic index, GRC, and MPG were obtained using the CGMS System Gold (CGMS). In T2DM patients [n = 16; age (mean +/- standard error) 56.0 +/- 2.25 years], foods were tested four times: tests 1, 2, and 3 were performed within one week in which placebo was introduced on day 2, and test 4 was carried out five weeks after reintroduction of OAD. Glycemic indexes, GRC, and MPG from tests 1, 2, 3, and 4 were compared. In a control group of 20 HP (age 24.4 +/- 0.71 years), the mean GIs were calculated as the mean from 20 subject-related GIs.

RESULTS

In T2DM patients, subject-related assessment of GIs, GRC, and MPG distinguished persons with and without OAD effect. Nevertheless, the group-related GIs and the MPG on days 2, 8, and 39 showed no significant difference. There was no significant difference between the GIs in OAD-treated T2DM patients (test 4) versus HP (except in apple baby food). Glucose response curves were significantly larger in T2DM patients (test 4) versus HP.

CONCLUSIONS

Determination of GRC and subject-related GI using the CGMS appears to be a potential means for the evaluation of efficacy of OAD treatment. Further studies are underway.