Effect of commercial breakfast fibre cereals compared with corn flakes on postprandial blood glucose, gastric emptying and satiety in healthy subjects: a randomized blinded crossover trial

<p>Abstract</p> <p>Background</p> <p>Dietary fibre food intake is related to a reduced risk of developing diabetes mellitus. However, the mechanism of this effect is still not clear. The aim of this study was to evaluate the effect of commercial fibre cereals on the rate of gastric emptying, postprandial glucose response and satiety in healthy subjects.</p> <p>Methods</p> <p>Gastric emptying rate (GER) was measured by standardized real time ultrasonography. Twelve healthy subjects were assessed using a randomized crossover blinded trial. The subjects were examined after an 8 hour fast and after assessment of normal fasting blood glucose level. Satiety scores were estimated and blood glucose measurements were taken before and at 0, 20, 30, 40, 60, 80, 100 and 120 min after the end of the meal. GER was calculated as the percentage change in the antral cross-sectional area 15 and 90 min after ingestion of sour milk with corn flakes (GER1), cereal bran flakes (GER2) or wholemeal oat flakes (GER3).</p> <p>Results</p> <p>The median value was, respectively, 42% for GER1, 33 % for GER2 and 51% for GER3. The difference between the GER after ingestion of bran flakes compared to wholemeal oat flakes was statistically significant (p = 0.023). The postprandial delta blood glucose level was statistically significantly lower at 40 min (p = 0.045) and 120 min (p = 0.023) after the cereal bran flakes meal. There was no statistical significance between the areas under the curve (AUCs) of the cereals as far as blood glucose and satiety were concerned.</p> <p>Conclusion</p> <p>The result of this study demonstrates that the intake of either bran flakes or wholemeal oat flakes has no effect on the total postprandial blood glucose response or satiety when compared to corn flakes. However, the study does show that the intake of cereal bran flakes slows the GER when compared to oat flakes and corn flakes, probably due to a higher fibre content. Since these products do not differ in terms of glucose response and satiety on healthy subjects, they should be considered equivalent in this respect.</p> <p>Trial registration</p> <p>ISRCTN90535566</p

The effects of progressive resistance training combined with a whey-protein drink and vitamin D supplementation on glycaemic control, body composition and cardiometabolic risk factors in older adults with type 2 diabetes: study protocol for a randomized controlled trial

Background - While physical activity, energy restriction and weight loss are the cornerstone of type 2 diabetes management, less emphasis is placed on optimizing skeletal muscle mass. As muscle is the largest mass of insulin-sensitive tissue and the predominant reservoir for glucose disposal, there is a need to develop safe and effective evidence-based, lifestyle management strategies that optimize muscle mass as well as improve glycaemic control and cardiometabolic risk factors in people with this disease, particularly older adults who experience accelerated muscle loss. Methods/Design - Using a two-arm randomized controlled trial, this 6-month study builds upon the community-based progressive resistance training (PRT) programme Lift for Life® to evaluate whether ingestion of a whey-protein drink combined with vitamin D supplementation can enhance the effects of PRT on glycaemic control, body composition and cardiometabolic health in older adults with type 2 diabetes. Approximately 200 adults aged 50 to 75 years with type 2 diabetes, treated with either diet alone or oral hypoglycaemic agents (not insulin), will be recruited. All participants will be asked to participate in a structured, supervised PRT programme based on the Lift for Life® programme structure, and randomly allocated to receive a whey-protein drink (20 g daily of whey-protein plus 20 g after each PRT session) plus vitamin D supplements (2000 IU/day), or no additional powder and supplements. The primary outcome measures to be collected at baseline, 3 and 6 months will be glycated haemoglobin (HbA1c) and insulin sensitivity (homeostatic model assessment). Secondary outcomes will include changes in: muscle mass, size and intramuscular fat; fat mass; muscle strength and function; blood pressure; levels of lipids, adipokines and inflammatory markers, serum insulin-like growth factor-1 and 25-hydroxyvitamin D; renal function; diabetes medication; health-related quality of life, and cognitive function. Discussion - The findings from this study will provide new evidence on whether increased dietary protein achieved through the ingestion of a whey-protein drink combined with vitamin D supplementation can enhance the effects of PRT on glycaemic control, muscle mass and size, and cardiometabolic risk factors in older adults with type 2 diabetes

Extremely short duration interval exercise improves 24-h glycaemia in men with type 2 diabetes

PurposeReduced-exertion high-intensity interval training (REHIT) is a genuinely time-efficient exercise intervention that improves aerobic capacity and blood pressure in men with type 2 diabetes. However, the acute effects of REHIT on 24-h glycaemia have not been examined.Methods11 men with type 2 diabetes (mean ± SD: age, 52 ± 6 years; BMI, 29.7 ± 3.1 kg/m2; HbA1c, 7.0 ± 0.8%) participated in a randomised, four-trial crossover study, with continual interstitial glucose measurements captured during a 24-h dietary-standardised period following either (1) no exercise (CON); (2) 30 min of continuous exercise (MICT); (3) 10 × 1 min at ~ 90 HRmax (HIIT; time commitment, ~ 25 min); and (4) 2 × 20 s ‘all-out’ sprints (REHIT; time commitment, 10 min).ResultsCompared to CON, mean 24-h glucose was lower following REHIT (mean ± 95%CI: − 0.58 ± 0.41 mmol/L, p = 0.008, d = 0.55) and tended to be lower with MICT (− 0.37 ± 0.41 mmol/L, p = 0.08, d = 0.35), but was not significantly altered following HIIT (− 0.37 ± 0.59 mmol/L, p = 0.31, d = 0.35). This seemed to be largely driven by a lower glycaemic response (area under the curve) to dinner following both REHIT and MICT (− 11%, p  0.9 for both) but not HIIT (− 4%, p = 0.22, d = 0.38). Time in hyperglycaemia appeared to be reduced with all three exercise conditions compared with CON (REHIT: − 112 ± 63 min, p = 0.002, d = 0.50; MICT: -115 ± 127 min, p = 0.08, d = 0.50; HIIT − 125 ± 122 min, p = 0.04, d = 0.54), whilst indices of glycaemic variability were not significantly altered.ConclusionREHIT may offer a genuinely time-efficient exercise option for improving 24-h glycaemia in men with type 2 diabetes and warrants further study

Induction of metabolic syndrome by excess fructose consumption

Fructose is an important nutritive component of foods such as honey and fruit, but this easily available sweetener may contribute to increased caloric consumption from overeating. Fructose is now a major component of the Western diet, with increased consumption associated with obesity, metabolic syndrome, and cardiovascular disorders in observational and short-term intervention studies, mainly in animal models. Rodent studies have identifi ed possible mechanisms for the adverse effects of fructose when ingested in large amounts. Fructose promoted de novo lipogenesis, infl ammation, and increased sympathetic tone. These mechanisms induced hepatic insulin resistance, increased total and visceral fat mass with accumulation of ectopic fat in the liver and skeletal muscle, and dyslipidemia. Fructose reduced leptin and insulin signals for satiety, caused structural and functional damage to the heart and blood vessels, and disrupted the diversity of the gut microbiota. These early effects may initiate the development of the metabolic syndrome. Despite this evidence from rodents, there are few long-term intervention studies in humans, especially at a moderate dose. The defi nition of prudent fructose consumption is needed, but this will require carefully controlled dose–response studies in humans