Coffee Increases Post-Exercise Muscle Glycogen Recovery in Endurance Athletes: A Randomized Clinical Trial

Coffee is one of the most widely consumed beverages worldwide and caffeine is known to improve performance in physical exercise. Some substances in coffee have a positive effect on glucose metabolism and are promising for post-exercise muscle glycogen recovery. We investigated the effect of a coffee beverage after exhaustive exercise on muscle glycogen resynthesis, glycogen synthase activity and glycemic and insulinemic response in a double-blind, crossover, randomized clinical trial. Fourteen endurance-trained men performed an exhaustive cycle ergometer exercise to deplete muscle glycogen. The following morning, participants completed a second cycling protocol followed by a 4-h recovery, during which they received either test beverage (coffee + milk) or control (milk) and a breakfast meal, with a simple randomization. Blood samples and muscle biopsies were collected at the beginning and by the end of recovery. Eleven participants were included in data analysis (age: 39.0 ± 6.0 years; BMI: 24.0 ± 2.3 kg/m2; VO2max: 59.9 ± 8.3 mL·kg−1·min−1; PPO: 346 ± 39 W). The consumption of coffee + milk resulted in greater muscle glycogen recovery (102.56 ± 18.75 vs. 40.54 ± 18.74 mmol·kg dw−1; p = 0.01; d = 0.94) and greater glucose (p = 0.02; d = 0.83) and insulin (p = 0.03; d = 0.76) total area under the curve compared with control. The addition of coffee to a beverage with adequate amounts of carbohydrates increased muscle glycogen resynthesis and the glycemic and insulinemic response during the 4-h recovery after exhaustive cycling exercise.

Low-Glycemic-Index/Load Desserts Decrease Glycemic and Insulinemic Response in Patients with Type 2 Diabetes Mellitus

Diabetes mellitus is a chronic disease whose prevalence is growing worldwide. Consumption of desserts with low glycemic index (GI) and low glycemic load (GL) in a balanced hypocaloric diet has a positive impact on anthropometric and metabolic parameters in patients with type 2 diabetes mellitus (T2DM). The aim of the present study was to evaluate the glycemic and insulinemic response after consumption of desserts with low GI/GL in patients with T2DM. Fifty-one patients consumed either 83 g of the conventional dessert or 150 g of the low GI/GL dessert in random order after an overnight fast. Serum glucose, triglycerides, and insulin were measured at baseline (immediately before ingestion) and at 30, 60, 90, and 120 min postprandially. Subjective appetite measurements were performed using visual analog scales (VASs). There were significant differences at 30 (p = 0.014), 60 (p < 0.001), and 90 min (p < 0.001) postprandially between the two desserts for glucose and at 30 (p = 0.014) and 60 min (p = 0.033) postprandially for insulin. Glucose iAUC was significantly lower in low-GI/GL dessert compared to control (p < 0.001). Serum triglycerides and insulin iAUC did not differ between the two trials. Fullness VAS ratings were significantly higher after consumption of the low-GI/GL dessert compared to conventional dessert. Likewise, hunger, additional food, and additional food quantity VAS ratings were significantly lower after the consumption of the low-GI/GL dessert compared to control. Consumption of low-GI/GL dessert indicates a positive impact on metabolic parameters in T2DM patients.

Glycemic and Insulinemic Response to Two Doses of Resistant Starch Type 4: A Randomized Controlled Crossover Trial

Objectives Resistant starches (RS) have beneficial effects on glucose and insulin responses in the postprandial period following carbohydrate (CHO) consumption. In comparison to resistant starch types 1–3, evidence regarding the effects of resistant starch type 4 (RS4) on metabolic responses is sparse. The primary aim of the current study was to determine whether the glycemic and insulinemic responses to a nutritional RS4 bar (RS4) were lower as compared to a puffed wheat bar (PWB), when provided at the standard testing amounts of 50 g available CHO, as well as at a lower dose of 30 g available CHO. Methods Apparently healthy adults (n = 15; 9 M/6F; 26.1 ± 4.8 yrs) participated in this randomized controlled crossover trial. All participants completed six sessions, consuming a dextrose beverage or nutrition bar at each session. Two doses of 50 g and 30 g of available CHO were tested using dextrose control beverages (50DEX; 30DEX), puffed wheat bars (50PWB; 30PWB) and RS4 bars (50RS4; 30RS4). Participants fasted for 10–12 hrs prior to each visit with a minimum 72hr washout between sessions. Whole blood glucose and plasma insulin were measured at baseline and 10, 20, 30, 60, 90, and 120 min post consumption. Primary outcomes were determined using mixed-effects models in GraphPad Prism 8.0.1. Results Glucose incremental area under the curve (iAUC) was not significantly different between the 50 g conditions (P = 0.054). Insulin iAUC was lower for the 50RS4 bar compared to the 50PWB (Mean ± SD; DEX: 3339 ± 2020, PWB: 3968 ± 2454, RS4: 2046 ± 928.7μIU/mL; P = 0.034), with no differences between 50PWB and 50DEX or 50RS4 and 50DEX (ps &gt; 0.05). Both 30 g bars had lower glucose iAUCs compared to 30DEX (ps &lt; 0.05), with no difference between bars (P &gt; 0.05). The 30RS4 bar elicited a lower insulin iAUC compared to 30PWB and 30DEX (DEX: 2400 ± 1689, PWB: 1855 ± 665.7, RS4: 1115 ± 832.2 μIU/mL; ps &lt; 0.05) with no difference between 30PWB and 30DEX (P &gt; 0.05). Conclusions Resistant starch type 4 elicited a reduced insulinemic response despite a similar glycemic response, at standard testing amounts of 50 g CHO, as compared to puffed wheat. This effect was also observed at the 30 g dose, thereby showing consistent results following consumption. Therefore, RS4 seems to improve insulin function in apparently healthy adults regardless of the amount of RS4 consumed. Funding Sources MGP Ingredient Inc.

In Vivo Effects of Einkorn Wheat (Triticum monococcum) Bread on the Intestinal Microbiota, Metabolome, and on the Glycemic and Insulinemic Response in the Pig Model

Einkorn wheat (Triticum monococcum) is characterized by high content of proteins, bioactive compounds, such as polyunsaturated fatty acids, fructans, tocols, carotenoids, alkylresorcinols, and phytosterols, and lower α-, β-amylase and lipoxygenase activities compared to polyploid wheat. These features make einkorn flour a good candidate to provide healthier foods. In the present study, we investigated the effects of einkorn bread (EB) on the intestinal physiology and metabolism of the pig model by characterizing the glycemic and insulinemic response, and the microbiota and metabolome profiles. Sixteen commercial hybrid pigs were enrolled in the study; four pigs were used to characterize postprandial glycemic and insulinemic responses and twelve pigs underwent a 30-day dietary intervention to assess microbiota and metabolome changes after EB or standard wheat bread (WB) consumption. The postprandial insulin rise after an EB meal was characterized by a lower absolute level, and, as also observed for glucose, by a biphasic shape in contrast to that in response to a WB meal. The consumption of EB led to enrichment in short-chain fatty acid producers (e.g., Blautia, Faecalibacterium, and Oscillospira) in the gut microbiota and to higher metabolic diversity with lower content of succinate, probably related to improved absorption and therefore promoting intestinal gluconeogenesis. The observed changes, at both a compositional and metabolic scale, strongly suggest that EB consumption may support a health-promoting configuration of the intestinal ecosystem.