Effect Of Glycemic Index Research Articles

The effects of glycemic index on prostate cancer progression in a xenograft mouse model.

Previously, we found low-carbohydrate diets slowed prostate cancer (PC) growth and increased survival vs. a Western diet in mice, by inhibiting the insulin/IGF-1 axis. Thus, we tested whether modifying carbohydrate quality to lower glycemic index (GI) without changing quantity results in similar benefits as with reduced quantity. Male SCID mice injected with LAPC-4 cells were single-housed and randomized when their tumors reached 200 mm3 on average to a LoGI (48% carbohydrate kcal, from Hylon-VII) or HiGI Western diet (48% carbohydrate kcal, from sucrose). Body weight and tumor volume were measured weekly. Body composition was assessed 35 days after randomization. Blood glucose and serum insulin, IGF-1 and IGFBP3 were measured at study end when tumor volumes reached 800 mm3. We analyzed gene expression of mice tumors by RNA-sequencing and human tumors using the Prostate Cancer Transcriptome Atlas. There were no significant differences in tumor volume (P > 0.05), tumor proliferation (P = 0.29), and overall survival (P = 0.15) between groups. At 35 days after randomization, the LoGI group had 30% lower body fat (P = 0.007) despite similar body weight (P = 0.58). At sacrifice, LoGI mice had smaller livers (P < 0.001) and lower glucose (P = 0.15), insulin (P = 0.11), IGF-1 (P = 0.07) and IGF-1:IGFBP3 ratio (P = 0.05), and higher IGFBP3 (P = 0.09) vs. HiGI, although none of these metabolic differences reached statistical significance. We observed differential gene expression and pathway enrichment in mice tumors by diet. The most upregulated and downregulated gene in the LoGI group showed expression patterns more closely resembling expression in human benign prostate tissue vs. PC. In this single mouse xenograft model, consuming a low GI diet did not delay PC growth or survival vs. a high GI diet despite suggestions of decreased activation of the insulin/IGF-1 pathway. These data suggest that improving carbohydrate quality alone while consuming a high carbohydrate diet may not effectively slow PC growth.

Response to Comment on "Effect of Glycemic Index and Glycemic Load on Atherosclerotic Stenosis and Stroke".

Response to Comment on "Effect of Glycemic Index and Glycemic Load on Atherosclerotic Stenosis and Stroke".

Effect of Glycemic Index and Glycemic Load on Atherosclerotic Stenosis and Stroke

Effect of Glycemic Index and Glycemic Load on Atherosclerotic Stenosis and Stroke

Effects of Glycemic Index and Intake of Dietary Fiber on Serum HDL-Cholesterol Levels

Effects of Glycemic Index and Intake of Dietary Fiber on Serum HDL-Cholesterol Levels

A Concept Paper: The Effect of Glycemic Index on Weight Management in Female Athletes

The aim of this study is to determine glycemic index and weight management in female athletes. This is a randomised cross-over study investigating the effects of the following ad libitum low and high GI diet with 50% energy from CHO for 4 weeks on insulin sensitivity and blood lipids in overweight female’s athletes. All subject needs to report to the laboratory for preliminary test and the actual experimental trials. The test will involve the measurement of body composition, RMR, fasting blood and ECG of the subject. Subjects will be explain thoroughly about the exercise protocol and equipment used during the experimental trials. The expected outcome for the study is to identify and plan better strategies for weight loss in female athletes. Hence, the result will produce a proper way of planning a program to suit the needs of athletes. The glycemic index was not identified as risk factors for overweight and adiposity in this cross-sectional study.

Effect of glycemic index and carbohydrate intake on kidney function in healthy adults.

BackgroundReplacing carbohydrate with protein acutely increases glomerular filtration rate (GFR) but is associated with faster, long-term kidney disease progression. The effects of carbohydrate type (i.e. glycemic index, GI) on kidney function are unknown.MethodsWe conducted an ancillary study of a randomized, crossover feeding trial in overweight/obese adults without diabetes or kidney disease (N = 163). Participants were fed each of four healthy, DASH-like diets for 5 weeks, separated by 2-week washout periods. Weight was kept constant. The four diets were: high GI (GI ≥65) with high %carb (58 % kcal) (reference diet), low GI (≤45) with low %carb (40 % kcal), low GI with high %carb; and high GI with low %carb. Plasma was collected at baseline and after each feeding period. Study outcomes were cystatin C, β2-microglobulin (β2M), and estimated GFR based on cystatin C (eGFRcys).ResultsMean (SD) age was 52 (11) years; 52 % were women; 50 % were black. At baseline, mean (SD) cystatin C, β2M, and eGFRcys were 0.8 (0.1) mg/L, 1.9 (0.4) mg/L, and 104 (16) mL/min/1.73 m2. Compared to the high GI/high %carb diet, reducing GI, %carb, or both increased eGFRcys by 1.9 mL/min/1.73 m2 (95 % CI: 1.1, 2.7; P < 0.001), 3.0 mL/min/1.73 m2 (1.9, 4.0; P < 0.001), and 4.5 mL/min/1.73 m2 (3.5, 5.4; P < 0.001), respectively. Increases in eGFRcys from reducing GI were significantly associated with increases in eGFRcys from reducing %carb (P < 0.001). Results for cystatin C and β2M reflected eGFRcys.ConclusionsReducing GI increased GFR. Reducing %carb by increasing calories from protein and fat, also increased GFR. Future studies on GI should examine the long-term effects of this increase in GFR on kidney injury markers and clinical outcomes.Trial registrationClinical Trials.gov, number: NCT00608049 (first registered January 23, 2008)Electronic supplementary materialThe online version of this article (doi:10.1186/s12882-016-0288-5) contains supplementary material, which is available to authorized users.

Ingesting breakfast meals of different glycaemic load does not alter cognition and satiety in children

The effect of Glycaemic Index (GI) and Load (GL) of breakfasts on satiety and aspects of cognitive function in children is inconclusive. We aimed to assess if isocaloric breakfasts differing in GL (by replacing high-GI carbohydrate foods with dairy protein foods) acutely alter cognitive function and satiety in 10- to 12-year-old children. A total of 39 children, aged 11.6±0.7 years with body mass index 18.9±3.0 kg/m² (Mean±s.e.) participated in a randomised crossover trial of three isocaloric breakfasts (1.3 MJ): high GL (HGL: 7 g protein, 9 g fat, 50 g carbohydrate, GL 33); medium GL (MGL: 14 g protein, 9 g fat, 45 g carbohydrate, GL 24) and low GL (LGL: 18 g protein, 10 g fat, 38 g carbohydrate, GL 18). Blood glucose was recorded using a continuous glucose monitor. Subjective hunger and cognitive performance were measured before and hourly after consuming the test breakfast via a computer-delivered battery. Ad libitum intake at a buffet lunch meal was measured at 3 h at the end of testing. Incremental area under the glucose curve (iAUC) was significantly different with HGL>MGL>LGL (P<0.001). Glucose concentrations fell below baseline after 83±6 min for HGL, 63±5 min (MGL) and 67±5 min (LGL)(P=0.009). Breakfast GL did not significantly alter changes in cognitive function or self-reported satiety throughout testing. Energy intake at lunch was not significantly different between treatments (HGL 2943±168 kJ; MGL 2949±166 kJ; LGL 2993±191 kJ). Reducing breakfast GL by replacing carbohydrate with protein does not alter satiety or cognition over 3 h in 10- to 12-year-old children.

The effect of glycaemic index of high carbohydrate diets consumed over 5 days on exercise energy metabolism and running capacity in males

The aim of this study was to determine whether rates of total fat and carbohydrate oxidation and endurance capacity during running conducted in the fasted state are influenced by the glycaemic index (GI) of high carbohydrate diets consumed over 5 days. Nine healthy males performed three treadmill runs to exhaustion at 65% of maximum oxygen uptake ([Vdot]O2max): after a habitual diet (control trial), after 5 days on a high carbohydrate/high glycaemic index diet, and after 5 days on a high carbohydrate/low glycaemic index diet in randomized counterbalanced order. No significant differences in rates of fat and carbohydrate oxidation, concentrations of plasma insulin, glucose, non-esterified fatty acids and glycerol, or time to exhaustion were observed between the high carbohydrate/high glycaemic index and high carbohydrate/low glycaemic index trials. Compared with the control trial, the concentration of plasma glycerol and rate of fat oxidation were lower (P < 0.05) and the rate of carbohydrate oxidation higher (P < 0.05) in both the high carbohydrate/high glycaemic index diet and high carbohydrate/low glycaemic index trials during the run to exhaustion. In conclusion, the extent by which a high carbohydrate diet consumed over 5 days reduces rate of fat oxidation during subsequent running exercise in the fasted state is not influenced by the glycaemic index of the diet.

The Effect of Glycemic Index and Timing of Meal on Exercise to Fatigue

Pre-exercise meals have been studied in the past. In addition, the glycemic index (GI) of these meals has also been the subject of investigations. The timing of these meals may also have an impact on the efficacy of these pre-exercise meals to maintain blood glucose and to offset time to fatigue. PURPOSE: The purpose of this study was to investigate and describe the influence of pre-carbohydrate (low and high glycemic) feedings and timing of meal prior to exercise to fatigue. METHODS: Five individuals performed a peak bike test and four experimental trials, separated by 7 days. Upon arrival, subjects ingested 1g of carbohydrates (CHO) for every kilogram of body weight (BW) of a high glycemic index meal (H) or a low glycemic index meal (L) prior to exercise to fatigue. Subjects waited 30 or 60-minutes following each test meal, totaling four experimental conditions (H30, L30, H60, L60). These conditions were completed in a counterbalanced fashion. The exercise regiment was consistent following each meal; 90 minutes cycling at 70% peak oxygen consumption (VO2peak) followed by an all-out sprint until fatigue. The subjects, for the 60 minute trial, had blood draws taken at −30, 0, +10, +30, +60, +90-min, and fatigue. One less blood sample was taken from the subjects waiting 30 minutes (0, +10, +30, +60, +90-min, and fatigue). Heart rate was taken at rest, every 10 minutes of exercise, and at fatigue. VO2 and respiratory exchange ratio (RER) measurements were taken for the first 30 minutes of exercise and at 10 minutes surrounding each blood draw. RESULTS: No significant statistical differences (p>0.05) were found for any of the variables between trials (H30, L30, H60, L60) including blood glucose, blood lactate, RPE, RER, VO2, and performance time. CONCLUSION: The timing and GI of meals Time(min| used in this study did not effect time to fatigue. In addition, blood glucose levels remained essentially the same between conditions with no impact due to timing and/or GI.Figure

Erratum: Effect of glycemic index on whole-body substrate oxidation in obese women

Erratum: Effect of glycemic index on whole-body substrate oxidation in obese women

Effect of glycaemic index on body weight

Dietary carbohydrates result in different postprandial blood glucose and insulin responses, depending on the rate of digestion. The glycaemic index (GI) classification allows for ranking foods according to their effect on the glycaemic response: a high glucose response (high GI) or low glucose response (low GI). There has been great interest in recent years in whether low-GI foods are more satiating and lead to lower body weight than high-GI foods when incorporated into whole diets. Only a few studies with similar macronutrient and fibre intake have assessed the effect of GI on body weight. These studies, ranging from 5 to 16 weeks, have not been able to show improved satiation or lower energy intake or body weight. However, in one study the interesting observation was made that total fat mass was decreased. Further long-term studies using adequate differences in GI are needed to determine whether low-GI diets can beneficially affect long-term body weight homoeost asis in humans. Keywords: energy intake; fat mass; glucose; glycaemic index; insulin; obesity

Effect of glycaemic index on body weight

Dietary carbohydrates result in different postprandial blood glucose and insulin responses, depending on the rate of digestion. The glycaemic index (GI) classification allows for ranking foods according to their effect on the glycaemic response: a high glucose response (high GI) or low glucose response (low GI). There has been great interest in recent years in whether low-GI foods are more satiating and lead to lower body weight than high-GI foods when incorporated into whole diets. Only a few studies with similar macronutrient and fibre intake have assessed the effect of GI on body weight. These studies, ranging from 5 to 16 weeks, have not been able to show improved satiation or lower energy intake or body weight. However, in one study the interesting observation was made that total fat mass was decreased. Further long-term studies using adequate differences in GI are needed to determine whether low-GI diets can beneficially affect long-term body weight homoeost asis in humans. Keywords: energy intake; fat mass; glucose; glycaemic index; insulin; obesity

Effect of glycemic index on whole-body substrate oxidation in obese women

Glycemic index is hypothesized to determine fuel partitioning through serum plasma insulin modifications induced by dietary carbohydrates, thereby modulating fat accretion or oxidation. To assess the glycemic effects on postprandial fuel oxidation and blood response. In all, 12 obese women were fed on a randomized crossover design with two test meals (breakfast+lunch). High- or low-glycemic meals were provided on separate days. Energy intake on high-glycemic meal was 7758+/-148 kJ and for low-glycemic meal was 7806+/-179 kJ. Carbohydrates supplied were 273+/-5 and 275+/-6 g, respectively. Macronutrient distribution was 55% carbohydrates, 30% fat and 15% protein. Fuel oxidation was measured continuously in a respiratory chamber for 10 h. Serum glucose, free fatty acids (FFA), insulin and glucagon samples were taken for 5 h after breakfast. Glucose AUC changed significantly in response to different glycemic breakfast. Low- vs high-glycemic breakfast was 211+/-84 and 379+/-164 mmol/l (P<0.05). Similarly, insulin changed from 94+/-37 and 170+/-87 nmol/l (P<0.05), respectively. The rate of increment for serum glucose and insulin reached by the high- vs low-glycemic meal was 1.8 times more with the high-glycemic breakfast. Serum FFA were similarly suppressed by both meal types by 3 h after meal intake, but then raised significantly more with the low-glycemic meal by the fourth and fifth hour (P<0.05). Plasma glucagon did not show a significant variation with glycemic index. Carbohydrate and fat oxidation was not modified by glycemic meal characteristics, being virtually the same for low- vs high-glycemic comparisons in the 5 h following breakfast and lunch (P=NS). This study demonstrates that dietary glycemic characteristics were unable to modify fuel partitioning in sedentary obese women.