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The British Journal of Nutrition Sep 2016The positive effects of dietary fibre on health are now widely recognised; however, our understanding of the mechanisms involved in producing such benefits remains... (Review)
Review
The positive effects of dietary fibre on health are now widely recognised; however, our understanding of the mechanisms involved in producing such benefits remains unclear. There are even uncertainties about how dietary fibre in plant foods should be defined and analysed. This review attempts to clarify the confusion regarding the mechanisms of action of dietary fibre and deals with current knowledge on the wide variety of dietary fibre materials, comprising mainly of NSP that are not digested by enzymes of the gastrointestinal (GI) tract. These non-digestible materials range from intact cell walls of plant tissues to individual polysaccharide solutions often used in mechanistic studies. We discuss how the structure and properties of fibre are affected during food processing and how this can impact on nutrient digestibility. Dietary fibre can have multiple effects on GI function, including GI transit time and increased digesta viscosity, thereby affecting flow and mixing behaviour. Moreover, cell wall encapsulation influences macronutrient digestibility through limited access to digestive enzymes and/or substrate and product release. Moreover, encapsulation of starch can limit the extent of gelatinisation during hydrothermal processing of plant foods. Emphasis is placed on the effects of diverse forms of fibre on rates and extents of starch and lipid digestion, and how it is important that a better understanding of such interactions with respect to the physiology and biochemistry of digestion is needed. In conclusion, we point to areas of further investigation that are expected to contribute to realisation of the full potential of dietary fibre on health and well-being of humans.
Topics: Biological Availability; Dietary Fiber; Digestion; Food Analysis; Humans; Nutritive Value; Postprandial Period
PubMed: 27385119
DOI: 10.1017/S0007114516002610 -
Nutrition, Metabolism, and... Feb 2022Almost all of the energy in noodle dishes is derived from carbohydrates, particularly starch. Recently, we invented a pasta with reduced starch content to about 50% and... (Randomized Controlled Trial)
Randomized Controlled Trial
BACKGROUND AND AIMS
Almost all of the energy in noodle dishes is derived from carbohydrates, particularly starch. Recently, we invented a pasta with reduced starch content to about 50% and increased dietary fiber content, designated low-starch high-fiber pasta (LSHFP). In this study, we investigated the ingestion of LSHFP on the postprandial glucose response as a breakfast meal.
METHODS AND RESULT
This was a randomized, single-blinded, crossover study. The postprandial glucose area under the curve for 4 h (4h-gluAUC), as the primary outcome, and the extent of postprandial glucose elevation (maxΔBG) were evaluated using a continuous glucose monitoring system in healthy volunteers and patients with type 2 diabetes (T2DM) after intake of LSHFP, standard pasta (SP), and rice. The amount of total carbohydrate was matched between LSHFP and SP. Ten individuals with T2DM and 10 individuals who did not have T2DM and were otherwise healthy were enrolled in this crossover study. The 4h-gluAUC for LSHFP (137.6 ± 42.2 mg/dL・h) was significantly smaller than the 4h-gluAUC for rice (201.7 ± 38.7 mg/dL・h) (p = 0.001) and SP (178.5 ± 59.2 mg/dL・h) (p = 0.020). The maxΔBG for rice (118.6 ± 24.2 mg/dL) was significantly higher than those for SP (87.5 ± 19.9 mg/dL) (p < 0.001) and LSHFP (72.7 ± 26.2 mg/dL) (p = 0.001), while the maxΔBG for LSHFP (p = 0.047) was significantly lower than that for SP, in T2DM patients as well as in healthy participants.
CONCLUSIONS
This study demonstrated that LSHFP can reduce postprandial glucose elevation compared with SP in both healthy participants and patients with T2DM.
Topics: Blood Glucose; Blood Glucose Self-Monitoring; Cross-Over Studies; Diabetes Mellitus, Type 2; Dietary Carbohydrates; Dietary Fiber; Humans; Insulin; Postprandial Period; Starch
PubMed: 34893415
DOI: 10.1016/j.numecd.2021.10.019 -
Metabolism: Clinical and Experimental Sep 2015To examine the influence of exercise intensity on postprandial health outcomes in adolescents when exercise is accumulated throughout the day. (Randomized Controlled Trial)
Randomized Controlled Trial
PURPOSE
To examine the influence of exercise intensity on postprandial health outcomes in adolescents when exercise is accumulated throughout the day.
METHODS
19 adolescents (9 male, 13.7±0.4 years old) completed three 1-day trials in a randomised order: (1) rest (CON); or four bouts of (2) 2×1 min cycling at 90% peak power with 75 s recovery (high-intensity interval exercise; HIIE); or (3) cycling at 90% of the gas exchange threshold (moderate-intensity exercise; MIE), which was work-matched to HIIE. Each bout was separated by 2 hours. Participants consumed a high fat milkshake for breakfast and lunch. Postprandial triacylglycerol (TAG), glucose, systolic blood pressure (SBP) and fat oxidation were assessed throughout the day.
RESULTS
There was no effect of trial on total area under the curve (TAUC) for TAG (P=0.87). TAUC-glucose was lower in HIIE compared to CON (P=0.03, ES=0.42) and MIE (P=0.04, ES=0.41), with no difference between MIE and CON (P=0.89, ES=0.04). Postprandial SBP was lower in HIIE compared to CON (P=0.04, ES=0.50) and MIE (P=0.04, ES=0.40), but not different between MIE and CON (P=0.52, ES=0.11). Resting fat oxidation was increased in HIIE compared to CON (P=0.01, ES=0.74) and MIE (P=0.05, ES=0.51), with no difference between MIE and CON (P=0.37, ES=0.24).
CONCLUSION
Neither exercise trial attenuated postprandial lipaemia. However, accumulating brief bouts of HIIE, but not MIE, reduced postprandial plasma glucose and SBP, and increased resting fat oxidation in adolescent boys and girls. The intensity of accumulated exercise may therefore have important implications for health outcomes in youth.
Topics: Adolescent; Anaerobic Threshold; Blood Pressure; Diet, High-Fat; Exercise; Female; Humans; Lipid Metabolism; Lipids; Male; Oxidation-Reduction; Postprandial Period; Pulmonary Gas Exchange; Rest; Triglycerides
PubMed: 26116999
DOI: 10.1016/j.metabol.2015.05.016 -
The Journal of Nutrition Apr 2022Few studies have assessed the integrative effects of diet, BMI, and exercise on postprandial changes in energy and circulating metabolic profiles. (Randomized Controlled Trial)
Randomized Controlled Trial
Different Isocaloric Meals and Adiposity Modify Energy Expenditure and Clinical and Metabolomic Biomarkers During Resting and Exercise States in a Randomized Crossover Acute Trial of Normal-Weight and Overweight/Obese Men.
BACKGROUND
Few studies have assessed the integrative effects of diet, BMI, and exercise on postprandial changes in energy and circulating metabolic profiles.
OBJECTIVES
We aimed to assess the collective effects of 3 isocaloric meals high in carbohydrate (74.2% energy), fat (64.6% energy), or protein (39.5% energy) on energy expenditure and clinical and metabolomic biomarkers under resting and exercise conditions in normal-weight and overweight/obese men.
METHODS
This crossover controlled acute trial included 20 normal-weight (BMI, 18.5 to <24 kg/m2) and 20 overweight/obese (BMI ≥24 kg/m2) men aged 18-45 years. Each of 3 test meals was provided for 2 continuous days: a resting day without exercise, followed by an exercise day with a bicycling exercise of 50% maximal oxygen consumption (postprandial 90-120 minutes). Energy expenditure (exploratory outcome of primary interest) was measured using indirect calorimetry. Fasting and postprandial 2-hour serum clinical and metabolomic biomarkers (secondary interest) were measured. Mixed models were used to examine the effects of meal, time, and/or BMI category.
RESULTS
On the resting day, no significant between-meal differences were detected for energy expenditure. However, high-carbohydrate and high-fat meals induced the highest postprandial 2-hour increase in glucose (0.34 ± 0.15 mmol/L) and triglyceride (0.95 ± 0.09 mmol/L), respectively, while the high-protein meal reduced glucose (-0.48 ± 0.08 mmol/L) and total cholesterol (-0.01 ± 0.03 mmol/L; all Pmeal values < 0.001). On the exercise day, a high-carbohydrate meal significantly promoted the carbohydrate oxidation rate but suppressed the fat oxidation rate (Pmeal < 0.05), while its postprandial glucose response was attenuated by bicycling (-0.31 ± 0.03 mmol/L; Pexercise < 0.001). We identified 69 metabolites as key features in discriminating between the 3 meals, and overweight/obese men had more varieties of metabolites than normal-weight men.
CONCLUSIONS
Three isocaloric meals induced unique postprandial changes in clinical and metabolomic biomarkers, while exercise prevented the hyperglycemia induced by a high-carbohydrate meal. Overweight/obese men were more responsive to the meal challenges than normal-weight men. This trial was registered at clinicaltrials.gov as NCT03231618.
Topics: Adiposity; Adolescent; Adult; Biomarkers; Blood Glucose; Cross-Over Studies; Energy Metabolism; Humans; Insulin; Male; Meals; Middle Aged; Obesity; Overweight; Postprandial Period; Young Adult
PubMed: 35020917
DOI: 10.1093/jn/nxac006 -
Journal of Applied Physiology... Feb 2021High-intensity interval exercise (HIIE) has been shown to be more effective than moderate-intensity exercise for increasing acute lipid oxidation and lowering blood...
High-intensity interval exercise (HIIE) has been shown to be more effective than moderate-intensity exercise for increasing acute lipid oxidation and lowering blood lipids during exercise and postprandially. Exercise in cold environments is also known to enhance lipid oxidation; however, the immediate and long-term effects of HIIE exercise in cold are unknown. The purpose of this study was to examine the effects cold stress during HIIE on acute exercise metabolism and postprandial metabolism. Eleven recreationally active individuals (age: 23 ± 3 yr, weight: 80 ± 9.7 kg, V̇O: 39.2 ± 5.73 mL·kg·min) performed evening HIIE sessions (10 × 60 s cycling, 90% V̇O interspersed with 90 s active recovery, 30% V̇O) in thermoneutral (HIIE-TN, control; 21°C) and cold environment (HIIE-CO; 0°C), following a balanced crossover design. The following morning, participants consumed a high-fat meal. Indirect calorimetry was used to assess substrate oxidation, and venous blood samples were obtained to assess changes in noncellular metabolites. During acute exercise, lipid oxidation was higher in HIIE-CO ( = 0.002) without differences in V̇O and energy expenditure ( ≥ 0.162) between conditions. Postprandial V̇O, lipid and CHO oxidation, plasma insulin, and triglyceride concentrations were not different between conditions ( > 0.05). Postprandial blood LDL-C levels were higher in HIIE-CO 2 h after the meal ( = 0.003). Postprandial glucose area under curve was 49% higher in HIIE-CO versus HIIE-TN ( = 0.034). Under matched energy expenditure conditions, HIIE demonstrated higher lipid oxidation rates during exercise in the cold; but only marginally influenced postprandial lipid metabolism the following morning. In conclusion, HIIE in the cold seemed to be less favorable for postprandial lipid and glycemic responses. This is the first known study to investigate the effects of cold ambient temperatures on acute metabolism during high-intensity interval exercise, as well as postprandial metabolism the next day. We observed that high-intensity interval exercise in a cold environment does change acute metabolism compared to a thermoneutral environment; however, the addition of a cold stimulus was less favorable for postprandial metabolic responses the following day.
Topics: Adult; Blood Glucose; Calorimetry, Indirect; Energy Metabolism; Exercise; Humans; Postprandial Period; Young Adult
PubMed: 33270513
DOI: 10.1152/japplphysiol.00384.2020 -
IEEE Transactions on Bio-medical... Nov 2022The motility patterns in the gastrointestinal tract are regulated, in part, by bioelectrical events known as slow waves (SWs). Understanding temporal and spatial...
BACKGROUND
The motility patterns in the gastrointestinal tract are regulated, in part, by bioelectrical events known as slow waves (SWs). Understanding temporal and spatial features of gastric SWs can help reveal the underlying causes of functional motility disorders.
OBJECTIVE
This study investigated the ability of source localization techniques to characterize the spatial signatures of SW activity using simulated and experimental magnetogastrography data.
METHODS
Two SW propagation patterns (antegrade and retrograde) with two rhythms (normogastric and bradygastric) were used to simulate magnetic fields using 4 anatomically realistic stomach and torso geometries. Source localization was performed utilizing the equivalent current dipole (ECD) and the equivalent magnetic dipole (EMD) models.
RESULTS
In the normogastric simulations when compared with the SW activity, the EMD model was capable of identifying the SW propagation in the lateral, antero-posterior, and supero-inferior axes with the median correlation coefficients of 0.66, 0.53, and 0.83, respectively, whereas the ECD model produced lower correlation scores (median: 0.52, 0.44, and 0.44). Moreover, the EMD model resulted in distinct and opposite spatial signatures for the antegrade and retrograde propagation. Similarly, when experimental data was used, the EMD model revealed antegrade-like signatures where the propagation was mostly towards the third quadrant in the supero-inferior (preprandial: 49%, postprandial: 35%) and antero-posterior (preprandial: 49%, postprandial: 50%) axes.
CONCLUSION AND SIGNIFICANCE
The EMD model was able to identify and classify the spatial signatures of SW activities, which can help to inform the interpretation of non-invasive recordings of gastric SWs as a biomarker of functional motility disorders.
Topics: Stomach; Gastrointestinal Tract; Magnetics; Magnetic Fields; Postprandial Period; Gastrointestinal Motility
PubMed: 35560086
DOI: 10.1109/TBME.2022.3174847 -
Annals of Nutrition & Metabolism 2022The clinical relevance of excess intrapancreatic fat deposition (IPFD) is increasingly appreciated. Leptin and ghrelin are key players in the regulation of food intake,...
BACKGROUND
The clinical relevance of excess intrapancreatic fat deposition (IPFD) is increasingly appreciated. Leptin and ghrelin are key players in the regulation of food intake, energy balance, and body fat mass. The aim was to investigate the associations of the leptin/ghrelin ratio and its components with IPFD.
METHODS
All participants underwent magnetic resonance imaging on a 3T scanner to quantify IPFD. Both fasting and postprandial blood samples were analyzed for leptin and acylated ghrelin. Linear regression analysis was conducted, accounting for visceral/subcutaneous fat volume ratio, glycated hemoglobin, and other covariates.
RESULTS
A total of 94 participants (32 women) with a median age of 56 (interquartile range 44-66) years were studied. Their median IPFD was 9.6% (interquartile range 8.8-10.4%). In the fasted state, the leptin/ghrelin ratio (β = 0.354; 95% confidence interval 0.044-0.663; p = 0.025, in the most adjusted model) and leptin (β = 0.040; 95% confidence interval 1.003-1.078; p = 0.035, in the most adjusted model) were significantly associated with IPFD. Ghrelin in the fasted state was not significantly associated with IPFD. In the postprandial state, the leptin/ghrelin ratio, leptin, and ghrelin were not significantly associated with IPFD.
CONCLUSION
Fasting circulating levels of leptin are directly associated with IPFD. Purposely designed mechanistic studies are warranted to determine how high leptin may contribute to excess IPFD.
Topics: Adult; Aged; Fasting; Female; Ghrelin; Humans; Leptin; Magnetic Resonance Imaging; Middle Aged; Postprandial Period
PubMed: 34710871
DOI: 10.1159/000520068 -
JPEN. Journal of Parenteral and Enteral... Jan 2022Postprandial rise of plasma essential amino acids (EAAs) determines the anabolic effect of dietary protein. Disturbed gastrointestinal function could impair the anabolic...
BACKGROUND
Postprandial rise of plasma essential amino acids (EAAs) determines the anabolic effect of dietary protein. Disturbed gastrointestinal function could impair the anabolic response in critically ill patients. Aim was to investigate the postprandial EAA response in critically ill patients and its relation to small-intestinal function.
METHODS
Twenty-one mechanically ventilated patients and 9 healthy controls received a bolus containing 100 ml of a formula feed (Ensure) and 2 g of 3-O-Methyl-d-glucose (3-OMG) via postpyloric feeding tube. Fasting and postprandial plasma concentrations of EAAs, 3-OMG, total bile salts, and the gut-released hormone fibroblast growth factor 19 (FGF19) were measured over a 4-hour period. Changes over time and between groups were assessed with linear mixed-effects analysis. Early (0-60 minutes) and total postprandial responses are summarized as the incremental area under the curve (iAUC).
RESULTS
At baseline, fasting EAA levels were similar in both groups: 1181 (1055-1276) vs 1150 (1065-1334) μmol·L-1, P = .87. The early postprandial rise in EAA was not apparent in critically ill patients compared with healthy controls (iAUC , -4858 [-6859 to 2886] vs 5406 [3099-16,853] µmol·L ·60 minutes; P = .039). Impaired EAA response did not correlate with impaired 3-OMG response (Spearman ρ 0.32, P = .09). There was a limited increase in total bile salts but no relevant FGF19 response in either group.
CONCLUSION
Postprandial rise of EAA is blunted in critically ill patients and unrelated to glucose absorption measured with 3-OMG. Future studies should aim to delineate governing mechanisms of macronutrient malabsorption.
Topics: Amino Acids, Essential; Critical Illness; Enteral Nutrition; Fasting; Humans; Postprandial Period
PubMed: 33666262
DOI: 10.1002/jpen.2103 -
Obesity (Silver Spring, Md.) Dec 2022This study investigated the effects of circadian misalignment (CM), induced by delaying mealtimes, independent of sleep timing and duration and eating window duration,... (Randomized Controlled Trial)
Randomized Controlled Trial
OBJECTIVE
This study investigated the effects of circadian misalignment (CM), induced by delaying mealtimes, independent of sleep timing and duration and eating window duration, on energy expenditure (EE), respiratory quotient (RQ), and substrate oxidation.
METHODS
Healthy adults, aged 20 to 49 years, participated in this randomized crossover study under controlled feeding conditions. Eating window duration was identical in both conditions (circadian alignment [CA]: 9:00 am-7:00 pm; CM: 1:00 pm-11:00 pm), and bedtimes were constant (11:30 pm-8:00 am). EE, RQ, and substrate oxidation were obtained over 23 hours in a metabolic chamber on days 3 and 4 and days 14 and 15 in each condition. Twenty-four-hour and post-meal outcomes were analyzed using a linear mixed-effects model including condition, day, and day-by-condition interaction as main predictors and sex as a covariate.
RESULTS
Three men and four women (age 37.4 ± 8.8 years, BMI 30.4 ± 3.3 kg/m ) completed the study. Twenty-four-hour EE did not differ between conditions. Post-meal RQ for dinner and snack was higher in CM versus CA (both p < 0.001) with correspondingly higher glucose oxidation (both p < 0.01) and lower fat oxidation (dinner only p = 0.0001).
CONCLUSIONS
CM, induced by delaying mealtimes by 4 hours relative to CA, independently shifts nutrient metabolism toward greater carbohydrate and lower fat oxidation.
Topics: Adult; Male; Humans; Female; Cross-Over Studies; Meals; Oxidation-Reduction; Energy Metabolism; Postprandial Period
PubMed: 36238978
DOI: 10.1002/oby.23566 -
Nutrients Apr 2020Approximately 22% of U.S. adults and 25% of adults globally have metabolic syndrome (MetS). Key features, such as dysglycemia and dyslipidemia, predict type 2 diabetes,... (Review)
Review
Approximately 22% of U.S. adults and 25% of adults globally have metabolic syndrome (MetS). Key features, such as dysglycemia and dyslipidemia, predict type 2 diabetes, cardiovascular disease, premature disability, and death. Acute supplementation of dietary polyphenols and post-meal physical activity hold promise in improving postprandial dysmetabolism. To our knowledge, no published review has described the effects of either intervention on postprandial glucose, insulin, lipids, and markers of oxidative damage and inflammation in adults with features of MetS. Thus, we conducted this review of controlled clinical trials that provided dietary polyphenols from oils, fruits, teas, and legumes during a dietary challenge, or implemented walking, cycling, and stair climbing and descending after a dietary challenge. Clinical trials were identified using ClinicalTrials.gov, PubMed, and Google Scholar and were published between 2000 and 2019. Dietary polyphenols from extra virgin olive oil, grapes, blackcurrants, strawberries, black tea, and black beans improved postprandial glucose, insulin, and markers of oxidative damage and inflammation, but results were not consistent among clinical trials. Freeze-dried strawberry powder distinctly improved postprandial insulin and markers of oxidative damage and inflammation. Post-meal physical activity attenuated postprandial glucose, but effects on postprandial lipids and markers of oxidative damage and inflammation were inconclusive. Consuming dietary polyphenols with a meal and completing physical activity after a meal may mitigate postprandial dysmetabolism in adults with features of MetS.
Topics: Blood Glucose; Dietary Supplements; Exercise; Female; Humans; Insulin; Male; Metabolic Syndrome; Polyphenols; Postprandial Period
PubMed: 32316418
DOI: 10.3390/nu12041120