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Obesity Reviews : An Official Journal... Feb 2023Determining if gastrointestinal (GI) hormone response to food intake differs between individuals with, and without, obesity may improve our understanding of obesity... (Meta-Analysis)
Meta-Analysis Review
Determining if gastrointestinal (GI) hormone response to food intake differs between individuals with, and without, obesity may improve our understanding of obesity pathophysiology. A systematic review and meta-analysis of studies assessing the concentrations of GI hormones, as well as appetite ratings, following a test meal, in individuals with and without obesity was undertaken. Systematic searches were conducted in the databases MEDLINE, Embase, Cochrane Library, PsycINFO, Web of Science, and ClinicalTrials.gov. A total of 7514 unique articles were retrieved, 115 included in the systematic review, and 70 in the meta-analysis. The meta-analysis compared estimated standardized mean difference in GI hormones' concentration, as well as appetite ratings, between individuals with and without obesity. Basal and postprandial total ghrelin concentrations were lower in individuals with obesity compared with controls, and this was reflected by lower postprandial hunger ratings in the former. Individuals with obesity had a lower postprandial concentration of total peptide YY compared with controls, but no significant differences were found for glucagon-like peptide 1, cholecystokinin, or other appetite ratings. A large methodological and statistical heterogeneity among studies was found. More comprehensive studies are needed to understand if the differences observed are a cause or a consequence of obesity.
Topics: Humans; Appetite; Gastrointestinal Hormones; Obesity; Ghrelin; Peptide YY; Cholecystokinin; Postprandial Period
PubMed: 36416279
DOI: 10.1111/obr.13531 -
IEEE Transactions on Bio-medical... Apr 2022Pediatric obesity predisposes children and adolescents to early onset insulin resistance and dysglycemia. In the last 20 years this has led to a rise in the prevalence...
OBJECTIVE
Pediatric obesity predisposes children and adolescents to early onset insulin resistance and dysglycemia. In the last 20 years this has led to a rise in the prevalence of prediabetes, diabetes and fatty liver in youngsters, due to the high degree of insulin resistance experienced by these patients and the consequent high availability of glucose. As glucose accesses the liver, it is partly metabolized through glycolysis, whose main product is pyruvate that is then converted into Acetyl CoA and lactate. Therefore, lactate production rate (LPR) represents the best proxy for the assessment of glycolysis. Since to date there are not methods to estimate postprandial LPR, here we proposed a novel oral glucose-lactate model to estimate LPR during an oral glucose tolerance test and tested it in 24 youth with and without obesity.
METHODS
The model is based on the oral glucose minimal model and assumes that LPR is a fraction (fr) of glucose disposal rate, proportional to glucose concentration and controlled by insulin action.
RESULTS
The model well fitted the glucose and lactate data, and provided both precise parameter estimates (e.g., fr = 22.5 [12.6-54.1]%, median [IQR]), CV = 18 [13-25]%) and LPR time course.
CONCLUSIONS
The proposed model is a valid tool to assess LPR, and thus glycolysis, during OGTT in nondiabetic subjects.
SIGNIFICANCE
The proposed methodology will allow to assess postprandial LPR in simple and cost-effective way.
Topics: Adolescent; Blood Glucose; Child; Glucose; Glucose Tolerance Test; Humans; Insulin; Insulin Resistance; Lactic Acid; Postprandial Period
PubMed: 34727021
DOI: 10.1109/TBME.2021.3124143 -
Metabolomics : Official Journal of the... May 2024Analysis of time-resolved postprandial metabolomics data can improve our understanding of the human metabolism by revealing similarities and differences in postprandial...
INTRODUCTION
Analysis of time-resolved postprandial metabolomics data can improve our understanding of the human metabolism by revealing similarities and differences in postprandial responses of individuals. Traditional data analysis methods often rely on data summaries or univariate approaches focusing on one metabolite at a time.
OBJECTIVES
Our goal is to provide a comprehensive picture in terms of the changes in the human metabolism in response to a meal challenge test, by revealing static and dynamic markers of phenotypes, i.e., subject stratifications, related clusters of metabolites, and their temporal profiles.
METHODS
We analyze Nuclear Magnetic Resonance (NMR) spectroscopy measurements of plasma samples collected during a meal challenge test from 299 individuals from the COPSAC cohort using a Nightingale NMR panel at the fasting and postprandial states (15, 30, 60, 90, 120, 150, 240 min). We investigate the postprandial dynamics of the metabolism as reflected in the dynamic behaviour of the measured metabolites. The data is arranged as a three-way array: subjects by metabolites by time. We analyze the fasting state data to reveal static patterns of subject group differences using principal component analysis (PCA), and fasting state-corrected postprandial data using the CANDECOMP/PARAFAC (CP) tensor factorization to reveal dynamic markers of group differences.
RESULTS
Our analysis reveals dynamic markers consisting of certain metabolite groups and their temporal profiles showing differences among males according to their body mass index (BMI) in response to the meal challenge. We also show that certain lipoproteins relate to the group difference differently in the fasting vs. dynamic state. Furthermore, while similar dynamic patterns are observed in males and females, the BMI-related group difference is observed only in males in the dynamic state.
CONCLUSION
The CP model is an effective approach to analyze time-resolved postprandial metabolomics data, and provides a compact but a comprehensive summary of the postprandial data revealing replicable and interpretable dynamic markers crucial to advance our understanding of changes in the metabolism in response to a meal challenge.
Topics: Humans; Postprandial Period; Male; Female; Metabolomics; Adult; Fasting; Principal Component Analysis; Magnetic Resonance Spectroscopy; Middle Aged; Data Analysis; Metabolome
PubMed: 38722393
DOI: 10.1007/s11306-024-02109-y -
Journal of Applied Physiology... Apr 2020Our objective was to determine the influence of a high-fat diet (HFD) on fasting and postprandial skeletal muscle substrate metabolism in endurance-trained (ET) compared...
Our objective was to determine the influence of a high-fat diet (HFD) on fasting and postprandial skeletal muscle substrate metabolism in endurance-trained (ET) compared with sedentary (SED) humans. SED ( = 17) and ET ( = 7) males were control-fed a 10-day moderate-fat diet followed by a 5-day isocaloric HFD (55% fat, 30% carbohydrate). Skeletal muscle biopsies were taken in the fasted condition and 4 h after a high-fat meal (820 kcals; 63% fat and 25% carbohydrate). Palmitate-induced suppression of pyruvate oxidation, an indication of substrate preference, and oxidation of fat and glucose were measured in homogenized skeletal muscle in fasted and fed states. Postprandial responses were calculated as percent changes from fasting to fed states. Postprandial suppression of pyruvate oxidation was maintained after the HFD in ET, but not SED skeletal muscle, suggesting greater adaptability to dietary intake changes in the former. Fasting total fat oxidation increased due to the HFD in ET skeletal muscle ( = 0.006), which was driven by incomplete fat oxidation ( = 0.008). Fasting fat oxidation remained unchanged in skeletal muscle of SED individuals. Yet, postprandial fat oxidation was similar between groups. Fasting glucose oxidation was elevated after the HFD in ET ( = 0.036), but not SED, skeletal muscle. Postprandial glucose oxidation was reduced due to the HFD in SED ( = 0.002), but not ET, skeletal muscle. These findings provide insight into differing substrate metabolism responses between SED and ET individuals and highlight the role that the prevailing diet may play in modulating fasting and postprandial metabolic responses in skeletal muscle. The relationship between high dietary fat intake and physical activity level and their combined effect on skeletal muscle substrate metabolism remains unclear. We assessed the influence of the prevailing diet in modulating substrate oxidation in skeletal muscle of endurance-trained compared with sedentary humans during a high-fat challenge meal. Collectively, our findings demonstrate the adaptability of skeletal muscle in endurance-trained individuals to high dietary fat intake.
Topics: Diet, High-Fat; Endurance Training; Fasting; Humans; Male; Muscle, Skeletal; Postprandial Period
PubMed: 32163335
DOI: 10.1152/japplphysiol.00576.2019 -
Animal : An International Journal of... Jan 2023Dietary proteins need to be digested first while free amino acids (AAs) and small peptides are readily available for absorption and rapidly appear in the blood. The...
Dietary proteins need to be digested first while free amino acids (AAs) and small peptides are readily available for absorption and rapidly appear in the blood. The rapid postprandial appearance of dietary AA in the systemic circulation may result in inefficient AA utilisation for protein synthesis of peripheral tissues if other nutrients implicated in AA and protein metabolism are not available at the same time. The objective of this experiment was to compare the postprandial concentrations of plasma AA and other metabolites after the ingestion of a diet that provided AA either as proteins or as free AA and small peptides. Twenty-four male growing pigs (38.8 ± 2.67 kg) fitted with a jugular catheter were assigned to one of three diets that provided AA either in protein form (INT), free AA and small peptides (HYD), or as free AA (FAA). After an overnight fast and initial blood sampling, a small meal was given to each pig followed by serial blood collection for 360 min. Postprandial concentrations of plasma AA, glucose, insulin, and urea were then measured from the collected blood. Non-linear regression was used to summarise the postprandial plasma AA kinetics. Fasting concentrations of urea and some AA were higher (P < 0.05) while postprandial plasma insulin and glucose were lower (P < 0.01) for INT than for HYD and FAA. The area under the curve of plasma concentration after meal distribution was lower for INT for most AAs (P < 0.05), resulting in a flatter curve compared to HYD and FAA. This was the result of the slower appearance of dietary AA in the plasma when proteins are fed instead of free AA and small peptides. The flatter curve may also result from more AAs being metabolised by the intestine and liver when INT was fed. The metabolism of AA of the intestine and liver was higher for HYD than FAA. Providing AA as proteins or as free AA and small peptides affected the postprandial plasma kinetics of AA, urea, insulin, and glucose. Whether the flat kinetics when feeding proteins has a positive or negative effect on AA metabolism still needs to be explored.
Topics: Swine; Male; Animals; Amino Acids; Insulin; Diet; Urea; Glucose; Postprandial Period
PubMed: 36542911
DOI: 10.1016/j.animal.2022.100684 -
Diabetes Care May 2020Debate continues regarding the influence of dietary fats and sugars on the risk of developing metabolic diseases, including insulin resistance and nonalcoholic fatty... (Randomized Controlled Trial)
Randomized Controlled Trial
OBJECTIVE
Debate continues regarding the influence of dietary fats and sugars on the risk of developing metabolic diseases, including insulin resistance and nonalcoholic fatty liver disease (NAFLD). We investigated the effect of two eucaloric diets, one enriched with saturated fat (SFA) and the other enriched with free sugars (SUGAR), on intrahepatic triacylglycerol (IHTAG) content, hepatic de novo lipogenesis (DNL), and whole-body postprandial metabolism in overweight males.
RESEARCH DESIGN AND METHODS
Sixteen overweight males were randomized to consume the SFA or SUGAR diet for 4 weeks before consuming the alternate diet after a 7-week washout period. The metabolic effects of the respective diets on IHTAG content, hepatic DNL, and whole-body metabolism were investigated using imaging techniques and metabolic substrates labeled with stable-isotope tracers.
RESULTS
Consumption of the SFA diet significantly increased IHTAG by mean ± SEM 39.0 ± 10.0%, while after the SUGAR diet IHTAG was virtually unchanged. Consumption of the SFA diet induced an exaggerated postprandial glucose and insulin response to a standardized test meal compared with SUGAR. Although whole-body fat oxidation, lipolysis, and DNL were similar following the two diets, consumption of the SUGAR diet resulted in significant ( < 0.05) decreases in plasma total, HDL, and non-HDL cholesterol and fasting β-hydroxybutyrate plasma concentrations.
CONCLUSIONS
Consumption of an SFA diet had a potent effect, increasing IHTAG together with exaggerating postprandial glycemia. The SUGAR diet did not influence IHTAG and induced minor metabolic changes. Our findings indicate that a diet enriched in SFA is more harmful to metabolic health than a diet enriched in free sugars.
Topics: Adult; Blood Glucose; Cross-Over Studies; Diet; Diet, High-Fat; Dietary Carbohydrates; Dietary Fats; Fatty Acids; Humans; Insulin Resistance; Lipid Metabolism; Lipids; Liver; Male; Meals; Middle Aged; Non-alcoholic Fatty Liver Disease; Postprandial Period; Risk Factors
PubMed: 32165444
DOI: 10.2337/dc19-2331 -
International Journal of Sports Medicine Nov 2022We review recent findings on the ability of exercise to lower postprandial lipemia (PPL). Specifically, we answer why exercise is important in lowering PPL, when it is... (Review)
Review
We review recent findings on the ability of exercise to lower postprandial lipemia (PPL). Specifically, we answer why exercise is important in lowering PPL, when it is most effective to exercise to achieve this, what the preferred exercise is and how exercise reduces PPL. Most findings confirm the power of exercise to lower PPL, which is an independent risk factor for cardiovascular disease. Exercise is most effective when performed on the day preceding a high- or moderate-fat meal. This effect lasts up to approximately two days; therefore, one should exercise frequently to maintain this benefit. However, the time of exercise relative to a meal is not that important in real-life conditions, since one consumes several meals during the day; thus, an exercise bout will inevitably exert its lowering effect on PPL in one or more of the subsequent meals. Although moderate-intensity continuous exercise, high-intensity intermittent exercise, resistance exercise and accumulation of short bouts of exercise throughout the day are all effective in lowering PPL, submaximal, high-volume interval exercise seems to be superior, provided it is tolerable. Finally, exercise reduces PPL by both lowering the rate of appearance and increasing the clearance of triacylglycerol-rich lipoproteins from the circulation.
Topics: Humans; Dietary Fats; Postprandial Period; Hyperlipidemias; Exercise; Triglycerides
PubMed: 35345016
DOI: 10.1055/a-1810-5118 -
Obesity (Silver Spring, Md.) Jul 2021Studies have shown that fidgeting augments metabolic demand and increases blood flow to the moving limbs, whereas prolonged sitting suppresses these factors and... (Randomized Controlled Trial)
Randomized Controlled Trial
OBJECTIVE
Studies have shown that fidgeting augments metabolic demand and increases blood flow to the moving limbs, whereas prolonged sitting suppresses these factors and exacerbates postprandial glucose excursions. Therefore, the hypothesis of this study was that leg fidgeting during prolonged sitting would improve postprandial glycemic control.
METHODS
Adults with obesity (n = 20) participated in a randomized crossover trial in which blood glucose and insulin concentrations were measured during a 3-hour sitting period following the ingestion of a glucose load (75 g). During sitting, participants either remained stationary or intermittently fidgeted both legs (2.5 minutes off and 2.5 minutes on). Accelerometer counts, oxygen consumption, and popliteal-artery blood flow were also measured during the sitting period.
RESULTS
As expected, fidgeting increased accelerometer counts (P < 0.01), oxygen consumption (P < 0.01), and blood flow through the popliteal artery (P < 0.05). Notably, fidgeting lowered both glucose (P < 0.01) and insulin (P < 0.05) total area under the curve (AUC) and glucose incremental AUC (P < 0.05). Additionally, there was a strong negative correlation between fidgeting-induced increases in blood flow and reduced postprandial glucose AUC within the first hour (r = -0.569, P < 0.01).
CONCLUSIONS
Leg fidgeting is a simple, light-intensity physical activity that enhances limb blood flow and can be incorporated during prolonged sitting to improve postprandial glycemic control in people with obesity.
Topics: Adult; Blood Glucose; Cross-Over Studies; Glycemic Control; Humans; Insulin; Leg; Obesity; Postprandial Period; Sedentary Behavior; Sitting Position
PubMed: 34159757
DOI: 10.1002/oby.23173 -
The Journal of Nutrition, Health & Aging 2018To compare the postprandial metabolic responses to a high-fat meal in healthy adults who differ by age and physical activity level.
OBJECTIVES
To compare the postprandial metabolic responses to a high-fat meal in healthy adults who differ by age and physical activity level.
DESIGN
Cross-sectional, quasi-experimental design.
SETTING
Physical Activity and Nutrition Clinical Research Consortium (PAN-CRC) at Kansas State University (Manhattan, KS, USA).
PARTICIPANTS
Twenty-two healthy adults: 8 younger active (YA) adults (4M/4W; 25 ± 5 yr), 8 older active (OA) adults (4M/4W; 67 ± 5 yr), and 6 older inactive (OI) adults (3M/3W; 68 ± 7 yr).
INTERVENTION
Following an overnight (10-hour) fast and having abstained from exercise for 2 days, participants consumed a high-fat meal (63% fat, 34% CHO; 12 kcal/kg body mass; 927 ± 154 kcal). To assess the metabolic response, blood draws were performed at baseline and each hour following the meal for 6 hours.
MEASUREMENTS
Fasting and postprandial triglycerides (TG), glucose, Total-C, and HDL-C were measured. Metabolic load index (MLI) and LDL-C were calculated.
RESULTS
There were significant group x time interactions for TG (p < 0.0001) and MLI (p = 0.004). The TG total area-under-the-curve (tAUC) response was significantly lower in YA (407.9 ± 115.1 mg/dL 6 hr) compared to OA (625.6 ± 169.0 mg/dL 6 hr; p = 0.02) and OI (961.2 ± 363.6 mg/dL 6 hr; p = 0.0002), while the OA group TG tAUC was lower than the OI group (p = 0.02). The TG peak was significantly lower in YA (90.5 ± 27.0 mg/dL) than OA (144.0 ± 42.2 mg/dL; p = 0.03) and OI (228.2 ± 96.1 mg/dL; p = 0.0003), and was lower in the OA group compared to the OI group (p = 0.03). Glucose was significantly lower 1 hour after the meal in YA (89.4 ± 10.1 mg/dL; p = 0.01) and OA (87.3 ± 22.3 mg/dL; p = 0.005) versus OI (110.7 ± 26.9 mg/dL). MLI tAUC was significantly lower in YA (936.8 ± 137.7 mg/dL 6 hr; p = 0.0007) and OA (1133.0 ± 207.4 mg/dL; p = 0.01) versus OI (1553.8 ± 394.3 mg/dL), with no difference (p = 0.14) between YA and OA groups. Total-C and LDL-C were generally lower in younger compared to older participants at baseline and throughout the postprandial period, while no group or time effects were evident in HDL-C.
CONCLUSION
Both physical activity status and aging appear to affect the postprandial metabolic, namely TG, response to a high-fat meal. These findings point to an inherently diminished metabolic capacity with aging, but suggest that physical activity may help minimize this decrement.
Topics: Adult; Age Factors; Aged; Cross-Sectional Studies; Exercise; Female; Humans; Male; Middle Aged; Postprandial Period
PubMed: 29300434
DOI: 10.1007/s12603-017-0956-6 -
Trials Jun 2023Different dietary protein sources are supposed to have various effects on metabolic responses and arterial stiffness in the postprandial period. This study aims to...
Postprandial effects of dietary protein source on metabolic responses, appetite, and arterial stiffness indices in overweight and obese men: the study protocol for a randomized crossover clinical trial.
BACKGROUND
Different dietary protein sources are supposed to have various effects on metabolic responses and arterial stiffness in the postprandial period. This study aims to assess the postprandial effects of dietary protein sources, including animal-based protein (AP) and plant-based protein (PP), as part of a high-protein breakfast on appetite response, energy metabolism, and arterial stiffness in overweight and obese men.
METHODS
This acute randomized crossover clinical trial will be conducted at the Persian study research center at Imam Reza Hospital, affiliated with the Mashhad University of Medical Sciences, located in the northeast of Iran. Forty-six healthy overweight, and obese men aged 18-60 years will be enrolled based on the eligibility criteria. The subjects will complete two interventions (high-protein AP and PP meals) with 1 week washout period. The primary outcome will be the acute effect of the two test meals on appetite response, energy metabolism parameters, including resting metabolism rate (RMR), diet-induced thermogenesis (DIT), and substrate oxidation (SO), and arterial stiffness indices, including pulse wave velocity (PWV) and pulse wave analysis (PWA). The secondary outcomes include changes in lipemia, glycemia, and insulinemia.
DISCUSSION
The findings of this study will provide novel insight regarding the acute effects of different protein sources on energy metabolism, appetite, and arterial stiffness as a significant cardiovascular disease (CVD) risk factor. It will help dieticians develop effective and efficient meal plans to improve weight reduction and maintenance in overweight/obese individuals.
TRIAL REGISTRATION
Iranian Registry of Clinical Trials; code: IRCT20211230053570N1; registered on February 10, 2022.
Topics: Humans; Appetite; Overweight; Postprandial Period; Vascular Stiffness; Iran; Pulse Wave Analysis; Blood Glucose; Obesity; Meals; Dietary Proteins; Cross-Over Studies; Randomized Controlled Trials as Topic
PubMed: 37337271
DOI: 10.1186/s13063-023-07374-1