Carbohydrate Supplementation Research Articles

A randomised controlled study of preoperative oral carbohydrate loading versus fasting in patients undergoing colorectal surgery

PurposeThis study aimed to evaluate the effect of preoperative carbohydrate oral (CHO) loading on the postoperative metabolic and inflammatory response, perioperative discomfort and surgical clinical outcomes in open colorectal surgery compared with a conventional fasting protocol.MethodsFifty patients were randomly allocated to either the intervention group (CHO), to receive preoperative oral carbohydrate supplementation, or the control group (FAST), to undergo preoperative fasting. Insulin resistance, insulin sensitivity, the Glasgow Prognostic Score (GPS) and IL-6 levels were analysed at 06 h on the day of surgery (T1), 6 h after surgery (T2) and at 06 h on postoperative day 1 (T3) and postoperative day 2 (T4). Thirst, hunger, dry mouth, weakness, anxiety and pain were assessed using the visual analogue scale (VAS) prior to anaesthesia induction and at 0–4, 4–8, 8–12 and 12–24 h after surgery. Surgical clinical outcomes included the return of gastrointestinal function, time to independent ambulation and postoperative discharge day.ResultsPostoperative insulin resistance was 30% lower (p < 0.03) and insulin sensitivity was 15% higher (p < 0.05) in the CHO group than in the FAST group. The GPS was lower in the CHO group at T1 (p < 0.001), T3 (p < 0.01) and T4 (p < 0.004). IL-6 serum levels were lower at the analysed postoperative time points in the CHO group (p < 0.001). The VAS well-being score was lower in the intervention group (p < 0.001); however, the VAS pain score was not significantly different between the groups. The evaluated surgical outcomes appeared earlier in the CHO group (p < 0.001).ConclusionA preoperative CHO drink reduced the postoperative metabolic and inflammatory response and improved subjective well-being and surgical clinical outcomes but did not diminish the VAS pain score.

Glucose Ingestion Inhibits Endurance Exercise-Induced IL-6 Producing Macrophage Infiltration in Mice Muscle.

Background: Carbohydrate (CHO) supplementation during exercise attenuates exercise-induced increases in plasma Interleukin (IL)-6 concentration. However, the effects of CHO supplementation on muscle IL-6 production during endurance exercise is controversial. The purpose of this study was to investigate the effects of CHO supplementation on muscle IL-6 production during endurance exercise with a special focus on the IL-6 producing cells. Methods: C57BL/6J mice were divided into three groups—sedentary with water ingestion group as the control (Con; n = 10), exercise with water ingestion group (Ex; n = 10), and exercise with 6% glucose ingestion group (Ex + glucose; n = 10). The Ex and Ex + glucose groups completed 3 h of treadmill running (24 m/min, 7% incline) and were sacrificed immediately after exercise. Results: The exercise-induced increases of plasma IL-6 concentration and gastrocnemius IL-6 gene expression were attenuated by glucose ingestion. However, the increases of soleus IL-6 gene expression and gastrocnemius and soleus IL-6 protein expression were not attenuated by glucose ingestion. Furthermore, we observed that macrophages that infiltrated muscle produce IL-6 and glucose ingestion attenuated the infiltration of IL-6-producing macrophages. Conclusion: This study revealed that infiltrating macrophages may be one type of IL-6-producing cells during endurance exercise, and the infiltration of these cells in muscle was attenuated by glucose ingestion. However, the effects of glucose ingestion on muscle IL-6 production were limited.

Combined HIIT and Resistance Training in Very Long-Chain Acyl-CoA Dehydrogenase Deficiency: A Case Report.

Very long-chain acyl-CoA dehydrogenase deficiency (VLCADD) is a rare disorder of mitochondrial fatty acid β-oxidation characterized by a spectrum of clinical manifestations. Patients with the adult-onset form can present with muscle pain, rhabdomyolysis and myoglobinuria after physiological stress, such as fasting and exercise. We report on a 23-year-old female patient with a history of recurrent rhabdomyolysis. The patient completed a 6-month supervised combined (high-intensity interval training [HIIT] + resistance training) program, with the addition of a medium chain triglyceride + carbohydrate supplement provided 60 min before each session. The HIIT consisted of 6 sets of 70–80 s performed at maximum intensity with a minimum cadence of 100 rpm. Resistance training consisted of a circuit of basic exercises with dumbbells and elastic bands, with sets of 4–7 repetitions. The patient was evaluated at months 0, 3 and 6 using an incremental discontinuous step protocol, with steps of 1 min of exercise/1 min of passive recovery, at a high pedal cadence. The test started at 10 W, with a load increase of 10 W/step. Blood creatine kinase (CK) concentration was measured before each evaluation. There was a training-induced increment of 90.2% in peak oxygen uptake (VO2peak), 71.4% in peak power output and 24.7% in peak heart rate. The patient reported no muscle pain, contractures, rhabdomyolysis (basal CK concentration was always <200 U/L) or hospital admissions during the training period. After completion of 6-month program, the patient remained active, doing similar but non-supervised training for 1.5 years (to date). During this period, the patient has not reported myalgias, contractures, rhabdomyolysis or hospital admissions. Our preliminary data suggest that it is possible to carry out a combined (HIIT + strength) training program in patients with VLCADD, safely (without muscle contractures or rhabdomyolysis) and obtaining high values of VO2peak and cycling power output.

Effects of energy sources and inclusion levels of concentrate in sugarcane silage-based diets of finishing Nellore young bulls: Feeding behaviour, performance and blood parameters

AbstractReplacing ground maize (GM) with steam-rolled maize typically increases feed efficiency in maize-silage-based diets. However, little is known about optimal carbohydrate supplementation in sugarcane silage-based diets. The objective was to quantify the effect of partially replacing GM with steam-rolled maize (SRM) or pelleted citrus pulp (PCP) at two concentrate levels (600 or 800 g/kg DM) in sugarcane-based diets on feeding behaviour, performance and blood parameters of finishing Nellore bulls. One hundred and eight young bulls were allocated to 36 pens in a randomized block design and fed for 84 d. Feeding 800 g/kg concentrate decreased time spending eating and ruminating, but improved G:F ratio, hot carcass weight and carcass dressing, compared to 600 g/kg concentrate. Bulls fed SRM and PCP diets with 600 g/kg concentrate had lower intake compared to GM. Both final weight and average daily gain decreased when bulls were fed PCP and SRM with 600 g/kg concentrate compared to GM diets, and when fed with PCP and 800 g/kg concentrate. Substituting PCP for GM decreased gain efficiency, carcass weight, rumination time and intake efficiency, indicating that the bulls consumed less feed per hour spent eating. Substituting SRM for GM increased backfat thickness and blood urea concentration. In conclusion, the replacement of GM with PCP reduces intake and enhances selection against large particles, decreasing rumination, performance and final carcass weight and dressing. Replacement of GM with SRM increases blood urea and fat deposition, with no impact on performance.

Effect of a Ketogenic Diet on Submaximal Exercise Capacity and Efficiency in Runners.

We investigated the effect of a 31-d ketogenic diet (KD) on submaximal exercise capacity and efficiency. A randomized, repeated-measures, crossover study was conducted in eight trained male endurance athletes (V˙O2max, 59.4 ± 5.2 mL⋅kg⋅min). Participants ingested their habitual diet (HD) (13.1 MJ, 43% [4.6 g⋅kg⋅d] carbohydrate and 38% [1.8 g⋅kg⋅d] fat) or an isoenergetic KD (13.7 MJ, 4% [0.5 g·kg⋅d] carbohydrate and 78% [4 g⋅kg⋅d] fat) from days 0 to 31 (P < 0.001). Participants performed a fasted metabolic test on days -2 and 29 (~25 min) and a run-to-exhaustion trial at 70% V˙O2max on days 0 and 31 following the ingestion of a high-carbohydrate meal (2 g⋅kg) or an isoenergetic low-carbohydrate, high-fat meal (<10 g CHO), with carbohydrate (~55 g⋅h) or isoenergetic fat (0 g CHO⋅h) supplementation during exercise. Training loads were similar between trials and V˙O2max was unchanged (all, P > 0.05). The KD impaired exercise efficiency, particularly at >70% V˙O2max, as evidenced by increased energy expenditure and oxygen uptake that could not be explained by shifts in respiratory exchange ratio (RER) (all, P < 0.05). However, exercise efficiency was maintained on a KD when exercising at <60% V˙O2max (all, P > 0.05). Time-to-exhaustion (TTE) was similar for each dietary adaptation (pre-HD, 237 ± 44 vs post-HD, 231 ± 35 min; P = 0.44 and pre-KD, 239 ± 27 vs post-KD, 219 ± 53 min; P = 0.36). Following keto-adaptation, RER >1.0 vs <1.0 at V˙O2max coincided with the preservation and reduction in TTE, respectively. A 31-d KD preserved mean submaximal exercise capacity in trained endurance athletes without necessitating acute carbohydrate fuelling strategies. However, there was a greater risk of an endurance decrement at an individual level.

Enzymatic demethylation of Kraft lignin for lignin-based phenol-formaldehyde resin applications

Wood-rot fungi from the Boreal Forest of Canada were studied for their ability to demethylate Kraft lignin (KL). Demethylation by the action of enzymes (O-demethylases) removed the O-methyl/methoxyl groups of lignin liberating methanol, and produced a demethylated KL enriched in vicinal-hydroxyl groups with potential to serve as lignin-based phenol-formaldehyde polymers. Screening experiments identified the liberation of methanol (measured by selected-ion flow-tube mass spectrometry), lignin-demethylating enzymes, alcohol oxidase, and other ligninolytic enzymes. Highest amounts of headspace methanol (parts-per-billion) were detected in the genus Aspergillus, Ctenomyces, Cunninghamella, Penicillium, and Sporobolomyces. Methanol generated from lignin demethylation induced alcohol oxidase activity, but which was higher in Aspergillus, Ctenomyces, Entoloma, and non-sporulating fungi. Among the fungi tested, three brown-rot, i.e., Fomitopsis pinicola and Galerina autumnalis and a mitosporic Aspergillus sp.3 BRI 270, were cultured solely on KL, and lignin model compounds (LMCs) to determine lignin demethylation. Various carbohydrate supplements added to nutrient media containing KL significantly influenced demethylating activity. Aspergillus sp.3 BRI 270 showed the highest degree of lignin demethylation (30.1%) which no evidence presented for this comment occurred when cultivated on KL media supplemented with birchwood xylan as analyzed by 1H NMR following O-acetylation of modified KLs. All fungi demonstrated considerable demethylating activity by utilizing softwood KL, but OrganoSolv lignins (poplar, willow, wheat straw, and mixed agricultural wastes), because of their harsh chemical treatments of extraction, affected the microbial and enzymatic demethylation. Extracellular demethylating enzymes from Aspergillus sp.3 BRI 270 generated high vicinal-diol content (measured by the pyrocatechol titanium(III)-nitrilotriacetate method) in LMCs: 4-hydroxy-3-methoxy cinnamaldehyde (326.00 μmol/mL), syringaldehyde (102.67 μmol/mL), and Kraft lignin (397.46 μmol/mL) as analyzed by 1H NMR analysis.

SAT-271 Higher C-Peptide Levels and Glucose Requirements May Identify Neonates with Transient Hyperinsulinism Hypoglycemia Who Will Benefit from Diazoxide Treatment

Background: Hyperinsulinism hypoglycemia in infants is characterized by inappropriate insulin secretion from pancreatic beta-cells. Prompt recognition and treatment are essential to decrease the risk of neurologic sequelae. Neonates with transient hyperinsulinism usually do not require treatment due to its self-limited clinical course, but some may benefit from diazoxide treatment which inhibits insulin secretion. Objectives: To find factors that may serve as a clinical tool to identify neonates with transient neonatal hyperinsulinemia who may benefit from diazoxide treatment. Patients & methods: Retrospective chart review of neonates with transient hyperinsulinism hypoglycemia who were born between 01/01/2015 and 30/04/2018. Results: The study included 141 neonates (93 males). Thirty-four (24%) were treated with diazoxide. Mean gestational age (GA) was 36.0 ± 2.7 weeks (range: 26.2-41.4) and mean birth weight (BW) was 2.175 ± 0.699 Kg (range: 0.744-5.519). The diazoxide-treated and untreated groups were similar in perinatal (GA, BW, Apgar score) and maternal factors (age, number of pregnancies, number of deliveries, diabetes, hypertension, eclampsia). Diazoxide treatment was started at mean age of 14.6 ± 8.0 days (median 13.0, range: 5-35, 95% CI: 11.8-17.4) and discontinued on day 49.2 ± 40.2 of life (median 42.0, range: 14-224, 95% CI: 34.4-63.9). The treatment was well tolerated and without side effects (except for mild hypertrichosis). The maximal diazoxide dose was 7.1 ± 2.3 mg/kg/day (95% CI: 6.3-7.9). Diazoxide-treated neonates required a higher glucose infusion rate (GIR) compared to untreated neonates (16.6 ± 3.4 vs 10.4 ± 4.0 mg/kg/min, p<0.01), had a longer duration of intravenous fluids (15.9 ± 19.3 vs 7.8 ± 6.5 days, p<0.01), longer duration of hospitalization (32.8 ± 22.7 vs 20.4 ± 13.4 days, p<0.01), longer duration of carbohydrate supplementation (38.9 ± 40.4 vs 17.8 ± 21.4 days, p<0.01), and higher mean C-peptide levels (1.4 ± 0.9 vs 0.8 ± 0.5 ng/ml, p<0.01). Their insulin levels tended to be higher (3.5 ± 2.9 vs 2.2 ± 3.8 µU/ml, p=0.07). Summary: Neonates who were treated with diazoxide had a more severe clinical course manifested by higher glucose requirements, longer duration of intravenous glucose infusion, and longer duration of hospitalization. Higher C-peptide levels and higher GIR requirement may serve as a clinical tool to identify neonates with transient hyperinsulinism hypoglycemia who may benefit from diazoxide treatment.

Postprandial Effects on ENaC‐Mediated Sodium Absorption

Recent studies have suggested that postprandial increases in insulin directly contribute to reduced urinary sodium (Na+) excretion by altering renal Na+ transport. While there are a number of renal transporters that respond to insulin stimulation, which of these transporters are involved in this Na+ sparing mechanism under normal physiological conditions is not fully established. The epithelial sodium channel (ENaC) is the rate limiting step for sodium reabsorption in the distal nephron and its regulation by insulin is well established; however, the regulatory effect of acute hyperinsulinemia (as would result from a meal) on ENaC under normal conditions is still being debated. The main objective of this study was to test the contribution of ENaC as well as other Na+ transporters to the increase in renal Na+ reabsorption following a meal. To test this, we used fasted Sprague Dawley rats that had been given a high carbohydrate supplement to simulate a meal and analyzed changes to ENaC activity as well as expression of other renal transporters involved in sodium homeostasis. Postprandial changes in circulating renin‐angiotensin‐aldosterone system (RAAS) hormones known to enhance ENaC activity were also tested. We found that 4 hours post carbohydrate stimulus, ENaC open probability increased relative to controls in split‐open isolated collecting duct tubules (0.34 ±0.06 vs. 0.70 ± 0.07, n≥5, p&lt;0.01), while the number of channels at the surface and total ENaC α‐ and β‐subunit levels remained unchanged. We also examined expression levels of the Na+‐Cl− cotransporter (NCC), Na+‐K+‐2Cl− cotransporter (NKCC2), and Na+‐K+‐ATPase (NKA). While there were no significant differences in expression of NCC or NKCC2 in either group, NKA expression in the postprandial group was significantly increased (1.0 ± 0.08 vs. 1.62 ± 0.10, n=5, p&lt;0.001). Additionally, using mass spectrometry‐based analysis, we interrogated different metabolites of RAAS signaling between the stimulated and fasted rats and found no significant changes in aldosterone or angiotensin metabolite levels. These results suggest that acute hyperinsulinemia following a meal increases ENaC activity independent of the RAAS signaling cascade. Our study demonstrates that ENaC and NKA regulation via insulin is a likely contributor to an evolutionary mechanism for preserving sodium and volume loss after a meal, and that this regulation is distinct from classical ENaC regulation by RAAS.Support or Funding InformationT32 HL134643; R35 HL135749, HL56259This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

P4 medicine for epilepsy and intellectual disability: nutritional therapy for inherited metabolic disease.

Early identification and treatment of inherited metabolic diseases (IMDs) are essential to prevent and minimize intellectual disability (ID) and epilepsy. The oldest form of treatment, nutritional modulation, has proved beneficial for many IMDs. These conditions represent a promising model for P4 medicine - predictive, preventive, personalized, and participatory - specifically through the interpretation of individual genetic, pathophysiological, and clinical characteristics. More than 1000 IMDs have been described, and for these different nutritional modulation strategies are applied, varying from substrate reduction, supplementation of vitamins for catalyzation of enzymatic reactions or supplementation of amino acids or other nutrients, to substitution for deficient or inactivated products. This review provides an overview of all IMDs presenting with epilepsy and/or ID amenable to nutritional modulation; these are 85 in number, belonging to 27 categories. Therapeutic strategies include protein-restricted diet, ketogenic diet, fat-restricted diet, lactose-restricted diet; supplementation of amino acids, carbohydrates, or others; and supplementation of vitamins or cofactors as well as a sick-day protocol. Nutritional therapies are generally safe, affordable, and accessible, but compliance is an issue. Three different types of response exist: (1) a positive effect on seizure control and/or psychomotor development; (2) efficacy in prevention of decompensation but ongoing damage occurs; and (3) insufficient insights or evidence to establish the treatment as effective. For the latter category, we describe pyridoxine-dependent epilepsy as a case vignette for P4 medicine, discuss the benefits and challenges of nutritional modulation in IMDs, and outline novel approaches and solutions.

Using poly-β-hydroxybutyric as an additional carbohydrate for biofloc in a shrimp Litopenaeus vannamei bioflocs nursery system with brackish water

Biofloc technology involves manipulation of the C/N ratio to convert toxic nitrogenous wastes into useful microbial protein and helps improve the water quality in a closed system. Poly-β-hydroxybutyric (PHB) has been demonstrated to have positive effects on aquatic animals in an aquaculture system. A 40-day lab scale trial was carried out to investigate the potential of PHB as an additional carbohydrate for a shrimp Litopenaeus vannamei bioflocs nursery in brackish water. Three methods of carbohydrate supplementation were investigated. The first method was the addition of glucose daily at a percentage of 75% of the feed (GLU-group). The second method was the addition of PHB plus glucose; when the total ammonia nitrogen (TAN) level above 2 mg L−1 was observed, glucose was added, 6 g C to 1 g TAN (PHB + GLU-group). The third method was the addition of PHB only (PHB-group). During the 40-d trial, most of the ratios of dissolved organic carbon to total ammonium nitrogen (DOC/TAN) were maintained at 20 in the three groups. The average concentration of TAN in the PHB + GLU-group (0.23 ± 0.19 mg L−1) was significantly lower than those of the GLU-group (0.28 ± 0.26 mg L−1) and the PHB-group (0.30 ± 0.33 mg L−1) (P < .05). The average concentration of nitrite nitrogen in the PHB-group (0.16 ± 0.24) was significantly lower than those of the GLU-group and the PHB-group (P < .05). The concentrations of TAN and nitrite nitrogen from the PHB + GLU-group were more stable than those from the PHB-group and GLU-group. Nitrate nitrogen accumulated, as expected, in the three groups, and no significant differences were observed (P > .05). The survival rate and final weight in the PHB + GLU group were significantly higher than those of the other groups (P < .05). The food conversion ratio of the PHB group (1.52 ± 0.23) was significantly lower than those of the other groups. Taken together, our results showed that PHB is a favorable and convenient additional carbohydrate for shrimp Litopenaeus vannamei biofloc nurseries in brackish water. PHB + GLU was the best carbohydrate supplementation method.

Responses of glucosensing system to glucose in Japanese flounder Paralichthys olivaceus fed diets with different carbohydrate content.

A 10-week feeding trial was conducted to investigate the response of glucosensing system to glucose in Japanese flounder Paralichthys olivaceus (initial body weight: 7.14 ± 0.10 g) fed diets with different carbohydrate content. Two experimental diets were designed as carbohydrate free (CF) and suitable carbohydrate (SC) supplementation, respectively. The dietary carbohydrate contents were 0.93% and 15.6%, respectively. After a 10-week feeding trial, a glucose tolerance test (GTT) was performed. Results showed that after the last meal in the feeding trial, the blood glucose of fish fed with diet CF peaked at 3 h (4.64 ± 0.29 mM), the duration of hyperglycemia was about 5 h (1-6 h). The blood glucose in SC group peaked at 9 h (3.28 ± 0.66 mM), and the duration of hyperglycemia was approximately 6 h (6-12 h). After GTT, blood glucose reached the first peak at 6 h both in the two groups, and the duration of hyperglycemia was obvious 24 h. During the 3-12 h after injection, blood glucose level in SC group was significantly higher than that in CF group. However, blood glucose level in group SC was significantly lower than that in group CF at 24 h. The blood glucose level decreased to half of the peak at 10.97 h after injection of glucose in SC group and at 27.26 h in CF group. The 6-24 h clearance ability in SC group (6.57 ± 1.68%/h) was significantly higher than that in CF group (2.81 ± 1.11%/h). Compared with CF diet, SC diet significantly increase the expression of glucosensing-related genes including glucose facilitative transporter type 2, glucokinase, inward rectifier K+ channel pore type 6.2, sulfonylurea receptor, carnitine palmitoyltransferase 1b, hydroxyacyl-CoA dehydrogenase, cytochrome c oxidase subunit 4, mitochondrial uncoupling protein 2a, liver X receptor, sodium/glucose co-transporter 1, a heterodimer of type 1 receptor subunits depending on T1R2 + T1R3 in liver and intestine. Meanwhile, activities of glucokinase, pyruvate kinase and glycogen synthase in liver, and hepatic glycogen content were also increased. In conclusion, glucosensing systems in Japanese flounder are responsive to dietary carbohydrate levels, especially the suitable dietary carbohydrate level, at which the glucose tolerance capacity of Japanese flounder was improved.

Carbohydrate consumption and variable-intensity exercise responses in boys and men.

The effect of carbohydrate (CHO) supplementation on physiological and perceptual responses to steady-state exercise has been studied in children. However, little is known about these responses to variable-intensity exercise (VIE) and how these responses might differ from adults. This study examined the physiological and perceptual effects of CHO on VIE in boys and men. Eight boys (11.1 ± 0.9years) and 11 men (23.8 ± 2.1years) consumed CHO or a placebo (PL) beverage before and throughout VIE (three 12-min cycling bouts with intensity varying every 20-30s between 25, 50, 75, and 125% peak work rate). Pulmonary gas exchange was assessed during the second 12-min bout. RPE was assessed twice per bout. In CHO, blood glucose increased and then decreased more from pre-exercise to 12min and was higher in this trial at the end of exercise in men versus boys. In boys, blood glucose in CHO was higher at 24 and 36min of exercise than in PL. RER during the CHO trial was higher in both groups; the other physiological responses were unaffected by CHO. All RPE measures (whole body, legs and chest) increased over time, but were not different between groups or trials. Blood glucose patterns during VIE were differentially affected by CHO in boys and men, but most physiological and perceptual responses to VIE were unaffected by CHO in either group. Knowledge of the underlying mechanisms of glucose regulation and effects on physical performance during this type of exercise in children is warranted.

Body Composition and Dietary Pattern of Iranian Male Soccer Players, a Large National Study

Background: Body composition and dietary pattern in athletes are important factors in improving performance. The athletes use a wide range of supplements, most of which are not prescribed by specialists. Objectives: The aims of the present study were the assessment of body composition and food frequency questionnaire of elite Iranian soccer players in Tehran province. The type and frequency of used supplements were assessed. Methods: The study was a cross-sectional study on 10 - 34 year-old male soccer players. Body composition was measured by body impedance analyzer. Dietary pattern was assessed by food frequency questionnaire. The type and frequency of used supplements assessed was evaluated by an open-ended questionnaire with the main supplement groups. Results: In total, 3839 soccer players from Tehran leagues participated in this study. The mean ± SD height, age, weight, and body mass index (BMI) of the participants were 170.7 ± 10.6 cm, 17.8 ± 4.2 years, 61.9 ± 12.9 kg and 21.0 ± 2.8 Kg/m2, respectively. The most frequently used in the main food groups was bread in grain group (82%, 4 - 7 times/week). Skeletal muscle mass had a significant relationship with the frequency of high protein containing foods consumption (P: 0.007) (CI: 0.004 - 0.02). Energy drinks (11.4%), antioxidant and vitamins supplements (6.4%), carbohydrate supplements (6.3%) and protein supplements (5.7%) were the more frequent supplements used. Conclusions: The present study showed that body composition of Iranian young male soccer players had some differences in relation to that in the other countries. The soccer players should be educated in the field of healthy nutrition and best food groups and supplement selection.

Chocolate Milk versus carbohydrate supplements in adolescent athletes: a field based study

PurposeThe purpose of this study is to translate laboratory-based research on beverage-based supplements to a naturalistic, field setting in adolescent athletes. To this end, we tested the effects of two commercially-available drinks on strength in a field-based setting with both male and female high school athletes completing a summer training program.MethodsOne hundred and three high school athletes completed the study (M age = 15.3, SD = 1.2; 70.9% male; 37.9% Afr. Amer.). Measures included a composite strength score (bench press + squat). Participants completed 1 week of pre- and post-testing, and 4 days per week of strength and conditioning training for 5 weeks. Participants were randomly-assigned to receive either CM or CHO immediately post-exercise.ResultsA 2 (group) × 2 (time) repeated measures ANOVA showed there was a significant main effect on time for increase in the composite strength score (p = .002, ŋp2 = .18). There was a significant interaction of composite strength score between groups, (p = .04, ŋp2 = .08). The CM group (12.3% increase) had significantly greater improvements in composite strength from pre- to post-test than CHO (2.7% increase). There were no differences in these results based on demographic variables.ConclusionThis is the first study comparing the impact of CM and CHO on athletic outcomes in an adolescent population in a field-based environment. CM had a more positive effect on strength development and should be considered an appropriate post-exercise recovery supplement for adolescents. Future research will benefit from longer study durations with larger numbers of participants.

Effects of previous carbohydrate supplementation on muscular fatigue: double-blind, randomized, placebo-controlled crossover study

Abstract AIMS The aim of this study was to examine the effects of previous carbohydrate supplementation on high-volume resistance exercise performance METHODS Twenty males physically independent adults aged ≥18 years participated in a double-blind randomized placebo-controlled crossover study. Sixty minutes before the experimental protocol, each participant ingested 0,6 g.kg of body mass-1 of carbohydrate supplementation or placebo. Maximum voluntary isometric contraction tests were performed before and after the dynamic fatigue induction protocol consisting of 10 sets of 8 repetitions of right leg knee extensors at 120o s-1. RESULTS Lower decrement of the isometric peak torque (p<0,001) and of the rate of torque development (p<0,001) was observed in carbohydrate supplementation after the dynamic protocol. Both concentric and eccentric peak torque differed significantly (p<0,001) between carbohydrate supplementation and placebo treatments from the second set, although the slope of the force-repetitions curve was not different between them. Additionally, the carbohydrate supplementation resulted in a lower session rating of perceived exertion (p<0,05). CONCLUSIONS Previous carbohydrate supplementation attenuates muscle fatigue and internal load exercise in a high-volume isokinetic leg protocol.

Case studies: Effects of beef, whey and carbohydrate supplementation in female master triathletes

Appropriate nutritional supplementation is crucial for athletic performance, particularly for female endurance athletes as their numbers steadily increase. This report involves a set of six case studies examining the effects of ingesting a post-workout supplement containing beef, or whey or carbohydrate on iron status, blood indices, muscular thickness, peak oxygen consumption (VO2 max) and body composition in six female masters-age (> 35 years old) triathletes. Over a 10-week training period, a 20 g supplement was ingested immediately post workout or during breakfast on the non-training days. Of the six analyzed cases, two ingested protein powder from beef, two consumed whey, and two consumed maltodextrin. Data showed that concomitant with increased dietary iron ingestion, levels of the iron-storage protein ferritin increased in beef-consumers (by 56% and 74 %) and carbohydrate-consumers (by 71% and 27 %), but decreased in whey-consumers (by 55% and 36%). Contrastingly, the effect on transferrin levels was highly variable between participants in each supplementation case. The whey-consumers showed reduced RBC count (by 6%), hematocrit (by 8%) and red blood cell distribution width (by 14% and 5%). While one beef-consumer showed a remarkable 34% increase in platelets, the whey and carbohydrate-consumers showed reduced platelets, but increased neutrophil: lymphocyte ratio. Vastus medialis thickness reduced in carbohydrate-consumers (by 6% and 5%), unlike the beef and whey-consumers. Females consuming beef increased iron stores and platelets, while those ingesting whey were unable to maintain specific RBC indices. Only the four athletes ingesting protein-containing supplements were able to maintain muscle thickness, thereby averting muscle loss.

Late-Evening Carbohydrate and Branched-Chain Amino Acid Snacks Improve the Nutritional Status of Patients Undergoing Hepatectomy Based on Bioelectrical Impedance Analysis of Body Composition

Background: This prospective study measured body composition based on bioelectrical impedance analysis (BIA) in relation to preoperative and postoperative nutritional support and status in patients undergoing liver surgery. Methods: Thirty-sevenpatients with impaired liver function (indocyanine green retention rate at 15 min >15%) undergoing hepatectomy for hepatocellular carcinoma or colorectal liver metastasis were enrolled. The control group (n = 10) received no nutritional supplementation. The late-evening snack (LES, n = 26) group received a 210-kcal snack comprising a carbohydrate with branched-chain amino acids for 2 weeks before surgery through to 12 weeks after surgery. BIA of body composition, including body cell mass and skeletal muscle volume, was performed. Results: Although there was no sarcopenia based on the consensus report of the Asian Working Group 2 weeks before surgery, the skeletal muscle volumes in the control and LES groups were at the lower limit of the normal range. Body cell mass and skeletal muscle volume were significantly lower in the control group than in the LES group at 4 (p = 0.03) and 12 (p = 0.02) weeks after surgery. Conclusion: Late-evening carbohydrate and branched-chain amino acid snack supplementation may improve nutritional status in patients with impaired liver function undergoing hepatectomy.

The effect of 1,3-butanediol and carbohydrate supplementation on running performance

ObjectivesIngested ketogenic agents offer the potential to enhance endurance performance via the provision of an alternative exogenous, metabolically efficient, glycogen-sparing fuel (i.e. ketone bodies). This study aimed to assess the impact of combined carbohydrate and 1,3-butanediol (CHO-BD) supplementation on endurance performance, blood beta-hydroxybutyrate (βHB) concentration and glycolytic activity, in comparison to carbohydrate supplementation alone (CHO). DesignEleven male runners (age 38±12years, mass 67.3±6.5kg, height 174.5±5.0cm, V˙O2peak 64.2±5.0ml⋅kg−1⋅min−1) performed two experimental trials in a randomised crossover design. MethodsEach trial consisted of 60min of submaximal running, followed by a 5km running time-trial (TT), and was performed following the ingestion of an energy matched ∼650ml drink (CHO-BD or CHO). ResultsThere was no difference in TT completion time between the trials (CHO: 1265±93, CHO-BD: 1261±96s; p=0.723). However, blood βHB concentration in the CHO-BD trial was at least double that of the CHO trial at all time points following supplementation (p<0.05). While blood lactate concentration was lower in the CHO-BD versus CHO trial after 30min submaximal exercise (CHO-BD: 1.46±0.67mmol⋅L−1, CHO: 1.77±0.46mmol⋅L−1, p=0.040), it was similar at other time points. Blood glucose concentrations were higher post-TT in the CHO-BD trial (CHO-BD: 5.83±1.02mmol⋅L−1, CHO: 5.26±0.95mmol⋅L−1, p=0.015). ConclusionsAn energy matched CHO-BD supplementation drink raised βHB concentration and acutely lowered blood lactate concentration, without enhancing 5km TT running performance.

EFFECTS OF RESISTANCE TRAINING COMBINED WITH WHEY PROTEIN AND CARBOHYDRATES SUPPLEMENTATION ON BODY COMPOSITION AND STRENGTH IN YOUNG ADULT MEN

The purpose of this study was to determine the effects of whey protein vs carbohydrate supplementation during eight weeks of resistance training on body composition and strength in young adult men. Fifteen young adult men (age 21±5 years; body height: 178.63±4.1 cm; body mass 81.73 ± 4.97 kg) were randomly assigned to three groups: a whey protein group (WP; 1g/kg immediately after resistance training, n=5), a carbohydrates group (CHO; 30g during and 30g immediately after resistance training, n=5) or a control group (K; n=5) for 8 weeks of resistance training. All the participants were tested for each of the following body composition parameters: body mass (BM), fat free mass (FFM), fat mass (FM), glycogen mass (GM), muscle mass (MM), total body water (TBW), extracellular water (EW), intracellular water (IW). Also, the participants were assessed for muscle strength 1RM bench press, 1RM squat, 1RM shoulder press and maximum pull-ups. Data were analyzed with a two-way mixed model ANOVA (p&lt;0.05). The results indicated that the WP group decreased FM, increased MM and had greater results for the 1RM squat than the CHO and K group (p&lt;0.05). The CHO group improved their results for the 1RM bench press, 1RM squat and 1RM seated barbell press behind the neck and decreased FM more than the K group (p&lt;0.05). In conclusion, young adult men who consumed whey protein during 8 weeks of resistance training achieved greater effects on body composition and strength than adult men who consumed carbohydrates supplementation during 8 weeks of resistance training or young adult men who trained 8 weeks without supplementation.

Effects of rumen-protected carbohydrate supplementation on performance and blood metabolites in feedlot finishing steers during heat stress

The objective of this experiment was to evaluate the inclusion of a rumen-protected carbohydrate (RPC) on growth performance and blood metabolites of finishing steers during the summer. A 62-d feedlot study was conducted using 135 Angus crossbred steers (body weight = 287 ± 13 kg). All animals were fed a basal diet (BD), then treatments were top-dressed. The treatments were the same composition and only varied in ruminal degradability. Treatments were 1) a BD with 1 kg/d of a control supplement (0RPC), 2) the BD plus 0.5 kg/d of the control supplement and 0.5 kg/d of RPC (0.5RCP), and 3) the BD with 1 kg/d of RPC supplement (1RPC). Temperature humidity index and cattle panting scores (CPS) were measured daily during the experiment. Growth performance, back-fat over the 12th rib (BF), LM area, blood glucose and plasma insulin, urea, and nonesterified fatty acid concentrations were measured. Data were statistically analyzed (PROC Mixed, SAS) using treatment, time, and their interaction as a fixed variable and pen as a random variable. There were no differences (P > 0.10) between the three treatments on CPS, BF, and LM area on day 62. There was a trend (P = 0.06) for treatment effect for a greater body weight on the 0.5RPC, and a treatment effect for dry matter intake (P = 0.05). Treatment × day interactions were observed for average daily gain (ADG, P =0.04), suggesting a different response to treatments during the different sampling periods. There was a treatment effect for blood glucose concentration (P = 0.03), having the 0RPC the greatest concentration. Treatment × day interactions were found for plasma insulin concentration (P = 0.01). The results suggest that the response to RPC supplementation depends in part on environment. The use of 0.5 kg/d of RPC tends to improve overall body weight; however, the response to RPC on ADG and plasma insulin concentration depend on the time of sampling.