A Whey-Supplemented, High-Protein Diet versus a High-Carbohydrate Diet: Effects on Endurance Cycling Performance

2006 ◽  
Vol 16 (1) ◽  
pp. 65-77 ◽  
Author(s):  
Paul W. Macdermid ◽  
Stephen R. Stannard
Keyword(s):  
High Protein Diet ◽  
Cycling Performance ◽  
High Protein ◽  
Protein Diet ◽  
Endurance Athletes ◽  
Fat Intake ◽  
Physiological Measures ◽  
Carbohydrate Diet ◽  
Endurance Cycling ◽  
Diet Versus

This study compared a training diet recommended for endurance athletes (H-CHO) with an isoenergetic high protein (whey supplemented), moderate carbohydrate (H-Pro) diet on endurance cycling performance. Over two separate 7-d periods subjects (n = 7) ingested either H-CHO (7.9 ± 1.9 g · kg−1 · d−1 carbohydrate; 1.2 ± 0.3 g · kg−1 · d−1 fat; 1.3 ± 0.4 g · kg−1 · d−1 protein) or H-Pro (4.9 ± 1.8 g · kg−1 · d−1; 1.2 ± 0.3 g · kg−1 · d−1; 3.3 ± 0.4 g · kg−1 · d−1) diet in a randomized, balanced order. On day 8 subjects cycled (self-paced) for a body weight dependent (60 kJ/bm) amount of work. No differences occurred between energy intake (P = 0.422) or fat intake (P = 0.390) during the two dietary conditions. Performance was significantly (P = 0.010) impaired following H-Pro (153 ± 36) compared with H-CHO (127 ± 34 min). No differences between treatments were observed for physiological measures taken during the performance trials. These results indicate an ergolytic effect of a 7-d high protein diet on self-paced endurance cycling performance.

scholarly journals Acute effects of glucagon on citrulline biosynthesis

1982 ◽  
Vol 206 (3) ◽  
pp. 627-631 ◽  
Author(s):  
D Rabier ◽  
P Briand ◽  
F Petit ◽  
P Parvy ◽  
P Kamoun ◽  
...  
Keyword(s):  
High Protein Diet ◽  
High Protein ◽  
Protein Diet ◽  
Carbamoyl Phosphate Synthetase ◽  
Acute Effects ◽  
Carbamoyl Phosphate ◽  
Carbohydrate Diet ◽  
Acetylglutamate Synthase

Mitochondria isolated from livers of rats fed on different diets showed altered capacity to synthesize citrulline. Glucagon, 15 min after injection, increases citrulline biosynthesis, except after the high-protein diet. A significant correlation between citrulline biosynthesis and N-acetylglutamate content with and without glucagon treatment was shown when rats were fed on a standard or a carbohydrate diet. Different diets modified carbamoyl phosphate synthetase I (EC 6.3.4.16) and N-acetylglutamate synthase (acetyl-CoA:L-glutamate N-acetyltransferase, EC 2.3.1.1) activities. Glucagon did not modify these activities.

scholarly journals Biochemical aspects of malabsorption in marasmus: effect of dietary rehabilitation

1985 ◽  
Vol 54 (3) ◽  
pp. 567-575 ◽  
Author(s):  
H. C. Mehta ◽  
A. S. Saini ◽  
Harjit Singh ◽  
P. S. Dhatt
Keyword(s):  
Total Energy ◽  
High Fat Diet ◽  
High Protein Diet ◽  
High Carbohydrate Diet ◽  
High Protein ◽  
Protein Diet ◽  
Duodenal Juice ◽  
High Fat ◽  
Carbohydrate Diet ◽  
High Carbohydrate

1. Sixty marasmic children were investigated for the absorption of xylose, proteins and fats. Their duodenal juice samples were also analysed for bile salts and microflora.2. The marasmic children were then studied in three groups of twenty by allocating them to three different dietary schedules: a high-protein diet (30% of the total energy from protein), a high-fat diet (40% of the total energy from fat) and a high-carbohydrate diet (70% of the total energy from carbohydrate) for 2 weeks and the previous measurements repeated.3. Whereas the high-fat diet resulted in improved fat absorption, along with an increase in total and conjugated bile acids, and the high-carbohydrate diet led to improved xylose absorption, the diet rich in protein resulted in an improvement in the absorption of all three dietary ingredients. It appears that a high-protein diet improves the overall absorption process by improving the intestinal environment as a whole, while high-carbohydrate and high-fat diets bring about adaptive changes related to the respective absorptive processes.

Stearic Acid Supplementation in High Protein to Carbohydrate (P:C) Ratio Diet Improves Physiological and Mitochondrial Functions of Drosophila melanogaster parkin Null Mutants

2017 ◽  
Vol 74 (10) ◽  
pp. 1564-1572 ◽  
Author(s):  
Rijan Bajracharya ◽  
Sonia Bustamante ◽  
John William O Ballard
Keyword(s):  
Fatty Acids ◽  
Stearic Acid ◽  
High Protein Diet ◽  
High Carbohydrate Diet ◽  
High Protein ◽  
Protein Diet ◽  
Carbohydrate Diet ◽  
High Carbohydrate ◽  
Mitochondrial Functions ◽  
And Mitochondrial Functions

Abstract Optimizing dietary macronutrients benefits the prevention and management of many human diseases but there is conflicting dietary advice for Parkinson’s disease (PD), and no single strategy is universally recommended. Recently, it was shown that dietary stearic acid (C18:0) improves survival and mitochondrial functions in the parkin null Drosophila model of PD. Here, we incorporate stearic acid into high protein and high carbohydrate diets and study survival, climbing ability, mitochondrial membrane potential, respiration, basal reactive oxygen species, and conduct lipidomics assays. We observed that parkin null flies showed improvement in all assays tested when stearic acid was added to the high protein diet but not to the high carbohydrate diet. When lipid proportion was examined, we observed higher levels in flies fed the high protein diet with stearic acid diet and the high carbohydrate diet. Unexpectedly, free levels of fatty acids exhibited opposite trend. Combined, these data suggest that dietary Protein: Carbohydrate ratio and stearic acid influences levels of bound fatty acids. The mechanisms that influence free and bound fatty-acid levels remain to be explored, but one possible explanation is that breakdown products can bind to membranes and improve the mitochondrial functions of parkin null flies.

Hypocaloric high-protein diet improves glucose oxidation and spares lean body mass: Comparison to hypocaloric high-carbohydrate diet

Metabolism ◽  
1994 ◽  
Vol 43 (12) ◽  
pp. 1481-1487 ◽  
Author(s):  
P.M. Piatti ◽  
L.D. Monti ◽  
Fulvio Magni ◽  
Isabella Fermo ◽  
L. Baruffaldi ◽  
...  
Keyword(s):  
Lean Body Mass ◽  
Body Mass ◽  
Glucose Oxidation ◽  
High Protein Diet ◽  
High Carbohydrate Diet ◽  
High Protein ◽  
Protein Diet ◽  
Carbohydrate Diet ◽  
High Carbohydrate ◽  
Mass Comparison

scholarly journals The effect of dietary composition and of insulin on gluconeogenesis in rainbow trout (Salmo gairdneri)

1977 ◽  
Vol 38 (3) ◽  
pp. 385-395 ◽  
Author(s):  
C. B. Cowey ◽  
M. De La Higuera ◽  
J. W. Adron
Keyword(s):  
Rainbow Trout ◽  
High Protein Diet ◽  
High Carbohydrate Diet ◽  
High Protein ◽  
Protein Diet ◽  
Salmo Gairdneri ◽  
Carbohydrate Diet ◽  
Commercial Diet ◽  
High Carbohydrate ◽  
Gluconeogenesis From Alanine

1. The activities at 15° of three gluconeogenic enzymes, d-fructose-1,6-diphosphate, 1-phosphohydrolase (EC 3.1.3.11), pyruvate carboxylase (EC 6.4.1.1) and phosphoenolpyruvate carboxykinase (4.1.1.32), were determined in liver, kidney, gill and muscle of rainbow trout (Salmo gairdneri) given a commercial diet. The results indicated that liver and kidney are the main sites of gluconeogenesis.2. Glucose formation from pyruvate was approximately 6 μmol/h per g wet weight at 15° in liver slices of trout given a commercial diet.3. Glucose diffusion space in trout was measured by the dilution principle after intravascular injection of a trace dose of [U-14C]glucose. Glucose space was found to be 13.7% of the body-weight. Gluconeogenesis in vivo amounted to approximately 45 μmol/kg body-weight per h.4. Intraperitoneally injected [U-14C]alanine was quickly converted to glucose. Maximal incorporation of alanine into glucose occurred 6 h after alanine administration.5. Rainbow trout given a high-protein diet gained in weight significantly during a 4-week period. Those given a high-carbohydrate diet did not make a significant weight gain over the same period. Gluconeogenesis from alanine was markedly reduced in fish given the high-carbohydrate diet. There was no significant difference in gluconeogenesis from alanine in fish given a high-protein diet and fish which were fasted for 21 d.6. Gluconeogenesis from alanine in trout was suppressed by intravenous injection of insulin. This effect was found both in trout given a high-protein diet and in fasted trout.

Hypocaloric high-protein diet improves fatty liver and hypertriglyceridemia in sucrose-fed obese rats via two pathways

2009 ◽  
Vol 297 (1) ◽  
pp. E76-E84 ◽  
Author(s):  
Takashi Uebanso ◽  
Yutaka Taketani ◽  
Makiko Fukaya ◽  
Kazusa Sato ◽  
Yuichiro Takei ◽  
...  
Keyword(s):  
Lipid Metabolism ◽  
Fatty Liver ◽  
Control Diet ◽  
High Protein Diet ◽  
High Protein ◽  
Protein Diet ◽  
Fibroblast Growth Factor 21 ◽  
Carbohydrate Diet ◽  
Low Carbohydrate Diet ◽  
Obese Rats

The mechanism by which replacement of some dietary carbohydrates with protein during weight loss favors lipid metabolism remains obscure. In this study, we investigated the effect of an energy-restricted, high-protein/low-carbohydrate diet on lipid metabolism in obese rats. High-sucrose-induced obese rats were assigned randomly to one of two energy-restricted dietary interventions: a carbohydrate-based control diet (CD) or a high-protein diet (HPD). Lean rats of the same age were assigned as normal control. There was significantly greater improvement in fatty liver and hypertriglyceridemia with the HPD diet relative to the CD diet. Expression of genes regulated by fibroblast growth factor-21 (FGF21) and involved in liver lipolysis and lipid utilitization, such as lipase and acyl-CoA oxidase, increased in obese rats fed the HPD. Furthermore, there was an inverse correlation between levels of FGF21 gene expression (regulated by glucagon/insulin balance) and increased triglyceride concentrations in liver from obese rats. Expression of hepatic stearoyl-CoA desaturase-1 (SCD1), regulated primarily by the dietary carbohydrate, was also markedly reduced in the HPD group (similar to plasma triglyceride levels in fasting animals) relative to the CD group. In conclusion, a hypocaloric high-protein diet improves fatty liver and hypertriglyceridemia effectively relative to a carbohydrate diet. The two cellular pathways at work behind these benefits include stimulation of hepatic lipolysis and lipid utilization mediated by FGF21 and reduction of hepatic VLDL-TG production by SCD1 regulation.

scholarly journals Inter-organ relationships between glucose, lactate and amino acids in rats fed on high-carbohydrate or high-protein diets

1978 ◽  
Vol 170 (2) ◽  
pp. 321-329 ◽  
Author(s):  
Christian Rémésy ◽  
Christian Demigné ◽  
Jocelyne Aufrère
Keyword(s):  
Amino Acids ◽  
Portal Vein ◽  
High Protein Diet ◽  
High Carbohydrate Diet ◽  
High Protein ◽  
Protein Diet ◽  
Carbohydrate Diet ◽  
Peripheral Tissues ◽  
Main Site ◽  
High Carbohydrate

1. Inter-organ relationships between glucose, lactate and amino acids were studied by determination of plasma concentrations in different blood vessels of anaesthetized rats fed on either a high-carbohydrate diet [13% (w/w) casein, 79% (w/w) starch] or a high-protein diet [50% (w/w) casein, 42% (w/w) starch]. The period of food intake was limited (09:00–17:00h), and blood was collected 4h after the start of this period (13:00h). 2. Glucose absorption was considerable only in rats fed on a high-carbohydrate diet. Portal-vein–artery differences in plasma lactate concentration were higher in rats fed on this diet, but not proportional to glucose absorption. Aspartate, glutamate and glutamine were apparently converted into alanine, but when dietary protein intake was high, a net absorption of glutamine occurred. 3. The liver removed glucose from the blood in rats fed on a high-carbohydrate diet, but glucose was released into the blood in rats fed on the high-protein diet, probably as a result of gluconeogenesis. Lactate uptake was very low when amino acid availability was high. 4. In rats on a high-protein diet, increased uptake of amino acids, except for ornithine, was associated with a rise in portal-vein plasma concentrations, and in many cases with a decrease in hepatic concentrations. 5. Hepatic concentrations of pyruvate and 2-oxo-glutarate decreased without a concomitant change in the concentrations of lactate and malate in rats fed on the high-protein diet, in spite of an increased supply of pyruvate precursors (e.g. alanine, serine, glycine), suggesting increased pyruvate transport into mitochondria. 6. High postprandial concentrations of plasma glucose and lactate resulted in high uptakes of these metabolites in peripheral tissues of rats on both diets. Glutamine was released peripherally in both cases, whereas alanine was taken up in rats fed on a high-carbohydrate diet, but released when the amino acid supply increased. 7. It is concluded that: the small intestine is the main site of lactate production, and the peripheral tissues are the main site for lactate utilization; during increased ureogenesis in fed rats, lactate is poorly utilized by the liver; the gut is the main site of alanine production in rats fed on a high-carbohydrate diet and the liver utilizes most of the alanine introduced into the portal-vein plasma in both cases.

Influence of high-protein and high-carbohydrate diets on serum lipid and fructosamine concentrations in healthy cats

2021 ◽  
pp. 1098612X2110470
Author(s):  
Chad F Berman ◽  
Remo G Lobetti ◽  
Eric Zini ◽  
Geoffrey T Fosgate ◽  
Johan P Schoeman
Keyword(s):  
Serum Cholesterol ◽  
Body Condition Score ◽  
High Protein Diet ◽  
High Carbohydrate Diet ◽  
High Protein ◽  
Protein Diet ◽  
Carbohydrate Diet ◽  
High Carbohydrate ◽  
Lower Serum Cholesterol ◽  
Condition Score

Objectives The aim of this study was to determine whether high-protein and high-carbohydrate diets exert differential effects on serum cholesterol, triglyceride and fructosamine concentrations in healthy cats. Methods A randomised, crossover diet trial was performed in 35 healthy shelter cats. Following baseline health assessments, cats were randomised into groups receiving either a high-protein or high-carbohydrate diet for 4 weeks. The cats were then fed a washout diet for 4 weeks before being transitioned to whichever of the two studied diets they had not yet received. Fasting serum cholesterol, triglyceride and fructosamine concentrations were determined at the end of each 4-week diet period. Results Cats on the high-carbohydrate diet had significantly lower serum cholesterol ( P <0.001) concentrations compared with baseline measurements. Cats on the high-protein diet had significantly higher serum cholesterol ( P <0.001) and triglyceride ( P <0.001) concentrations, yet lower fructosamine ( P <0.001) concentrations compared with baseline measurements. In contrast, overweight cats (body condition score [BCS] >5) had lower cholesterol ( P = 0.007) and triglyceride ( P = 0.032) concentrations on the high-protein diet than cats within other BCS groups. Conclusions and relevance Diets higher in protein and lower in carbohydrates appear beneficial for short-term glucose control in healthy cats. A high-protein diet was associated with significantly elevated cholesterol and triglyceride concentrations in healthy cats, even though the increase was significantly less pronounced in cats with a BCS >5. This finding suggests that overweight cats process high-protein diets, cholesterol and triglycerides differently than leaner cats.

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