Concurrent and carryover effects of feeding blends of protein and amino acids in high protein diets with different concentrations of forage fiber to fresh cows. 2. Protein balance and body composition

2021 ◽  
Author(s):  
A.W. Tebbe ◽  
W.P. Weiss
Keyword(s):  
Amino Acids ◽  
Body Composition ◽  
High Protein ◽  
Carryover Effects ◽  
Protein Balance ◽  
High Protein Diets ◽  
Protein Diets

Dietary protein paradox: decrease of amino acid availability induced by high-protein diets

1993 ◽  
Vol 264 (6) ◽  
pp. G1057-G1065 ◽  
Author(s):  
C. Moundras ◽  
C. Remesy ◽  
C. Demigne
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Dietary Protein ◽  
High Protein ◽  
Glutamine Metabolism ◽  
Metabolic Adaptation ◽  
Casein Diet ◽  
Serine Dehydratase ◽  
High Protein Diets ◽  
Protein Diets

The aim of the present study was to evaluate the effect of changes in dietary protein level on overall availability of amino acids for tissues. For this purpose, rats were adapted to diets containing various concentrations of casein (7.5, 15, 30, and 60%) and were sampled either during the postprandial or postabsorptive period. In rats fed the protein-deficient diet, glucogenic amino acids (except threonine) tended to accumulate in plasma, liver, and muscles. In rats fed high-protein diets, the hepatic balance of glucogenic amino acids was markedly enhanced and their liver concentrations were consistently depressed. This response was the result of a marked induction of amino acid catabolism (a 45-fold increase of liver threonine-serine dehydratase activity was observed with the 60% casein diet). The muscle concentrations of threonine, serine, and glycine underwent changes parallel to plasma and liver concentrations, and a significant reduction of glutamine was observed. During the postabsorptive period, adaptation to high-protein diets resulted in a sustained catabolism of most glucogenic amino acids, which accentuated the drop in their concentrations (especially threonine) in all the compartments studied. The time course of metabolic adaptation from a 60 to a 15% casein diet has also been investigated. Adaptation of alanine and glutamine metabolism was rapid, whereas that of threonine, serine, and glycine was delayed and required 7-11 days. This was paralleled by a relatively slow decay of liver threonine-serine dehydratase (T-SDH) activity in contrast to the rapid adaptation of pyruvate kinase activity after refeeding a high-carbohydrate diet.(ABSTRACT TRUNCATED AT 250 WORDS)

scholarly journals Impact of dietary macronutrient profile on feline body weight is not consistent with the protein leverage hypothesis

2018 ◽  
Vol 120 (11) ◽  
pp. 1310-1318
Author(s):  
David Allaway ◽  
Carlos H. de Alvaro ◽  
Adrian Hewson-Hughes ◽  
Ruth Staunton ◽  
Penelope Morris ◽  
...  
Keyword(s):  
Body Composition ◽  
Body Weight ◽  
Energy Content ◽  
High Protein ◽  
Protein Energy ◽  
Average Loss ◽  
Metabolisable Energy ◽  
Adult Cats ◽  
High Protein Diets ◽  
Protein Diets

AbstractThe protein leverage hypothesis proposes that the need to prioritise protein intake drives excess energy intake (EI) when the dietary ratio of protein to fat and carbohydrate is reduced. We hypothesised that cats may become prone to overconsuming energy content when moderate protein diets were offered, and considered the potential influence of fat and carbohydrate on intake. To determine the effect of dietary protein and macronutrient profile (MNP) on EI, weight and body composition, cats (1–4 years) were offered food in excess of energy requirements (ER). A total of six diets were formulated, containing moderate (approximately 7 % w/w; approximately 22 % metabolisable energy (ME)) or high (approximately 10 % w/w; approximately 46 % ME) protein and varying levels of carbohydrate and fat. For 4 weeks, 120 cats were offered 100 % of their individual ER of a diet at the MNP selected by adult cats (50:40:10 protein energy ratio:fat energy ratio:carbohydrate energy ratio). EI, body weight (BW), body composition, activity and palatability were measured. Subsequently, cats were offered one of the six diets at 200 % of their individual ER for 4 weeks when measurements were repeated. Cats offered excess high protein diets had higher EI (kJ/kg) throughout, but at 4 weeks BW was not significantly different to baseline. Cats offered excess moderate protein diets reduced EI and gradually lost weight (average loss of 0·358 (99 % CI 0·388, 0·328) kg), irrespective of fat:carbohydrate and initial palatability. The data do not support the protein leverage hypothesis. Furthermore, cats were able to adapt intake of a wet diet with high protein in an overfeeding environment within 28 d.

scholarly journals Stimulation of amino acid transport into liver cells from rats adapted to a high-protein diet

1982 ◽  
Vol 206 (1) ◽  
pp. 13-18 ◽  
Author(s):  
P Fafournoux ◽  
C Rémésy ◽  
C Demigné
Keyword(s):  
Amino Acids ◽  
Decisive Role ◽  
High Protein Diet ◽  
Isolated Hepatocytes ◽  
Hepatic Uptake ◽  
High Protein ◽  
Protein Diet ◽  
High Protein Diets ◽  
Protein Diets

After adaptation of rats to a 90%-casein diet, hepatic uptake of alanine is strikingly increased in vivo, with concomitant appearance of a concentration of favourable for uptake. With a high-protein diet, uptake of 2-aminoisobutyrate by isolated hepatocytes in the presence of various concentrations of substrates suggested induction of the A system (high-affinity system), whose emergence has been reported during starvation or after glucagon treatment. The other system (ASC, L) were characterized: induction processes only affected the A system. Dibutyryl cyclic AMP addition resulted in an increase in 2-aminoisobutyrate transport at low substrate concentration, the response being greater after adaptation to a high-protein diet. Evidence is presented suggesting that the increased uptake of amino acids by the liver of rats fed on high-protein diets is obtained by developing favourable gradients and enhancing transport capacities. These adaptations allow sufficient amounts of amino acids to enter the liver, where accelerated metabolism plays a decisive role.

Familial Hypoglycemia Precipitated by Amino Acids

PEDIATRICS ◽  
1956 ◽  
Vol 18 (2) ◽  
pp. 192-192
Keyword(s):  
Amino Acids ◽  
Isovaleric Acid ◽  
High Protein ◽  
Dramatic Effect ◽  
Low Protein ◽  
Normal Individuals ◽  
True Blood ◽  
Protein Feeding ◽  
High Protein Diets ◽  
Protein Diets

This paper reports three cases of hypoglycemia in one family and an unrelated case in which profound hypoglycemia and convulsions were produced by the administration of proteins or amino acids. The patients described are similar to the group which have been reported in the literature as infantile idiopathic hypoglycemosis. Casein, leucine, and isovaleric acid fed to the patients caused a marked fall in the fasting concentration of true blood sugar. High protein feeding led to more convulsions and lower concentrations of sugar in the blood than did a low protein diet. Leucine had the most dramatic effect. Casein and leucine did not produce a fall in the sugar in the blood in normal individuals. The literature on metabolic interrelations between amino acids and carbohydrates and the concentration of sugar in the blood is reviewed. The mode of action of amino acids in depressing the concentration of sugar in the blood in infants with spontaneous hypoglycemia is considered and several hypotheses proposed. This paper is of unusual interest and of great importance for the treatment of infants with spontaneous idiopathic hypoglycemia. It is suggested that in this particular type of hypoglycemia high protein diets should be avoided. Small amounts of carbohydrate may be given 30 to 40 minutes after the ingestion of a meal containing protein to offset the effect of protein in lowering the concentration of sugar in the blood.

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