scholarly journals Effect of Overeating Dietary Protein at Different Levels on Circulating Lipids and Liver Lipid: The PROOF Study

Nutrients ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 3801
Author(s):  
George A. Bray ◽  
Leanne M. Redman ◽  
Jennifer Rood ◽  
Lilian de Jonge ◽  
Steven R. Smith
Keyword(s):  
Fatty Acids ◽  
Free Fatty Acids ◽  
Dietary Fat ◽  
Dietary Protein ◽  
Hdl Cholesterol ◽  
Fat Free Mass ◽  
Protein Diet ◽  
Liver Fat ◽  
Low Protein ◽  
Protein Diets

Background: During overeating, a low protein diet slowed the rate of weight gain and increased the energy cost of the added weight, suggesting that low protein diets reduced energy efficiency. The Protein Overfeeding (PROOF) study explored the metabolic changes to low and high protein diets, and this sub-study examined the changes in body composition and blood lipids when eating high and low protein diets during overeating. Methods: Twenty-three healthy volunteers (M = 14; F = 9) participated in an 8-week, parallel arm study where they were overfed by ~40% with diets containing 5% (LPD = low protein diet), 15% (NPD = normal protein diet), or 25% (HPD = high protein diet) protein. Dual energy X-ray absorptiometry (DXA) and computer tomography (CT) were used to quantify whole body and abdominal fat and intrahepatic lipid, respectively. Metabolites were measured by standard methods. Results: Protein intake and fat intake were inversely related since carbohydrate intake was fixed. Although overeating the LPD diet was associated with a significant increase in high density lipoprotein (HDL)-cholesterol (p < 0.001) and free fatty acids (p = 0.034), and a significant decrease in fat free mass (p < 0.0001) and liver density (p = 0.038), statistical models showed that dietary protein was the main contributor to changes in fat free mass (p = 0.0040), whereas dietary fat was the major predictor of changes in HDL-cholesterol (p = 0.014), free fatty acids (p = 0.0016), and liver fat (p = 0.0007). Conclusions: During 8 weeks of overeating, the level of dietary protein intake was positively related to the change in fat free mass, but not to the change in HDL-cholesterol, free fatty acids, and liver fat which were, in contrast, related to the intake of dietary fat.

scholarly journals Severe protein deficiency induces hepatic expression and systemic level of FGF21 but inhibits its hypothalamic expression in growing rats

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Joanna Moro ◽  
Catherine Chaumontet ◽  
Patrick C. Even ◽  
Anne Blais ◽  
Julien Piedcoq ◽  
...  
Keyword(s):  
Body Weight ◽  
Food Intake ◽  
Energy Expenditure ◽  
Energy Intake ◽  
Dietary Protein ◽  
Protein Deficiency ◽  
Protein Diet ◽  
Growing Rats ◽  
Low Protein ◽  
Protein Diets

AbstractTo study, in young growing rats, the consequences of different levels of dietary protein deficiency on food intake, body weight, body composition, and energy balance and to assess the role of FGF21 in the adaptation to a low protein diet. Thirty-six weanling rats were fed diets containing 3%, 5%, 8%, 12%, 15% and 20% protein for three weeks. Body weight, food intake, energy expenditure and metabolic parameters were followed throughout this period. The very low-protein diets (3% and 5%) induced a large decrease in body weight gain and an increase in energy intake relative to body mass. No gain in fat mass was observed because energy expenditure increased in proportion to energy intake. As expected, Fgf21 expression in the liver and plasma FGF21 increased with low-protein diets, but Fgf21 expression in the hypothalamus decreased. Under low protein diets (3% and 5%), the increase in liver Fgf21 and the decrease of Fgf21 in the hypothalamus induced an increase in energy expenditure and the decrease in the satiety signal responsible for hyperphagia. Our results highlight that when dietary protein decreases below 8%, the liver detects the low protein diet and responds by activating synthesis and secretion of FGF21 in order to activate an endocrine signal that induces metabolic adaptation. The hypothalamus, in comparison, responds to protein deficiency when dietary protein decreases below 5%.

EFFECTS OF GRADED DIETARY PROTEIN LEVELS ON UREA RECYCLING IN THE PIG

1982 ◽  
Vol 62 (4) ◽  
pp. 1193-1197 ◽  
Author(s):  
P. A. THACKER ◽  
J. P. BOWLAND ◽  
L. P. MILLIGAN ◽  
E. WELTZIEN
Keyword(s):  
Dietary Protein ◽  
Protein Diet ◽  
Nitrogen Excretion ◽  
Entry Rate ◽  
Protein Nitrogen ◽  
Protein Levels ◽  
Low Protein ◽  
Key Words Pig ◽  
Urea Recycling ◽  
Protein Diets

The kinetics of urea recycling were determined in six female crossbred pigs utilizing a radioisotope dilution technique. The experimental animals were fed three times daily 500 g of a corn-soybean meal diet formulated to contain 8.4, 15.8 or 24.7% crude protein. Nitrogen digestibility, urinary nitrogen excretion, total nitrogen excretion and retained nitrogen were highest on the 24.7% protein diet and decreased with decreasing dietary protein. Urea pool size, entry rate and excretion rate were also highest on the 24.7% protein diet and decreased with decreasing protein intake. Expressed as a percentage of the total entry rate, a significantly higher percentage of urea was recycled in pigs fed the low protein diets compared with those fed a higher protein diet. Key words: Pig, urea, recycling, kinetics, protein

scholarly journals Low Crude Protein Diet Affects the Intestinal Microbiome and Metabolome Differently in Barrows and Gilts

2021 ◽  
Vol 12 ◽  
Author(s):  
Xin Tao ◽  
Bo Deng ◽  
Qizhi Yuan ◽  
Xiaoming Men ◽  
Jie Wu ◽  
...  
Keyword(s):  
Intestinal Microbiota ◽  
Dietary Protein ◽  
Crude Protein ◽  
High Protein Diet ◽  
Stage I ◽  
Protein Diet ◽  
Stage Ii ◽  
Protein Levels ◽  
Low Protein ◽  
Protein Diets

Low protein diets are commonly used in the growing-finishing pig stage of swine production; however, the effects of low dietary protein on the intestinal microbiota and their metabolites, and their association with pig sex, remain unclear. The present study aimed to assess the impact of a low crude protein (CP) diet on the gut microbiome and metabolome, and to reveal any relationship with sex. Barrows and gilts (both n = 24; initial body = 68.33 ± 0.881 kg) were allocated into two treatments according to sex. The four groups comprised two pairs of gilts and barrows fed with a high protein diet (CP 17% at stage I; CP 13% at stage II) and a low protein diet (CP 15% at stage I; CP 11% at stage II), respectively, for 51 d. Eight pigs in each group were slaughtered and their colon contents were collected. Intestinal microbiota and their metabolites were assessed using 16S rRNA sequencing and tandem mass spectrometry, respectively. The low protein diet increased intestinal microbiota species and richness indices (P &lt; 0.05) in both sexes compared with the high protein diet. The sample Shannon index was different (P &lt; 0.01) between barrows and gilts. At the genus level, unidentified Clostridiales (P &lt; 0.05), Neisseria (P &lt; 0.05), unidentified Prevotellaceae (P &lt; 0.01) and Gracilibacteria (P &lt; 0.05) were affected by dietary protein levels. The relative abundance of unidentified Prevotellaceae was different (P &lt; 0.01) between barrows and gilts. The influence of dietary protein levels on Neisseria (P &lt; 0.05), unidentified Prevotellaceae (P &lt; 0.01) and Gracilibacteria (P &lt; 0.05) were associated with sex. Metabolomic profiling indicated that dietary protein levels mainly affected intestinal metabolites in gilts rather than barrows. A total of 434 differentially abundant metabolites were identified in gilts fed the two protein diets. Correlation analysis identified that six differentially abundant microbiota communities were closely associated with twelve metabolites that were enriched for amino acids, inflammation, immune, and disease-related metabolic pathways. These results suggested that decreasing dietary protein contents changed the intestinal microbiota in growing-finishing pigs, which selectively affected the intestinal metabolite profiles in gilts.

Corrigendum to: IGF-I is not a useful marker for nutritional status in the growing pig under commercial conditions

2001 ◽  
Vol 52 (7) ◽  
pp. 791
Author(s):  
L. Ma ◽  
F. R. Dunshea ◽  
Y. M. Brockwell ◽  
R. L. Inglis ◽  
D. J. Kingston ◽  
...  
Keyword(s):  
Weight Gain ◽  
Nutritional Status ◽  
Dietary Protein ◽  
High Protein Diet ◽  
High Protein ◽  
Protein Diet ◽  
Low Protein ◽  
Igf I ◽  
Protein Diets

Plasma hormone concentrations were measured in gilts after fasting, long-term protein restriction, or supplementation. In 11-week-old pigs fasted overnight, plasma insulin, glucagon, gastrin, urea, and glucose were increased 30 min after re-feeding (P < 0.05), whereas IGF-I did not change. In 16-week-old gilts fed a standard commercial diet [14.6% crude protein (CP)], or a high-protein diet (16.7% CP) for 4 weeks, the high-protein diet increased weight gain (13%; P < 0.05) and carcass weight (4%; P < 0.05), but did not alter plasma IGF-I, insulin, or glucagon. In 10-week-old gilts fed high-protein diets (19.4% and 18.3% CP), or low-protein diets (15.5% and 13.3% CP) for 12 weeks during the grower and finisher phases, respectively, the low-protein diet decreased weight gain (18%; P < 0.001) and carcass weight (11%; P < 0.01), with a marked increase in plasma glucagon (P < 0.05), no change in insulin, and only a trend towards decreased IGF-I (P = 0.1). The pigs were more sensitive to altered dietary protein at 10 weeks of age than at 16 weeks. Plasma IGF-I was not responsive to the short-term effects of feeding or the long-term effects of dietary protein. Glucagon could provide a useful marker for nutritional status in young pigs, provided that time of feeding is taken into account.

Protein content of CBA/Ca mouse diet: relationship with host antibody responses and the population dynamics ofTrichuris muris(Nematoda) in repeated infection

Parasitology ◽  
1992 ◽  
Vol 105 (1) ◽  
pp. 139-150 ◽  
Author(s):  
E. Michael ◽  
D. A. P. Bundy
Keyword(s):  
Population Dynamics ◽  
Dietary Protein ◽  
Protein Diet ◽  
Intestinal Helminth ◽  
Acquired Immunity ◽  
Trichuris Muris ◽  
Infection Dose ◽  
Low Protein ◽  
Repeated Infection ◽  
Protein Diets

The influence of host dietary protein on acquired immunity and intestinal helminth population dynamics during repeated infection was studied using the mouse–Trichuris murisexperimental model. CBA/Ca mice fed a 2% (by mass) protein dietad libitummaintained body weight during the experiment, but when fed diets containing either 4% or 16% (by mass) protein gained weight steadily. Infection withT. murisdid not affect the growth of the latter mice but significantly reduced the growth of animals fed on the 2% protein diet. When repeatedly infected with either 5 or 50 eggs every 10 days, the mice fed the 2% or 4% protein diet accumulated adults in proportion to infection dose. The results show that this is due to both the establishment of larvae at each repeated infection and the survival of established adults. In contrast, very few worms were recovered from animals fed the 16% protein diet, principally as a result of the development of strong acquired immunity to reinfection.T. murisegg output/mouse increased with infection dose in animals fed the low protein diets, but no parasite eggs were detected in the faeces of hosts fed the 16% protein diet. Mouse antibody reponses to adult worm excretory/secretory antigen were time- and infection dose-dependent in all 3 dietary groups. The major finding was that the specific antibody response was more intense, both quantitatively (serum OD levels) and qualitatively (antigen recognition by IgG1), in mice fed the low protein diets, even though they remained susceptible to infection. This study shows that host dietary protein deficiency, even at levels irrelevant to normal growth, can markedly potentiate the transmission ofT. murisvia alterations in host resistance. The high levels of antibody in susceptible animals suggest that this defect in resistance is unlikely to be due to nutrient deficiency-associated defects in humoral immunity.

scholarly journals Effects of dietary protein and fat level on oxidative phosphorylation in rat heart mitochondria

1993 ◽  
Vol 69 (1) ◽  
pp. 97-102 ◽  
Author(s):  
Masaaki Toyomizu ◽  
M. Thomas Clandinin
Keyword(s):  
Oxidative Phosphorylation ◽  
Dietary Fat ◽  
Dietary Protein ◽  
Rat Heart ◽  
Heart Mitochondria ◽  
Protein Levels ◽  
Low Protein ◽  
Fat Level ◽  
Rat Heart Mitochondria ◽  
Protein Diets

The effect of dietary protein and fat levels on cardiac mitochondrial oxidative phosphorylation was assessed polarographically. Weanling rats were fed on semi-purified diets containing different protein levels (10, 30, 50 and 70%) on a gross energy basis (PGE) for 9, 23 and 58 d. Cardiac mitochondria isolated from rats fed on a 70% PGE diet for 23 d exhibited significantly reduced ADP: oxygen (ADP: O) values compared with mitochondria from rats fed on a low-protein diet. Feeding low-protein diets for 58 d increased the ADP:O value. When the dietary fat level was altered to provide (% PGE: % fat-energy): 30:14, 30:30, 70:14, 70:30, feeding 70% PGE diets reduced the ADP:O value compared with the 30 % PGE level, but no difference was observed between low-fat and high-fat groups. These results indicate that the impaired ADP:O value for rats fed on very-high-protein diets was not due to the dietary fat level but that the level of dietary protein is an important determinant of oxidative phosphorylation in rat heart mitochondria.

Dietary protein in relation to bone stiffness index and fat-free mass in a population consuming relatively low protein diets

2013 ◽  
Vol 31 (4) ◽  
pp. 433-441 ◽  
Author(s):  
Sun Min Oh ◽  
Hyeon Chang Kim ◽  
Yumie Rhee ◽  
Seon-Joo Park ◽  
Hae-Jeung Lee ◽  
...  
Keyword(s):  
Dietary Protein ◽  
Fat Free Mass ◽  
Stiffness Index ◽  
Bone Stiffness ◽  
Low Protein ◽  
Protein Diets

THE EFFECT OF DIETARY FAT AND PROTEIN LEVELS UPON THYROID ACTIVITY IN THE CHICK

1964 ◽  
Vol 42 (3) ◽  
pp. 333-339 ◽  
Author(s):  
B. E. March ◽  
Jacob Biely
Keyword(s):  
Dietary Fat ◽  
Dietary Protein ◽  
Protein Level ◽  
High Protein Diet ◽  
Protein Diet ◽  
Thyroid Activity ◽  
Protein Levels ◽  
Dietary Protein Level ◽  
Low Protein ◽  
Fat Diets

The effects on thyroid activity of dietary protein level and of dietary fat level were studied. Diets containing 18 and 26% of protein were fed with and without 8% of supplementary fat. Thyroid weights and thyroidal uptake of I131 of chicks fed the diets were determined. The chicks fed the higher dietary protein level had consistently greater thyroid weights. The effect of supplementary fat on thyroid weight was variable. Total thyroidal uptake of I131 in chicks fed the fat-supplemented diets was greater when the diets contained 26% of protein. With the low-fat diets, protein level did not significantly affect uptake of I131. Supplementary fat decreased I131 uptake in chicks fed the low-protein diet and increased I131 uptake in chicks fed the high-protein diet. Thus, although it is evident that diet affects thyroid activity, conclusions regarding the effect of diet will depend upon the parameter used as a measure of thyroid activity.

IGF-I is not a useful marker for nutritional status in the growing pig under commercial conditions

2001 ◽  
Vol 52 (5) ◽  
pp. 603
Author(s):  
L. Ma ◽  
F. R. Dunshea ◽  
Y. M. Brockwell ◽  
R. L. Inglis ◽  
D. J. Kingston ◽  
...  
Keyword(s):  
Weight Gain ◽  
Nutritional Status ◽  
Dietary Protein ◽  
High Protein Diet ◽  
High Protein ◽  
Protein Diet ◽  
Low Protein ◽  
Igf I ◽  
Protein Diets

Plasma hormone concentrations were measured in gilts after fasting, long-term protein restriction, or supplementation. In 11-week-old pigs fasted overnight, plasma insulin, glucagon, gastrin, urea, and glucose were increased 30 min after re-feeding (P < 0.05), whereas IGF-I did not change. In 16-week-old gilts fed a standard commercial diet [14.6% crude protein (CP)], or a high-protein diet (16.7% CP) for 4 weeks, the high-protein diet increased weight gain (13%; P < 0.05) and carcass weight (4%; P < 0.05), but did not alter plasma IGF-I, insulin, or glucagon. In 10-week-old gilts fed high-protein diets (19.4% and 18.3% CP), or low-protein diets (15.5% and 13.3% CP) for 12 weeks during the grower and finisher phases, respectively, the low-protein diet decreased weight gain (18%; P < 0.001) and carcass weight (11%; P < 0.01), with a marked increase in plasma glucagon (P < 0.05), no change in insulin, and only a trend towards decreased IGF-I (P = 0.1). The pigs were more sensitive to altered dietary protein at 10 weeks of age than at 16 weeks. Plasma IGF-I was not responsive to the short-term effects of feeding or the long-term effects of dietary protein. Glucagon could provide a useful marker for nutritional status in young pigs, provided that time of feeding is taken into account.

scholarly journals Low Crude Protein Diet Affects the Intestinal Microbiome and Metabolome Differently in Barrows and Gilts

2021 ◽  
Author(s):  
Xin Tao ◽  
Bo Deng ◽  
Qizhi Yuan ◽  
Xiaoming Men ◽  
Jie Wu ◽  
...  
Keyword(s):  
Intestinal Microbiota ◽  
Dietary Protein ◽  
Crude Protein ◽  
Shannon Index ◽  
Protein Diet ◽  
Intestinal Microbiome ◽  
Protein Levels ◽  
Low Protein ◽  
The Impact ◽  
Protein Diets

Abstract Background Low protein diets are commonly used in the growing-finishing pig stage of swine production; however, the effects of low dietary protein on the intestinal microbiota and their metabolites, and their association with pig sex, remain unclear. The present study aimed to assess the impact of a low crude protein (CP) diet on the gut microbiome and metabolome, and to reveal any relationship with sex. Results Barrows and gilts (both n= 24; initial body = 68.33 ± 0.881 kg) were allocated into two treatments according to sex. The four groups comprised two pairs of gilts and barrows fed with a high protein diet (HPD, CP 17% at stage Ⅰ; CP 13% at stage Ⅱ) and a low protein diet (LPD, CP 15% at stage Ⅰ; CP 11% at stage Ⅱ), respectively, for 51 d. Eight pigs in each group were slaughtered and their colon contents were collected. Intestinal microbiota and their metabolites were assessed using 16S rRNA sequencing and tandem mass spectrometry, respectively. The LPD increased intestinal microbiota species and richness indices significantly in both sexes compared with the HPD. The Sample Shannon index was significantly different between barrows and gilts. At the phylum level, the LPD increased the relative abundance of Actinobacteria significantly. The influence of dietary protein levels on Proteobacteria and Synergistetes were associated significantly with sex. At the genus level, Clostridiales, Neisseria, and Prevotellaceae were affected significantly by dietary protein levels. In the latter two genera, the effects were significantly different between barrows and gilts. Metabolomic profiling indicated that dietary protein levels mainly affected intestinal metabolites in gilts rather than barrows. A total of 434 differently expressed metabolites were identified in gilts fed the two protein diets. Correlation analysis identified that six differentially abundant microbiota communities were closely associated with twelve metabolites that were enriched for amino acids, inflammation, immune, and disease-related metabolic pathways. Conclusions These results suggested that decreasing dietary protein contents benefitted the intestinal microbiota in growing-finishing pigs, which selectively affected the microbiota and metabolite profiles in gilts.

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