The impact of habitually consuming a high protein (HP) diet at the upper limit of the acceptable macronutrient distribution range (AMDR) on kidney health is unknown. The current study was designed to test the hypothesis that long-term consumption of a diet providing 35% of energy as protein will have negative consequences on renal health, as assessed in a pig model. Methods: Adult female, non-pregnant, commercial pigs (Genesus) were randomized to receive either NP (15% energy from protein) or HP (35% energy from protein) isocaloric diets for either 4 or 8 months. Diets contained whole protein sources with an animal: plant ratio of 2:1 in the NP diet to mimic the average Canadian diet. The increased protein in the HP diet was achieved by increasing egg and dairy protein sources. Body composition was measured by dual-energy X-ray absorptiometry. Glomerular volume and kidney fibrosis were evaluated on kidney sections by quantitative image analysis. The inflammatory marker monocyte chemoattractant protein-1 (MCP-1) and the growth factor transforming growth factor beta-1(TGFβ1) were assessed in renal tissue using commercial ELISA kits. Results: Pigs given the HP diet had lower body weights and percentage of body fat. Pigs consuming the HP diet had significantly higher glomerular filtration rates (GFR) and larger kidneys. Renal MCP-1 levels and renal fibrosis also were significantly higher in pigs given the HP diet, while proteinuria and renal TGFβ1 expression did not differ. Conclusion: These findings suggest that, despite the potential benefit of the HP diet on body composition, long-term intakes of protein at the upper limit of the AMDR may compromise renal health in healthy female pigs. / October 2008

The impact of habitually consuming a high protein (HP) diet at the upper limit of the acceptable macronutrient distribution range (AMDR) on kidney health is unknown. The current study was designed to test the hypothesis that long-term consumption of a diet providing 35% of energy as protein will have negative consequences on renal health, as assessed in a pig model. Methods: Adult female, non-pregnant, commercial pigs (Genesus) were randomized to receive either NP (15% energy from protein) or HP (35% energy from protein) isocaloric diets for either 4 or 8 months. Diets contained whole protein sources with an animal: plant ratio of 2:1 in the NP diet to mimic the average Canadian diet. The increased protein in the HP diet was achieved by increasing egg and dairy protein sources. Body composition was measured by dual-energy X-ray absorptiometry. Glomerular volume and kidney fibrosis were evaluated on kidney sections by quantitative image analysis. The inflammatory marker monocyte chemoattractant protein-1 (MCP-1) and the growth factor transforming growth factor beta-1(TGFβ1) were assessed in renal tissue using commercial ELISA kits. Results: Pigs given the HP diet had lower body weights and percentage of body fat. Pigs consuming the HP diet had significantly higher glomerular filtration rates (GFR) and larger kidneys. Renal MCP-1 levels and renal fibrosis also were significantly higher in pigs given the HP diet, while proteinuria and renal TGFβ1 expression did not differ. Conclusion: These findings suggest that, despite the potential benefit of the HP diet on body composition, long-term intakes of protein at the upper limit of the AMDR may compromise renal health in healthy female pigs.

The impact of habitually consuming a high protein (HP) diet at the upper limit of the acceptable macronutrient distribution range (AMDR) on kidney health is unknown. The current study was designed to test the hypothesis that long-term consumption of a diet providing 35% of energy as protein will have negative consequences on renal health, as assessed in a pig model. Methods: Adult female, non-pregnant, commercial pigs (Genesus) were randomized to receive either NP (15% energy from protein) or HP (35% energy from protein) isocaloric diets for either 4 or 8 months. Diets contained whole protein sources with an animal: plant ratio of 2:1 in the NP diet to mimic the average Canadian diet. The increased protein in the HP diet was achieved by increasing egg and dairy protein sources. Body composition was measured by dual-energy X-ray absorptiometry. Glomerular volume and kidney fibrosis were evaluated on kidney sections by quantitative image analysis. The inflammatory marker monocyte chemoattractant protein-1 (MCP-1) and the growth factor transforming growth factor beta-1(TGFβ1) were assessed in renal tissue using commercial ELISA kits. Results: Pigs given the HP diet had lower body weights and percentage of body fat. Pigs consuming the HP diet had significantly higher glomerular filtration rates (GFR) and larger kidneys. Renal MCP-1 levels and renal fibrosis also were significantly higher in pigs given the HP diet, while proteinuria and renal TGFβ1 expression did not differ. Conclusion: These findings suggest that, despite the potential benefit of the HP diet on body composition, long-term intakes of protein at the upper limit of the AMDR may compromise renal health in healthy female pigs.

Dissertation (Ph.D.)--Auburn University, 2006. / Abstract. Vita. Includes bibliographic references.

No description available.

Typescript (photocopy). / Digitized by Kansas Correctional Industries

Long-term, high protein diets at 35% of energy may have implications in bone biology. The objective of this study was to comprehensively examine whether a high mixed protein diet at the 35% energy level can be deemed safe with respect to long-term bone health. Eighty female Sprague-Dawley rats were randomized to receive 4, 8, 12, or 17 months of a control (15% of energy as protein) or the high protein diet (35% of energy). Statistical analyses of biochemical, biomechanical, morphological, microarchitectural, and densitometric examinations using a 2-way factorial ANOVA with interaction revealed that elevated protein consumption had no negative consequences to bone health. High protein fed rats had increased lean body mass and decreased body weight and body fat. Thus preliminary results suggest that protein consumption at 35% of energy has a positive effect on body weight and does not hinder the mechanical abilities of bone.

No description available.

Weight loss maintenance and emotional and physical problems were investigated in subjects on a protein-sparing modified fast. Four months following a weight reduction program using the protein-sparing modified fast, twenty of the forty-two subjects were contacted. Each was asked to complete a questionnaire related to emotional and physical effects of the diet and a diet history checksheet. Each subject was weighed to determine if weight loss had been maintained. Results of the questionnaire, diet history, and blood chemistry analysis indicate that for these subjects, the modified fast may be safe and effective in reducing and maintaining weight loss over a short time period under close supervision by a physician.

In setting the AMDR for protein at 10-35% of daily energy, the Institute of Medicine acknowledged a lack of data regarding the safety of long-term intakes. The current study assessed the impact of chronic (17 months) protein consumption at the upper end of the AMDR on renal function, histology, and inflammation. Using plant and animal whole protein sources, female Sprague-Dawley rats (70 days old; n=8-11 at 4, 8, 12, or 17 mo.) were randomized to either a normal (NP; 15% of energy) or high protein (HP; 35% of energy) diet. Egg albumen and skim milk replaced carbohydrates in the HP diet. Diets were balanced for energy, fat, vitamins and minerals, and offered ad libitum. Renal function was analyzed by creatinine clearance and urinary protein levels. Glomerular hypertrophy, glomerulosclerosis and tubulointerstitial fibrosis were assessed on kidney sections. Kidney disease progression was determined by the measurement of transforming growth factor beta-1 (TGF-β1) and renal inflammation by the measurement of chemokines monocyte chemoattractant protein-1 (MCP-1) and regulated upon activation normal T-cell expressed and secreted (RANTES). Rats consuming the HP compared to NP diet had ~17% higher kidney weights (P<0.0001) and ~4.8 times higher proteinuria (P<0.0001). There was a trend towards higher creatinine clearance with HP (P=0.055). Consistent with this, HP compared to NP rats had ~22% larger glomeruli (P<0.0001) and ~33% more glomerulosclerosis (P=0.0003). The HP diet had no significant effect on tubulointerstitial fibrosis and renal TGF-β1 levels and did not result in higher renal levels of MCP-1 and RANTES. In fact, per mg renal protein, HP rats had ~16% lower MCP-1 (P<0.0001) and ~34% lower levels of RANTES (P<0.0001) than NP. The absence of an increase in cytokine levels may be a reflection of the moderate changes in renal pathology observed in rats offered HP diets. These data in normal female rats suggest that protein intakes at the upper end of the AMDR are detrimental to kidney health in the long-term. While modest, this may have implications for individuals whose kidney function is compromised, especially given the prevalence of those unaware of their kidney disease within North America. / October 2007