Characteristics of the included studies in the meta-analyses.

<p>BMI, Body-Mass-Index; CKD, chronic kidney disease; HP, high protein; n.d, no data; NP/LP, normal/low protein; RCT, randomized controlled trial; VLC, very-low carbohydrate.</p

Forest plot showing pooled MD with 95% CI for serum urea (mmol/l) of 13 randomized controlled HP diet trails.

<p>For each high protein study, the shaded square represents the point estimate of the intervention effect. The horizontal line joins the lower and upper limits of the 95% CI of these effects. The area of the shaded square reflects the relative weight of the study in the respective meta-analysis. The diamond at the bottom of the graph represents the pooled MD with the 95% CI. HP, high protein; NP/LP, normal protein/low protein.</p

Comparison of High vs. Normal/Low Protein Diets on Renal Function in Subjects without Chronic Kidney Disease: A Systematic Review and Meta-Analysis

<div><p>Background</p><p>It was the aim of the present systematic review and meta-analysis to investigate the effects of high protein (HP) versus normal/low protein (LP/NP) diets on parameters of renal function in subjects without chronic kidney disease.</p><p>Methods</p><p>Queries of literature were performed using the electronic databases MEDLINE, EMBASE, and the Cochrane Trial Register until 27^th February 2014. Study specific weighted mean differences (MD) were pooled using a random effect model by the Cochrane software package Review Manager 5.1.</p><p>Findings</p><p>30 studies including 2160 subjects met the objectives and were included in the meta-analyses. HP regimens resulted in a significantly more pronounced increase in glomerular filtration rate [MD: 7.18 ml/min/1.73 m², 95% CI 4.45 to 9.91, p<0.001], serum urea [MD: 1.75 mmol/l, 95% CI 1.13 to 237, p<0.001], and urinary calcium excretion [MD: 25.43 mg/24h, 95% CI 13.62 to 37.24, p<0.001] when compared to the respective LP/NP protocol.</p><p>Conclusion</p><p>HP diets were associated with increased GFR, serum urea, urinary calcium excretion, and serum concentrations of uric acid. In the light of the high risk of kidney disease among obese, weight reduction programs recommending HP diets especially from animal sources should be handled with caution.</p></div

Pooled estimates of effect size (95% confidence intervals) expressed as weighted mean difference for the effects of HP vs. NP/LP diets on outcomes of renal function.

<p>Pooled estimates of effect size (95% confidence intervals) expressed as weighted mean difference for the effects of HP vs. NP/LP diets on outcomes of renal function.</p

Forest plot showing pooled MD with 95% CI for glomerular filtration rate (ml/min/1.73 m²) of 21 randomized controlled HP diet trails.

<p>For each high protein study, the shaded square represents the point estimate of the intervention effect. The horizontal line joins the lower and upper limits of the 95% CI of these effects. The area of the shaded square reflects the relative weight of the study in the respective meta-analysis. The diamond at the bottom of the graph represents the pooled MD with the 95% CI. HP, high protein; NP/LP, normal protein/low protein.</p

Pooled estimates of effect size (95% confidence intervals) expressed as weighted mean difference for the effects of AET vs. RT, CT vs. AET and CT vs. RT on anthropometric outcomes, blood lipids and cardiorespiratory fitness.

<p>₂ max, maximal oxygen uptake; WC, waist circumference; WHR, waist to hip ratio. BW, body weight; CRP; FM, fat mass; HDL-C, high density lipoprotein cholesterol; LBM, lean body mass; LDL-C, low density lipoprotein cholesterol; TC, total cholesterol; TG, triacyglycerols; VO</p

Additional file 1: Figure S1. of A systematic review and meta-analysis of carbohydrate benefits associated with randomized controlled competition-based performance trials

Effects of carbohydrate interventions as compared to placebo on time required to finish a time trial. Forest plot shows pooled standardized mean differences with 95 % confidence intervals (CI) for 6 randomized controlled trials. Subgroup analyses show the results for carbohydrate concentrations ranging between 6–8 % and 10–12 %, respectively. The diamond at the bottom of the graph and the subgroups represents the pooled mean difference with the 95 % CI for all trials following fixed effect meta-analyses. GLU = glucose; FRU = fructose; MAL = maltodextrin; SUC = sucrose. Title: File format: tiff (TIF 7950 kb

General study characteristics.

<p>₂ max, maximal oxygen uptake; WC, waist circumference; WHR, waist to hip ratio; ↑, higher/more; ↓, lower/less. AET, aerobic endurance training; BW, body weight; CR, caloric restriction; CT, combined training (RT and AET); Ex, exercises; FM, fat mass; HDL-C, high-density lipoprotein cholesterol; HRR, heart rate reserve; LBM, lean body mass; LDL-C, low-density lipoprotein cholesterol; MHR, maximum heart rate; n.d, no data; R, Repetition; RT, resistance training; S/MG/W, sets for each muscle group per week; TC, total cholesterol; TG, triacylglycerols; VO</p

Additional file 4: Figure S4. of A systematic review and meta-analysis of carbohydrate benefits associated with randomized controlled competition-based performance trials

Effects of carbohydrate interventions as compared to placebo on mean power output. Forest plot shows pooled standardized mean differences with 95 % confidence intervals (CI) for 4 randomized controlled trials. Subgroup analyses show the results for exercise duration shorter than 90 min or longer than 90 min, respectively. The diamond at the bottom of the graph and the subgroups represents the pooled mean difference with the 95 % CI for all trials following fixed effect meta-analyses. (TIF 5891 kb

Flow diagram.

<p>Flow diagram.</p