Teplan 2006.

Study characteristics
Methods	Study design: parallel RCT Recruitment: enrolment start and finish date not reported Study duration: 3 years
Participants	Country: Czech Republic Setting: not reported Inclusion criteria: CKD stages 3 to 4 with eGFR 28 to 48 mL/min/1.73 m²; obese BMI > 30 kg/m²; waist‐to‐hip ratio > 85; good compliance and adherence to a diet for the 4 weeks prior to the start of the study. Metabolic acidosis was corrected in all patients Number: intervention group (66); control group (65) Mean age ± SD: 52 ± 7 years Sex (M/F): 54/57* Baseline characteristics Nationality: not reported Ethnicity: not reported Mean baseline BMI (kg/m²): intervention group (32.0 ± 3.30; control group (31.6 ± 3.9) Stage of CKD: stages 3 to 4 Mean baseline CrCl ± SD (mL/min/1.73 m²): intervention group (36.2 ± 15.4); control group (37.4 ± 16.0) Mean baseline SBP ± SD (mmHg): intervention group (135 ± 10); control group (132 ± 6) Mean baseline DBP ± SD (mmHg): intervention group (90 ± 9); control group (92 ± 7) Mean baseline energy intake ± SD (kcal/day): not reported Comorbid conditions: diabetes mellitus (39%) Exclusion criteria: smoker; history of CVD
Interventions	Intervention type classification: lifestyle Weight loss intervention/s used: dietary Intervention group (diet group + keto‐amino acid supplementation) Prescribed a low protein diet 0.6 g/kg/day with energy restriction of 120 to 125 kJ/kg/day for first 6 months and 125 to 130 kJ/kg/day thereafter. Diet was supplemented with keto‐amino acid supplementation (Ketosteril, Fresenius Kabi) at a dose of 100 mg/kg/day The composition of the diet was individualised in terms of taste preferences for participants. Participants were on follow up under balanced conditions for 3 days at baseline and then followed up every 3 months for 3 years. Control group (diet group + placebo) Prescribed a low protein diet 0.6 g/kg/day with energy restriction of 120 to 125 kJ/kg/day for first 6 months and 125 to 130kJ/kg/day thereafter. Diet was supplemented with placebo The composition of the diet was individualised in terms of taste preferences for participants. Participants were on follow up under balanced conditions for 3 days at baseline and then followed up every 3 months for 3 years Co‐interventions All patients had regular treatment with ACEi, ARB and statins
Outcomes	BMI (kg/m²) Waist‐to‐hip ratio (units) Body composition: visceral fat (cm³) and subcutaneous fat (cm³) CrCl (mL/min/1.73 m²) Proteinuria (g/24 hour) Measured GFR (inulin clearance rate) SBP (mmHg) DBP (mmHg) HbA1c (%) Total cholesterol (mmol/L) LDL cholesterol (mmol/L) Triglycerides (mmol/L)
Notes	Founding source: Grant NR/8509‐3 awarded by the Internal Grant Agency of the Czech Republic Trial registration: not provided Possible conflicts of interest for study author: Not declared (no statement provided) * Number of reported males and females (111) does not agree with number randomised (131)
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Double blind RCT
Allocation concealment (selection bias)	Unclear risk	Insufficient information to permit judgement. Double blind RCT however no information on allocation concealment reported
Blinding of participants and personnel (performance bias) All outcomes	Low risk	Double blind RCT
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Insufficient information to permit judgement. It was not reported if the outcome assessors were blind to group allocation
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	Insufficient information to permit judgement ‐ no information on completion rates
Selective reporting (reporting bias)	Low risk	No study protocol however appear to report on all stated outcomes
Other bias	Unclear risk	Insufficient information to permit judgement