Bazzano 2014.

Study characteristics
Methods	Review comparison(s) addressed by this study: 1 Study design: RCT, parallel, single‐centre (1) Trial registry number: NCT00609271 Total number of trial arms: 2 Year trial started: 2008 Sample size calculation: yes Outcome(s) used for sample size calculation: weight change Duration of run‐in period (weeks): NA What was the duration of the weight loss phase: 52 weeks What was the duration of the weight maintenance phase: NA Other notes about methods: NA
Participants	Country and setting: USA, outpatient university health sciences centre in New Orleans. One low‐carbohdyrate or low‐fat meal replacement (bar or shake) per day was provided. Eligibility criteria: Participants aged 22 to 75 years with a BMI 30 to 45 kg/m2. Participants were excluded if they had self‐reported cardiovascular disease, type 2 diabetes or kidney disease; used prescription medication for weight loss; had surgery or weight loss of more than 6.8 kg in the past six months. Type 2 diabetes at baseline: No Impaired glucose tolerance at baseline: Unclear Cardiovascular conditions/risk factors/events at baseline: No Gender: Mixed Total number randomised: 148 Total attrition in trial: 29 Treatment diet Participants randomised: 75 Participants withdrawn (voluntary): NR Total attrition: 16 Control diet: Participants randomised: 73 Participants withdrawn (voluntary): NR Total attrition: 13 Baseline data treatment diet: Randomised participants not included: None Age (years): mean (SD) 45.8 (9.9) Gender distribution (as reported): female 66/75 (88%), male 9/75 (12%) Weight (kg): mean (SD) 96.3 (12.7) BMI (kg/m2): mean (SD) 35.2 (3.8) DBP (mmHg): mean (SD) 77.5 (9.0) SBP (mmHg): mean (SD) 120.3 (12.8) HbA1c (%): NR LDL (mmol/L): mean (SD) 3.2 (0.9) HDL (mmol/L): mean (SD) 1.4 (0.3) Non‐HDL (mmol/L): NR TC (mmol/L): mean (SD) 5.1 (1.1) TG (mmol/L): mean (SD) 1.3 (0.6) Baseline data control diet: Randomised participants not included: None Age (years): mean (SD) 47.8 (10.4) Gender distribution (as reported): female 65/73 (89%), male 8/73 (11%) Weight (kg): mean (SD) 97.9 (13.5) BMI (kg/m2): mean (SD) 35.6 (4.5) DBP (mmHg): mean (SD) 79.4 (8.3) SBP (mmHg): mean (SD) 124.9 (13.8) HbA1c (%): NR LDL (mmol/L): mean (SD) 3.2 (1.0) HDL (mmol/L): mean (SD) 1.5 (0.3) Non‐HDL (mmol/L): NR TC (mmol/L): mean (SD) 5.3 (1.1) TG (mmol/L): mean (SD) 1.4 (0.9) Group differences at baseline: no Characteristic(s) with significant group difference and relevant statistic: NA Other notes about participants: NA
Interventions	Energy (E) comparison of treatment vs control diets: Unrestricted/ad libitum prescription in both diets Treatment diet: Name (as reported) and brief description: Low‐carbohydrate diet. Participants assigned to the low‐carbohydrate diet were instructed to maintain intake of digestible carbohydrate (total carbohydrate minus total fiber) of less than 40 g/d. Diet did not include a specific calorie or energy goal. Treatment diet type (carbohydrate‐fat‐protein): Very low‐unclear‐unclear Exercise component? No Recipients: N = 75 of which N = 66 (88%) female, mean (SD) age 45.8 (9.9) years, mean (SD) weight 96.3 (12.7) kg, mean (SD) BMI 35.2 (3.8) kg/m2, mean (SD) waist circumference 108.4 (9.3) cm, mean (SD) systolic BP 120.3 (12.8) mmHg, mean (SD) diastolic BP 77.5 (9.0) mmHg, mean (SD) total cholesterol 5.1 (1.1) mmol/L, mean (SD) LDL 3.2(0.9) mmol/L, mean (SD) HDL 1.4 (0.3) mmol/L, mean (SD) triglycerides 1.3 (0.6) mmol/L, mean (SD) plasma glucose 5.2 (0.6) mmol/L. Why? "Few randomized, controlled trials thus far have examined the effects of carbohydrate restriction on CVD risk factors in a diverse population with a significant proportion of black persons." What (materials)? "A handbook was given to participants that contained recipes, sample menus for 1 week of food intake at various energy levels, food lists, shopping lists, meal planners, and guides on counting macronutrients and reading nutrition labels. We also provided 1 low‐carbohydrate or low‐fat meal replacement (bar or shake) per day to participants in each group for the duration of the study." What (procedures)? Participants assigned to the low‐carbohydrate diet were instructed to maintain an intake of digestible carbohydrate (total carbohydrate minus total fiber) of less than 40 g/d. Dietary advice as per the "National Cholesterol Education Program guidelines". Neither diet included a specific calorie or energy goal. Participants in each group were asked to refrain from changing their physical activity levels during the intervention. Meetings were conducted with the dietitian weekly then monthly for the study period; these meetings were initially individualised and then group wise. Dietary recalls were also conducted to reflection on consumption over weekday and weekend. Who provided? Dietitian conducted the counselling sessions and all dietary recalls were obtained by a trained and certified staff member. How and where? Face‐to‐face at the Tulane University Health Sciences Center in New Orleans, Louisiana When and how much? "Participants met with a dietitian in weekly individual counseling sessions for the first 4 weeks, followed by small group counseling sessions every other week for the next 5 months (a total of 10 sessions) and monthly for the last 6 months of the intervention period. Individual sessions generally lasted about 1 hour and included dietary instruction and supportive counseling. Group counseling sessions were held separately for participants in the low‐fat and low‐carbohydrate groups but followed a common behavioral curriculum." Strategies to improve or maintain fidelity; tailoring and modification: Trained and certified staff, single calibrated scales, standard procedures for all Extent of intervention fidelity: NR Concomitant interventions: N = 21 (28%) on antihypertensive meds, N = 12 (16%) were on lipid‐lowering meds. Control diet: Name (as reported) and brief description: Low‐fat diet. Those assigned to the low‐fat diet were instructed to maintain less than 30% of their daily energy intake from total fat (with < 7% saturated fat) and 55% from carbohydrate. Diet did not include a specific calorie or energy goal. Control diet type (carbohydrate‐fat‐protein): Balanced‐balanced‐balanced Exercise component? No Recipients: N = 73 of which N =  65 (89%) female, mean (SD) age 47.8 (10.4) years, mean (SD) weight 97.9 (13.4) kg, mean (SD) BMI 35.6 (4.5) kg/m2, mean (SD) waist circumference 111.0 (10.7) cm, mean (SD) systolic BP 124.9 (13.8) mmHg, mean (SD) diastolic BP 79.4 (8.3) mmHg, mean (SD) total cholesterol 5.3 (1.1) mmol/L, mean (SD) LDL 3.2 (1.0) mmol/L, mean (SD) HDL 1.5 (0.3) mmol/L, mean (SD) triglycerides 1.4 (0.9) mmol/L, mean (SD) plasma glucose 5.2 (0.5). mmol/L Why? NR What (materials)? "A handbook was given to participants that contained recipes, sample menus for 1 week of food intake at various energy levels, food lists, shopping lists, meal planners, and guides on counting macronutrients and reading nutrition labels. We also provided 1 low‐carbohydrate or low‐fat meal replacement (bar or shake) per day to participants in each group for the duration of the study." What (procedures)? Those assigned to the low‐fat diet were instructed to maintain less than 30% of their daily energy intake from total fat (with < 7% from saturated fat) and 55% from carbohydrate, based on National Cholesterol Education Program guidelines. Neither diet included a specific calorie or energy goal. Participants in each group were asked to refrain from changing their physical activity levels during the intervention. Who provided? Dietitian conducted the counselling sessions and all dietary recalls were obtained by a trained and certified staff member. How and where? Face‐to‐face at the Tulane University Health Sciences Center in New Orleans, Louisiana When and how much? "Participants met with a dietitian in weekly individual counseling sessions for the first 4 weeks, followed by small group counseling sessions every other week for the next 5 months (a total of 10 sessions) and monthly for the last 6 months of the intervention period. Individual sessions generally lasted about 1 hour and included dietary instruction and supportive counseling. Group counseling sessions were held separately for participants in the low‐fat and low‐carbohydrate groups but followed a common behavioral curriculum." Strategies to improve or maintain fidelity; tailoring and modification: Trained and certified staff, single calibrated scales, standard procedures for all Extent of intervention fidelity: NR Concomitant interventions: N = 24 (34.9%) on antihypertensive meds, N = 9 (12.3%) were on lipid lowering meds.
Outcomes	Change in body weight (kg) at 3 to < 12 months: Yes Change in body weight (kg) at ≥ 12 months: Yes Number of participants with 5% weight loss from baseline at 3 to < 12 months: No Number of participants with 5% weight loss from baseline at ≥ 12 months: No Change in BMI (kg/m2) at 3 to 12 months: No Change in BMI (kg/m2) at ≥ 12 months: No Number of participants with 5% BMI reduction from baseline at 3 to 12 months: No Number of participants with 5% BMI reduction from baseline at ≥ 12 months: No Change in DBP (mmHg) at ≥ 12 months: Yes Change in SBP (mmHg) at ≥ 12 months: Yes All‐cause mortality at ≥ 12 months: No Cardiovascular mortality at ≥ 12 months: No Non‐fatal myocardial infarction at ≥ 12 months: No Non‐fatal stroke at ≥ 12 months: No Diagnosis of type 2 diabetes mellitus at ≥ 12 months: No Change in HbA1c (%) at ≥ 12 months: No Change in LDL (mmol/L) at ≥ 12 months: Yes Change in HDL (mmol/L) at ≥ 12 months: Yes Change in non‐HDL (mmom/L) at ≥ 12 months: No Change in total cholesterol (TC) (mmol/L) at ≥ 12 months: Yes Change in triglycerides (or triacylglycerides) (TG) (mmol/L) at ≥ 12 months: Yes Participant‐reported adverse effects: Yes
Notes	Number and type of records(s): journal article Trial acronym/name: MACRO Trial funded by: NIH/NCRR P20‐RR017659 to the Tulane University Hypertension and Renal Center of Excellence Declaration of interest: Drs He, Chen, Yao, Reynolds, Klag, Bunol, Hu and Liu has nothing to disclose. "Dr. Whelton reports grants from the NIH, during the conduct of the study." "Dr. Bazzano reports grants from NIH, P20 RR017659 and K08 HL091108, during the conduct of the study."