Guldbrand 2012.

Study characteristics
Methods	Review comparison(s) addressed by this study: 3 Study design: RCT, parallel, multicentre (2) Trial registry number: NCT01005498 Total number of trial arms: 2 Year trial started: 2008 Sample size calculation: No Outcome(s) used for sample size calculation: NA Duration of run‐in period (weeks): NA What was the duration of the weight loss phase: 2 years What was the duration of the weight maintenance phase: NA Other notes about methods: NA
Participants	Country and setting: Sweden, outpatient primary healthcare centres in Motala and Borensberg Eligibility criteria: Participants had type 2 diabetes which was treated with diet, with or without orally administered glucose‐lowering medication, incretin or insulin. Participants were excluded if they were suffering from a severe mental disease; had a malignancy or were abusing drugs. Type 2 diabetes at baseline: Yes Impaired glucose tolerance at baseline: No Cardiovascular conditions/risk factors/events at baseline: Unclear Gender: Mixed Total number randomised: 61 Total attrition in trial: 21 Treatment diet Participants randomised: 30 Participants withdrawn (voluntary): 4 Total attrition: 14 Control diet: Participants randomised: 31 Participants withdrawn (voluntary): 3 Total attrition: 7 Baseline data treatment diet: Randomised participants not included: None Age (years): mean (SD) 61.2 (9.5) Gender distribution (as reported): female 16/30 (53.3%), male 14/30 (46.7%) Weight (kg): mean (SD) 91.4 (19) BMI (kg/m2): mean (SD) 31.6 (5.0) DBP (mmHg): mean (SD) 76 (11) SBP (mmHg): mean (SD) 135 (15) HbA1c (%): mean (SD) 7.5 (3.1) LDL (mmol/L): mean (SD) 2.7 (0.9) HDL (mmol/L): mean (SD) 1.13 (0.33) Non‐HDL (mmol/L): NR TC (mmol/L): mean (SD) 4.5 (1.0) TG (mmol/L): mean (SD) 1.7 (1.4) Baseline data control diet: Randomised participants not included: None Age (years): mean (SD) 62.7 (11) Gender distribution (as reported): female 18/31 (58.1%), male 13/31 (41.9%) Weight (kg): mean (SD) 98.8 (21) BMI (kg/m2): mean (SD) 33.8 (5.7) DBP (mmHg): mean (SD) 77 (9) SBP (mmHg): mean (SD) 136 (13) HbA1c (%): mean (SD) 7.2 (2.9) LDL (mmol/L): mean (SD) 2.4 (0.7) HDL (mmol/L): mean (SD) 1.09 (0.29) Non‐HDL (mmol/L): NR TC (mmol/L): mean (SD) 4.3 (1.0) TG (mmol/L): mean (SD) 1.8 (0.8) Group differences at baseline: No Characteristic(s) with significant group difference and relevant statistic: NA Other notes about participants: HbA1c mmol/mol baseline values also reported: intervention mean (SD) 58.5 (10.2) mmol/mol; control mean (SD) 55.6 (8.0) mmol/mol
Interventions	Energy (E) comparison of treatment vs control diets: Similar energy prescription/approach to restrict energy intake in both diets Treatment diet: Name (as reported) and brief description: Low‐carbohydrate diet, energy content with 50% from fat, 20% from carbohydrates and 30% from protein. Energy content of 6694 kJ/day for women or 7531 kJ/day for men Treatment diet type (carbohydrate‐fat‐protein): Low‐high‐high Exercise component? No Recipients: N = 14 men and N = 16 women, mean (SD) age 61.2 (9.5) years, mean (SD) weight 91.4 (19) kg, mean (SD) BMI 31.6(5.0) kg/m2, mean (SD) duration of known diabetes of 9.8 (5.5) years Why? High‐fat diet (i.e. with low carbs) would improve glycaemic control more efficiently than the traditional low‐fat diet (LFD). What (materials)? Menus for 1 week were provided to the participants as meal suggestions by the dietitian. Weighing scales and notebooks from the organisers with which to weigh and record all food items that were consumed during these periods What (procedures)? The LCD had an energy content where 50 energy per cent (E%) was from fat, 20 E% was from carbohydrate and 30 E% was from protein. Both diets had an energy content of 6694 kJ/day (1600 kcal/day) for women or 7531 kJ/day (1800 kcal/day) for men. 4 group meetings of 60 mins each for the first year. Group sessions on which food items to choose from and suitable recipes Who provided? Dietitian provided recipes and a menu for one week. Two different physicians conducted the group session where participants learnt which foods to chose from. How and where? Face‐to‐face at two primary healthcare centres in the cities of Motala and Borensberg, located in southeast Sweden When and how much? Four group meetings with a duration of 60 min each for the first year; no further group meetings during the remaining 12 months were held. Group sessions were given at baseline, and 2, 6 and 12 months by two different physicians. A dietitian was available consecutively during the trial for questions from the participants. Strategies to improve or maintain fidelity; tailoring and modification: Diet records were also performed at these four visits, with one additional recording at 3 months. The diet records were conducted during 3 consecutive days, of which 1 day was a Saturday or a Sunday. Extent of intervention fidelity: NR Concomitant interventions: Of the intervention participants the total insulin dose was 42 (65), metformin (mg) 1375 (950), glibenclamide (mg) 1.1 (2.6), simvastatin (mg) 19 (18) and atorvastatin (mg) 2 (5). Control diet: Name (as reported) and brief description: Low‐fat diet, energy content with 30% from fat (< 10% from saturated fat), 55 to 60% from carbohydrates and 10 to 15% from protein. Energy content of 6694 kJ/day for women or 7531 kJ/day for men Control diet type (carbohydrate‐fat‐protein): Balanced‐balanced‐balanced Exercise component? No Recipients: NR Why? NR What (materials)? Menus for 1 week were provided to the participants as meal suggestions by the dietitian. Weighing scales and notebooks from the organisers with which to weigh and record all food items that were consumed during these periods What (procedures)? The LFD had a nutrient composition that was similar to that traditionally recommended for the treatment of type 2 diabetes in Sweden, with 30 E% from fat (less than 10 E% from saturated fat), 55–60 E% from carbohydrate and 10–15 E% from protein. 4 group meetings of 60 mins each for the first year Who provided? Dietitian provided recipes and a menu for one week. Two different physicians conducted the group session where participants learnt which foods to chose from. How and where? Face‐to‐face at two primary healthcare centres in the cities of Motala and Borensberg, located in southeast Sweden When and how much? Four group meetings with a duration of 60 min each for the first year; no further group meetings during the remaining 12 months were held. Group sessions were given at baseline, and 2, 6 and 12 months by two different physicians. A dietitian was available consecutively during the trial for questions from the participants. Strategies to improve or maintain fidelity; tailoring and modification: Diet records were also performed at these four visits, with one additional recording at 3 months. The diet records were conducted during 3 consecutive days, of which 1 day was a Saturday or a Sunday. Extent of intervention fidelity: NR Concomitant interventions: Of the control participants the total insulin dose was 39 (51), metformin (mg) 1435 (946), glibenclamide (mg) 0.4 (1.9), simvastatin (mg) 19 (17) and atorvastatin (mg) 2 (5).
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: Yes Change in BMI (kg/m2) at ≥ 12 months: Yes 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: Yes 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: No
Notes	Number and type of records(s): journal article Trial acronym/name: VÄSTKOST Trial funded by: University Hospital of Linköping Research Funds, Linköping University, County Council of Östergötland and the Diabetes Research Centre of Linköping University Declaration of interest: "The authors declare that there is no duality of interest associated with this manuscript."