HERO‐Tapsell 2009.

Methods	Healthy Eating to Reduce Overweight in people with type 2 diabetes (HERO) RCT, parallel, (n3 ALA vs low n3), 12 months Summary risk of bias: moderate or high
Participants	Overweight adults with non‐insulin treated diabetes N: 26 intervention, 24 control (analysed, int: 18 cont: 17) Level of risk for CVD: moderate Male %: not reported Mean age (SD): 54 (8.7), not reported by arm Age range: 33‐70 Smokers: not reported Hypertension: not reported Medications taken by ≥ 50% of those in the control group: lipid‐lowering drugs, oral hypoglycemics Medications taken by 20%‐49% of those in the control group: not reported Medications taken by some, but < 20% of the control group: not reported Location: Australia Ethnicity: not reported
Interventions	Type: food supplement (walnuts) Comparison: ALA vs nil Intervention: 30 g/d snack portions of walnuts, aim 30% E fat (10% SFA, 10% MUFA, 10% PUFA), 20% E protein, 50% E CHO, P/S ratio of 1.0. Advised not to take fish oil supplements, ALA dose unclear Control: no supplements, aim 30% E fat (10% SFA, 15% MUFA, 5% PUFA), 20% E protein, 50% E CHO Both groups were given low‐fat isocaloric dietary advice plus advice to brisk walk 30 min 3 times/week Dose aim: increase 5% E PUFA Baseline PUFA: unclear but control 5.5% E PUFA Compliance by biomarkers: omega‐3 fats measured by erythrocyte membrane fatty acid levels which were similar in both groups, no other PUFAs reported. TC fell by 0.3 mmol/L from baseline to 12 months in control, and fell by 0.1 mmol/L in the intervention. Compliance by dietary intake: all assessed at 12 months using validated diet history interview and 3‐day food records Energy intake, kcal/d: intervention 1914 (SD 443), control 2112 (SD 685) Total fat intake, % E: control 29.3 (SD 7.2), int ervention34.1 (SD 5.8) SFA intake, % E: intervention 8.1 (SD 2.6) PUFA intake, % E: control 5.5 (SD 2.3), intervention 12.0 (SD 2.5)cont 9.6 (SD 3.2), PUFA n‐3 intake: not reported PUFA n‐6 intake: not reported Trans fat intake: not reported MUFA intake, % E: intervention 10.9 (SD 3.0), control 11.2 (SD 2.8) CHO intake, % E: intervention 41.4 (SD 6.2), control 42.3 (SD 7.6) Sugars intake: not reported Protein intake, % E: intervention 21.1 (SD 4.4), control 23.9 (SD 4.3) Alcohol intake, % E: not reported Compliance, other measures: not reported Inclusion basis: no intention to increase total PUFA. Intention was to increase walnuts, which included increasing PUFA in place of MUFA. Dietary intake data suggested an increase of 6.5% E from PUFA compared to control, > 10% increase from control group baseline of 5.1% E from PUFA PUFA dose: 6.5% E PUFA Duration of intervention: 12 months
Outcomes	Main trial outcome: change in body weight and % body fat Dropouts: 8 intervention, 5 control Available outcomes: all‐cause mortality (nil deaths), weight, visceral adipose tissue, lipids, glucose, insulin, HbA1c (body fat % and subcutaneous adipose tissue measured but too different at baseline to use) Response to contact: not yet attempted
Notes	Body fat % was too different between groups at baseline hence data not used. Trial funding: California Walnuts Commission
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Randomisation was conducted using a computerised random‐number generator by a researcher independent of the subject interface
Allocation concealment (selection bias)	Unclear risk	No further details
Blinding of participants and personnel (performance bias) All outcomes	High risk	Quote: "Subjects, but not dietitians, were blinded to the type of overall diet (a prepackaged 30 g snack portion of walnuts was given to the walnut group unbeknown to the controls)". However, there was no placebo supplement so blinding not truly feasible.
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Paper states “code was concealed from the researchers collecting data, as well as from subjects.” However as participants could not be blinded outcome assessors may not have been (problem for measures of adiposity, not for biochemical measures).
Incomplete outcome data (attrition bias) All outcomes	High risk	High dropout rate, 35 of 50 analysed (30% attrition rate)
Selective reporting (reporting bias)	Unclear risk	Trial was registered but post‐analysis
Attention bias	Low risk	Both groups appear to have had same level of attention
Compliance	High risk	Omega‐3 fats measured by erythrocyte membrane fatty acid levels which were similar in both groups, no other PUFAs reported. TC fell by 0.3 mmol/L from baseline to 12 months in control, and fell by 0.1 mmol/L in the intervention.
Other bias	Low risk	None noted