Methods	RCT
Participants	Moderately hypercholesterolaemic, non-obese Caucasian men and women aged 30-50 (USA) CVD risk: moderate Control: randomised 62, analysed 51 Intervention: randomised 56, analysed 47 Mean years in trial: control 0.91, intervention 0.92 % male: control 61, intervention 66 Age: mean control 40.3 (sd 5.4), intervention 40.7 (sd 5.2) (all 30-50)
Interventions	Reduced fat diet vs usual diet Control aims: no diet intervention Intervention aims: 25%E from fats, 20%E from protein, 55%E from CHO, <200mg chol /day (Also an intervention arm with similar aims plus increased fibre intake) Control methods: no intervention Intervention methods: seminars and individual eating patterns taught, 10 weeks teaching and 40 weeks maintenance Total fat intake (at 1 year): low fat 30 (sd 7.5), cont 31 (sd 5.7)%E Saturated fat intake (at 1 year): low fat 9 (sd 2.7), cont 10 (sd 2.9)%E Style: diet advice Setting: community
Outcomes	Stated trial outcomes: diet composition, lipids Data available on total mortality? yes (none) Cardiovascular mortality? yes (none) Events available for combined cardiovascular events: cardiovascular deaths, fatal and non-fatal MI, stroke (none) Secondary outcomes: total and non-fatal MI, stroke Tertiary outcomes: total, LDL and HDL cholesterol
Notes
Risk of bias
Bias	Authors’ judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	“matched on age, gender & cholesterol level, randomly assigned to intervention group using systematic random procedure”
Allocation concealment (selection bias)	Unclear risk	Randomisation method not clearly described
Blinding (performance bias and detection bias) All outcomes	High risk	Participants were aware of their dietary advice, researchers were not
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	Deaths, cancer and CV events are drop-outs, trialists asked for data
Selective reporting (reporting bias)	Low risk	Not relevant for primary and secondary outcomes as all trialists asked for data
Other bias	Low risk
Free of systematic difference in care?	High risk	See Control and Intervention Methods in Interventions section of the Table of Characteristics of Included Studies
Free of dietary differences other than fat?	Low risk	(As the high fibre arm has not been used in the data set). See Control and Intervention Aims in Interventions section of the Table of Characteristics of Included Studies