Methods	RCT
Participants	Adults with primary hyperlipoproteinaemia (Italy) CVD risk: moderate Intervention reduced fat: 33 randomised, 27 analysed Intervention modified fat: 30 randomised, 17 analysed Mean years in trial: reduced fat 0.4, modified fat 0.4 % male: reduced fat 82%, modified fat 63% Age, years: reduced fat 47.4 mean (sd 10.3), modified fat 48.6 (sd 8.1)
Interventions	Reduced fat vs Modified fat diet Reduced fat aims: total fat 25%E, SFA 8%E, MUFA 15%, PUFA 2%, dietary chol <300mg/d, CHO 58%, protein 17%E, soluble fibre 41g/d Modified fat aims: total fat 38%E, SFA <10%E, MUFA 20%E, PUFA 10%E, dietary chol<300mg/d, CHO 47%E, protein 15%E, soluble fibre 19g/d Reduced fat methods:seen monthly by dietitian and doctor, feedback based on 7 day food diary each time Modified fat methods: seen monthly by dietitian and doctor, feedback based on 7 day food diary each time Total fat intake (at 5-6 months): low fat 27 (sd unclear)%E, mod fat 36 (sd unclear)%E Saturated fat intake (at 5-6 months): low fat 6 (sd unclear)%E, mod fat 7 (sd unclear) %E Style: diet advice Setting: community
Outcomes	Stated trial outcomes: metabolic effects Data available on total mortality? yes (no events) Cardiovascular mortality? yes (no events) Events available for combined cardiovascular events: total MI, cardiovascular deaths, stroke (no events) Secondary outcomes: stroke, total and non-fatal MI (no events for any outcomes) Tertiary outcomes: total, LDL and HDL cholesterol, TGs
Notes
Risk of bias
Bias	Authors’ judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Following 3 or 6 weeks compliance with control diet run-in, stratified block randomisation with tables of random numbers
Allocation concealment (selection bias)	Unclear risk	Randomisation method not clearly described
Blinding (performance bias and detection bias) All outcomes	High risk	None
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	Unclear, deaths, cancer and CV events are drop-outs - unclear if any data missing
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?	Low risk	Identical follow up. See Control and Intervention Methods in Interventions section of the Table of Characteristics of Included Studies
Free of dietary differences other than fat?	High risk	Some differences in soluble fibre intake