Methods	RCT
Participants	Men living at the Veterans Administration Centre (USA) CVD risk: low Control: randomised 422, analysed 422 Intervention: randomised 424, analysed 424 Mean years in trial: control 3.7, intervention 3.7 % male: 100 age: mean control 65.6, intervention 65.4 (all 54-88)
Interventions	Modified fat vs. usual diet Control aims: provided, total fat 40%E Intervention aims: total fat 40%E, 2/3 of SFA replaced by unsaturated fats, dietary chol reduced Control methods: whole diet provided Intervention methods: whole diet provided Total fat intake (during trial): mod fat 38.9 (sd unclear), cont 40 (sd unclear)%E Saturated fat intake (during trial): mod fat 8.3 (sd unclear), cont 18.5 (sd unclear)%E Style: diet provided Setting: residential institution
Outcomes	Stated trial outcomes: mortality, heart disease Data available on total mortality? yes Cardiovascular mortality? yes Events available for combined cardiovascular events: sudden death, definite MI, definite stroke, angina, PV events Secondary outcomes: cancer deaths, cancer diagnoses, stroke, non-fatal MI, total MI Tertiary outcomes: none (some data on total cholesterol, but no variance info)
Notes
Risk of bias
Bias	Authors’ judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	“table of random numbers used”
Allocation concealment (selection bias)	Unclear risk	Randomisation method not clearly described
Blinding (performance bias and detection bias) All outcomes	Low risk	physician blinding: adequate participant blinding: adequate
Incomplete outcome data (attrition bias) All outcomes	Low risk	All followed up via Veterans Admin system
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	All ate centre food as usual. 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	See Control and Intervention Aims in Interventions section of the Table of Characteristics of Included Studies