Methods	RCT
Participants	People with well controlled type I diabetes mellitus (Canada) CVD risk: moderate Intervention reduced fat: 18 randomised, 15 analysed Intervention modified fat: 17 randomised, 15 analysed Mean years in trial: reduced fat 0.46, modified fat 0.47 % male: reduced fat unclear, modified fat unclear Age, years: 37.9 (8.1 SD) (not specified by study arm)
Interventions	Reduced fat vs Modified fat diet Reduced fat aims: total fat 27-30%E, SFA ≤10%E, MUFA 10%, CHO 54-57% Modified fat aims: total fat 37-40%E, SFA ≤10%E, MUFA 20%E, CHO 43-46%E Reduced fat methods: after initial dietary advice monitored weekly by phone by a dietitian (24 hour food recall). Glycaemia, insulin doses, CHO at meals, hypoglycaemic attacks all self-monitored daily and reported weekly Modified fat methods: after initial dietary advice monitored weekly by phone by a dietitian (24 hour food recall). Glycaemia, insulin doses, CHO at meals, hypoglycaemic attacks all self-monitored daily and reported weekly Total fat intake (at 6 months): not stated Saturated fat intake (at 6 months): not stated Style: diet advice Setting: community
Outcomes	Stated trial outcomes: Triglycerides and other CVD risk factors Data available on total mortality? yes (no events) Cardiovascular mortality? yes (no events) Events available for combined cardiovascular events: none Secondary outcomes: cancer deaths (no events) and cancer diagnoses (no events) Tertiary outcomes: weight; BMI; total, LDL and HDL cholesterol; TGs; systolic and diastolic blood pressure
Notes
Risk of bias
Bias	Authors’ judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	“randomly assigned”
Allocation concealment (selection bias)	Unclear risk	No details provided
Blinding (performance bias and detection bias) All outcomes	High risk	No details provided, but participants had to make decisions about what they ate
Incomplete outcome data (attrition bias) All outcomes	High risk	Data reported for those who completed
Selective reporting (reporting bias)	Unclear risk	Unclear
Other bias	Low risk
Free of systematic difference in care?	Low risk	Similar intervention in both groups
Free of dietary differences other than fat?	Low risk	Focus on fat and CHO intake