Simon 1997.

Study characteristics
Methods	RCT Summary risk of bias: moderate to high
Participants	Women with a high risk of breast cancer (USA) CVD risk: low Control: randomised 96, analysed 75 Intervention: randomised 98, analysed 72 Mean years in trial: control 1.8, intervention 1.7 % male: 0 Age: mean control 46, intervention 46 Ethnicity: White 89%, African‐American 9%, Hispanic 2% Statins use allowed? No (those on lipid‐lowering medications were excluded) % taking statins: 0%
Interventions	Reduced fat vs usual diet Control aims: usual diet Intervention aims: total fat 15%E Control methods: continued usual diet Intervention methods: Bi‐weekly individual dietetic appointments over 3 months followed by monthly individual or group appointments, including education, goal‐setting, evaluation, feedback and self‐monitoring Intervention delivered face‐to‐face by a dietitian Total fat intake, %E (at 12 months)§: int 17.6 (SD 5.8), cont 33.8 (SD 7.4) (mean difference ‐16.20, 95% CI ‐18.34 to ‐14.06) significant reduction Saturated fat intake, %E (at 12 months)§: int 6.0 (SD 3.0), cont 12.1 (SD 5.2) (mean difference ‐6.10, 95% CI ‐7.47 to ‐4.73) significant reduction PUFA intake, %E (at 12 months)§: int 3.8 (SD 1.7), cont 7.3 (SD 4.1) (mean difference ‐3.50, 95% CI ‐4.51 to ‐2.49) significant reduction PUFA n‐3 intake: not reported PUFA n‐6 intake: not reported MUFA intake, %E (at 12 months)§: int 6.1 (SD 3.0), cont 12.8 (SD 6.3) (mean difference ‐6.70, 95% CI ‐8.29 to ‐5.11) significant reduction CHO intake: not reported Protein intake: not reported Trans fat intake: not reported Replacement for saturated fat: unclear, either carbohydrate or protein (based on aims and achievements) Style: diet advice Setting: community §Kasim 1993
Outcomes	Stated trial outcomes: intervention feasibility Data available on total mortality? yes (2 deaths, but not clear in which arms) Cardiovascular mortality? no Events available for combined cardiovascular events: none Secondary outcomes: cancer diagnosis (8 diagnoses, but not clear in which arms) Tertiary outcomes: weight, total, LDL and HDL cholesterol, TGs
Notes	Study duration 2 years Study aim was to reduce total fat to 15%E (saturated fat not mentioned), but saturated fat intake in the intervention group was significantly lower than in the control group SFA reduction achieved Total serum cholesterol, difference between intervention and control, mmol/L: ‐0.34 (95% CI ‐0.64 to ‐0.04), statistically significant reduction Trial dates: Recruitment 1987 to 1989 Funding: Marilyn J Smith Fund, Harper‐Grace Hospitals, the Wesley Foundation, National Cancer Institute, Karmanos Cancer Institute Core Grant, the United Foundation of Detroit Declarations of Interest of primary researchers: none stated, all authors worked for academic or health institutions except PN Kim who was affiliated with Wesley Health Strategies (now Health Strategies, which offers a "full‐service health and fitness centre with an educated fitness staff and spacious workout areas", see healthstrategiesfitness.com/)
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Randomisation method not clearly described, but participants were stratified by age and randomised (block size 2).
Allocation concealment (selection bias)	Unclear risk	Allocation method not clearly described
Blinding of participants and personnel (performance bias) All outcomes	High risk	Participants knew their allocation.
Blinding of outcome assessment (detection bias) CVD outcomes	Unclear risk	Unclear whether physicians knew allocations
Blinding of outcome assessment (detection bias) All‐cause mortality	Low risk	Blinding is not relevant in assessment of mortality.
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	Unclear, deaths, cancer and CV events are dropouts ‐ unclear if any data missing
Selective reporting (reporting bias)	Low risk	Not relevant for primary and secondary outcomes as all trialists were asked for data
Free of systematic difference in care?	High risk	Very different contact time with dietitian, but medical appointments same in both groups. See control and intervention methods in the Interventions section of the table of Characteristics of included studies
Stated aim to reduce SFA	High risk	Aim to reduce SFA not stated
Achieved SFA reduction	Low risk	SFA reduction achieved
Achieved TC reduction	Low risk	Statistically significant TC fall
Other bias	Low risk	None noted