Macro partitioning
Replacing saturated fatty acids (SFA) with polyunsaturated fatty acids (PUFA) modestly lowers coronary heart disease (CHD) risk, whereas replacing SFA with carbohydrate yields no benefit.
Do not simply cut saturated fats (like butter or red meat) unless you are replacing them with unsaturated fats (like nuts, seeds, or fish). Replacing saturated fats with refined carbohydrates (like white bread or sugar) offers no heart health benefit. Focus on the quality of the replacement nutrient, not just the reduction of fat.
Based on consistent evidence from human studies, replacing SFA with polyunsaturated fat modestly lowers coronary heart disease risk, with ~10% risk reduction for a 5% energy substitution; whereas replacing SFA with carbohydrate has no benefit and replacing SFA with monounsaturated fat has uncertain effects.
Why this rating
Based on meta-analyses of RCTs and large prospective cohorts, though the paper notes mixed results for other endpoints like stroke and diabetes.
Source
Saturated Fat and Cardiometabolic Risk Factors, Coronary Heart Disease, Stroke, and Diabetes: a Fresh Look at the Evidence
Renata Micha et al. · Lipids · 2010
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