Macro partitioning
Replacing 5% of total energy intake from saturated fatty acids (SFAs) with either monounsaturated (MUFAs) or polyunsaturated fatty acids (PUFAs) is associated with a statistically significant reduction in overall mortality risk.
To lower your risk of death, swap 5% of your daily calories from saturated fats (found in red meat, butter, full-fat dairy) for unsaturated fats (found in olive oil, nuts, seeds, fish). You do not need to eat less food; just change the source of the fat. For example, if you usually use butter on toast, switch to olive oil or avocado spread. This simple swap is linked to a 12-13% lower risk of mortality.
The isocaloric substitutions of 5% energy from MUFAs and PUFAs for SFAs was associated with 13 and 12% lower risk of overall mortality.
Why this rating
Large prospective cohort (n=49,884) with long follow-up (up to 20 years) and rigorous adjustment for confounders, though observational design limits causal inference.
Source
The association of dietary fatty acids intake with overall and cause-specific mortality: a prospective cohort study from 1999–2018 cycles of the NHANES
Zhaoxiang Zhang et al. · Frontiers in Nutrition · 2025
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