Macro partitioning
High intake of plant-based essential polyunsaturated fatty acids (ePUFAs), specifically linoleic acid (LA) and alpha-linolenic acid (ALA), is associated with increased lean body mass and reduced central adiposity, whereas marine-derived long-chain n-3 PUFAs (EPA/DHA) show no significant impact on body composition.
To support lean mass and reduce central fat, prioritize dietary sources of plant-based polyunsaturated fats (like linoleic acid from vegetable oils and alpha-linolenic acid from flax/nuts) over marine-derived fish oil supplements. While fish oil has cardiovascular benefits, current evidence suggests it does not significantly alter body composition in adults.
high intakes of the plant-based essential fatty acids (ePUFAs)—n-6 linoleic acid (LA) and n-3 α-linolenic acid (ALA)—have a greater impact on body composition (fat mass and lean mass)... than the marine-derived long-chain n-3 PUFA—eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA).
Why this rating
Based on multiple observational studies and specific RCTs (e.g., Norris et al., Rosqvist et al.), though the authors note evidence for marine PUFAs is mixed.
Source
Polyunsaturated fatty acids as modulators of fat mass and lean mass in human body composition regulation and cardiometabolic health
Cathríona R. Monnard et al. · Obesity Reviews · 2021
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