The fat conversation has moved on from decades ago — here's the current, more nuanced picture.
Dietary fat recommendations have shifted substantially over recent decades, as research has increasingly focused on fat type and quality rather than total fat quantity.
Found in olive oil, avocados and most nuts — consistently associated with favourable cardiovascular and inflammatory markers.
Found in fatty fish, flaxseed, walnuts (omega-3) and most vegetable oils (omega-6) — see our foods list for the ratio discussion.
Found in red meat, butter and coconut oil — research has moved toward a more nuanced view than the older blanket "avoid saturated fat" advice, with effects varying by food source and what it replaces in the diet.
Industrially produced (partially hydrogenated oils) — this is the one fat category with genuinely strong, consistent evidence of harm, and has been banned or heavily restricted in many countries as a result.
Of everything in this fat conversation, avoiding trans fats (mostly eliminated from the food supply in many countries already) and favouring unsaturated fats over highly processed sources has the strongest, most consistent evidence behind it.