From my own experience (based on blood work, not a formal study), I’ve noticed that if I eat too many carbs, fats (including butter) seem to become a problem. But when I stick to very low-carb or carnivore eating, fats are no longer an issue—likely because I’m fat-adapted.
Bingo for me at least my bloodwork is great with carbs the triglycerides happen. So same with me.
High carb high fat means deadly ketoacidosis
Low carb high fat (butter, bacon, avocado) means healthy ketosis