I eat a pound of butter per week and I stay skinny.
Fat doesn't make you fat, carbs do.
Discussion
I do the same. Butter, duck fat, goose fat, beef dripping, bacon. Still skinny.
I drink buttered coffee for breakfast. Consume about 6-8 tablespoons of butter each morning that way. It keeps me from getting hungry until close to supper time, and I only eat one meal a day in the evening.