Answer: At zero carbs and nearly all fat, salted butter is a very keto food.
The keto diet is all about fats. Salted butter is almost nothing but fat. It's a match made in heaven!
Salted butter is zero carbs and is a good source of fats, at 11-12 g of fat per tablespoon. Some keto enthusiasts even add a tablespoon or two of butter to their coffee to bump up their fat counts for the day.
One issue some keto eaters run into with butter is that, as a dairy product, it contains some proteins that give people digestive issues, namely lactose, casein, and whey. If you fall into this category, some keto-friendly butter alternatives are ghee and coconut oil.