Just another option for adding some fat to your diet. I know some that will just eat straight butter during a fat fast or when they feel a bit hungry or whatever (which is fine). A similar possibility is just drink Heavy Cream. Butter is made from Heavy Cream, and if you look at the nutritional content, it appears that 1 serving of Heavy Cream is nearly exactly half of 1 serving of butter (1 tbsp each). That’s what the labels will show, but of course the specifics are a bit different, as Butter has the Buttermilk from the Cream removed in the churning process. In the end the Heavy Cream does have more carbs than butter, and more electrolytes, but both situations are in still usually negligible amounts (if you drink a cup of straight Heavy Cream, you may need to think about it). I sometimes will have a sip of Heavy Cream when I’m still a bit hungry after a meal.
Of course, most people already know you can add heavy cream to other foods or drinks in a similar way as they add butter with just a few culinary usage nuances.
So, similar taste, similar nutrition, but one you can drink the other you can eat (unless you melt your butter and drink that).
For more specifics of the nutrition, see these values:
Heavy Whipping Cream
Unsalted Butter
Note, specific brands and types may vary a bit (Grass-fed vs non grass-fed, for instance).