直覺上黃油（butter）可能不是很健康的食品，不宜多吃。但 search 一下，可以找到

"IS BUTTER KETO FRIENDLY?
Yes, butter is keto-friendly! Since it’s especially high in fat and low in carbohydrates compared to other dairy products, you can enjoy any kind of pure butter on a ketogenic or low carb diet. Along with olive oil, avocado oil, and coconut oil, butter is one of the most popular healthy fats for this lifestyle."

"Can you eat butter on a low carb diet?
Butter can be included as part of a healthy, low carb diet. However, there are many healthy fats to choose from and butter should not be relied upon as a main source of dietary fat."

 

Is butter a healthy fat?

https://www.healthline.com/nutrition/carbs-in-butter#is-it-healthy