Typically, this is done by your body in very low carb diet.
https://www.livestrong.com/article/517437-foods-that-have-ketones/
The everlasting clash of headlines written by someone who confuses those who read the article.
Headlines that are Bait and Switch lead me to not rely on the accuracy of the source. It is used by too many conservative websites these days. Breitbart is notorious for it, along with its tradition of typos that are never corrected.