https://en.wikipedia.org/wiki/Nina_Teicholz
I quote from it:
>>"Nina Teicholz is a journalist who became an advocate opposed to the idea that saturated fat is unhealthy and should be minimized in the American diet."
So, to begin with, she's a journalist who wrote a book about fat. In fact, she advocated that people should load up their diets on fat, particularly saturated fat:
>>Teicholz advised readers to "eat butter; drink milk whole, and feed it to the whole family. Stock up on creamy cheeses, offal, and sausage, and yes, bacon"
This advice runs counter to the advice of public health organisations and the opinionts of scientists:
>> Teicholz' claims were harshly criticized by the DGAC, the US Department of Health and Human Services, the Center for Science in the Public Interest, and others, including a petition signed by 180 scientists, and they called for BMJ to retract the article or issue corrections
My underlining.
I wouldn't trust that lady to tell me what to eat, or to criticise a scientific study's methodology. A journalist with a book has very clear incentives to "shake things up" by going against the scientific consensus. But, it's the opinion of experts that have studied the matter at length, who know the relevant bibliography well and understand its subtleties that one should trust more than outsiders who "rock the boat" for their own reasons.
Finally- it's really dangerous to listen to someone who tells you that, that thing you love to eat (or smoke, or drink, etc) that you always knew was not very good for you is actually very healthy. You have a big, fat incentive to blieve them unconditionally.