The main claim that is being made within this article is that overeating animal-based protein can take years off your life instead of adding to it. Typically, I would not consider BuzzFeed to be the most credible source. I believe that this clickbait esk title is exactly the kind of thing I would expect from a source like BuzzFeed. That being said, the author is not a bot. She (Emily Laurence) is noted as a Journalist and has written many articles for BuzzFeed, Parade Magazine, AOL.com, and more. This article is brand new. Posted within the day. As of writing this, the article is said to have been published 15hrs ago. However, it seems to be the only noteworthy article to talk about this in more recent history. If you look for other articles on "protein diets," you will mostly find articles that are encouraging protein diets.
I do find the quotes to all be very trustworthy. Every time there is a quote or a claim that is made, there is either a link to the person who said the quote or an article that made the claim. The majority of quotes and claims are also linked to people and articles with some kind of medical background. I also think the writing is fairly balanced. There isn't any reason for BuzzFeed to be biased toward whether you eat protein or not.
My biggest problem with this article is simply that it is on food health. Food health is a topic that is constantly evolving and also often doesn't have one right or wrong answer to anything. Health is such a fad-based system that even if part of this is true, it doesn't take away from the fact that protein still has benefits. There is so much unknown in the field that you can never go on one article alone, even if the information is backed up by extremely credible sources. So, overall, I do think the headline (As clickbaity as it may be) is supported by the content within the article. There isn't anything in this article that raises my eyebrow outside of the fact that health has always been a weird subject online.