"It's good for your well-being".
For now, Page content will remain on the Feed - although businesses are going to have to work harder to keep their content relevant when competing for less space on the News Feed.
The repercussions from Facebook's changes will nearly certainly be far-reaching. The move is widely expected to hurt publishers that rely on traffic from Facebook.
"We started making changes in this direction previous year, but it will take months for this new focus to make its way through all our products".
With social media under pressure for allowing the alleged Russian meddling, Facebook announced a new project to combat such efforts in November 2017.
In a blog post, Facebook argued that researchers had found connecting with friends and family on social media could be beneficial while passively consuming articles and videos was not.
Facebook has said before that it will emphasize personal connections over business pages and celebrities that people follow. The change is the biggest tweak the social network has made to the news feed - essentially the soul of Facebook - in years.
Mosseri said Facebook will "continue to value publisher content".
Facebook has conducted research and worked with outside academics for months to examine the effects that its service has on people. Last year, lawmakers berated Facebook, Alphabet Inc.'s Google and Twitter Inc. for failing to prevent Russian manipulation on their platforms during the 2016 USA presidential election. Zuckerberg anticipates Facebook's 2 billion-plus users will spend less time on and be less engaged with the social network - including watching videos, a lucrative new revenue stream. Zuckerberg later said he had been too hasty and dismissive of the concerns.
The company has been criticized for algorithms that may have prioritized misleading news and misinformation in people's feeds, influencing the 2016 American presidential election, as well as political discourse in many countries.
While the move was anticipated, Thursday's announcement filled in more of the details.
"Just because a tool can be used for good and bad, that doesn't make the tool bad.it just means you need to understand what the negative is so that you can mitigate it", he said.
The announcement is consistent with tests to the News Feed that Facebook ran a year ago, which moved all Page content (from the likes of businesses, brands, and media) from the News Feed to the Explore tab.
Zuckerberg, in a post on Facebook, said the company will change the filter for the News Feed to prioritize what friends and family share, while reducing the amount of non-advertising content from publishers and brands, Reuters reports.
A large part of brands and media companies' strategies is to post articles and videos from their pages to engage consumers - items that aren't considered "meaningful interactions" between people.
"We built Facebook to help people stay connected and bring us closer together with the people that matter to us", Zuckerberg wrote. Zuckerberg said that from now on, "you can expect to see more from your friends, family, and groups", and the public content that does appear should be the kind that encourages "meaningful interactions between people".
Zuckerberg added that his way of running Facebook has shifted since the birth of his two daughters, Maxima and August, in recent years.