“Social media is junk food…”: Tech entrepreneur Bryan Johnson shares his experience after a 40-hour social fast

Social media is a big part of our daily lives now. Smartphones keep getting notifications, timelines never stop refreshing, and short videos are always trying to get your attention. Even though these platforms are supposed to connect people, researchers and technologists are starting to wonder how being on them all the time affects the brain, attention span, and long-term mental health. Over the past few years, the idea of a “digital detox” has gone from being talked about on wellness blogs to being seriously discussed in the fields of technology and neuroscience.

Tech entrepreneur

Bryan Johnson is one of the most recent people to bring this topic back into the spotlight. Known for his work in technology and longevity research, Johnson shared a detailed post on X (formerly Twitter) describing his experience after stepping away from social media.

The post attracted attention because it framed social media use not as a moral issue, but as a technical and biological one. Johnson explained how modern platforms are built to keep people interested by using reward loops, notifications, and personalised feeds.

According to him, these systems interact directly with human neurochemistry, shaping behaviour in subtle but powerful ways.

Johnson’s message was more about personal awareness and choice than about asking for rules or bans. He said that taking a break from social media is like resetting your brain, just like cutting back on sugar resets your taste buds. His story adds to the growing conversation about how digital tools affect the brain and why taking a break, even for a short time, can help you focus in a world where you are always connected.

In his post published on X, Bryan Johnson explained that after removing social media from his daily routine, he noticed clear changes in how his mind worked. He stated that his thinking became calmer, his ability to focus improved, and his emotional reactions felt less intense over time.

Johnson pointed out that social media platforms are built using advanced technology designed to capture attention. These systems use algorithms, notifications, and endless scrolling to keep users engaged for as long as possible.

He said that taking a break from these systems helped his brain recover from being constantly stimulated.

Machine learning algorithms that look at how people use social media in real time are used by most modern sites. Every like, pause, share, or scroll feeds data back into the system. This data is then used to refine what content appears next.

Technology researchers have long noted that these platforms operate on variable reward systems, similar to those used in gaming.

Users do not know which post will be interesting or rewarding, so they keep scrolling. Over time, this can teach the brain to always look for new things to do.

Instead of blaming users, Johnson’s post focuses on this technical design. He says that being around these kinds of systems for a long time can make it harder to control your attention and make it hard to do quiet, focused work.

A social media detox doesn’t mean you have to stop using all technology.

Instead, it means taking away or limiting access to platforms that depend on loops of continuous engagement.

From a technical point of view, this lowers the risk of:

By lowering these inputs, the brain gets fewer quick signals, which lets natural attention rhythms come back.

Johnson said that taking a break from social media helped him get back to what he called “baseline mental clarity.” Tasks required less effort, and emotional responses became more stable when there were no constant interruptions.

His observations are in line with other research in cognitive science that shows that switching tasks often and getting notifications can make working memory worse. Johnson’s post is personal, but it agrees with what digital behaviour studies have found about how technology affects thinking.