Loneliness Is a Bigger Health Risk Than Obesity, Here Is What the Research Shows on Social Isolation

The study that changed how doctors think about loneliness

In 2015, psychologist Julianne Holt-Lunstad at Brigham Young University published a meta-analysis in Perspectives on Psychological Science covering 148 studies and roughly 308,000 participants. The finding: people with strong social connections had a 50% greater likelihood of survival over a given period than those who were socially isolated. A follow-up analysis in 2017, covering 3.4 million people across 70 studies, put the mortality risk from loneliness at 26% and from social isolation at 29%, both higher than the mortality risk associated with obesity. The US Surgeon General cited this body of work when declaring loneliness a public health epidemic. That declaration came from an American office, but the biology it describes has no passport.