As more people opt to live alone, delay or forego marriage, and recede into their smartphones, rates of loneliness are skyrocketing in the United States, according to new research.

Julianne Holt-Lunstad, a professor of psychology at Brigham Young University, presented the findings from two huge meta-analyses at this year's Annual Convention of the American Psychological Association.

Holt-Lunstad's research shows loneliness could pose an even greater threat to public health than obesity, and other research has found it even rivals the risks of smoking.

"Indeed, many nations around the world now suggest we are facing a 'loneliness epidemic,'" Holt-Lunstad said in a statement. "The challenge we face now is what can be done about it."

The first of the two meta-analyses included 148 studies as well as data on more than 300,000 participants. It found a 50% reduction in the risk of early death among people with greater social interaction.

The second analysis included data on 3.4 million people from 70 studies and looked at the role social isolation, loneliness, and living alone had on mortality. All three seemed to increase individuals' risk to similar or greater extents than obesity.

Researchers believe loneliness is so deadly because it can lead to a number of issues, including disrupted sleep patterns, high levels of stress hormones, increased inflammation, and worsening immune systems. Any one of those risk factors puts people at a greater risk for disease and life-threatening injury.

Based on the evidence, Holt-Lunstad doesn't think the loneliness problem is going away anytime soon. The latest AARP Loneliness Study found 42.6 million adults over the age of 45 suffer from chronic loneliness. With an aging baby boomer population, that number is expected to rise in the coming decades.

People can stave off the risks of loneliness by taking a more proactive approach to socializing, Holt-Lunstad said. Instead of scrolling through Facebook, older Americans can make a point to join social clubs or plan get-togethers with neighbors. Doctors can also play a role in alerting older patients to the risks of loneliness, and offer ways to combat its effects.

In some cases, countries that face loneliness epidemics have taken steps broadly to make people feel less alone. In England, lonely seniors can call a hotline, known as the Silver Line, to speak with someone for however long they want, on any topic. The center receives about 10,000 calls a week.