For years America has been talking about the obesity epidemic, but a new study points to a more serious health issue that could reach epidemic proportions: isolation and loneliness.

Research presented at the American Psychological Association convention found that the impact of loneliness and social isolation has been growing and will continue to grow.

"Being connected to others socially is widely considered a fundamental human need — crucial to both well-being and survival. Extreme examples show infants in custodial care who lack human contact fail to thrive and often die, and indeed, social isolation or solitary confinement has been used as a form of punishment," Julianne Holt-Lunstad, Ph.D., professor of psychology at Brigham Young University and lead author of the study, said in a statement. "Yet an increasing portion of the U.S. population now experiences isolation regularly."

More than 42 million adults over age 45 in the United States are estimated to be suffering from chronic loneliness, according to a study on loneliness from AARP. The most recent U.S. census showed that more than 25 percent of us live alone, and more than half of us are not married.

"There is robust evidence that social isolation and loneliness significantly increase risk for premature mortality, and the magnitude of the risk exceeds that of many leading health indicators," said Holt-Lunstad. "With an increasing aging population, the effect on public health is only anticipated to increase. Indeed, many nations around the world now suggest we are facing a 'loneliness epidemic.' The challenge we face now is what can be done about it."

Researchers analyzed health data from about 3.7 million people and more than 200 studies to reach this conclusion, but this study isn't the first time loneliness has been flagged as an emerging health issue.

An avalanche of evidence

Woman feeling sad, crying in pillow More than 42 million adults over age 45 in the United States are estimated to be suffering from chronic loneliness. (Photo: Stock-Asso/Shutterstock)

In 2015, researchers from Brigham Young University in Utah reviewed nearly 35 years of data from about 3 million participants and discovered that loneliness and isolation can impact our health, and even shorten our lives, just like obesity.

The study looked at both objective and subjective social isolation, meaning that it didn't distinguish between voluntary isolation (like living alone or those who just enjoy their alone time) and involuntary isolation (a person who describes himself as lonely). The researchers found that those who live alone, have infrequent social contact, and have few social network ties are all at risk for premature mortality. This was especially true for those younger than 65.

"In light of mounting evidence that social isolation and loneliness are increasing in society, it seems prudent to add social isolation and loneliness to lists of public health concerns," say the study's authors. "The professional literature and public health initiatives can accord social isolation and loneliness greater recognition."

Other items on the list of public safety concerns? Substance abuse, obesity, mental health and responsible sexual behavior, to name a few.

Co-author Tim Smith said of the findings, "Not only are we at the highest recorded rate of living alone across the entire century, but we're at the highest recorded rates ever on the planet. With loneliness on the rise, we are predicting a possible loneliness epidemic [by 2030]."

The study notes that affluent nations have the highest rates of people living alone. Those rates are projected to increase.

Loneliness can also have a stronger impact on people who already suffer from cardiovascular problems, according to a 2018 study. Researchers surveyed more than 13,000 people and discovered those who feel lonely (compared to those who live alone) had a higher risk of dying prematurely from heart-related issues.

"Loneliness is a strong predictor of premature death, worse mental health, and lower quality of life in patients with cardiovascular disease, and a much stronger predictor than living alone, in both men and women," said study author Anne Vinggaard Christensen.

There is also a wealth of data that ties current lifestyles and pastimes to isolation. With an increasing number of people working from home, binge-watching television or nursing an addiction to electronic devices, it has become too easy to be alone, even if that's not a person's intention. Modern day conveniences like having anything we want delivered make it possible to never need to leave the house.

A 2013 study found similar results looking at 6,500 elderly men and women in England. In a paper published in the Proceedings of the National Academy of Sciences, researchers showed that those who are socially isolated are more likely to die prematurely.

The younger you are, the lonelier you may feel

teenage girl feeling alone In a 2018 survey, participants ages 18 to 22 were reported as the loneliest generation. (Photo: Antonio Guillem/Shutterstock)

While so much focus over the years has been on older people living alone and feeling isolated, a recent survey shows that Generation Z (ages 18 to 22) is in fact the loneliest generation and claims to be in worse health, according to Cigna. But don't assume because younger people tend to use social media more that is a reason they feel more alone. Cigna reports that there was no significant difference in level of loneliness for heavy social media users compared to people who never use it.

Cigna surveyed more than 20,000 Americans and had them fill out a questionnaire on feelings of loneliness and social isolation. The results were staggering. 46 percent admit sometimes or always feeling alone, and 47 percent said they feel left out from time to time. Two out of five people believed their relationships weren't meaningful, and one in five reported never or rarely feeling close to people. Only half said they had significant social interactions with someone else on a daily basis.

Not surprisingly, those in the survey who live with someone else felt less lonely than someone who lived by themselves.

"In analyzing this closely, we're seeing a lack of human connection, which ultimately leads to a lack of vitality — or a disconnect between mind and body. We must change this trend by reframing the conversation to be about 'mental wellness' and 'vitality' to speak to our mental-physical connection," said Cigna President and CEO David Cordani. "When the mind and body are treated as one, we see powerful results."

Editor's note: This story has been updated with new information since it was originally published in March 2015.