Single Americans live very different lifestyles than their married counterparts. Do they need special financial plans, too?

According to recent research by Milwaukee-based Northwestern Mutual, single households, which now make up 45 percent of the U.S. population, are less likely to be satisfied with their finances.

In the company's 2016 "Planning and Progress Study," 55 percent of single women and 49 percent of single men are unhappy with their current financial situations, compared with one-third of married women and even fewer married men.

Singles are also more insecure about their financial circumstances. While 23 percent of married individuals say they are not at all financially secure, 38 percent of single respondents said the same.

Married couples are more likely to seek out professional financial advice. While 76 percent of married respondents had spoken to a professional about their retirement, only 51 percent of singles said the same. And two-thirds of single respondents said they didn’t have a financial advisor at all.

Overall, the singles in Northwestern Mutual’s survey felt uncertain about their financial plans. Nearly two-thirds said they weren’t confident their plan would be able to withstand market cycles.

Forty-five percent of single men and 50 percent of single women in the survey reported feeling either moderate anxiety or a lot of it about their personal financial security. At the same time, only 35 percent of married men and 41 percent of married women described similar feelings.

For the study, Harris Poll surveyed 2,646 individuals between February 1 and February 10, 2016.