Does this outfit make me look fat? It’s not just a question women are asking these days. New research suggests men are nearly as concerned about body image as women — and it can affect romantic relationships in surprising ways.

In what is believed to be one of the largest studies ever conducted of male body image, Chapman University researchers found that men worry about being thin and muscular nearly as much as women agonize about being slender and sexy, the Wall Street Journal reports.

The study, published in the journal Psychology of Men and Masculinity, also found women may become resentful and jealous if their partners lose weight without them — prompting concerns about the new attention their men receive, fears they may leave them for a slimmer partner, or feelings of pressure to shed pounds themselves.

“There’s a much more extreme model today of what a healthy man looks like,” says lead researcher David Frederick, assistant professor in health psychology at Chapman University, in Orange, Calif.

For the study, Frederick and his colleagues analyzed answers to five online surveys involving 111,958 heterosexual and 4,398 gay men between 2003 and 2012. The surveys were posted on MSNBC.com, NBCNews.com, and Today.com and drew responses from men ranging in age from 18 to 65 years old. For comparison, the researchers also analyzed the answers of 103,376 heterosexual women and 2,145 lesbians who responded to the surveys.

Among the specific findings:

• Men and women have similar levels of dissatisfaction with their physical appearance, regardless of age: 21 percent of straight men and 29 percent of gay men were dissatisfied, compared with 27 percent of straight women and 30 percent of lesbians.
• When it comes to weight, 39 percent of straight men and 44 percent of gay men were dissatisfied. In addition, 29 percent of straight men and 37 percent of gay men said they had gone on a weight-loss diet in the past year, and more than half of both straight and gay men had exercised to lose weight.
• When asked about muscle tone, 30 percent of heterosexual men and 45 percent of gay men were unhappy.
• About 61 percent of straight men and 77 percent of gay men believe people judged them on their looks and many said they felt pressured by magazines and television to have a better body.
• About one in five straight men and nearly two in five gay men said they hide parts of their bodies during sex — most often their stomachs. In addition, five percent of straight men said they avoided sex during the past month because they felt bad about their bodies, compared with 20 percent of gay men.

The researchers noted anxiety related to body image can put a strain on romantic relationships, with many studies showing men who are ashamed of the way they look are less likely to seek out — and maintain — romantic relationships.

Therapists say body image and weight loss are important issues for couples to be honest about, and that means communicating concerns, anxieties, and positive feelings, too. Couples should discuss how getting in better shape can benefit their relationship — before, during, and after weight loss:

1. Are you happier individually and as a couple?
2. Do you have a better physical relationship?
3. Do you sleep well with less snoring?

Experts say it’s also important to be honest if you’re uncomfortable receiving compliments about your looks or, on the other hand, are feeling insecure because your partner has slimmed down without you.