Here's the deal with the most recent study favoring the muscular man. Published in the Proceedings of the Royal Society B., it found a positive relationship between a male's level of attractiveness to a woman and their perceived upper body strength.
Shirtless or sleeveless photos were taken of all the males, and their strength was assessed. With the men's faces in the photos distorted, the study participants were then asked to rank the photos based on how strong they thought the person was. Then, they were asked to rank the photos based on level of attractiveness.
The researchers found two things: One, that people were pretty good at determining how strong a stranger was, their guesses lining up well with the male's actual strength. And two, there was, as previously stated, a direct correlation between a male's perceived upper body strength and his level of attractiveness.
But before you go cranking out an ungodly number of pull-ups, know this: The study isn't as black and white as it may seem. The research was done with only college-aged females evaluating college-aged males, 160 of each. The males were all students at the University of California at Santa Barbara. The females were a combination of students, all ranging from teens to early 20s, from the University of Oklahoma and Australia's Griffith University. In other words, it was a small-scale study on a pretty specific group of people.
What's more, the study pointed out that none of the males were at a level of extremely low body-fat, high muscle content that traditionally accompanies the "six-pack" ideal. The study's author, Aaron Lukaszewski, told the Washington Post that the males did include some buff "frat guy" types, but that none of the men had "exaggerated proportions." It stands to reason that if a guy has a dad bod—but also appears strong—women will find him more attractive.
And hey—there's still plenty of existing research that says women love the ol' dad bod. Planet Fitness conducted a survey earlier this year that asked over 2,000 men and women how they felt about the "dad bod." The survey found that 7 out of 10 women were more attracted to men that had up to an additional 20 pounds on their frame.
Additionally, a small study conducted at UCLA surveyed 82 college-aged coeds and found that women were more likely to have short-term relationships with more "muscular" men, but conversely, classified their long-term partners as "more trustworthy and romantic than their one-nightstands or brief affairs."
Our conclusion is, be healthy and work out regularly, but don't obsess over your body image. Women prefer a guy with a sense of humor over anything else anyway, so being confident and comfortable in your own skin and being able to make her laugh is your best bet. Work out and eat healthy because it makes you feel good.