BATAVIA, Ohio (AdAge.com) -- Mom is losing ground to Dad in the grocery aisle, with more than half of men now supposedly believing they control the shopping cart. The implications for many marketers may be as disruptive as many of the changes they're facing in media.

Through decades of media fragmentation, marketers of packaged goods and many other brands could take solace in one thing -- at least they could count on their core consumers being moms and reach them through often narrowly targeted cable TV, print and digital media.

But a study by Yahoo based on interviews last year of 2,400 U.S. men ages 18 to 64 finds more than half now identify themselves as the primary grocery shoppers in their households. Dads in particular are taking up the shopping cart, with about six in 10 identifying themselves as their household's decision maker on packaged goods, health, pet and clothing purchases. Not surprisingly, given that such ads long have been crafted for women, only 22% to 24% of men felt advertising in packaged goods, pet supplies or clothing speaks to them, according to the Yahoo survey.

The Great Recession has thrown millions of men in construction, manufacturing and other traditionally male occupations out of work and by extension into more domestic duties. At the same time, gender roles were already changing anyway, with Gen X and millennial men in particular more likely to take an active role in parenting and household duties.

Of course, in the survey, men could be overestimating their own role in shopping for the family. Lauren Weinberg, director-research and insights for Yahoo, acknowledges that could be possible -- and that women don't see them making as much progress on that front. But she said the fact that so many men now see themselves as masters of the shopping cart not only reflects real shifts but also means any stigma once attached to men as shoppers is fading fast.

Yahoo's interest in the subject is obvious: The portal has a lot of inventory geared toward men, such as page after page of fantasy-sports content, that could use more advertisers. But its research on men nonetheless seems to describe a new and disruptive reality.

Behavioral research of shoppers shows a number more like 35% of grocery and mass-merchandise shoppers are now men, said Mariana Sanchez, chief strategy officer for Publicis Groupe's Saatchi & Saatchi X. That number has been growing thanks to the economy and changing gender roles, she said.

And while that figure may be far from a majority , the fact that a third of a brand's shoppers are male is an awful lot to ignore. As a result, shopper-marketing efforts are increasingly gender-neutral rather than targeted for female shoppers, Ms. Sanchez said.

A subtle case in point came during the latest Procter & Gamble Co.-Walmart collaboration on "Family Movie Night" Jan. 8 on Fox. The program itself, "Change of Plans," did show a new dad more domestically impaired than a mom when unexpectedly thrust into adoptive parenthood. But in the commercial pod "story within a story" via Martin Agency, Richmond, the dad made a shopping trip to Walmart to load up on P&G and private-label Great Value products.

Such scenes could be a wave of the future for more categories as consumer packaged brands must elbow their way past car insurers, pickup trucks and erectile-dysfunction drugs into one of the surest and most-DVR-proof forums for reaching men: football.

P&G's Head & Shoulders and Prilosec already have become deeply involved in NFL marketing. But most P&G brands still primarily target moms, and it's not always easy to please both. While last year's tear-jerking "Behind Every Olympic Athlete is an Olympic Mom" Winter Olympics ads for P&G from Wieden & Kennedy were generally well received, the Twitter stream about them included an undercurrent of resentment from dads, who still make up the vast majority of volunteer coaches for youth sports.

The shift toward male shoppers, of course, didn't happen overnight, and that may also help explain why some brand managers for years have privately said more broadly focused network prime-time programming delivered better for their brands than more female-focused cable buys, regardless of the cost and what media optimizers indicated.

Perhaps favorably for marketers, Yahoo research finds men are more brand-loyal and less focused on promotions than women shoppers, Ms. Weinberg said. In advertising, they do more product research in packaged-goods categories than women, she said, and, because they're often newer to the categories, prefer ads with more information.

John Badalament, author of "The Modern Dad's Dilemma" and operator of ModernDads.net, does see more ads that speak to men, including recent ads for P&G's Old Spice and Kimberly-Clark Corp.'s Huggies. But many ads featuring men still portray them as hapless domestically, which he doesn't believe helps marketers. He likens such ads to the once laughable, now anachronistic grocery scene from 1983's "Mr. Mom."

"Men," he said, "need to be something other than invisible or buffoons in advertising."