More Americans are shopping for humanely raised and handled meat these days, some seeking health benefits and others because of concerns about the treatment of animals at factory farms.

The number of humanely raised products has boomed to meet that demand: just today, Perdue, the fourth-largest poultry producer in the U.S., announced an overhaul of its animal welfare practices -- an indication of the pressure the industry as a whole feels to respond to consumer concerns.

But those products will cost you — sometimes as much as three times the price of conventionally raised meat. That has put a premium on a shopper’s ability to unravel the tangle of labels, from loosely regulated terms like “natural” to the animal welfare programs that certify farms, that have become shoppers’ shorthand for understanding how meat is raised in the U.S.

The labeling mess is “preventing consumers from showing how deeply they care about this issue by voting with their dollars,” said Daisy Freund, senior manager of farm animal welfare at the American Society for the Prevention of Cruelty to Animals. “And I’m sad when that happens [because] people are wasting their money.”

To help you understand the options, MarketWatch investigated the most common labels, examined the top certification programs, and gathered resources to use when you shop.

Many animal welfare experts believe chickens have it worst when it comes to farm animal conditions today. Getty Images

Not all meat labels are worthy of your trust

Americans love meat. We consume about 200 pounds per capita a year, according to the Organization for Economic Cooperation and Development, second only to Australia. About 9 billion animals were slaughtered in the U.S. in 2014.

Animal advocates are increasingly drawing attention to the way meat is raised in the U.S. — sometimes in dramatic fashion. A recent video filmed undercover by Mercy For Animals showing birds beaten and stabbed to death at a McDonald’s chicken nugget supplier MCD, -0.66% has seen over 1 million YouTube views, for example, while the group’s videos showing abuse at Tyson Foods farms have set off an outcry across the Internet TSN, -3.87% .

“The majority of animals are suffering on factory farms under conditions that consumers wouldn’t accept if they could see them firsthand,” said Freund.

In a 2014 Consumer Reports survey, 80% of respondents considered better living conditions for farm animals to be important or very important, outranking the use of antibiotics and genetically modified organisms in feed. And shoppers are willing to put their money where their mouths are: A 2012 ASPCA study found that 67% of respondents were willing to pay more for a humanely raised chicken.

Unfortunately, most meat labeling offers little useful information.

The term “natural” (which is widely used on meat packaging today) is defined by the Department of Agriculture, but don’t mean what consumers might expect: it refers only to processing after slaughter.

A recent survey by Consumer Reports found that over 80% of participants believed meat with a “humanely raised” label comes from farms that are inspected to verify the claim. But “humanely raised” and “free range” — and all other “humane” claims, such as “animal friendly” or “raised in a stress free environment” — are loosely defined, so that practices only slightly better than conventional farming can count. “Pasture raised” has no regulated definition. Those claims, meanwhile, aren't verified, since the USDA doesn't visit farms to check them. Producers simply submit information about their practices for review.

And research shows that consumers misunderstand the USDA’s organic label to have meaning when it comes to animal welfare — which, mostly, it doesn’t: It has no requirements related to animals’ access to the outdoors, for instance, or pain management for surgical operations.

Certification programs: What the labels really mean

Those labeling issues have contributed to the rise of four main third-party animal welfare certification programs: Animal Welfare Approved, Certified Humane, Global Animal Partnership and American Humane Certified. They aim to codify practices to ensure farm animals have access to adequate space, nutritious food and appropriate medical treatment.

The Prather Ranch Meat Company in San Francisco displays its Certified Humane label on its packaging and at its butcher shop meat counters. Sally French

Farms and producers, seeing the influence these seals can have over consumers, have enrolled in growing numbers. Certified Humane, for example, went from 143,000 animals certified at the end of 2003, its first year, to about 20 million in 2007 — to 96.7 million in 2014.

These certifications vary widely in their availability and the details of their standards.

Animal Welfare Approved (AWA) is widely recognized as the gold star label among certification programs: It’s the only label to be granted “highly meaningful” status from Consumer Reports. But AWA enrollment, at about 1,000 farms, is on the smaller side, and it can be difficult to find AWA meat at the grocery store.

The other three programs have bigger reaches, and certify producers of all sizes and farming systems. It’s much easier to find their products at the grocery store — but harder to know if what they’re selling lives up to what most consumers would consider “humane.”

A Foster Farms chicken bears the marketing claims “fresh & natural” and the American Certified Humane label. Jessica Marmor Shaw

American Humane Certified (AHC) certifies well above 1 billion animals, and counts meat aisle standbys Foster Farms and Butterball as members.

The ASPCA doesn’t recommend AHC to consumers primarily because the program doesn’t require 100% of its standards be met when an auditor visits the farm. The farm must meet 85% of standards plus have a “fix-it plan” for standards that aren’t met.

AHC also has been questioned by rival programs for its certification of Foster Farms, particularly after a Mercy For Animals video surfaced in June showing chickens being slammed into metal shackles and punched while still alive at a Foster Farms slaughterhouse in California.

“We are certifying Foster Farms, not an individual group of employees,” said AHC’s chief veterinary officer, Marion Garcia. “There may be a bad actor now and again. The important thing is for the corporate culture to say, that’s not OK.”

As for Foster Farms, AHC says its auditors inspect every single farm that supplies meat to them.

“We don’t want to tell a company just because of their size it’s impossible for them to be humane,” Garcia said. “Because we don’t believe that to be true.”

GAP-certified chicken at a Whole Foods store in San Francisco. Sally French

Global Animal Partnership (GAP), which grew out of Whole Foods’s Animal Compassion Initiative US:WFM, is a five-step program that allows farmers to advance upward through five levels of certification. Whole Foods requires that every producer it sells get certified by GAP, even if they are already certified by another third party.

“If you can’t be organic, grass-fed tomorrow — but you can be something — that program offers farmers a way to try to start doing that and transition,” said Urvashi Rangan, Director of Consumer Reports’ Food Safety and Sustainability Center.

Critics charge that certifying producers at Step 1 may make them seem “greener” than they really are. They also charge that there’s little incentive for producers to move up through the steps, since consumers may not really understand the differences between them.

Of GAP’s 2,822 members, 730 are enrolled at Step 1. Enrollment does trend toward the lower steps, with the majority (61%) at Steps 1 to 3. Step 4 has 1,089, though almost all are beef producers. There are only 14 producers at Steps 5 to 5+.

Anne Malleau, who leads Whole Foods’ animal welfare initiatives, says Step 1 offers an achievable entry point for many ranches and farms, and that by the end of 2016, GAP will have revised standards that include tightened standards for Step 1. GAP recently announced movement on that front, pledging along with Whole Foods to phase out the fastest-growing strain of chickens from all of its certification levels.

Cattle grazing at a Niman Ranch farm. Animal advocates say the standards at most conventional American farms and ranches don’t live up to such bucolic images. Niman Ranch

Not all producers have jumped on the certification bandwagon — including some that are well regarded for their treatment of animals.

Niman Ranch, a network of family farmers and ranchers that is among the main suppliers of pork to Chipotle CMG, +1.11% , was setting groundbreaking animal welfare protocols long before it was the “in-thing” to be certified humane, according to General Manager Jeff Tripician.

It wasn’t until Whole Foods instituted its GAP requirement in 2011 that Niman, founded in the 1970s, sought certification.

Tripician says Niman only pays to certify the farms that supply Whole Foods, estimating that it would cost more than $1 million a year to certify all 726 of its farms. “We do GAP because Whole Foods is a partner and they asked us to do it,” Tripician said. “If they didn’t, we would not do GAP.”

Niman was purchased by Perdue in 2015, causing some animal rights groups and sustainability advocates to question the future of animal welfare at the company. But its GAP certification — as well as its reputation — may go some of the way toward easing concerns that standards might change under Perdue.

“Niman’s name is the promise that a certifier would provide,” Tripician said.

The Niman purchase is one of the factors credited with convincing higher-ups at Perdue that animal welfare can be improved without hurting business. Though the specifics and timeline of Perdue’s newly unveiled animal-welfare practices remain vague overall, animal-welfare experts say that the commitment to providing chickens with natural light and to exploring the benefits of slower growth are a first for a producer of Perdue’s size.

Resources you can use at the grocery store

The differences between certified humane labels can be confusing for consumers, but there’s a benefit, too. If you don’t have the budget for meat certified at the highest tier, you can still buy at the other levels — as long as you understand what you’re getting at that price.

“Too often, consumers just don’t have access to enough information to make a truly educated choice when they’re in the supermarket,” said Ben Goldsmith, executive director of sustainable agriculture advocacy group Farm Forward.

Farm Forward launched BuyingPoultry in 2015, a comprehensive directory of poultry products and brands in the U.S., all of which are graded on animal welfare. Consumer Reports and the ASPCA have guides that go into detail on the differences between the programs.

You can also download, save to your phone, or print MarketWatch’s Easy Guide to “Humane” Meat Labels, a basic primer in what you’re getting for the cost of meat labeled humane.

For food quality advocates, the bottom line is simple: The differences in the certification programs, while important, aren’t as large as the differences between certified and conventionally raised meat, says Consumer Reports’s Rangan.

“We certainly want consumers to know what they’re getting,” she said. “But we don’t begrudge the existence of [any] programs simply because they aren’t the best they can be.”