Sugar shocked.

That describes the reaction of many Americans this week following revelations that, 50 years ago, the sugar industry paid Harvard scientists for research that shifted the focus away from sugar's role in heart disease — and put the spotlight squarely on dietary fat.

What might surprise consumers is just how many present-day nutrition studies are still funded by the food industry.

Nutrition scholar Marion Nestle of New York University spent a year informally tracking industry-funded studies on food. "Roughly 90% of nearly 170 studies favored the sponsor's interest," Nestle tells us via email. Other, systematic reviews support her conclusions.

For instance, studies funded by Welch Foods — the brand behind Welch's 100% Grape Juice — found that drinking Concord grape juice daily may boost brain function. Another, funded by Quaker Oats, concluded, as a Daily Mail story put it, that "hot oatmeal breakfast keeps you full for longer."

While these examples might induce chuckles, the past year has seen several exposes that have raised serious concerns about the extent of industry's influence on food and nutrition research outcomes.

Last year, The New York Times revealed how Coca-Cola was funding high-profile scientists and organizations promoting a message that, in the battle against weight gain, people should pay more attention to exercise and less to what they eat and drink. In the aftermath of that investigation, Coca-Cola released data detailing its funding of several medical institutions and associations between 2010 and 2015, from the Academy of Family Physicians to the American Academy of Pediatrics. All told, Coca-Cola says it gave $132.8 million toward scientific research and partnerships.

And earlier this summer, the Associated Press released an investigation that looked at research funded by the National Confectioners Association, a trade group whose members include the makers of Tootsie Rolls, Hershey's kisses and Snickers bars. One study the group funded concluded that kids who eat candy tend to weigh less than those who don't. In an email to her co-author, the AP reported, one of the scientists behind that study wrote that the finding was "thin and clearly padded." Nonetheless, the paper was published in a journal called Food & Nutrition Research.

"It's definitely a problem that so much research in nutrition and health is funded by industry," says Bonnie Liebman, director of nutrition at the Center for Science in the Public Interest, a nonprofit advocacy group. "When the food industry pays for research, it often gets what it pays for." And what it pays for is often a pro-industry finding.

Michael Moss is an investigative journalist who focuses on the food industry and author of the expose Salt, Sugar, Fat: How The Food Giants Hooked Us. He says a lot of times, food firms are funding research that they know is going to go their way — a finding they can tout on their packaging to sway consumers to buy their products. The problem is, the findings that get published may be incomplete, highlighting positive outcomes while leaving out negative ones. And then, there are studies that are simply poorly designed.

As a researcher, notes Moss, one can tweak the experimental design "in subtle ways that can lead to a desired conclusion — whether you're taking money from industry or you yourself have a passion or conclusion you want" to see, he says. "There's just a lot of bad research out there."

And yet, as we've reported before, this junk nutrition science frequently gets touted in press releases written to drum up interest, then picked up and disseminated by journalists who lack the wherewithal to spot the bad research methodology. In May 2015, science journalist John Bohannon highlighted exactly how this process plays out: He conducted a real — but really poorly designed — study that concluded eating chocolate can help you lose weight, then watched as media outlets ran with the study.

While Bohannon's study was a deliberate hoax designed to expose the flaws in nutrition science journalism, similarly bad studies get reported on all the time. As Gary Schwitzer of Health News Review, a watchdog group for the media's coverage of health, told us last year, the problem is extensive. "We have examples of journalists reporting on a study that was never done," he told us in 2015. "We have news releases from medical journals, academic institutions and industry that mislead journalists, who then mislead the public."

Given this environment, where bad science on what to eat or drink is pervasive, what's a consumer to do?

Be skeptical when reading about the latest finding in nutrition science, says Moss.

Ignore the latest study that pops up on your news feed, adds Liebman. "Rely on health experts who've reviewed all the evidence," she says. She points to the official government Dietary Guidelines, which are based on reviews of dozens or hundreds of studies. "Experts are able to sift through the evidence and separate the good from bad," she says.

Copyright 2016 NPR. To see more, visit http://www.npr.org/.