Soft-drink purists have just a few months to scoop up as much Pepsi as possible: Starting in August, a new formulation of the soda is hitting store shelves.

PepsiCo announced last week that it's replacing the aspartame in Diet Pepsi with sucralose, the sweetener marketed under the brand name Splenda.

The reason for the change? "Customer worries" that aspartame isn't safe.

“Aspartame is the number-one reason consumers are dropping diet soda,” Seth Kaufman, a vice president at Pepsi, said.

That might be consumers' reason, but it's not a scientific one. As Julia Belluz points out at Vox, the European Food Safety Authority recently conducted a risk assessment on aspartame and "ruled out a potential risk of aspartame causing damage to genes and inducing cancer." Aspartame is not proven to cause bladder cancer, or brain cancer, or behavior problems, or any other diet-soda old-wives tales.

With the move, Pepsi becomes the latest in a string of food companies that have altered their recipes to include supposedly healthier ingredients based on pressure from nutrition-conscious consumers. These customer demands, however, have not tended to be supported by medical research.

Ben & Jerry's has been phasing genetically modified ingredients out of its products, and last year the company "ceremonially renamed" one of its ice-cream flavors to “Food Fight Fudge Brownie" as a show of support for GMO-labeling initiatives.  That might be because most American adults believe GMOs are unsafe—even though most scientists disagree.

Yesterday, Chipotle also announced it was going entirely GMO-free.

"They say these ingredients are safe," Chipotle co-CEO Steve Ells told CNNMoney, "but I think we all know we'd rather have food that doesn't contain them."

Amid declining soda sales, Pepsi has already introduced a line of sodas made with sugar rather than high-fructose corn syrup. As the Motley Fool's Daniel Kline explained, "According to a survey done by NPD Food Safety Monitor in 2008, high-fructose corn syrup was a top food-safety concern for 58 percent of Americans. Only Salmonella, E. Coli, trans fatty acids, mercury in fish, and Mad Cow disease scared more people." Meanwhile, high-fructose corn syrup has not been linked to either fatty-liver disease or obesity, and there's currently no evidence that it's more harmful than regular sugar.

After people began inexplicably dropping gluten from their diets en masse, Clif's Luna Bars went gluten-free, saying "It's just another reason to love LUNA!" The company paired the announcement with an infographic aimed at busting myths about gluten, which included the fact that less than one percent of Americans actually have celiac disease—the condition that causes gluten intolerance. Still, the energy-bar maker hedged, even for those who do not suffer from celiac, "going gluten-free may still be a healthy choice."

Even milk has changed its marketing to better suit the food whims of grocery shoppers. Last year, the Milk Processor Education Program shelved its long-running "Got Milk" campaign in favor of ads that promoted dairy's high protein content—even though Americans don't need to eat more protein.

And another soda manufacturer, Coca-Cola, this year introduced a premium milk called Fairlife, which costs nearly twice as much per gallon as regular milk and contains 50 percent more protein.

“Coke is taking a food that's wholesome—milk—and unnecessarily taking it apart and putting it back together, all the while charging more for its ‘services,’” Melanie Warner, the author of Pandora’s Lunchbox: How Processed Food Took Over the American Meal, told my colleague Joe Pinsker. “I don't think this is a product anyone should get excited about.”

There's nothing inherently good about these changes, but there's nothing terrible about them either. Splenda might not be any better than aspartame, but it's probably not any worse, either. GMOs are in 80 percent of our food, so eating a non-GMO burrito bowl or Chunky Monkey cone won't make much of a dent.

If consumers really wanted to make packaged food healthier, they could pressure snack companies to produce smaller portions, or to not market so aggressively to children.

Of course, those types of changes aren't as likely to "rain money" for investors, as Coke's global chief customer officer said he hopes Fairlife milk will. American sales of Diet Pepsi tumbled 5 percent last year, so with the recipe change perhaps PepsiCo executives are praying for a similar deluge.