Higher grocery bills continue to plague American consumers, as the Consumer Price Index for May shows that the "food at home index" was up another 1% in May. Food prices in April were already up 10.8% from where they were a year ago, the largest 12-month increase since November 1980, according to the Bureau of Labor Statistics.

It's not just consumers, though: Manufacturers are feeling the pinch of inflation as well, with ingredients costing more and supply chain issues making it harder to get goods to store shelves. 

Rather than just raise prices, some manufacturers shrink their packaging, a practice known as "shrinkflation." 

Shoppers across the US have reported smaller toilet paper rolls, fewer potato chips and other reductions in supermarket staples.

"It comes in waves," consumer advocate Edgar Dworsky told NPR. "We happen to be in a tidal wave at the moment because of inflation."

Read on to learn more about shrinkflation, including whether it's legal, how to guard against it and which manufacturers are downsizing their products.

What does "shrinkflation" mean?

Shrinkflation is the practice of reducing the size or quantity of a product while keeping the same price. It can mean fewer chips in the bag, fewer scoops of ice cream in the container. Basically, the purchase price remains the same but the cost per unit rises.

Customers may not notice what are effectively price increases, John Gourville, a professor of business administration at the Harvard Business School. "We found that consumers reacted greatly to periodic changes in price, but not at all to periodic (yet systematic) reductions in quantity," Gourville said in an interview back in 2004. 

Some companies disguise shrinkflation with a package redesign, according to Gourville, like adding dents to the bottom of bottles or touting claims of "lower calories." 

A Gatorade representative told Quartz in March that the company redesigned its bottles to be "more aerodynamic" and "easier to grab." It also happened to reduce the amount of Gatorade in the container from 32 to 28 ounces.

Is shrinkflation legal?

Shrinking package size is not illegal so long as the product amounts are clearly labeled and "and the business is not engaging in unfair or deceptive practices," according to the Massachusetts Office of Consumer Affairs.

"This is legal -- companies can change prices of their products however they want. This way they do it and it reduces the amount of complaints that the companies receive as a consequence of this stuff," Tom Fullerton, an economics professor at the University of Texas at El Paso, told KFOX.

How can I protect myself against shrinkflation?

Consumers tend to pay more attention to product prices than package sizes. Breaking that habit is the top tip for steeling yourself against shrinkflation: learn the package sizes and per-unit pricing for your favorite products.

If you notice that a product has shrunk or reduced the number of included items, consider competitors who offer a similar product at a lower cost per ounce or item. Compare per-unit prices to see which product provides a better deal.

Shrinkflation also offers an opportunity to wean yourself off packaged foods. Retailers might be able to make cereal boxes and granola bars smaller, but they can't shrink a pound of apples.  

Dworsky, the consumer advocate, has made shrinkflation (or "downsizing," as he calls it) a major focus of his website MousePrint, which is dedicated to examining the fine print of advertising claims.

Every few months, Dworsky publishescompilations of all the products he's found that have recently decreased in size. He usually posts on Mondays and crowdsources items from his readers to get a fuller picture of which products have changed.

The Reddit message board /r/shrinkflation also serves as a good source for tracking package size changes for your favorite products. Users post instances of shrinkflation that they've found in their local stores or online, usually with screenshots or photos as evidence.

Which products have shrunk?

Consumers have reported shrinkage in all kinds of household products. A keen eye on Reddit found that Huggies Little Snugglers packs dropped from 96 diapers per box to 84.

Procter & Gamble's Cascade reduced the number of dishwashing pods in a box from 78 to 63, while Unilever's Seventh Generation liquid dish soap dropped from 25 to 19 ounces with a bottle redesign.

Charmin has shrunk its Super Mega package from 396 double-ply sheets per roll to 366, MousePrint reported. The toiler paper company also reduced its Mega package from 266 sheets per roll to 244.

Cottonelle reduced the number of toilet paper sheets in its Ultra Clean line from 340 sheets to 312 and in its Ultra Comfort brand from 284 sheets to 268.

Other bath products have also gotten smaller: Pantene has rebranded its Curl Protection Conditioner and in the process reduced the size from 12 to 10.4 ounces, per Reddit. And MousePrint reports that Dove Body Wash recently shrunk from 24 to 22 ounces.

Snacks are another popular target for shrinkflation, as they often come in bags that make it difficult to spot changes. Last year, Doritos decreased the weight of its regular-size bags from 9.75 to 9.25 ounces, a loss of about five chips per bag. Redditors also noticed that Doritos' party-size bag has shrunk from 15.5 to 14.5 ounces.

A party-size bag of Fritos Scoops, which used to be 18 ounces, is now reportedly just under 16 ounces, the Associated Press reported. A tube of Pringles now carries 165 grams of potato chips, down from 200 grams.

Nabisco's Wheat Thins made its "Family Size" product smaller, too, lowering the package weight from 16 to 14 ounces, per Reddit.

A bag of Keebler's Vienna Fingers bag has shrunk from 14.2 to 12 ounces, per Reddit. And MousePrint reports that the size of the company's regular Chips Deluxe package dwindled from 11.3 to 9.7 ounces. (The "family size" package decreased from 17.2 to 14.6 ounces.) 

Package downsizing has also hit fast-food chains: Domino's has cut down the number of boneless wings in an order from ten to eight, citing "unprecedented ingredient costs." Burger King is doing the same with its chicken nuggets.

And Subway rotisserie chicken wraps and sandwiches now contain less meat, Bloomberg reported.