"It's a double whammy," said Jack Gillis, executive director of the Consumer Federation of America, an advocacy group. "Consumers are being hit with two things at the exact same time: severe inflation and the decision by many companies to shrink the size of the product contents of the things we buy every day."

The Federal Reserve raised its benchmark interest rate by 0.25% from near zero on Wednesday to rein in inflation. It's the first time the central bank has hiked rates since 2018.

Raising prices and reducing volume help companies buoy their bottom lines. Their costs are rising, too. Covid-19 outbreaks and the war in Ukraine are snarling supply lines, lifting prices for raw materials, and higher gas and fuel prices may cause elevated shipping costs to distribute goods, for example.

Companies are raising consumer prices but you have to be a sleuth to detect it

Consumer advocates suspect, however, that some companies may artificially lift prices for consumers to take advantage of the inflationary environment and boost profits.

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Consumers can fight shrinkflation by looking at a product's "unit pricing" at the store. This shows the cost per ounce or other unit of measure, letting buyers more easily judge which brand offers the best relative value.

"Cost per unit is your best weapon against shrinkflation," Gillis said.

Consumers should also get more accustomed to examining packaging for net weight, looking beyond a brand's marketing, Dworsky said.

Substituting store brands for higher-priced brand-name items is also a good way to save on grocery bills, often without sacrificing on quality, Gillis added.