Americans paid more for their groceries in April, with gasoline prices linked to the Iran war playing a role—but not the only one, according to U.S. data released Tuesday and economists who track how shocks spread through food supply chains.
The Labor Department’s consumer price index showed that prices for food in the category overall increased 3.2% from a year earlier. The data also showed that Americans paid 2.9% more for food eaten at home compared with the same month a year earlier, a pace the report characterized as the highest year-over-year inflation rate for that subcategory since August 2023.
Fuel costs have surged as the Iran war prevents cargo ships from passing through the Strait of Hormuz, a corridor that carries global oil supplies. Diesel fuel powers fishing boats, tractors and trucks that move much of U.S. agricultural output, and AAA reported that as of Tuesday the average price per gallon was up 61% from a year ago.
The supply-chain mechanics matter, Purdue University economists Ken Foster and Bernhard Dalheimer said. They said higher energy costs can take three to six months to appear in retail grocery prices, since they affect production, processing, storage and transport first—and prices at supermarkets often adjust more slowly.
In Michigan, Sparrow Market is among the small grocers feeling those upstream pressures. Owner Raymond Campise said the meat, produce and dry goods vendors that supply the store have added fuel surcharges to deliveries in recent weeks, and he said wholesale prices for meat, produce and some other products have risen as well.
“For independent markets operating on narrow margins, even small increases can have a major impact,” Campise said. Purdue’s Foster added that much of what consumers are seeing in the food price chain may have started before the Iran conflict, arguing that the industry is still waiting to see what later monthly readings show.
He said, “Most of what we’re seeing now in the food price chain probably predates the conflict,” and described the need to watch the June and May numbers as they come out to gauge the “extent” to which energy shocks tied to the Strait of Hormuz and shipping blockades affect food prices.
The April CPI also reflected other pressures beyond fuel, including U.S. trade policy and weather. The report cited that in July 2025 the Trump administration imposed a 17% duty on fresh tomatoes imported from Mexico, and said consumer prices rose 40% in the prior 12 months before April. It also pointed to dry weather in the Western U.S., which has helped push up beef prices; it reported April beef prices were 15% higher year-over-year, while coffee prices were up 18.5% and the report linked the rise partly to drought and other weather damage affecting global coffee production.
Some foods did not rise as sharply. The CPI report said milk and chicken dipped slightly, butter cost 5.8% less in April than a year earlier, and egg prices fell 39% as farmers rebuilt flocks after an ongoing bird flu outbreak.
Broader fuel costs can also flow into other parts of the consumer basket, Foster said, including packaging. He said, “It’s possible some of that’s starting to seep down the supply chain and get into those prices,” referring to the petroleum derivative used to make plastic bottles as part of an explanation for an increase in nonalcoholic beverages over the past year.
Over the longer term, energy-driven fertilizer costs could matter as well. Foster said around 30% of the world’s fertilizer travels through the Strait of Hormuz, and he said Americans could see higher food prices in the coming year or more if the conflict lasts. He also said that fertilizer has been less of an immediate issue for U.S. farmers this year because many had supplies already in place before the war began, but that effects could become more noticeable next year if the conflict drags on.
“I expect the Iran conflict to impact the coming years’ food prices through a couple of channels. One, the energy costs and transportation handling. The other would be through packaging costs,” Foster said. “If the conflict were to last longer, then we might see more coming online as fertilizer prices start to impact longer-term planting decisions and cropping decisions.”
Food inflation is likely to stay politically prominent as the midterm elections approach in November. The report noted that during the 2024 campaign, President Donald Trump frequently cited the prices of groceries such as bacon, cereal and crackers as reasons voters should return him to the White House.