Grocery retailer and distributor SuperValu (SVU) on Thursday became the latest industry player to warn about stiffer competition and lower food prices, slashing its full-year outlook amid what some analysts call signs of another grocery-store price war.

The announcement comes a day after natural foods store Sprouts Farmers Market(SFM) cut its full-year outlook for similar reasons. Dollar General (DG) also cited retail “food deflation” as a difficulty. Investors will be watching to see if grocery-store operator Kroger (KR) reports the same when it reports second-quarter earnings on Friday.

“The current landscape is now beginning to look a lot like 2009, when meaningful deflation resulted in an industry price war and multiple quarters of declining earnings,” Credit Suisse analyst Edward Kelly said in a research note dated Wednesday.

He added that the fall in food prices could last a few quarters and make it even harder for Whole Foods Market (WFM) to spin itself as a more value-oriented grocery store.

The slide in prices has occurred largely in beef, poultry and dairy, Edward Jones analyst Brian Yarbrough said.

Beef prices, he said, have largely fallen due for cyclical reasons — the general balancing of supply and demand. Last year’s bird flu outbreak constrained supply of poultry, drove up egg prices and prompted more people to buy egg substitutes, he added. But when some kept using those substitutes after the bird flu passed rather than switching back to eggs, egg production got too high and prices fell. As the U.S. dollar strengthened against other currencies, demand for milk in Asia and Europe waned, leading to an oversupply, Yarbrough also said.

Amid those trends, grocery stores have tried to cut prices to move items off shelves more quickly. Recent price cuts at Wal-Mart (WMT) have begotten price cuts at its rivals.

“The deflation in certain proteins has been sustained in a way that I have not previously seen,” CEO Mark Gross said at an investor conference.

“It’s interesting,” he continued, “the ability of U.S. producers to spring back from, let’s say, supply constraints of last year, particularly, say, the Avian bird flu that affected chicken flocks — the ability of producers to come back so fast and so strong that we would be experiencing substantial deflation in normal Grade A eggs is significant.”

At the conference, SuperValu management shied away from calling the climate a price war but did say that Wal-Mart, whose price cuts have reportedly also hurt the dollar stores, has “always been a tough competitor.” SuperValu also cited changes and cuts in food stamp benefit as affecting sales, as have others.

In a statement, SuperValu said it expected full-year adjusted EBITDA — or earnings before interest, taxes, depreciation and amortization — to be around 5% lower than last year. Earlier, the company had forecast for a 1.5% slip, according to the Wall Street Journal.

Shares sank 9.5% in the stock market today following the news, puncturing their 50-day and 200-day lines after finding support at the latter level for a few weeks. The stock fell 3.9% on Wednesday, joining the Sprouts-led sell-off.

SuperValu serves and operates conventional grocery stores and operates Save-A-Lot, a discount chain. The company said its retail division in its fiscal second quarter “has been impacted to a greater than anticipated degree by competitive openings and a challenging sales and operating environment for its stores.”

The Save-A-Lot segment in the second quarter had been hit by “deeper levels of deflation as well as lower levels of SNAP (supplemental nutrition assistance program) benefits compared to the first quarter,” SuperValu said, referring to a federal program that helps people in low-income brackets buy food.

Sprouts Farmers Market stock fell 1.3% after crashing nearly 14% on Wednesday. Kroger (KR) closed down 1 cent at 31.31, but that followed a 4% loss on Wednesday. and Whole Foods Market rose 0.6%, but after tumbling 5% on Wednesday.

Wal-Mart fell 0.3%, still stuck below its 50-day line.

Natural foods distributor United Natural Foods (UNFI) sank 3.7% after losing 4.3% on Wednesday.

Cheaper prices at grocery stores can’t be good news for restaurants either. Fast food prices have risen much faster than the cost of eating at home. Eateries may need to rein in menu prices to sustain customer traffic, but that could squeeze profit margins with labor costs rising from tighter job markets and higher minimum wages.

Kelly, in the research note, said it was “too early to call the bottom” of the current price drop. And predictions across the industry vary.

“I don’t think any of these grocery stores or any of these guys have any better idea than we do,” Yarbrough said. “I think they’re just speculating, and I think of it may be wishful thinking.”