Hedge fund manager Bill Ackman has a serious appetite for fast food companies like Burger King Worldwide Inc. (NYSE:BKW), McDonald’s Corporation (NYSE:MCD) and Wendy’s Co. (Nasdaq:WEN).

Earlier this week in a letter to shareholders, hedge fund manager Bill Ackman explained his commitment to Burger King, telling clients the global burger chain deserves to outpace fast food franchise rivals like Domino’s Pizza, Inc. (NYSE:DPZ) and Dunkin Brands Group Inc. (Nasdaq:DNKN).

In the letter, Ackman said that Burger King shares trade roughly evenly with Dominos, Dunkin and Tim Hortons, then added: “We believe this valuation understates Burger King’s intrinsic valuation.

"Burger King’s global brand and presence are superior to those rivals, and its joint venture model is  distinct from the more standard franchise model, will offer better investment returns," he wrote.

Ackman wrote that Burger King could significantly improve its earnings by refinancing about $1.4 billion in debt at more favorable market interest rates.

A large dividend or share buyback, of up to 30 percent of Burger King’s market value, could also provide a quick boost to share prices, Ackman said.

Ackman controls about 29 percent of Burger King through his U.K. investment vehicle Justice Holdings, and through his U.S. hedge fund Pershing Square Capital Management LP, which  holds an 11 percent stake in Burger King, according to the Wall Street Journal.

An activist investor pushing for share repurchases at restaurant companies, especially those with franchises, isn’t surprising, Morningstar (Nasdaq:MORN) analyst R.J. Hottovy told International Business Times.

“It does look like it’s trading at a discount to those names, and it does have a pretty big global footprint, though both those names [Domino’s Pizza and Dunkin Donuts] are also pretty big global companies,” said Hottovy, who covers the food and beverage industry, but he doesn’t cover Burger King specifically.

Ackman’s Pershing Square Capital has famously invested in McDonald’s and Wendy’s International in the past.

According to the letter and regulatory filings, Ackman acquired McDonald’s stock in June 2005, at about $28.98 per share, but exited in late 2009, when shares were at $58.66. He bought Wendy’s at $38.35 in December 2004, and h exited at $70.99 by November 2006.

In the past, Ackman has invested in major seafood restaurant operator Landry’s Restaurants, Inc. (NYSE:LNY) and Yum! Brands, Inc. (NYSE:YUM), the parent of KFC Corporation and Pizza Hut, Inc.

Not all food companies are to his taste, however. Ackman’s latest filings show that he has just exited Mondelez International Inc. (Nasdaq:MDLZ), a Kraft Food Groups Inc. (Nasdaq:KRFT) spinoff which owns the Jell-O, Oreo and Cadbury brands, among others.

In the wider fast food market, customers are increasingly turning to fast food trucks instead of traditional eateries, market researcher the NPD Group found  on Monday.

The food trucks may be snatching casual lunch hunters away from fast food giants, said NPD.

In recent months, McDonalds global sales have recovered somewhat from historic slumps seen last year, even as it maintains a large competitive moat between itself and its closest competitors, like Wendy’s.

Ackman’s Pershing Square funds gained between 5 and 6 percent overall in the first half of 2013, but they were surprisingly flat in the past three months.

His investments in faltering retailer J.C. Penney Company, Inc. (NYSE:JCP) and his shorting the successful Herbalife Ltd. (NYSE:HLF) nutrition business have been perceived lately as unwise.