The results come weeks after other established restaurant chains such as McDonald's Corp, Chipotle Mexican Grill and Starbucks Corp reported solid growth, driven by new menu additions and expanded delivery services.

Wendy's has also revamped its menus, launching the "$5 Biggie Bag combo", expanding its "Made to Crave" menu and adding a parmesan caesar chicken salad to its offering.

"We are pleased with Wendy's performance given McDonald's best U.S. comparable performance since 4Q15," Cowen analyst Andrew Charles said.

Wendy's has also invested in remodeling its restaurants and adding kiosks, while ramping up delivery through a partnership with DoorDash.

More than 80% of the burger chain's U.S. restaurants were covered by the DoorDash service at the end of second quarter, the company said.

These efforts lifted North America same-stores sales growth 1.4% in the quarter, slightly above analysts' average estimate of 1.36%.

Chief Executive Officer Todd Penegor on a post-earnings call said he was also looking at including plant-based proteins in the company's menu.

Meat alternatives from companies such as Beyond Meat Inc and its competitor Impossible Foods have seen booming demand from consumers and restaurants.

Excluding certain items, Wendy's posted adjusted profit of 18 cents per share in the quarter, beating estimates by 1 cent, according to IBES data from Refinitiv.

The company also reaffirmed its full-year adjusted profit forecast of about 3.5% to 7% growth, which Bernstein analyst Sara Senatore said was "likely to be viewed positively."

But Wendy's total revenue of $435.3 million came in below estimates of $439.9 million.

Shares, which have gained 16% this year, were up 7% at $19.37.

(Reporting by Soundarya J in Bengaluru; Editing by Bernard Orr, Sriraj Kalluvila)