OAKVILLE, ONT. — Restaurant Brands International Inc.’s expanded plant-based offerings brought about higher traffic and an influx of younger consumers at Burger King and Tim Hortons during the second quarter, said Jose E. Cil, chief executive officer.

The company recently expanded its Impossible Whopper to over 7,000 Burger Kings across the United States after launching in April. Tim Hortons, the company’s Canadian coffee brand, unveiled the Beyond Meat breakfast sandwich in June, with plans to roll out Beyond Meat burgers on its lunch and dinner menus. In Early August, the brand became the first major fast-food chain to test plant-based eggs through its partnership with Just, a company known for its vegan egg product.

Mr. Cil said customer interest in plant-based offerings across both restaurants is encouraging.

“We’re seeing really, really good response from our guests,” he said during an Aug. 2 conference call with analysts. “We see that there are two types of behaviors taking place. We’re seeing existing guests come more often and actually changing their orders, and try the same product but with different proteins, so that’s exciting. And then we’re seeing new guests as well, younger guests, we’re seeing a shift as well in demographics.”

System-wide sales across Restaurant Brands International’s three chains grew 8%, led by Burger King, which posted 9.8% growth during the second quarter ended June 30. Sales at Popeyes grew 8.8%, while Tim Hortons recorded sales growth of 1.6%.

Net income was $331 million, or 71c per share on the common stock, up 5% from $313 million, or 66c per share, during the same period last year.

Burger King saw strength outside of the United States. International system-wide sales grew approximately 18%, with 6.5% comparable stores sales growth and close to 10% unit expansion.

Comparable store sales in the United States were 0.5%, up slightly from the first quarter.

“We had a sales gap in value,” Mr. Cil said. “We know that the best way to grow our business is a balanced, core premium and value offering that caters to all guests, and it seems that we did not have strong enough value offers and messaging throughout most of the quarter.”

To help address this value gap, the company launched $1 tacos in the beginning of July. Results have so far been encouraging, according to the company.

Global comparable sales at Tim Hortons were 0.5% globally and 0.7% in Canada. Positive trends in the restaurant’s breakfast platform continued throughout the second quarter, as products like Omelet Bites and Beyond Meat breakfast sandwiches resonated with consumers. This menu innovation strength was partially offset by softness in the lunch daypart, with sales of sandwiches and wraps down from second quarter 2018, Mr. Cil said.

Efforts to drive comparable sales growth at Popeyes paid off. Global comparable sales grew 3% globally and 2.9% in the United States.

Restaurant Brands International also doubled down on efforts to expand Popeyes into international markets during the second quarter, announcing it will work with longtime partners T.F.I. and Gregario Jimenez to expand the restaurant’s footprint in China and Spain, respectively.