According to Starbucks' latest earnings report for the 13-week period ending June 29, store sales declined by 2% worldwide and in North America, while international store sales remained flat. Net revenue was the bright spot, rising 4% to $9.5 billion for the quarter, a 3% increase compared to the same period last year.

Starbucks says it’s confident that new products coming next year - including a cold foam protein drink and improved baked goods - will help turn around lagging U.S. sales.

Starbucks will soon offer protein cold foam and is exploring gluten free and protein-centric foods, CEO Brian Niccol said. The macronutrient is having a moment, with companies marketing everything from cereal to popcorn as a way to get more protein.