McDonald's stores in the U.K. are holding their own amid an economic downturn that's taking a toll on some of the chain's rivals, said U.K. chief executive Jill McDonald. For one thing, consumers are trading down from pricier casual dining options more often, she said, and for another, remodeled stores and upgraded menus are bringing in more customers. The chain plans to open about 20 new U.K. units this year.