Restaurant sales have generally slowed in the United States in the past year, due to high gasoline prices and lower consumer confidence in the wake of the housing market slowdown. This has hurt consumer spending. However, sales of less expensive fast food remain strong, particularly in developing regions such as Asia and Latin America. As market leaders, McDonald’s and Yum will continue to benefit from growing global demand for fast food. Their strong brands also make it easier for them to pass along higher food and labor costs. MCDONALD’S CORP. $61 (New York symbol MCD; Conservative Growth Portfolio, Consumer sector; Shares outstanding: 1.1 billion; Market cap: $67.1 billion; WSSF Rating: Above average) operates over 31,400 fast food restaurants in 118 countries. Much of McDonald’s recent growth comes from its overseas operations, which provide two-thirds of its sales and half of its earnings. That’s mainly because growing prosperity is making the company’s products more affordable in developing countries. The higher value of most foreign…