CHICAGO – Casual dining chains are among the biggest losers of a slumping $331 billion restaurant industry, causing concern among some industry analysts as to how long consumers will continue holding on to their disposable income for purposes other than dining out, reports AdAge.com.

According to NPD Group, restaurant traffic has been declining for years, but actual sales have declined “for the first time in two and a half years the week of July 28.”

John Glass, restaurant analyst for CIBC World Markets, told the news source that the restaurant industry is facing its worst sales slump since the 1991 recession. “This time around, the consumer faces a more volatile mix: Rising energy costs and interest rates have slowed personal consumption expenditures, while unit growth, especially in casual dining, has impeded same-store sales growth,” he said, adding, “While we are not in a recession, we have more industry-inflicted damage this time around.”

AdAge.com writes that even though restaurants represent about 4 percent to 6 percent of consumer disposable income, “patronage is viewed as a leading economic indicator as industry trends tend to shift ahead of the economy.”

Industry consultant Malcolm Knapp commented that casual dining chains such as Applebee’s are realizing customers with household incomes below $35,000 cannot afford to dine out. However, consumers with household incomes above $70,000 are not as affected.