Fast-food giants McDonald's and Wendy's, accused by Spain's leading consumer group of providing scant nutritional value in their hamburgers, have announced lawsuits against the organization.

Wendy's said it was suing the Consumer Organization for "spreading false and tendencious information" over the quality of the food it sells in its 14 restaurants in Spain, and McDonald's finalized legal steps for a suit on similar grounds.A Wendy's spokesman said its lawsuit sought $5.3 million that would be spent on investigating Spaniards' eating habits.

A McDonald's official said that firm also planned to initiate a lawsuit against the Consumer Organization.

The health ministry ordered quality and hygiene tests on burger-bars all over Spain earlier this month after a damning study by the Consumer Organization said hamburgers in U.S.-owned chains contained poor-quality meat and too much cholesterol.

The government says it is trying to counter the craze for fast food by promoting a healthier "Mediterranean diet" focusing on vegetables, fruit and fish and olive oil rather than animal and vegetable fats.