ORLANDO, Fla. - American restaurant-goers are ordering more tap water when they dine out, a beverage choice that is influencing the profits of restaurants.

Oviedo, Fla., resident John Hickey said he used to order a soft drink with every restaurant meal, but during the past few months and owing to a tightening budget, he has opted for free water. "It makes a big difference when you get that bill," Hickey said.

According to NPD Group, beverage purchases have dropped 6% since 2006 at restaurants, with many people ordering water. In the past two years, water orders have increased 3.2% while orders for sodas, coffee and other beverages have dropped 3.6%. "[C]onsumers believe the cost of beverages in restaurants has gotten too expensive," said Warren Solochek, vice president of client development for NPD.

Restaurants are feeling the pinch. Drink orders at Tony Roma€™s have "definitely declined," said marketing director Monique Yeager. "It's harder and harder for people when they go out to buy full meals during times like this."

McDonald€™s has fought back against the water trend by bolstering its beverage lineup, adding smoothies and specialty coffees. Meanwhile, Wendy€™s added all-natural lemonade last year to its menu.

The Coca-Cola Freestyle machine has been a strategic addition to many area restaurants, which have seen the 100-drink machine spike beverage sales. "It's just so innovative and different," Yeager said.

Solochek called the Freestyle "an excellent example" of how restaurants are trying to increase beverage orders. However, he cautioned that once customers are used to water, it might be a challenge to get them to begin paying again for a drink. "If I've been able to get away with drinking water, and it's healthier for me, why would I go back?" he said.