01/08/2014 12:15 EST | Updated 03/09/2014 05:59 EDT

Sodium in 1 restaurant meal tops recommended daily intake

Restaurant meals for adults at full-service chains topped the daily recommended levels for sodium by 153 per cent on average and many meals provided an entire day's calories, a new U.S. study finds. 

Consumers tend to see full-service restaurants as better in quality and healthfulness compared with fast-food restaurants, but previous studies suggest that full-service eateries serve oversized portions and foods of low nutritional quality.

Researchers analyzed the nutrients from printed menus or web sites for 21 full-service restaurant chains in Philadelphia that offered single-serving entrees. Chains included:

- Red Lobster.

- Pizza Hut.

- Dennys.

- Perkins.

- Olive Garden.

"Values exceeded appropriate levels for a single meal, and under common meal scenarios, exceeded maximum recommended intakes for an entire day, particularly for sodium and saturated fat," Amy Auchincloss of the Drexel University School of Public Health and her co-authors concluded in Wednesday's Journal of Nutrition Education and Behavior.

On average, adult meals (entree, side dish and half an appetizer) on menus averaged 75 per cent to 100 per cent of calories for an entire day at 1,500 calories, according to a summary provided by the researchers.

For sodium, the average adult meal exceeded daily recommended levels by 153 per cent, with 3,510 milligrams.

A U.S.-based salt reduction plan aimed to reduce salt in processed and restaurant foods by 25 per cent by 2014.

"However, current sodium levels at full-service restaurants are so high that even after a reduction of 25 per cent, mean sodium in à la carte entrées would still be about 1,300 milligrams," the researchers said.

The à la carte entrees were typically a single portion that was the main course and included a protein source, such as burgers and sandwiches.

For children's menus, the average meals (children's entree, side dish and beverage) had 49 per cent of a daily recommend intake with 690 calories. The sodium was 86 per cent of the limit with 1,380 mg and saturated fat was 71 per cent at 10 grams.

The researchers also looked at "healthy choice" à la carte entrees targeted to children and seniors. They found these entrees had lower calories than other entree categories but still exceed the recommended values for saturated fat and sodium.

They concluded standard definitions are needed for "healthy choice" tags and for entrées targeted to "vulnerable age groups."

A Canadian study in 2013 also found sodium levels in many foods served at Canadian fast-food restaurants and sit-down restaurant chains also exceed the amount an adult should take in during a day.

Many Canadian chains post nutritional breakdowns, including fat and sodium content, on their websites.

The Canadian Restaurant and Foodservices Association, the province of British Columbia and Heart and Stroke Foundation of Canada collaborated on B.C.'s voluntary Informed Dining nutrition information program that provides guests with nutrition information at or before the point of purchase for standard menu items.

The study was funded by the U.S. Centers for Disease Control and Prevention, U.S. Department of Health and Human Services and the Philadelphia Department of Public Health. The city introduced a labelling ordinance.