Although a number of chain restaurants have announced healthy menu changes over the years, the overall calorie and sodium levels in main entrees offered by top U.S. chain restaurants assessed from 2010 to 2011 have remained the same, according to a study published in the Journal of the Academy of Nutrition and Dietetics.

The study, "Changes in the Energy and Sodium Content of Main Entrées in U.S. Chain Restaurants from 2010 to 2011," evaluated the nutritional content changes of more than 26,000 regular menu entrées in a year by 213 major U.S. chain restaurants nationwide. It also looked at entrées among restaurants that included children's menus.

"Restaurant menus did not get any healthier over time," said Helen Wu, a policy and research analyst at the Institute for Population Health Improvement at UC Davis Health System.

Between the spring of 2010 and spring of 2011, Wu and Roland Sturm, senior economist at the RAND Corp., reviewed restaurant websites for nutrition information. They found that, even with all the substitutions and reformulations eateries made to their menus, restaurants made no meaningful nutrition changes overall. The average entrée in 2010 contained 670 calories and remained at 670 calories one year later. Sodium levels only dropped from 1,515 milligrams per entrée to 1,500 milligrams at follow-up.

"Across the restaurant industry, we see a pattern of one step forward, one step back," Wu said. "Restaurants make changes to their menus regularly, but they may make both healthy and unhealthy changes simultaneously. This study provides objective evidence that overall, we did not see a new wave of healthier entrées come in to replace less healthy ones."

The study was conducted at a time when restaurants faced ongoing internal and external pressures to increase healthier menu offerings. For example, the study examined restaurant menu changes in the year following passage of a federal menu-labeling mandate, which was passed as part of the Patient Protection and Affordable Care Act of 2010. More than three years later, the U.S. Food and Drug Administration (FDA) has not issued final regulations directing chain restaurants to post calorie information on menus, though some restaurants, such as McDonald's, have already started posting calorie counts on their menu boards.

Americans consume approximately one-third of their total calories and spend half of their food budget eating away from home. Yet restaurant menu offerings do not encourage healthy eating.

This new study is a follow up to an earlier Wu and Sturm study, published online in May 2012 by the journal Public Health Nutrition, which found 96 percent of entrées by top U.S. chain restaurants failed to meet daily limits for calories, sodium, fat and saturated fat recommended by the U.S. Department of Agriculture.

Within individual restaurant brands, a few brands did significantly lower the average calorie or sodium levels of their main entrées, but some brands significantly increased them. The vast majority of restaurant brands did not have significantly different calorie or sodium levels for their main entrées.

The study also found that overall, children's entrées did not become healthier in the period studied, although fast-food restaurant entrées were reported to be 40 calories lower, on average.

The study also specifically examined those entrées that were added or reformulated between 2010 and 2011, and found no differences in calories. At family-style restaurants, new entrees at the 75th percentile (i.e., those at relatively higher sodium levels to start) were 70 mg lower in sodium in 2011, but even with those changes, entrées at family-style restaurants are still far too high in sodium for anyone watching their sodium intake.

"Consumers need to be aware that when they step into a restaurant, they are playing a high-stakes game with their health by making dietary choices from menus that are loaded with high-calorie, high-sodium options," Wu said. "This is a game that health-conscious consumers have a very low chance of winning, given the set of menu offerings available in U.S. chain restaurants today."

More change could be seen with a longer-term study, and after the federal menu labeling requirement of the Affordable Act Care is implemented, but multiple strategies will be needed to make progress on restaurant menu nutrition.

"The implementation of a national menu labeling law could be an important strategy to accelerate progress on menu nutrition in restaurants by encouraging more substantial menu nutrition changes," Wu said.

"Maybe some more encouragement is needed, as in the Choose Health LA Restaurants program that the Department of Public Health started in September," Sturm said. "Restaurants participating can post a large decal in their window if they offer smaller portion sizes and healthier children's meals with less fried food and more fruits and vegetables."

In the United States, 82 percent of adults eat out at least once a week. Previous research has shown that increased consumption of food away from home is associated with increased consumption of calories, fat and sodium. Currently, two-thirds of U.S. adults and nearly one-third of children and teens are obese or overweight.