Study: One large Mexi-fries, please, and bring on the fat

A new study (PDF) published in the American Journal for Preventive Medicine suggests not. Two years after King County began requiring many chain restaurants to post nutritional information on menus and boards, researchers found the law had no effect on consumer behavior in its first year.

The study, done by researchers at Duke University and Public Health -- Seattle & King County, looked at what people ordered at 14 Taco Times. Seven of the restaurants were in King County, which had to post calorie, saturated fat, carbohydrate and sodium information for consumers.

The other seven Taco Times were outside of King County and didn't have to change their menu boards. Researchers used a one-year baseline of sales data before the law went into effect in January of 2009 and compared it with a 13-month span afterward.

The study found no statistically significant difference in "food-purchasing behavior" before and after the law took effect. For both the King County and non-county groups, the passage of the law had no effect on the total number of sales and average number of calories per transaction.

In other words, if consumers wanted Mexi-fries, a Casita Burrito, and large Coke, the posting of fat, sodium and calorie content didn't change their orders.

"The results suggest that mandatory menu labeling, unless combined with other interventions, may be unlikely to significantly influence the obesity epidemic," Eric Finkelstein, a Duke University associate health-services professor, said in a statement.

Finkelstein said researchers had expected any menu-labeling behavioral impact to be small, but were surprised when they couldn't detect "even the slightest hint of changes."

But he said the lack of impact may be because Taco Time, a Washington state chain, was already identifying healthier options with a "Healthy Highlights" logo, when the law took effect. He said a simple logo may be all it takes to convey healthier choices to consumers.