Even if you're not counting your calories, date night at that restaurant down the street is still a more healthful choice than McDonald's, right?

Don't count on it.

Dining out at a sit-down restaurant can mean far more sodium in your diet-- and nearly as much saturated fat — as eating at a fast-food joint, according to a recent study in the European Journal of Clinical Nutrition. What's more, people consumed more calories when they sat down for their meal at a full-service place rather than taking it to go, the study found.

"People regard fast food as junk food and tend to believe that full-service restaurants are better in terms of quality and healthiness," says Ruopeng An, an assistant professor of kinesiology and community health at the University of Illinois, Urbana-Champaign. So he was "a little bit surprised" by his findings, he tells The Salt.

An dug through seven years of data from the National Health and Nutrition Examination Survey, which polled some 18,000 U.S. adults. During an in-person interview, survey participants were asked to recall what they had eaten during the previous 24 hours, where the food was from and where they ate it. In a follow-up phone interview a few days later, participants once again reported their previous-day meals, this time using measuring spoons, cups and other tools to measure their intake.

He then calculated nutrient intake (fat, saturated fat, sodium, sugar, etc.) from the raw data. The results: A full-service restaurant meal added an extra 412 milligrams to daily sodium intake compared with a home-cooked meal, while a fast-food meal added 300 milligrams. Eating out, he found, also increased saturated fat intake — by an additional 3.5 grams at a fast-food joint and 2.5 grams at a sit-down eatery.

So what about ordering takeout? An found that people scarf down about the same amount of fast-food calories regardless of where they eat those chicken nuggets. But it's a different story when it comes to meals from full-service restaurants: In that case, he found, people consumed significantly fewer calories when they took their meals to go than when they ate them at the restaurant. An thinks it has something to do with the convivial nature of restaurant dining.

"If people choose to dine at the restaurant, they have more time, it's likely a social event, they stay longer and consume more, enjoying the environment," he speculates.

Now, as An notes, the data have limitations: The questionnaire depended on self-reporting, and participants weren't asked for specific restaurant names, so we don't know if these were calorie-bomb-serving chain restaurants. Instead, those who reported dining out were asked to indicate whether the restaurant was a fast-food or pizza place, an eatery with a waiter, a bar or lounge, or no additional information — and whether they ate there or took it home.

Even so, the findings have important implications for public health policy, says Sara Bleich, an assistant professor of health policy at Johns Hopkins University's Bloomberg School of Public Health in Baltimore, who was not involved in the research.

As Bleich notes, "almost half of our food dollars are spent on food away from home." And as previous research has shown, when those dollars are spent at a sit-down chain restaurant, chances are good that they're paying for more calories served in big portions. "And the more you put in front of a person, the more they eat," she says.

The good news, Bleich says, is that federal rules requiring chain restaurants to list nutritional information on menus could help moderate how much we eat when dining out. One study of a similar mandate in Seattle found that menu labels made people significantly more aware of calorie information and more likely to use it to guide their choices. Another study found that 18 months after the rule was put in place, the mean amount of calories purchased at Seattle's chain restaurants dropped.

The federal menu-labeling requirements kick in this December. But as Bleich notes, diners will still need to educate themselves on how to interpret the numbers for their own health.

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