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American portion sizes, our couch-potato ways and our waistlines are the punchlines of jokes around the world. But how bad are we really? Out here on the East Coast, in an urban area full of lots of highly educated people sporting all manner of Apple Watches, Fitbits and the like on their wrists, you might come to the conclusion that the stereotypes are an exaggeration. You'd be wrong.

A study conducted by Oregon State University, the University of Mississippi and the University of Tennessee at Chattanooga has awarded nearly every adult in the country a failing grade. The researchers used four barometers to measure whether someone's behavior could be considered healthy. They include an appropriate balanced diet, being active, meeting the recommended criteria for body fat percentage and not smoking.

Using data from the 2003-2006 National Health and Nutrition Examination Survey data, they found that 97.3 percent of the 4,745 people they looked at did not meet the criteria.

Writing in Mayo Clinical Proceedings, the researchers described the standards as very reasonable. That is, they weren't looking for people to be marathon runners but just have a moderate amount of 150 minutes of activity a week.

"This is pretty low, to have so few people maintaining what we would consider a healthy lifestyle," Ellen Smit, a researcher at Oregon State and a co-author, said in a statement. "This is sort of mind boggling. There's clearly a lot of room for improvement."

The study's results are considered to be more reliable than previous ones because researchers used technology to track participants instead of self-reported surveys. For exercise, for instance, the researchers used an accelerometer, such as the ones in a phone or fitness band, to track movement. And blood samples were taken to confirm whether people were smokers.

There were, of course, many people who met one or more of the criteria. Only 11 percent were in the supremely unhealthy range meeting zero of the goals, 34 percent met one, 37 percent met two, 16 percent met three and 2.7 percent met all four. There were big differences among some of the subgroups studied. Women were more likely to have a healthy diet and not smoke — but they were less likely to exercise enough. Mexican American adults, it turned out, were more likely to have a healthy diet than their non-Hispanic white or black counterparts. Older Americans — 60 years and over — were overall less healthy than those ages 20-39 but were more likely to have healthy diets and not smoke.

The researchers emphasized that meeting all four goals is important because these factors have been linked to increased risk of cardiovascular disease and other medical conditions.

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