“Ten Signs America Is Getting Healthier,” exclaimed a typical headline earlier this year. Among the evidence listed: the rise of the FitBit and similar mobile health apps, as well as the prevalence of different diets, from Paleo (also known as the “Caveman Diet”) to Flexitarian (which emphasizes fruits, veggies, whole grains, and plant-based proteins). Add to that the standing-desk craze—and even, for the diehard fanatics, the treadmill-desk craze—and it’s easy to conclude that America’s waistlines must be slimming down by the day.

Not so fast. Other recent stories have been saying exactly the opposite. “America Keeps Getting Fatter,” was the headline on one such story, and another said, “Americans Are Fat, Stressed, and Unhealthy.”

Such contradictory signs are everywhere: from a rise in cycling to work on the one hand to a boom in fast-food franchises—as well as in obesity and diabetes—on the other. Which one is it, then? As a nation are we becoming healthier or unhealthier?

A closer look at the data suggests that these parallel trends, though seemingly opposed, are actually entwined, products of a society that is split between those at the higher end of the socioeconomic scale and those at the lower end.

Think about it: What unites the young professional who uses a standing desk, the Paleo health freak, and the new mother getting back in shape with the help of a personal trainer? One thing: ability to pay. Such health routines are not as readily available to the person manning the counter at the local Walmart or working the graveyard shift at Starbucks.

In other ways, too, the data give off mixed messages, a statistical dissonance summed up last year in the headline of an Economist article as: “Healthier, not healthy.” In 2010, the magazine reported, American adults ate an average of 78 fewer calories each day than they had in 2005. But it also showed that, while in 1980 no state had an obesity rate higher than 15 percent, today every state has an obesity rate above 20 percent. “Millions of Americans are ill thanks to factors that have nothing to do with the health system, from poverty to food marketing to poor urban planning to strapped school athletic programs,” the Economist concluded.

There are some encouraging signs. According to the Robert Wood Johnson Foundation, a nonprofit dedicated to health, obesity prevalence among 2- to 5-year olds dropped by about 40 percent over eight years; 70 percent of kids in middle school and 63 percent of high school students said they liked the healthier lunches that their schools rolled out in 2012; and workplace wellness programs are multiplying.

These are positive changes that affect everyone, not just those at the high end of the income scale. With nothing costlier than increased awareness, the future of our health can change, one step—or push-up, or well-chosen meal—at a time.

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