Over the last decade, smartphones have become ubiquitous not just for sending texts and staying abreast of news, but also for monitoring daily activity levels.

Among the most common, and arguably the most meaningful, tracking method for daily physical activity is step counting.

Counting steps is far more than a fad: The U.S. Department of Health and Human Services dedicated a sizable portion of its most recent physical activity guidelines to documenting the relationship between daily step counts and several chronic diseases.

Unfortunately, the guidelines have little to say about how step counts might be used to aid in weight management, an outcome of critical importance given the high rates of overweight and obesity in the U.S.

In the early 1980s, fewer than 14% of adults in the U.S. were classified as having obesity. Today, just over 40 years later, the prevalence of obesity is greater than 40% in the adult population, and current trends suggest that almost half of adults in the U.S. will be obese by 2030.

I am a professor of exercise science at Kennesaw State University, and our lab has been conducting studies examining relationships among step counts and a number of health outcomes.

While the evidence is clear that increasing numbers of adults are living in a chronic energy surplus that leads to weight gain, a key question is – why? What has changed so dramatically since 1980 that could explain why obesity rates have tripled?

Although the American diet is likely a key contributor, a wealth of research points to a reduction in physical activity as a major culprit behind the expanding waist lines – and step counts are an excellent indicator of physical activity.

A number of recent studies have looked at whether increasing step counts can lead to weight loss over a certain period of time. One large-scale study called a meta-analysis concluded that increasing physical activity by way of step counts was effective for attaining modest weight loss. However, many if not most studies examining the effect of exercise on weight loss report modest outcomes, with results that are variable and often disappointing.

That may be in part because the step count targets used in many weight management studies are most often set in an arbitrary manner, such as targeting 10,000 steps per day. Or, if they’re individualized at all, they’re based on initial behavioral characteristics, like adding a given number of steps to what a person is already accumulating in a typical day. Rarely, if ever, are the step targets in research studies based on any physical attributes of the participants.

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