Stanford researchers find intriguing clues about obesity by counting steps via smartphones

Stanford researchers using smartphones to track the activity levels of hundreds of thousands of people around the globe made an intriguing discovery: In countries with little obesity, people mostly walked a similar amount per day. But big gaps between people who walked a lot and those who walked very little coincided with much higher levels of obesity.

The ground-breaking study, appearing in Nature, used data captured from smartphones to analyze the habits of 717,000 men and women from 111 countries, whose steps were studied for an average of 95 days.