A new Stanford University study has found an "activity inequality" around the world — in countries with high rates of obesity, there is greater variation in the number of steps people walk each day compared to populations with lower rates of obesity. And, one of the biggest contrasts is between men and women. The study's findings, analyzed from smartphone step-count data from more than 700,000 people in 111 countries, should inform policies to curb obesity, researchers wrote.

Key findings:There's a gender gap: In every country studied by the researchers, men logged more daily steps than women. But in certain countries, such as Qatar and Saudi Arabia, results showed that men walked nearly 40% more than women. The U.S. also had one of the largest gender gaps, with men walking 25% more than women.Inactivity is worse for women than men, according to findings. Women who walked about 1,000 steps per day were more than 3 times as likely to be obese than women who walked about 10,000 steps. Similarly inactive men were less than twice as likely to be obese than their active counterparts. The obesity rate was 30% for both men and women who logged around 1,000 daily steps. Limitations: Smartphone algorithms and apps aren't entirely accurate at measuring steps, and researchers are limited by who can afford to use them. Data was therefore largely collected from relatively wealthy people, though smartphones are gaining popularity even in developing nations. Still, the study did not include low-income countries.

Go deeper: 2.2 billion people worldwide are obese or overweight.