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Pairing low recreational screen time with a high daily step count may be an effective combo for curbing weight gain in kids, findings from a cross-sectional study suggested.

Looking at nearly 6,000 adolescents between the ages of 10 to 14, those averaging medium (more than 4 to 8 hours) or high (over 8 hours) amounts of screen time per day were significantly more likely to be overweight or have obesity compared with kids averaging 4 hours or less of screen time each day:

• Medium screen time: risk ratio 1.24 (95% CI 1.12-1.37)
• High screen time: RR 1.29 (95% CI 1.16-1.44)

In addition, kids hitting a medium amount of steps each day (>6,000-12,000) or a low amount of steps (1,000-6,000) had 19% and 30% higher risks for overweight or obesity compared with kids achieving over 12,000 daily steps, respectively, reported Jason M. Nagata, MD, MSc, of the University of California San Francisco, and colleagues in .

"The results suggest that the combination of less than 4 hours per day of screen time and greater than 12,000 steps per day of physical activity is beneficial to minimize the risk of higher [body mass index] BMI percentile," the group wrote.

But when looking at various combinations of step counts and screen times, hitting a daily target in one wasn't enough to offset the harmful effects of the other.

For example, when compared with kids achieving the ideal daily combination -- a high step count and low amount of screen time -- those with a low or medium daily step count tended to fall into much higher BMI percentiles even if they had low screen time (a 7.48 and 1.55 higher BMI percentile, respectively).

Similarly, even kids who hit a high daily step count tended to fall into a higher BMI category if their screen time was also high. Compared with the ideal combination, kids with high screen use fell into much higher BMI percentiles across all step count levels (low step count: 8.79 higher BMI percentile; medium step count: 8.76 higher BMI percentile; high step count: 8.26 higher BMI percentile).

"[N]o amount of steps per day attenuated the association between high recreational screen use and BMI percentile," the researchers emphasized. "Similarly, the association between low step count and high BMI was not attenuated by minimal screen use."

They added that these findings "are consistent with those reported in previous studies involving and , which suggest an upper limit of screen time hours is needed to observe a compensatory consequence of physical activity for BMI."

Nagata's group said they hope these findings better inform the Health and Human Services' 2018 , which doesn't currently recommend a set limit on daily screen time for adolescents, but does advise at least 60 minutes of daily moderate- to vigorous-intensity physical activity.

Data for the analysis were drawn from the Adolescent Brain Cognitive Development () Study. A total of 5,797 adolescents were included. The average age was 12, half were male, 61% were white, and 35% had overweight or obesity.

The average daily screen time was 6.5 hours per day with a daily step count of 9,246.6. Steps were counted over a 3-week span using Fitbits. Screen time was self-reported by each adolescent, which included time watching television shows and movies, videos, video games, texting, social media, and video chat.

"Future research should use a longitudinal study design and analyze additional chronic disease risk factors and outcomes, including sleep, which would further inform physical activity and screen time guidelines for adolescents," the researchers suggested.

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