More than 6 hours per day of screen time has been linked to increased cardiovascular risk and higher BMI in young adults, independent of physical activity levels, a new observational study suggested.

Though screen time appeared to be an independent predictor for increased blood pressure, cholesterol levels, and BMI, when combined with low levels of activity, the two factors had a “synergistic effect” on BMI and blood pressure, the researchers said.

“The principal takeaway is that excessive screen exposure should be considered an independent and modifiable cardiovascular risk factor in young adults,” first author Zain Islam, MD, of Taqi Medical Center in Hyderabad, Pakistan, told Medscape Medical News. “Importantly, the observed associations with adverse cardiometabolic markers persist even after accounting for physical activity levels, underscoring that screen time represents a distinct behavioral determinant of cardiovascular risk.”

The research is set to be presented at the upcoming American College of Cardiology (ACC) Scientific Session 2026.

Study Results

Islam and colleagues conducted a prospective observational study of 382 adults in Pakistan who completed a questionnaire about their daily screen time habits and physical activity. The researchers also evaluated baseline and clinical measurements for each participant, which included BMI, waist circumference, blood pressure, and fasting lipid profile.

Using regression analyses, the researchers analyzed the relationship that screen time and physical activity had on cardiovascular risk markers. They assessed the proportion of patients who used screens more or less than 6 hours per day outside of work or school on devices such as smartphones, tablets, computers, televisions, and other digital interfaces. Physical activity was evaluated based on whether participants reported more or fewer than 150 minutes of exercise per week.

The researchers found there was an independent association between participants who reported screen time of 6 hours or more per day and higher systolic blood pressure (17.9 mm Hg), low-density lipoprotein cholesterol (28.5 mg/dL), and BMI (2.9; P < .001 for all).

When comparing physical activity and cardiovascular risk factors, Islam and colleagues found an independent association between participants with 150 minutes per week of moderate-to-vigorous physical activity and lower waist circumference (-6.2 cm) and triglyceride levels (-38.9 mg/dL; P < .001 for all).

Researchers said participants who reported high screen time and low physical activity together were significantly more likely to have an adverse impact on BMI and systolic blood pressure (P < .05).

Screen Time as Risk Factor

The underlying mechanisms of why screen time was an independent risk factor are likely multifactorial and could include the physiologic changes of sedentary behavior, sleep disruption, psychosocial stressors associated with digital content, and adverse behavioral patterns during screen use, like increased caloric intake, Islam said. 

“Collectively, these factors may contribute to unfavorable cardiometabolic profiles,” he said.

Future studies should look at whether this association persists in cohorts with greater diversity that use more objective measures of screen exposure, such as device-based tracking, Islam said.

“Longitudinal studies evaluating hard cardiovascular endpoints, as well as interventional trials assessing the impact of screen time reduction on cardiometabolic outcomes, will be essential to further elucidate causality and clinical relevance,” he said.

“Digital behavior has emerged as a central component of modern lifestyle and should be integrated into cardiovascular risk assessment frameworks. Preventive strategies must evolve to address both physical inactivity and excessive screen exposure, with an emphasis on structured behavioral modification and digital health awareness,” Islam added.

Managing Screen Time

The results by Islam and colleagues show screen time is “not just a surrogate for physical inactivity” but has its own association with increased cardiovascular risk and BMI, Srihari Naidu, MD, professor of medicine at New York Medical College, Valhalla, New York, told Medscape Medical News.

“The study is important as society increasingly recognizes the hazards of having a life heavily tied to technology, whether it be social or work-related, and that it is an uphill battle to tackle our cardiovascular risk in the present era of significant screen time amongst young adults,” said Naidu, who was not involved with the study.

He said it may be worth having clinicians begin asking patients about screen time in the same way they ask about step count.

“These are loose guides to how we partition our day between things we need to do and encourage stepping away from our phones and computers for sufficient periods of time,” Naidu said.

However, he noted the study was not a controlled experiment, and there is no evidence that reducing screen time will reduce risk factors or cardiovascular events. Clinicians asking patients about lifestyle aspects associated with cardiovascular risk is important because they “create the culture in which the risk factors thrive,” Naidu explained.

“Low step count and activity, high screen time, both of which link to sedentary behavior and obesity, can open up a conversation about the patient’s ecosystem and how to change it, along with appropriate medications, to hopefully improve their lifespan,” he said.

“At the very least, it adds to the conversation between clinicians and their patients that if screen time is excessive, we really need to be looking at and managing all the risk factors aggressively, including hypertension, smoking, diabetes, lipids, and obesity,” he added.

Regardless, Naidu said screen time is “here to stay,” and the situation is not dissimilar to how the widespread adoption of television or video games fueled sedentary behavior.

“The difference, of course, is that now we can carry both of those on our phones, and so everyone is doing it — young and old — for different reasons and in different ways,” he said. “Individuals should start looking at their screen time on their own and hopefully provide themselves, together with step count, a way to focus on other things associated with health — such as social interaction, physical activities, or events that require putting the phone down.”

Islam and Naidu reported having no relevant financial relationships.

Jeff Craven is an independent journalist living in Wilmington, Delaware.