Watching TV while snacking makes people eat more, but scrolling on a phone may not. In a lab experiment disguised as a taste test, college students ate significantly more chips and candy while watching a show they picked on Netflix than when eating undistracted, while using their own smartphone made no measurable difference.
The study was carried out by Angela C. Incollingo Rodriguez, Mira S. Kirschner and Lorena S. Nunes and published as a short communication in Physiology & Behavior in its May 15, 2025 volume.
A “multitasking” study with hidden scales
Undergraduates at a northeastern polytechnic university were told they were taking part in “A Study of Multitasking” that would test how sensory stimulation changes ratings of new snack foods. They were asked not to eat for at least an hour beforehand, and all sessions ran in the afternoon.
Each participant did two ten-minute taste tests of potato chips and M&Ms in unusual flavors, filling in a rating form and left alone in the room. In one session they used technology; in the other they ate without distraction. Bowls were weighed before and after to calculate calories eaten.
Half the students were assigned to a TV protocol, choosing any episode on Netflix; New Girl and The Office were the most popular picks. The other half used their smartphones as they normally would for texting, email or social media. The order of the two sessions was randomized. Data were collected between Fall 2019 and Spring 2022, with a pause during the pandemic, and the final sample was 114 students, average age 19.4.
TV raised intake, phones did not
In the TV group, students ate an average of 163.88 calories while watching versus 131.60 calories undistracted, a statistically significant difference of about 25%.
In the smartphone group, there was no significant difference: 158.40 calories while on the phone and 150.24 without it.
The authors suggest one reason may be the hands. Using a smartphone usually occupies one or both hands, which may get in the way of eating in the moment, while TV is largely hands free. They note that phones might still reduce memory of eating and affect later meals, something this study did not measure.
Caveats from the lab
Students ate more in the first session regardless of condition, possibly because one second-session chip flavor, chile limón, was unpopular, or because they were less hungry after just eating. The authors acknowledge the food order was not fully counterbalanced and that hunger was not measured, to protect the cover story.
The sample was mostly White, and the design could not test what happens when people watch TV and use their phone at the same time. The difference between the TV and phone groups, compared directly, was also not statistically significant.
Even so, the researchers conclude that avoiding TV while eating snacks and meals remains a sensible recommendation, while smartphone use is unlikely to drive extra eating in the moment.
Study Details:
- Title: To stream or not to stream? Watching TV while eating promotes increased calorie consumption, but using a smartphone does not
- Authors: Angela C. Incollingo Rodriguez, Mira S. Kirschner, Lorena S. Nunes
- Journal: Physiology & Behavior
- Publication Date: May 15, 2025
- DOI: 10.1016/j.physbeh.2025.114878