Be careful if eat while your brain is occupied.

Researcher shows people who engage in perceptually demanding activities may miss fullness cues and consumed more food than those who eat while performing tasks that required less attention.


Distracted eating can be dangerous like distracted driving but for a different reason. It may cause your brain to miss the stop sign from your stomach that says you are full. Researchers from the University of Sussex in England found people who were engaged in perceptually demanding activities missed fullness cues and consumed more food than those who ate while performing tasks that required less attention.

The findings published in the journal Appetite confirmed the theory researchers had regarding the brain’s inability to handle too many tasks at one time. What researchers termed the Load Theory of attention refers to the brain prioritizing some activities requiring more attention. This can lead to overeating for those who like to eat while also engaging in attention-requiring activities such as watching shows or playing games.

"Our study suggests that if you're eating or drinking while your attention is distracted by a highly engaging task, you're less likely to be able to tell how full you feel,” said Martin Yeomans from the School of Psychology at the University of Sussex. “You're more likely to keep snacking than if you'd been eating while doing something less engaging.”

Yeomans and his team tested 120 people by giving them either low calorie drinks or high calorie drinks that were also thicker to promote a feeling of fullness. They were then asked to eat snack food while engaging in tasks demanding different levels of attention. When the demand for mental attention was high the study participants ate the same amount of food regardless of what they drank previously. However, when the perceptual demand was low, those who had the high calorie drink first ate 45 percent less than those who started with a low-calorie drink.

Previous research revealed when the brain is fully engaged it filters out some sensory information in order to focus on what it considers more important at the time. Yoemans said this is the first time this type or experiment was able to show the cues associated with being full (satiety) could be filtered out as well.

“This is important for anyone wanting to stay a healthy weight: if you're a habitual TV-watching snacker—watching, say, an engaging thriller or mystery, or a film with a lot of audio or visual effects—you're not likely to notice when you feel full,” Yoemans said. “Video-gamers and crossword solvers should also take note. We already knew that feeling full could be affected by the texture and appearance of food, as well as pre-existing expectations about how full we think a type of food should make us feel. Now we also know that feeling full depends on how much sensory information our brains are processing at the time."

Click here to read more in the journal Appetite.

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