If you like to watch TV with a bag of snacks nearby, here's a tip: Avoid watching action movies.
New research suggests people eat twice as much food while watching a fast-paced action flick compared with those watching a slow-moving talk show.
"It's something I noticed in myself," said Aner Tal, a researcher with the Cornell University Food and Brand Lab. "When I go to the cinema and watch a movie I'm really engrossed in, my popcorn will go from full to empty without me realizing it. But if it is a movie I'm less into, I pay more attention to what I'm eating."
There is a large body of evidence that we eat more when we are watching TV, but much less is known about whether the content of a TV show can affect mindless eating.
To find out if it does have an effect, the researchers recruited 94 undergraduate students to watch 20 minutes of television in a group setting.
One third of the students watched the 2005 film "The Island" starring Ewan McGregor, another third watched 20 minutes of the same film with no sound on, and the final third watched 20 minutes of the PBS talk show "Charlie Rose."
All of the students were given easy access to generous amounts of snacks including M&Ms, cookies, grapes and carrots while they watched.
The results of the study published Monday in JAMA Internal Medicine were unambiguous. The students who watched "The Island" with the sound on ate 98% more food and 65% more calories than the students who watched "Charlie Rose." Students who watched "The Island" with the sound turned off ate 36% more food and 46% more calories than those watching "Charlie Rose."
The researchers note that "The Island" has 24.7 camera cuts per minute while "The Charlie Rose Show" has just 4.8 camera cuts per minutes, but whether the pacing affects snacking rate is still unknown.
"One thing we are going to do as a follow-up is to nail down more precisely what the factors behind these effects are," said Tal, lead author of the paper. "Right now we have several suspects -- pacing is one, but level of engagement is the primary suspect."
While they work that out, Tal offered a few tips for healthy eating and TV watching based on this current research.
1. Do not bring a bag of chips into the living room when you plan to watch an action movie on TV. "Mindless eating occurs when snacks are right there. Keep them in the kitchen, and then it won't all disappear without you realizing it."
2. Be aware that watching TV in bars and restaurants, even with the sound off, could cause you to overeat. "People still ate more watching 'The Island' without the sound on than watching 'Charlie Rose.' That tells us that it might be the visuals that are affecting the eating."
3. Do snack on a big bowl of vegetables while watching action movies. "One thing we noticed is people eating without paying attention will eat anything. If you don't really like broccoli but you don't hate it, this could be a good way for you to get your daily dose of vegetables."
4. Do watch "Charlie Rose." "You'll eat less and you will get more intelligent television."