“Want to lose weight? Play Tetris: Classic game distracts dieters from food cravings,” reports the Mail Online.
This misleading headline comes from a new study into cravings. Researchers were interested in whether a demanding visual task, in this case playing the uber-addictive 80s video game Tetris would reduce cravings.
The results of the study tentatively suggest that it might. After playing Tetris for three minutes there was a self-reported reduction in immediate cravings for food and drink by around 20%. It wasn’t clear if the drink craving was for alcohol or not.
The study has many limitations. It did not investigate the link between cravings and behaviour. So there was no assessment of whether a temporary reduction in food cravings led to weight loss, so much of the media’s reporting of the study is misleading in this regard.
Secondly, the sense of craving was based on self-reported feelings at the time participants were doing the Tetris task, rather than at any time after. So it is not clear if the craving reductions were immediate and temporary, or if they lasted for any significant time.
A third point that remained unanswered was the question of whether there was anything specific about Tetris that reduced cravings. Or could any mildly involved task, such as a crossword, reading a magazine, or other games, equally distract people from their cravings in the same way?
The many unanswered questions and limitations to this research mean we shouldn’t jump to any rash conclusions about whether playing Tetris will help you quit, or alternatively, just lead to RSI.
Where did the story come from?
The study was carried out by researchers from Plymouth University. The funding source for the study was not reported.
The study was published in the peer-reviewed science journal Appetite.
The media coverage was generally factually accurate but it was not balanced. Most reporting took the study findings at face value and did not report them critically or discuss any of the limitations inherent in the research.
What kind of research was this?
This was laboratory research using humans aiming to see if giving someone a visual task could reduce their cravings for food or drink, caffeine or nicotine.
The authors report that a theory called elaboration intrusion theory states that imagery is important to cravings. For example, people craving caffeine have reported that they suddenly start vividly imaging the taste and smell of fresh coffee and then these mental images come to dominate their thinking. A sentiment Shakespeare delicately outlined with, “The imaginary relish is so sweet, that it enchants my sense.”
They mention people can visualise what they crave and imagine the reward and satisfaction that giving into the craving might bring. The idea behind the research was that a task that interrupts this mental craving and imagery cycle might reduce the craving.
What did the research involve?
The study took 80 adults who reported craving food or drink (58), caffeine (10), or nicotine (12) and measured their cravings using a single scale from 1 (not craving at all) to 100 (craving something very much). Cravings were assessed before and after they completed one of two randomly assigned tasks so see if one of the tasks reduced their cravings in any way.
It was not clear whether the drink element of the cravings was referring specifically to alcoholic drinks.
One task involved playing the popular block based building game Tetris for three minutes. The second involved sitting in front of a screen that was rigged to show a slowly progressing “loading” bar that eventually led to a message of “Load Error” (three minutes in total).
The participants underwent further retrospective testing using a more sophisticated questionnaire measuring additional information on craving strength, image vividness and intrusiveness of their craving during the tasks. Cravings were retrospectively assessed to take a snap shot of the craving experience while the participants were carrying out the task, rather than once the tasks had ended.
Participants were Plymouth university undergraduates, mostly women and aged between 18 and 30 years (mean average 19.74 years). They were tested at different times in the day and tested in pairs to control for any time of day effects, with one person in each pair assigned randomly to each task.
What were the basic results?
Before task completion, craving scores between the two groups did not differ. However, participants who played Tetris had significantly lower craving scores and less vivid craving imagery than those viewing the loading screen.
For example, on the craving scale from 1 (not craving at all) to 100 (craving something very much), the score in the Tetris group before the task (58.82) was close to the “Load” screen group (57.90). However, craving after the task had reduced to 44.84 in the Tetris group (a 23.8% reduction) compared to 54.74 in the Load group (a 5.5 % reduction).
How did the researchers interpret the results?
The researchers concluded, “the findings support EI [elaboration intrusion] theory, showing that a visuospatial working memory load reduces naturally occurring cravings, and that Tetris might be a useful task for tackling cravings outside the laboratory.”
This human study tentatively indicates that an involved visual task, such as playing Tetris for three minutes, might reduce the immediate cravings of adults more than a less involved control task of the same duration – in this case showing them a loading screen progress bar. This lends support to the idea that cravings may have a visual element but there are many questions still unanswered.
For instance, was there anything specific about Tetris that reduced cravings, or could any mildly involved task, such as a crossword or reading a magazine, equally distract people from their cravings in the same way? This element was not addressed in this current research, which tested only Tetris against the loading screen comparator group.
The results also came from a relatively unrepresentative group who were predominantly young adult women and who were craving food and drink items. Only a small number craved nicotine and caffeine so the findings are a lot less generalizable to these specific cravings. The results in older people, who may be less willing and interested in playing Tetris, were also not assessed and may be different.
The group was relatively small, 80 people analysed in the results, so it was not possible to see if the task varied by underlying craving intensity. For example, was the task particularly effective in those with the strongest cravings?
The craving information gathered related to feelings at the time participants were doing the task, rather than immediately after, which might have been more informative and realistic to normal life. So it isn’t clear if the craving reductions were immediate and temporary, or if they lasted for any significant time after the task completed.
The authors themselves highlight the possibility that “temporary reductions in craving might lead to later increases”, through a process of behavioural rebound – suppressing one thing temporarily only to yield to the craving in a more dramatic fashion further down the line.
Perhaps most importantly, the study did not investigate the link between the cravings and behaviour. For instance, did a reduction in food cravings actually lead to reductions in binge eating or any weight loss?
It was also not clear how valid and reliable the 1 to 100 scale the researchers used to assess cravings was, as well as the other more sophisticated additional questionnaires they used. Error in the measurement of craving would likely bias the results, but it is not clear in what direction.
The many questions and limitations to this research outlined above mean we should not jump to any rash conclusions about whether playing Tetris would help people lose weight or stop smoking, as some of the media reports have hinted at. It is simply too early to say and the evidence too weak.
The science behind the headlines was preliminary and unlikely to have a significant impact on weight loss practice.
Most of us experience occasional cravings, but if you have developed a strong, uncontrollable desire for a substance or an activity then you may have an addiction.
Read more advice about addictions and the treatments available.
Analysis by Bazian
Edited by NHS Website
Links to the headlines
The Guardian, 21 February 2014
Mail Online, 21 February 2014
Daily Express, 21 February 2014
Daily Star, 21 February 2014
Links to the science
Addiction. Published online February 5 2014