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    The Importance of Being Consistent: the case of bowel cancer screening participation

    By Siu Hing ( Siu Hing ) Lo, on 12 May 2014

    “Consistency is the last refuge of the unimaginative” – Oscar Wilde

    Consistency may be the last refuge of the unimaginative, but the results of our latest study on participation in the NHS Bowel Cancer Screening Programme suggests it is important to cancer outcomes.

    In England, all adults aged 60 to 74 are invited every other year for bowel cancer screening using a guaiac-based Faecal Occult Blood (gFOB) test. This is a home-based stool test that aims to detect tiny traces of blood in faeces. Those who test positive are offered a colonoscopy examination to look for bowel cancer and polyps. In a small minority of cases, a gFOB test yields an unclear result. The test will then need to be repeated once or twice.

    In our study, we examined responses to three successive invitations using NHS records from the South of England. While over 70% participated at least once, only 44% participated all three times they were invited.

    In line with expectations, individuals who did not respond to a previous invitation were less likely to respond to subsequent invitations. Most interestingly, however, our study also showed that the timing of non-response to invitations predicted subsequent response. Those who took part in the first round, but ‘dropped out’ in the second round were less likely to respond in the third round than those who skipped the first round and ‘entered late’ in the second round.

    Another novel finding was that previous response to gFOB invitations predicts more than subsequent (single) gFOB screening. It also predicts compliance with colonoscopy examinations and completion of multiple gFOB tests if the results are unclear. Compliance with follow-up colonoscopies and multiple gFOB screening is particularly important because those who require these additional tests are at higher risk of bowel cancer.

    The need for regular participation should therefore be emphasised in communications about bowel cancer to the public. Interventions and screening service improvements should also aim to increase participation and compliance at all stages of the bowel cancer screening process among those identified to be ‘at-risk’ of non-participation.


    Lo, S.H., Halloran, S., Snowball, J., Seaman, H., Wardle, J. & C. von Wagner (2014), Colorectal cancer screening uptake over three biennial invitation rounds in the English Bowel Cancer Screening Programme, Gut, Published Online First: 7th May 2014, doi:10.1136/gutjnl-2013-306144.

    Disentangling the complex relationship of obesity and colorectal cancer risk

    By Susanne Meisel, on 8 May 2014

    One of the groups most at risk of colorectal cancer – the severely obese (BMI ≥ 40) – appear to be less likely to take up colorectal cancer screening than people in lower weight categories.

    We know from previous research that obese individuals are not only more likely to be diagnosed with both colorectal cancer and breast cancer, but also more likely to die from them.  However, because earlier detection of these cancers increases chances of survival, researchers from our department wanted to know whether lower rates of cancer screening participation in this group might play a part in their comparatively poorer survival rates.

    The NHS breast screening programme invites women aged 50 to 70 (extended to 74 in some areas) for screening by mammography every three years . which is carried out by a health professional.  In contrast, in the NHS Bowel Screening Programme, men and women aged 60–69 (which will be extended to 74) are sent a Faecal Occult Blood Testing kit (FOBT) every two years which they complete at home and return for analysis.

    The research was conducted with 1,804 persons eligible for NHS colorectal screening and 2,401 persons eligible for NHS breast screening in the UK, who were each asked if they had ever been screened and if this was part of the NHS screening programme.  Of those, 131 were severely overweight.

    The results showed that an individual’s weight has no impact on whether or not they are likely to attend breast cancer screening (in fact overall rates are high at 92%).  However, weight does  affect participation in colorectal cancer screening. We found that rates of colorectal cancer screening decreased as weight increased, and that those who are severely obese, are significantly less likely than their lean counterparts to take part in colorectal screening (just 45% reported participating, compared to the overall rate of 63%).

    So, delayed detection may play a role in the relationship between overweight and the risk of being diagnosed later, when colorectal cancer may be more advanced.  As these findings come from a large sample of people, it is unlikely that these results were due to chance.  But why might weight impact whether or not a person participates in colorectal cancer screening but not breast cancer screening?   Perhaps heavier people find it difficult to actually carry out the colorectal screening test, which they are required to do at home, as it necessitates a certain amount of flexibility and mobility and we know obesity is associated with mobility problems, particularly in older adults. This is speculation at the moment, and it is likely other factors are involved. We did not ask participants why they did not attend screening, so more research needs to be done to find out more about attitudes to cancer screening.

    This could help us to develop interventions that might help combat the double disadvantage these individuals face, in terms of having both a higher risk of developing colorectal cancer and a lower uptake of screening. The NHS is currently rolling out a different method of colorectal cancer screening, in which people will receive a flexible sigmoidoscopy which, like mammography, is a procedure carried out by Health Professionals.  It will be interesting to see whether there are still differences in participation for this method of screening according to weight status.



    Article reference:

    Beeken RJ, Wilson R, McDonald L, Wardle J. Body mass index and cancer screening: Findings from the English Longitudinal Study of Ageing. Journal of Medical Screening, published online first 22nd April, 2014. doi:10.1177/0969141314531409


    ‘Health and happiness are more important than weight’: Why telling parents that their child is overweight may be ineffective at encouraging behaviour change

    By Susanne Meisel, on 24 March 2014

    Childhood obesity is becoming more common.  The latest available statistics show that about 1 in 5 of 4-5year old children (22%), and about 1 in 3 (33%) of 10-11year old children were overweight or obese in the UK .  This puts more and more children at risk of serious, chronic health conditions such as diabetes and heart disease which have traditionally only been observed in adults.  Overweight and very overweight children are also at risk of mental health problems such as depression; sometimes made worse because of weight-related teasing or bullying by their peers.  Preventing more children from becoming overweight, and helping those who already are overweight to prevent further weight gain, or to lose weight, is therefore important. 

    However, a huge number of factors contribute to the rising obesity rates in adults and children.  The solution is certainly not simple, and our researchers are working at finding out more about the many different factors that contribute to the current ‘obesity epidemic’. 

    Some people think that one factor that plays a part in childhood obesity is that some parents don’t know that their child is overweight and because they don’t know, they don’t do anything about it.  Therefore, it was thought that telling parents that their child is overweight could prompt some action to avoid further weight gain. However, studies so far have shown that telling parents about their child’s weight status has very little effect on behaviour change; although some parents are more likely to agree that their child is overweight after having been informed about it by researchers, many parents do not agree with the feedback or think that their child’s weight puts them at risk of health problems.  In other words, they seem to disregard the information for some reason.

    Researchers from our department wanted to better understand why telling parents about their child’s weight status had so little effect; and in fact often resulted in negative reactions. 

    They interviewed 52 parents, who received a letter from the National Child Measurement Programme (NCMP), which informed them that their child was overweight or very overweight.  The National Child Measurement Programme was established by the Department of Health in 2005 to monitor national trends in heights, weights and BMIs of children in Reception (aged 4-5 years) and Year 6 (10-11 years) in publicly funded primary schools in England.

    The researchers asked questions about parents’ thoughts on the feedback, and whether they agreed with it.

    It transpired that in all interviews, parents used a variety of markers, other than weight, to decide whether their child was a healthy weight or at risk of health problems caused by their weight.  The majority of parents felt that their child ate a healthy diet, was physically active, and was not teased or bullied, and therefore they were not concerned about their child’s weight.  Furthermore, many parents did not think their child ‘looked overweight’, often in comparison with the child’s peers. In this context parents also often referred to build (‘big bones’), or to ‘puppy fat’ which they expected their child to lose during puberty. Parents shared the view that ‘health and happiness is more important than weight.’

    This means that simply telling some parents that their child is overweight might not be an effective means of raising awareness about potential health problems, because they might not think that weight is a very accurate measure of their child’s health.  Taking a child’s lifestyle into account (diet, physical activity, and emotional health) might be a good way to improve the dialogue with parents about a child’s health. 

    Furthermore, because there seems to be an assumption that children will lose any extra weight during puberty, parents may think that overweight is an issue that will correct itself over time.  However, there is plenty of good research showing that overweight children are highly likely to turn into overweight adults; perhaps not least because of differences in appetite, as discussed in our previous blog.  Findings from this study showed us that more work needs to be done to communicate the link between child weight and adult weight better. 

    Lastly, because parents compare their own children to others, and weight has overall gone up in the population, they may consider their child ‘normal weight’ when it is, in fact, overweight.  Although there is also the argument that all measures of weight status are somewhat arbitrary and not without their faults, they do give a good indication about where things are headed, particularly for those at the upper end of the range.

    Although these findings are from only one study, and interviewed only a small number of parents and may therefore not hold true for a larger number of parents, they nonetheless bring up some points that might be worth thinking about in more detail. No doubt, weight is certainly not the only important marker for a child’s well-being, but given that many overweight children and adults suffer from related physical and mental difficulties, paying attention to a child’s weight is also not insignificant. Because ultimately, parents and health professionals want the same thing: keeping children happy and healthy.

    Article Reference:  Syrad H, Falconer C, Cooke L et al. Health and happiness is more important than weight: a qualitative investigation of the views of parents receiving written feedback on their child’s weight as part of the National Child Measurement Programme. J Hum Nutr Diet. 2014;n/a.  http://onlinelibrary.wiley.com/doi/10.1111/jhn.12217/abstract


    Why tackling appetite could hold the key to preventing childhood obesity

    By Susanne Meisel, on 19 February 2014

    A heartier appetite is linked to more rapid infant growth and to genetic predisposition to obesity, according to two studies recently published by our researchers in the journal JAMA Pediatrics.

    Although it is clear that some people seem to struggle much more than others to keep a healthy weight, so far it has been less obvious why this is the case.  Researchers from our department have now shown that differences in appetite, and especially lower satiety sensitivity (a reduced urge to eat in response to internal ‘fullness’ signals) and higher food responsiveness (an increased urge to eat in response to the sight or smell of nice food) may hold the key to unhealthy weight gain.

    In the first study, the researchers showed that infants with a heartier appetite grew more rapidly up to age 15 months, potentially putting them at increased risk of obesity.

    Our researchers used data from non-identical, same-sex twins born in the UK in 2007.  As we have previously discussed, twins are a good model to study differences between people because they are born at the same time, and usually grow up in a very similar environment.

    Twin pairs were selected that differed in measures of satiety responsiveness (172 pairs) and food responsiveness (121 pairs) at 3 months, and their growth up to age 15 months was compared. Within pairs, the infant who was more food responsive or less satiety responsive grew faster than their co-twin.

    The more food responsive twin was 654g heavier (1.4lbs) than their co-twin at six months and 991g heavier (2.1lbs) at 15 months. The less satiety responsive twin was 637g heavier (1.4lbs) than their co-twin at six months and 918g heavier (2lbs) at 15 months. 

    This is a considerable weight difference for children of this age, and represents a 10% weight difference. Over time as weight differences increase, these children are at a higher risk of obesity.  Therefore, it might be beneficial to watch out if a child seems to have difficulties filling up, or seems to be somewhat responsive to food cues in the environment.

    However, this first study could not tell whether children with low satiety responsiveness or high food responsiveness would continue to be heavier; nor did it tell about possible underlying genetics. 

    Therefore, the second study was set up to shed more light on how appetite, and especially low satiety responsiveness, acts as one of the mechanisms underlying genetic predisposition to obesity.  For this study, our researchers collaborated with a team from King’s College, London.

    The researchers accessed data from over 2,000 unrelated 10-year-old children born in the UK between 1994 and 1996.  First, the team created a combined genetic risk score (polygenic risk score) for each child.  To do this, they added up the number of higher risk versions of 28 obesity-related genes (each gene has 2 versions, as we all get one version from Mum and one version from Dad). A higher polygenic risk score meant that the child was at higher genetic risk of obesity.

    The researchers then looked at how the children’s genetic risk scores related not only to their satiety responsiveness, but also to their body fatness (measured using body mass index and waist circumference).  

    As expected, they found that children at a higher genetic risk of obesity had higher BMIs (which is a measure of weight status) and a larger waist circumference.  This finding was in line with what we already know about the genetic basis of obesity (see our other blogpost).  But key to our study was showing that they were also less sensitive to satiety. 

    This finding suggests that satiety responsiveness is one of the mechanisms through which ‘obesity genes’ influence body weight.  Therefore, it might indeed be beneficial to teach children with lower satiety sensitivity techniques that might improve their fullness signals when eating.  Advice to parents on encouraging children to eat more slowly, having a ‘no second helpings’ policy, and keeping tempting treats out of sight between meals could help. Knowing that there are genetic influences on appetite might help parents understand and accept that children differ, and that some need more support in learning the boundaries of appropriate eating.

    Likewise, for adults who feel they have difficulty controlling their weight, it might be beneficial to understand that differences in appetite might be one contributing reason.  Techniques that help adults to ‘feel’ the fullness, such as ‘mindful eating’ and portion control may be useful aides in ‘outsmarting’ any biological tendencies to eat too much.

    Article references: JAMA Pediatrics

    van Jaarsveld CM, Boniface D, Llewellyn CH, Wardle J. Appetite and Growth: A Longitudinal Sibling Analysis. JAMA Pediatr. 2014;():. doi:10.1001/jamapediatrics.2013.4951.


    Llewellyn CH, Trzaskowski M, van Jaarsveld CM, Plomin R, Wardle J. Satiety Mechanisms in Genetic Risk of Obesity. JAMA Pediatr. 2014;():. doi:10.1001/jamapediatrics.2013.4944.


    Actions do not only speak louder than words

    By Siu Hing ( Siu Hing ) Lo, on 21 November 2013

    Failing to do as you say is so common that it is considered part of human nature. New Year’s resolutions – also discussed in one of our blog posts on habits last year – are one of the most telling examples of failed good intentions. Even when the objective is less ambitious than changing bad habits, good intentions often don’t translate into actions. One-off or infrequent behaviours like screening for cancer are also prone to the “intention-behaviour gap” problem.

    “Implementation intentions” have been one of the most promising areas of psychological research in the past one or two decades. They are a form of action plans which aim to reduce the intention-behaviour gap. People are typically asked to respond to practical questions about when, where and how they are going to perform the intended actions and how they will overcome potential obstacles. This simple intervention has been consistently shown to increase the odds of people undertaking action.

    However, a conventional implementation intentions intervention requires people to formulate an answer for themselves which is difficult to accomplish in large scale public health interventions. For this reason, we described solutions to common barriers in the same format as implementation intentions in our recently published bowel cancer screening field study. These pre-formulated implementation intentions were then incorporated into the existing bowel cancer screening instruction leaflet.

    Unfortunately our intervention did not have an effect on overall participation in the bowel cancer screening programme. It seems that the intention-behaviour gap cannot be overcome through passive exposure to action plans. Paradoxically, people apparently need to do something in order to increase the chances of actually doing what they intend to do. Actions not only speak louder than words, they are also more effective than words.


    Gollwitzer, P.M. & P. Sheeran (2006), ‘Implementation intentions and goal achievement: a meta-analysis of effects and processes’, Advances in Experimental Social Psychology, 38, 69-119.

    Lo, S.H., Good, A., Sheeran, P., Baio, Gianluca, Rainbow, S., Vart, G., von Wagner, C. & J. Wardle (2013), Pre-formulated Implementation Intentions to Promote Colorectal Cancer Screening: a Cluster-Randomized Trial, Health Psychology.

    Internet use promotes cancer preventive behaviours, but mind the ‘digital divide’

    By Lindsay C Kobayashi, on 4 November 2013

    The saturation of the Internet into daily life in many parts of the world has characterised the early part of the 21st century.  As a communication medium, the Internet has huge potential to increase health-related knowledge and behaviours among the general population to ultimately help prevent chronic diseases such as cancer.  However, the actual effectiveness of the Internet in improving cancer-preventive behaviours among older adults, who are among the most at risk for cancer, is unclear.  Importantly, there is unequal access to and use of the Internet in the population.  In the United Kingdom, women, older adults, and those with low income are less likely to use the Internet; this phenomenon is called the ‘digital divide’.  If using the Internet leads to participation in healthy behaviours and ultimately lower chances of cancer, then inequalities in access to online health information may increase inequalities in cancer outcomes.

    Our study examined whether Internet use is associated with cancer-preventive behaviours and whether a ‘digital divide’ exists. To do this we used data from 5,943 participants in the English Longitudinal Study of Ageing: a nationally-representative study of English adults aged 50 years and older.  The study participants responded to questions about Internet and email use, self-reported colorectal and breast cancer screening, physical activity, eating habits, physical and cognitive abilities, and demographics every two years from 2002 to 2011.

    We found that 41.4% of older English adults reported not using the Internet at all between 2002 and 2011, while 38.3% used the Internet intermittently and 20.3% used the Internet continuously during this time period.  Men and women who consistently used the Internet were two times more likely to participate in colorectal cancer screening than those who never used the Internet. They were also 50% more likely to take part in regular physical activity, 24% more likely to eat at least five daily servings of fruit and vegetables, and 44% less likely to be current smokers.

    In short, we found that Internet plays a positive role in promoting healthy cancer-preventive behaviours.  Our research also confirmed that a ‘digital divide’ exists: Internet use in this study was higher in younger, male, white, wealthier, and more educated adults and lower in older, female, non-white, poorer, and less well-educated adults.  Age is a particularly important factor in the ‘digital divide’, as over 40% of all adults aged 50 and up reported never using the Internet.  Providing appropriate support and opportunities for Internet access among older adults may be a key first step to improving health among the ageing population. More generally, increasing Internet access among groups with low rates of Internet usage may have substantial public health benefits.  Policymakers must understand this potential for ‘digital divides’ to influence inequalities in cancer outcomes – whether for worse, or, for better if targeted efforts are made to increase Internet access and literacy among vulnerable groups.


    Office for National Statistics. Internet access quarterly update, 2013 Q1. 2013 [cited 25 October 2013]. Available from: http://www.ons.gov.uk/ons/rel/rdit2/internet-access-quarterly-update/2013-q1/stb-ia-q1-2013.html

    Viswanath K, Nagler R, Bigman-Galimore C, McCauley MP, Jung M, Ramanadhan S. The communications revolution and health inequities in the 21st century: implications for cancer control. Cancer Epidemiol Biomarkers Prev 2012;21:1701-8.

    Xavier AJ, d’Orsi E, Wardle J, Demakakos P, Smith SG, von Wagner C. Internet use and cancer-preventive behaviours in older adults: findings from a longitudinal cohort study. Cancer Epidemiol Biomarkers Prev 2013 (in press).


    A Problem with Poo

    By Siu Hing ( Siu Hing ) Lo, on 1 July 2013

    The NHS in England invites all adults aged 60 to 69 (currently being extended to 74) for bowel cancer screening. Eligible individuals are sent a test kit which requires them to take three samples from their bowel motions. Unlike breast and cervical screening, the test can be completed at home and sent back to the laboratory in an envelope. This process ensures privacy and avoids potential scheduling difficulties.

    Nevertheless, only about one in two return their bowel cancer screening test kit. In comparison, 74-79% of women attend their appointments for breast and cervical screening. Suggested reasons for lower participation in bowel cancer screening include low perceived risk of bowel cancer, the risk of procrastination with a home-based test and the unpleasantness of stool sampling. What we do not know, however, is whether similar reasons are equally barriers to other types of cancer screening.

    To address this question, we compared reasons women gave for not participating in bowel, breast and cervical screening in our most recent study. Rather surprisingly, few differences emerged. For example, we did not find that low perceived risk or procrastination stood out as barriers specific to bowel cancer screening. However, we did observe that women who did not participate in bowel cancer screening were more likely to cite ‘not liking the idea of test’. This lends further support to previous research showing that stool-sampling is off-putting.

    It seems that many have a problem with poo. Aversion against stool sampling should therefore be tackled for bowel cancer screening to gain the same level of acceptance as other established screening programmes.


    Chapple, A., Ziebland, S., Hewitson, P. & A. McPherson (2008), ‘What affects the uptake of screening for bowel cancer using a faecal occult blood test (FOBt): a qualitative study’, Social Science and Medicine, 66, 2425–35.

    Consedine, N., Ladwig, I., Reddig M.K. & E.A. Broadbent (2011), ‘The many faeces of colorectal cancer screening embarrassment: Preliminary psychometric development and links to screening outcome. British Journal of Health Psychology, 16, 559-579.

    Lo, S.H., Waller, J., Wardle, J. & C. von Wagner (2013), ‘Comparing barriers to colorectal cancer screening with barriers to breast and cervical screening: a population-based survey of screening-age women in Great Britain’, Journal of Medical Screening, published Online First 10th June 2013, doi: 10.1177/0969141313492508.

    O’Sullivan I. & S. Orbell (2004), ‘Self-sampling in screening to reduce mortality from colorectal cancer: a qualitative exploration of the decision to complete a faecal occult blood test (FOBT)’, Journal of Medical Screening, 11, 16–22.

    von Wagner C., Good A., Smith S., & J. Wardle (2012), ‘Responses to procedural information about colorectal screening using Faecal Occult Blood testing: the role of consideration of future consequences’, Health Expectations, 15, 176–86.

    Michael Douglas: ‘My particular cancer is caused by cunnilingus’ – what do we really know?

    By Rachael Dodd, on 7 June 2013

    Comments by Michael Douglas about the cause of his throat cancer over the last few days have caused quite a stir. In an interview with the Guardian, he suggested that his cancer had been caused by oral sex although he now claims that he was misquoted. So what is the truth behind the hype?  Does oral sex really cause cancer?

    Douglas’ assertion that human papillomavirus (HPV) is implicated in head and neck cancer is rooted in strong scientific evidence.  HPV is a very common sexually transmitted virus – around 80% of sexually active people will contract it at some point in their lives.  In the vast majority of cases, the immune system clears the virus without the person even knowing they have it.  In rare cases, the virus persists and that’s when cancer can develop.  The virus has long been known to be the main cause of cervical cancer in women, and girls aged 12-13 are routinely vaccinated against HPV in schools in the UK.

    It is now known that HPV also plays a role in the development of other cancers, including some head and neck cancers.  As yet, we understand relatively little about exactly what puts people at higher risk of oral HPV, although sexual behaviour is likely to play a role.  Given that HPV is so common, it could be considered a normal consequence of being sexually active; the key scientific question is why, when most people clear the infection without any problems, some people don’t get rid of it.  

    What we do know is that oral cancer is on the rise.  In the past, drinking alcohol and smoking were the main risk factors, but that seems to be changing. HPV-related oral cancer is often seen in people who don’t drink and smoke, and who tend to be younger and more affluent than non-HPV oral cancer patients.  The good news is that the prognosis appears to be better for these types of cancers – something that’s borne out by Douglas’ successful treatment despite late-stage disease.

    For some patients, being told that their cancer is caused by HPV might raise difficult questions about when and how they got the virus.  Michael Douglas was refreshingly open and up-front in his discussion of cunnilingus but not everyone is so comfortable talking about sex and sexually transmitted infections.  While scientific research continues to push forward our understanding of the virus, we also need good communication and information about HPV as a cause of head and neck cancer.  Previous research has shown that women who test positive for HPV in cervical screening can sometimes experience feelings of stigma and anxiety, but understanding that the virus is very common can help reduce these feelings.

    Very little psychological research has been done in the area of HPV and head and neck cancer. This is why I am beginning a PhD in September which is going to look at the psychosocial implications of a diagnosis of HPV-related head and neck cancer. I will be starting with interviewing health professionals and ask them about their experiences of talking to patients about the causes of their cancer. I will also talk to patients about their experiences with a view to developing information about HPV that can address patients’ needs. I hope that my research will assist health professionals in talking to patients with HPV-related head and neck cancer and also provide patients with much needed information they can use to address questions or concerns they may have around their diagnosis.


    Rachael Dodd (r.dodd@ucl.ac.uk)


    Brooks, X. (2013, June 3) ‘My particular cancer is caused by cunnilingus. And if you have it, cunnilingus is also the best cure’. The Guardian, p6-9

    McCaffery K, Waller J, Nazroo J, Wardle J. Social and psychological impact of HPV testing in cervical screening: a qualitative study. Sex Transm Infect. 2006 Apr;82(2):169-74.


    Taking the leap: Giving people ‘real’ genetic test feedback for weight gain susceptibility

    By Susanne Meisel, on 10 May 2013

    This post really follows my previous one (http://tinyurl.com/d6qo5wl ) about asking people to imagine receiving genetic test feedback for weight gain susceptibility and investigating their anticipated reactions. These types of studies are very valuable when not very much is known about a topic, because they provide us with hints about people’s reactions. However, they can only get us so far.  At some point, we have to take the leap and expose people to the ‘real’ condition we want to test – in this case, whether receiving personal genetic test feedback in addition to generic weight gain prevention advice will motivate people more to prevent unhealthy weight gain than receiving only generic weight gain prevention advice.

    This type of question can be best investigated in an experiment involving two groups, one group that receives the ‘intervention’, and one that is the ‘control’ group.  Participants are randomly (by chance) put into either group. We decided to give the ‘control’ group a leaflet with seven memorable tips for weight gain prevention, adapted from a leaflet that has been shown to help people lose weight.  The other group – the ‘intervention’ group – also receives the leaflet, as well as their personal genetic test result for weight gain susceptibility. This means both groups receive exactly the same information, the only difference is that the intervention group will know if they are genetically predisposed to weight gain. This allows us to say whether differences between the groups in their motivation to prevent weight gain are due to receiving the genetic test result.

    We decided to use approximately 800 first-year university students in this experiment, because the chance of already being overweight at that age is low, but starting university is linked with weight gain (just think of all the late nights, pizza- and kebab feasts!). One month after the intervention, we will send questionnaires to both groups asking about their motivation to prevent weight gain as well as questions about what they have done if they were trying, and whether they followed any of the tips outlined in the leaflet

    This is going to be the first study investigating the effects of genetic testing for weight gain susceptibility and will be completed by September 2013. We hope that our findings contribute to the debate about whether genetic test feedback could be used to help motivate healthy lifestyle behaviours.

    Meisel, S. F., Beeken, R. J., van Jaarsveld, C. H., & Wardle, J. (2012). Genetic test feedback with weight control advice: study protocol for a randomized controlled trial. Trials, 13(1), 235.  http://www.biomedcentral.com/content/pdf/1745-6215-13-235.pdf

    Letting your imagination run wild – genetic testing for risk of weight gain

    By Susanne Meisel, on 5 April 2013

    These are exciting times for people working in genetics.  The field has become trendy.  ‘DNA’, ‘genes’ and ‘genetic code’ are no longer specialist terms, but used casually in everyday language. The media love ‘The gene for’ stories  and attributing individual differences to biology and less to environment is becoming commonplace.  I recently read an interview with a singer who explained that she could not imagine being anything else but a singer, because singing ‘was in her DNA’. If this still does not convince you: The pop band ‘Little Mix’ recently released a new song titled ‘DNA’ (http://www.youtube.com/watch?v=D3h-lLj3xv4).

    Why the fascination with genes?  To a degree, it appears to stem from the inherent assumption that our genes can give us insights into ourselves that would otherwise remain inaccessible. Although our DNA is  99.9% identical, this is not interesting – it is all about the tiny bit of difference, the bit which sets us apart and makes us unique.

    Companies have been quick to capitalise on our curiosity of what would be possible once the Human Genome was decoded.  Genetic tests for an array of traits and conditions, including those that are common and driven by lifestyle, such as obesity or heart disease, are already available over the Internet.  So far, we are not sure about the effects of giving this type of information to people. It could be that people will use it to prevent the condition. Alternatively, it could be that they become fatalistic or complacent. I have written in more detail about the current debate in a previous blogpost ( http://tinyurl.com/bve6y2m).  I hope to add some evidence to the debate by looking at the psychological and behavioural consequences of receiving genetic test feedback using obesity as an example for a very common, very complex condition.

    Because we do not know yet how people react to knowing about their genetic susceptibility to weight gain, it would be unwise to give them this information right away.  Instead, we set up an online study where people were asked to imagine their reactions to receiving a ‘higher-risk’ or an ‘average-risk’ genetic test result for weight gain. They were then asked questions on a broad range of feelings and behaviours. We included 2 sets of people, nearly 400 students, who were predominantly of healthy weight and almost as many people from the general public who were or had been overweight.

    Results showed that people in both groups reported to be more motivated to make lifestyle changes after imagining getting a ‘higher’ genetic risk result than after imagining getting an ‘average’ genetic risk result. On average, negative feelings and feelings of fatalism were anticipated to be very low and did not differ between risk scenarios. Those who were already overweight or obese were more likely to think that in comparison with an ‘average’ genetic risk result, receiving a ‘higher’ genetic risk result would offer them an explanation for their weight status.  Finally, people in both groups thought that they would be more likely to seek out information about what their result means in the ‘higher-risk’ than in the ‘average-risk’ scenario.

    These findings are good news, because they suggest that giving people feedback for susceptibility to weight gain is unlikely to have unanticipated negative effects, and may even be motivating.  Furthermore, people who are already overweight may also benefit from genetic feedback.  However, these findings may not hold up once people are actually given genetic test feedback, because they only tell us about what people think they might do – and people find it generally quite difficult to imagine to be negatively affected by an event.  The next step is now to give people ‘real’ genetic feedback for risk of weight gain to discover the effect of this type of information.



    Meisel, S. F., Walker, C., & Wardle, J. (2011). Psychological Responses to Genetic Testing for Weight Gain: A Vignette Study. Obesity (Silver Spring); 20 (3).DOI: 10.1038/oby.2011.324