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    Archive for the 'Diet and obesity' Category

    Forming habits and improving self-regulatory skills help people lose weight

    By Moritz P Herle, on 16 October 2017

    by Nathalie Kliemann and Becca Beeken

    Obesity is a growing public health concern. Individuals with obesity (Body Mass Index ≥30) are at increased risk for a range of diseases including cardiovascular diseases and a number of cancers. There is therefore a need to find effective ways to help individuals with obesity to lose weight. Evidence from recent studies suggests that brief interventions based on habit theory may be a novel approach. Interventions based on habit theory encourage people to repeat certain behaviours in a consistent context (in the same place or at the same time of day). This helps to make the behaviours more automatic (do them without really thinking about them) over time. These interventions also encourage people to set goals, plan when they will perform their behaviours, and monitor how they are getting on during the habit formation process. This can improve people’s ability to control their behaviours or their ability to ‘self-regulate’. Self-regulation refers to the ability to control behaviours, attention and thoughts to achieve a goal (e.g. avoid eating chocolate to lose weight).

    Our research group at University College London developed a habit-based weight loss intervention, called 10 Top Tips (10TT), with the charities Cancer Research UK and Weight Concern. The 10TT are a set of everyday healthy eating and activity behaviours that are described in a leaflet alongside advice for turning the behaviours into habits. The leaflet recommends making specific plans, repeating the behaviours in a consistent context, and monitoring performance daily using a log book.

    The leaflet was tested in a randomised controlled trial in primary care. Patients with obesity from 14 GPs across England were invited to take part. Those who consented were randomly allocated to 1 of 2 groups. Individuals in one group were given the 10TT by a practice nurse in an appointment at their GP surgery. The other groups were referred to the usual care offered by their GP.  Initial results of this trial demonstrated that patients who received the 10TT intervention lost almost one kilo more than those receiving usual care. Furthermore, patients who received 10TT reported the behaviours had become more automatic over three months. This suggests that 10TT was more effective at establishing new habits by the end of the intervention period. In the present study, we aimed to understand the effect of 10TT on self-regulatory skills and whether changes in self-regulatory skills and automaticity explained why the intervention helped people to lose weight over three months.

    In our latest research we found that over three months patients who were given 10TT reported greater increases in self-regulatory skills than those who received usual care. Changes in self-regulatory skills and automaticity over 3 months appeared to, at least partially, explain how the intervention helped people to lose weight. Participants who monitored their behaviours for longer, recorded their weight more often, and made more plans, experienced the greatest changes. This findings support the proposition that self-regulatory training and habit formation are important features of weight loss interventions.

    We hope the results of our research will improve our understanding of how interventions based on habit theory work. These findings could guide the development of more effective habit-based weight loss interventions to help people to lose weight.

    In future studies, we aim to explore whether the effects of the 10TT intervention can be enhanced through making it easier to use the log books (e.g. through digital self-monitoring via a mobile phone app). We are also interested in whether adding self-regulatory training to help people break existing habits (as well as forming new habits) would increase weight loss.

     

    Article link: Kliemann N, Vickerstaff V, Croker H, Johnson F, Nazareth I, Beeken B. The role of self-regulatory skills and automaticity on the effectiveness of a brief weight loss habit-based intervention: secondary analysis of the 10 top tips randomised trial. International Journal of Behavioural Nutrition and Physical Activity. 2017, 14:119.

     

     

    Perceived weight discrimination linked to physical inactivity

    By Sarah Jackson, on 8 March 2017

    Rises in obesity prevalence over recent decades have corresponded with increasing stigmatisation of, and discrimination against, individuals living with obesity. Weight stigma is often justified on the basis that it might encourage people to lose weight, but a growing evidence base indicates that experiences of weight-related stigmatisation may in fact encourage behaviours that promote obesity.

    A few small studies have indicated that people who face weight stigma are more inclined to avoid physical activity, but none have been able to clearly establish what effect experiencing stigma has on actual exercise behaviour.

    In a new study published today in BMJ Open we explored the relationship between weight discrimination and physical activity. The research involved 5,480 men and women aged 50 years and older taking part in the English Longitudinal Study of Ageing, a large population-based cohort of middle-aged and older adults living in England.

    Overall, one in twenty people said they had been discriminated against because of their weight, ranging from lack of respect or courtesy to being threatened or harassed. Rates of weight discrimination varied considerably according to how overweight a person was, from 0.9% of people with a body mass index (BMI) in the overweight range (25-29.9) to 13.4% of people with obesity (BMI greater than 30).

    Importantly, we found that people who had experienced weight-related discrimination had almost 60% higher odds of being inactive and 30% lower odds of engaging in moderate or vigorous exercise once a week than their peers.

    Interestingly, a person’s BMI in itself did not affect the relationship between weight discrimination and exercise, indicating that people who experience weight-related discrimination are likely to be less physically active, regardless of their weight.

    There could be several reasons for our findings. People who feel stigmatised may be more self-conscious about exercising in front of others for fear they will attract undesirable attention, leading to embarrassment or teasing. They may also begin to believe the negative stereotypes against themselves as lazy and worthless, leaving them wondering why they should bother trying to be active.

    Given the substantial benefits of being physically active for both physical and mental health, interventions that aim to reduce weight bias at a population level – for example through schools, local communities or national campaigns – may have greater impact on health than those that encourage people to lose weight. A Health at Every Size approach may be helpful in encouraging people to develop and maintain healthy habits, including regular physical activity, for the sake of health and wellbeing as opposed to weight control.

     

    Article link:
    Jackson SE, Steptoe A. Association between perceived weight discrimination and physical activity: a population-based study in English middle-aged and older adults. BMJ Open. 2017;7:e014592.
    http://bmjopen.bmj.com/content/7/3/e014592.info

    Weight discrimination is chronically stressful

    By Sarah Jackson, on 18 October 2016

    Stigmatisation of obesity remains one of “the last acceptable forms of prejudice”.  People with obesity are widely stereotyped as lazy, weak willed and personally to blame for their weight by the media, employers, educators, health care professionals, and even their friends and family.

    Facing discrimination can understandably be very stressful in the moment.  Small experiments have shown that asking people to watch a video that stigmatises obesity, or telling them that their body size and shape are unsuitable to take part in a group activity, increases levels of the stress hormone cortisol in their saliva.

    But what wasn’t known until now was whether discrimination has lasting effects on stress levels.  This is important because acute (short-term) stress is a protective, adaptive response whereas chronic stress can have a damaging effect on the body.

    In a new study published last week in Obesity we explored the relationship between weight discrimination and chronic stress.  The research involved 563 men and women with obesity (body mass index ≥30) aged 50 years and older taking part in the English Longitudinal Study of Ageing (ELSA), a large population-based cohort of middle-aged and older adults living in England.

    Rather than measuring levels of cortisol in saliva, which are sensitive to daily fluctuations and short-term factors such as diet, we analysed cortisol levels in hair.  Measuring hair cortisol is a new technique that gives an indication of average levels of cortisol in the body over several months.  Hair grows at approximately 1 cm per month, so the 1 cm of hair nearest to the scalp represents average exposure to cortisol over the last month.

    We found that one in eight people with obesity had experienced discrimination because of their weight, ranging from lack of respect or courtesy to being threatened or harassed.  Among people with severe obesity (BMI ≥40), one in three reported discrimination.

    Importantly, our findings revealed that average levels of cortisol in hair were 33% higher in individuals who had experienced weight discrimination than those who had not.  People who experienced more frequent weight discrimination had higher hair cortisol levels than those who faced less regular discrimination.

    The results of this study provide evidence that weight discrimination is associated with the experience of stress at a biological level.  Because experiencing high levels of cortisol over a prolonged period can have a substantial impact on health and wellbeing, it is likely that weight discrimination contributes to many of the negative psychological and biological consequences of obesity.  In addition, cortisol is known to increase appetite and fat storage, making people who experience weight discrimination more likely to gain weight.

     

    Article link:

    Jackson SE, Kirschbaum C, Steptoe A. Perceived weight discrimination and chronic biochemical stress: A population-based study using cortisol in scalp hair. Obesity. First published ahead of print 14 October 2016. doi:10.1002/oby.21657

    http://onlinelibrary.wiley.com/doi/10.1002/oby.21657/full

    Toddlers’ food fussiness is heavily influenced by genes

    By Andrea D Smith, on 14 October 2016

    Written by Andrea Smith, Alison Fildes and Clare Llewellyn

    In early childhood, children are gradually introduced to an increasingly varied diet. While some children happily accept new foods and enjoy eating lots of different kinds of foods, many are hesitant. Food avoidant behaviour can be broadly classified into two traits: ‘Food Fussiness’ and ‘Food Neophobia’. Food Fussiness is the tendency to be highly selective about the textures, taste and smell of foods you are willing to eat and is often seen as a consequence of inadequate parenting. However, Food Neophobia – the refusal to try new foods – is often seen as a normal development stage experienced by most young children regardless of the way their parents feed them. Fussy and neophobic eating behaviours typically emerge in toddlerhood and commonly peak between two and six years of age; but for some children these traits persist into later childhood.

    Food avoidant behaviour can be both frustrating and worrying for parents; children who eat only a restricted range of foods might miss out on key dietary nutrients essential for healthy development. In particular, fussy eaters tend to reject nutrient-dense foods such as vegetables. Early childhood is also an important period during which food preferences develop; learning to like a range of healthy foods requires the child to try a wide variety of different foods. Researchers have therefore been interested in finding out what shapes food avoidant behaviour in early life. Some research has suggested that children who are breastfed for longer and whose parents use less persuasive feeding practices (e.g. rewarding with food) are less likely to display fussy eating behaviours; suggesting that there are important environmental shapers of this behaviour. On the other hand, Food Neophobia is associated with temperamental traits such as shyness or inhibition; these characteristics have an established genetic influence, indicating that neophobia might also have a strong genetic basis.

    In a new study published in the Journal of Child Psychology and Psychiatry we used data from the Gemini twin cohort to investigate the extent to which genes and environmental factors influence children’s food fussiness and food neophobia. Gemini is a large study of 2400 pairs of twins that was set up in 2007 to explore early life growth and behaviour. Twin studies are useful for investigating the relative importance of genetic- and environmental factors on individual differences in traits such as food avoidant behaviours. The current study was based on data from 1,932 families collected when the twins where 16 months old.

    We found that both food fussiness and food neophobia have a strong genetic basis, with 46% and 58% of the variation in each trait explained by genetic influences respectively. The shared home environment (which includes factors such as parental feeding practices) was a more important influence on Food Fussiness than Food Neophobia; but overall, these environmental factors were less important than a child’s genetic predisposition towards these behaviours.

    The finding that there is substantial genetic influence on fussy eating behaviour in early childhood might be quite a relief for some parents who can often feel judged or guilty about their children’s fussy eating. Understanding that these traits are largely innate might help to deflect this blame.

    However, our genes are not our destiny. Establishing the importance of genetic influences on fussy eating behaviours in early childhood does not imply that these behaviours cannot be changed. An effective intervention to overcome food rejection is through repeated exposure to the problem food; the more a child tries a food, the more familiar it becomes and the more they learn to like it. In our group we have developed a tasting game called ‘Tiny Tastes’ to help families introduce foods to reluctant and fussy eaters. This is an avenue through which parents might be able to positively change fussy or neophobic eating behaviours.

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    Food fussiness and food neophobia share a common etiology in early childhood

    Andrea D. Smith, Moritz Herle, Alison Fildes, Lucy Cooke, Silje Steinsbekk, and Clare H. Llewellyn

    Article link: http://onlinelibrary.wiley.com/doi/10.1111/jcpp.12647/epdf

    New evidence supports the use of twin studies to explore the effects of nature and nurture on human behaviours in childhood

    By Moritz P Herle, on 5 August 2016

    Written by Moritz Herle, Alison Fildes and Clare Llewellyn

    Over the past century twin studies have been used to explore how nature and nurture influence individual differences in human characteristics (such as personality, intelligence or height). Identical twins share the same genes, while non-identical twins share about half of the same genes; but both types of twins grow up in the same family environment. This means that researchers can compare similarities between identical twins, and similarities between non-identical twins, to get an idea about how much differences between people in characteristics such as height are caused by nature (genes), and nurture (the environment).

    The Health Behaviour Research Centre set up the Gemini twin cohort in 2007.  Gemini is a landmark study of early life growth and behaviour which has been following 2400 British families with twins born in 2007.  Gemini was established to help understand how genes (nature) and the environment (nurture) influence the development of eating behaviours, food preferences and growth in early childhood. Previous studies conducted by the Gemini team have suggested that individual differences in eating behaviours during childhood are strongly influenced by genes.

    Like much research into early child development, these studies have had to rely on parents’ ratings of their children’s eating behaviour. This is because large sample sizes make it difficult to measure behaviours in a laboratory and because young children are unable to report accurately on their own characteristics. Parents of Gemini twins provided information about their children’s behaviour using a widely-used questionnaire called the Child Eating Behaviour Questionnaire (CEBQ).  However, a criticism of twin studies is that parents might be biased by their beliefs about their twins’ zygosity (whether they are identical or non-identical) when rating each of their eating behaviours. For example, parents of identical twins might rate them more similarly simply because they think of them as ‘two peas in a pod’, while parents of non-identical twins might exaggerate the differences between them. Because twin studies are based on the comparison of similarity between identical and non-identical twin pairs, reliable and unbiased parental ratings are crucial.

    We recently published a new study that set out to test if parents are biased by their twins’ zygosity when they rate their eating behaviours. Using the Gemini sample we compared eating behaviour ratings from parents who held a false belief about their twins’ zygosity (i.e. they believed them to be non-identical, when they were in fact identical) to those from parents who held an accurate belief. The only way to conclusively know whether a twin pair is identical is to conduct a genetic test, which compares the DNA of the two siblings. However these genetic tests are not routinely carried out and parents can sometimes be misinformed about their twins’ zygosity. A more thorough account of why these misunderstandings occur has been discussed in a previous study.

    We established whether the Gemini twins were identical or non-identical using a combination of DNA testing and a questionnaire that accurately measures twin similarity. We also asked parents about whether they thought their twins’ were identical or not. Using this information we were able to identify parents who held a false belief about their twins’ zygosity, and those who were right. We found that approximately one third of parents of identical twins falsely believed them to be non-identical when they were about eight months old.

    In order to test if parents’ ratings of their twins’ behaviours are biased by their beliefs about their zygosity, we compared the ratings of parents with false and accurate beliefs about their twins’ zygosity, on a range of eating behaviours during infancy and toddlerhood. If parent ratings were biased then we would expect identical twins whose parents believed them to be non-identical to be rated as less similar than identical twin pairs correctly identified by their parents as identical.

    Interestingly, parents’ reports of their identical twins’ eating behaviours were the same, regardless of whether they had false or accurate beliefs about their twins’ zygosity. In other words, parents rated identical twins as more similarly than non-identical twins on all eating behaviours (in both infancy and toddlerhood), regardless of whether they believed them to be identical or non-identical. This indicates that parents of twins can be relied upon to provide unbiased reports of their young children’s eating behaviour, and that findings from twin studies can be trusted.

     

     

    Article link:

    Herle, M., Fildes, A., van Jaarsveld, C., Rijsdijk, F. & Llewellyn, C. H. (2016). Parental Reports of Infant and Child Eating Behaviors are not Affected by Their Beliefs About Their Twins’ Zygosity. Behavior Genetics. doi: 10.1007/s10519-016-9798-y

    Family upbringing has no impact on adolescents’ food preferences

    By Alison Fildes, on 11 July 2016

    Written by Andrea Smith, Alison Fildes and Clare Llewellyn

    Understanding the factors behind food likes and dislikes has important implications for politicians and clinicians. Our food preferences strongly influence what we chose to eat, affecting our health in the short- and long-term. Previous studies carried out by our group have shown that aspects of the shared family environment played an important role in shaping young children’s food preferences.  However, the relative influences of genes and the environment on older teenagers’ preferences was previously unknown.

    In a new study published this week in the American Journal of Clinical Nutrition we explored the relative importance of genetic and environmental influences on adolescents’ food preferences using a twin design. The findings revealed that the effects of family upbringing on teenagers’ food preferences seem to disappear as they start to make their own meal choices, to the point where they have no detectable impact by late adolescence. Instead the ‘unique environment’ – aspects of the environment that are not shared by both twins in a pair (e.g. experiences  unique to each twin, such as having different friends) were found to effect food likes and dislikes at this age. Genes were also found to have a moderate impact on food preferences in late adolescence, in keeping with earlier findings from young children.

    The research involved 2,865 twins aged 18-19 years from the Twins Early Development Study (TEDS), a large population based cohort of British twins born in 1994 to 1996. Food preferences were measured using a self-report questionnaire of 62 individual foods which were categorised into six food groups – fruits, vegetables, meat/fish, dairy, starch food and snacks. It is the first study to show how substantial influences of the shared family environment in early childhood are replaced by environmental influences unique to each individual by the time they enter young adulthood. The decreasing influence of the family environment in adolescence has also been observed for other traits, such as body weight.

    The results of this study mean that efforts to improve adolescent nutrition may be best targeted at the wider environment rather than the home, with strategies focused on increasing the availability and lowering the cost of ‘healthier foods’. The substantial influence of the non-shared environment, suggests that food preferences can be successfully shifted towards more healthy choices in late adolescence. Policies that make the healthier food choice, the easier choice for everyone, have potential to achieve substantial public health improvements. In particular, the UK sugar-sweetened beverage levy soon to be introduced is one initiative that has the potential to promote a healthy food and drink environment.

     

    Article link:

    Smith AD, Fildes A, Cooke L, Herle M, Shakeshaft N, Plomin R, and Llewellyn C. Genetic and environmental influences on food preferences in adolescence. American Journal of Clinical Nutrition. First published ahead of print July 6, 2016. doi:10.3945/ajcn.116.133983

    http://ajcn.nutrition.org/content/early/2016/07/05/ajcn.116.133983.full.pdf+html

    Measuring appetitive traits in adults. What do we know about their relationships to weight.

    By Claudia M E Hunot, on 6 July 2016

    By Claudia Hunot, Alison Fildes and Rebecca Beeken.
    Some people are more likely to put on weight than others, and may find it harder to lose weight. One of the ways in which people differ is in how they respond to food; their ‘appetitive traits’. For example, how full you tend to feel after a meal, how much you want to eat when you see or smell delicious foods, or how fast you eat. These traits are partly influenced by genes, and they explain individual differences in the way we all eat. In the present-day food-filled environment people who are more responsive to food cues (want to eat when they see or smell delicious food), and less sensitive to satiety (take longer to feel full) are more susceptible to over-eat and gain weight.

    For a number of years, appetitive traits have been measured in children using the ‘Child Eating Behaviour Questionnaire’ (CEBQ) and more recently in infancy using the ‘Baby Eating Behaviour Questionnaire’ (BEBQ). These questionnaires measure a number of appetitive traits that can be grouped into two broad categories: food approach and food avoidance traits. Food approach traits, such as ‘food responsiveness’, are associated with a larger appetite or greater interest in food, while food avoidance traits such as ‘satiety responsiveness’ are associated with a smaller appetite and/or a lower interest in food. Research has shown higher scores on food approach traits and lower scores on food avoidance traits are associated with increased weight and weight gain. However, so far most of this research has been carried out in children. Until now no matched questionnaire existed for measuring the same appetitive traits in adults.

    Therefore, in our latest study we developed the ‘Adult Eating Behaviour Questionnaire’ (AEBQ) to measure these appetitive traits in adults. We also wanted to explore whether these traits relate to adult weight, as they do in children. Adult samples were recruited at two time points, one-year apart, from an on-line survey panel. Participants completed the AEBQ and provided their weight and height measurements to calculate BMI. Data from a total of 1662 adults was analysed and showed the 35 item AEBQ to be a reliable questionnaire measuring 8 appetitive traits similar to the CEBQ.

    We also showed that food approach traits such as ‘food responsiveness’, ‘emotional over-eating’ and ‘enjoyment of food’ were positively associated with BMI. This means people with higher scores for these traits were heavier on average. While food avoidance traits including ‘satiety responsiveness’, ‘emotional under-eating’ and ‘slowness in eating’ were negatively associated with BMI. This means people with higher scores for these traits were lighter on average.

    These findings suggest appetitive traits are likely to be important for weight across the life course. The newly developed AEBQ is a reliable instrument, which together with the BEBQ and the CEBQ, could be used to track weight-related appetitive traits from infancy into adulthood. The AEBQ may also help to identify individuals at risk of weight gain and could inform targeted interventions tailored to help people manage their appetitive traits, and in turn control their weight.

    Article link:
    Hunot, C., Fildes, A., Croker, H., Llewellyn, C. H., Wardle, J., & Beeken, R. J. (2016). Appetitive traits and relationships with BMI in adults: Development of the Adult Eating Behaviour Questionnaire. Appetite. http://dx.doi.org/10.1016/j.appet.2016.05.024
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    Updating the General Nutrition Knowledge Questionnaire for adults

    By Nathalie Kliemann, on 17 June 2016

    By Nathalie Kliemann, Fiona Johnson and Helen Croker

    Access to nutrition information is widespread and many people rely on sources such as newspapers, websites, magazines, and TV programmes. Some of the information is conflicting and misleading, and the sheer quantity can be overwhelming, leaving many people confused as to what is the current nutrition advice. In an attempt to understand how well UK adults understand nutrition information, in the 1990’s researchers at the Health Behaviour Research Centre developed a questionnaire to assess general nutrition knowledge (GNKQ) in the UK adult population. This measure has been widely used since then and is cited in over than 150 research papers, which have explored the relationship between nutrition knowledge and other factors, such as dietary intake, socio-economic status, and use of food labels. It has also been adapted for use in different populations and translated into other languages, including Turkish, Romanian, and Portuguese.

    Why update it?

    Since the GNKQ was developed 20 years ago,  there have been developments in our understanding of the links between diet and health, and big changes in the food supply including the introduction of new types of foods and processing methods. This has resulted in new advice regarding good nutrition, and the GNKQ needed updating to reflect the way we eat today and bring it into line with current recommendations. Our recent publication reported the development of a revised GNKQ, with four main sections measuring: knowledge of dietary recommendations; food groups; healthy food choices, and links between diet and ill health. We also conducted 4 studies to test how well the questionnaire measures nutrition knowledge in adults (tests of reliability and validity).

    Main results

    Our findings showed that the revised version of the GNKQ is a consistent, reliable and valid measure of nutrition knowledge, and that scores improve when people undertake nutrition training. It also showed some differences between people, as the GNKQ-R scores were higher among women, people with a degree, those with better health status and in younger adults. The sections can be administered individually to measure specific areas of nutrition knowledge. We concluded that the revised version of the GNKQ will be a useful tool to assess nutrition knowledge among the UK adult population, and identify groups of people who might benefit from nutrition education to navigate their way through the mass of nutrition information available.

    Article link:

    Kliemann N, Wardle J, Johnson F & Croker H. Reliability and validity of a revised version of the General Nutrition Knowledge Questionnaire. European Journal of Clinical Nutrition, 2016, 1-7.

    www.nature.com/ejcn/journal/vaop/ncurrent/pdf/ejcn201687a.pdf

     

    Remembering Professor Jane Wardle – Part 5 – Ten Top Tips

    By Alice Forster, on 24 January 2016

    In the fifth and final post in our series remembering Professor Jane Wardle and some of the contributions she has made to the field of behavioural science, Dr Becca Beeken writes about Jane’s work on the Ten Top Tips and habits.

    Novel approaches to weight management

    As part of Jane’s pioneering work on obesity, she developed novel, evidence-based methods for weight control. Jane recognised that there was a real need for weight loss advice for the general public that is easy to communicate, straightforward to follow, and applicable across a variety of lifestyles. She also acknowledged that while most weight management programmes talk about ‘habits’, they often just mean things we do all the time, and it’s usually in the context of breaking bad habits. Jane was one of the first behavioural scientists to explore whether we can teach people to form healthy habits, using habit formation theory.

    According to psychological theory, habits are (relatively) automatically triggered actions that are formed through repetition in a consistent context, which makes them more and more automatic. Jane and one of her PhD students, Pippa Lally, asked people to pick a simple healthy behaviour, such as doing 50 sit ups, and then instructed them to repeat it in a consistent context (e.g. after their morning coffee). They showed that as time went on, individuals performed the behaviour more often, and they also reported that it felt more automatic- it was becoming a habit. Based on this study, Jane worked with the charities Cancer Research UK and Weight Concern to develop the Ten Top Tips.

    The Ten Top Tips is a simple leaflet, which describes a set of ten simple energy balance behaviours that can be turned into habits. The leaflet explains the habit model and how to repeat the behaviours in a consistent context. Jane believed that this kind of intervention, which requires very little time to explain and is easy to understand, may be beneficial in primary care where time is short and effective advice for weight management is needed. Weight management advice that promotes permanent behaviour change is particularly important, because not only is losing weight very difficult, keeping the weight off is notoriously hard. Jane felt the Ten Top Tips could meet this need through helping people to make small changes that would become automatic over the longer term.

    Jane led a large randomised controlled trial in obese adults in primary care (GP practices), across England, comparing weight loss in patients receiving the Ten Top Tips vs. ‘usual care’. This was the first time an intervention explicitly based on habit-formation theory had been delivered in the primary care context, and importantly the first evaluation of a simple weight loss advice leaflet. Jane and her team found that that the Ten Top Tips led to significantly more weight loss over 3 months than usual care, with 16% of patients achieving at least 5% weight loss; twice as many as in the usual care arm (8%). At 2 years over a quarter (27%) of patients who received the Ten Tops Tips had achieved at least 5% weight loss, suggesting patients maintained the changes made to their behaviours in the first few months after receiving the Ten Top Tips; they had become ‘habits’.

    Jane’s work on the development and evaluation of the Ten Top Tips represents an important milestone for translational behavioural research. The Ten Top Tips could offer a low cost option for weight management in primary care and it has already been widely disseminated across the UK as part of Cancer Research UK’s Reduce the Risk campaign, which aims to raise the awareness of the avoidable risks of cancer. Her research group are continuing to take this important work forward, with new studies exploring the effectiveness of habit based advice for cancer survivors-‘Heathy Habits for Life’, and adapting the Ten Top Tips for families with overweight children-‘Tips for Tots’.

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    Remembering Professor Jane Wardle – Part 1 – Understanding the causes of obesity

    By Alice Forster, on 20 December 2015

    On 20th October, we lost the Director of our Health Behaviour Research Centre. Professor Jane Wardle, one of the UK’s leading health psychologists, was an extraordinary woman. She had an apparently insatiable appetite for research and new ideas, and the breadth of her expertise was simply awesome. She nurtured us, her PhD students and staff, to develop into independent researchers and supported us when we had personal difficulties. There was always laughter coming out of her office when she was in meetings and Jane’s door was always open to us. We miss her terribly.

    While much has been written and said about her achievements and how extraordinary she was by Cancer Research UK, in the Guardian, Lancet, BMJ, The Times, The Psychologist and on Radio 4, we wanted to write about the science behind just a few of her contributions to behavioural science in cancer prevention. Over the next few weeks, our blog will do just that, starting with Jane’s work on understanding the causes of obesity written by Dr Clare Llewellyn and Dr Ali Fildes.

    Our understanding of the causes of obesity

    Professor Jane Wardle revolutionized our understanding of the genetic basis of human body weight. She was particularly interested in advancing our understanding of the causes of obesity because obesity is an important risk factor for cancer. In fact, obesity is the most important known avoidable cause of cancer after smoking.

    We have known for many years that weight has a strong genetic basis.  Importantly, Jane established that weight is as heritable now as it was 30 years ago, despite the recent large increases in obesity. This observation has been difficult for researchers to explain given the changes to the food and activity environments that are widely believed to have caused the rising rates of obesity. Researchers were confronted with the question, how can obesity be caused by both genes and the environment at the same time?

    In order to answer this question, Professor Wardle developed the ‘Behavioural Susceptibility Theory’. She proposed that genes could be influencing weight through their effects on appetite.  The key idea was that individuals who inherit a set of genes that make them more responsive to food cues (want to eat when they see, smell or taste delicious food), and less sensitive to satiety (take longer to feel full) are more susceptible to overeat in the current food environment, and become obese.

    In order to test this theory Jane developed a parent-report measure of children’s appetite – the Child Eating Behaviour Questionnaire (CEBQ), and explored the genetic basis of appetite using 10-year-old twins from The Twins Early Development Study (TEDS). Researchers can compare how similar identical twins are, with how similar non-identical twins are, to estimate the importance of genes versus environment for any characteristic, such as appetite.  Using the CEBQ she showed for the very first time that food responsiveness and satiety sensitivity both have a strong genetic basis. She also showed that the FTO gene (the first ‘obesity gene’ to be discovered in 2007), and other obesity genes, appear to be influencing weight through impacting satiety sensitivity.

    After finding out that appetite is already highly heritable by age 10, Jane realized that she needed to go right back to the beginning of life to explore how genes are influencing appetite and weight from birth. She therefore established Gemini – the largest study of twins ever set up to study genetic and environmental influences on weight from birth. The Gemini study includes over 2400 British families with twins born in 2007, and has now been running for over 8 years. Under Jane’s leadership Gemini has become an internationally recognised study that has advanced our understanding of childhood growth. The success of the study can be measured in its numerous publications on a range of topics from appetite, to food preferences, sleep, physical activity and the home environment. Jane loved the Gemini study, and it shone through in every aspect of her work, from discussions about complex genetic analyses to the design of the annual newsletter sent to the many dedicated families who participate. In total, Gemini has trained (and continues to train) 7 PhD students, 5 postdoctoral researchers, and numerous MSc students. The Gemini team miss Jane terribly but are committed to continuing her incredible legacy.

    The Gemini team