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Archive for the 'Diet and obesity' Category

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

By Susanne F 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 F 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


Busting the 21 days habit formation myth

By Ben D Gardner, on 29 June 2012

Have you ever made a New Year’s resolution? If so, you may have been assured – usually by a well-meaning supporter of your attempted transformation – that you only have to stick with your resolution for 21 days for it to become an ingrained habit. The magic number 21 creeps up in many articles about forming a new habit or making a change, but little is known about the origins of the ’21 days’ claim.

Psychologists from our department have devoted extensive time and effort to find out what it takes to form ‘habits’ (which psychologists define as learned actions that are triggered automatically when we encounter the situation in which we’ve repeatedly done those actions).

We know that habits are formed through a process called ‘context-dependent repetition’.  For example, imagine that, each time you get home each evening, you eat a snack. When you first eat the snack upon getting home, a mental link is formed between the context (getting home) and your response to that context (eating a snack). Each time you subsequently snack in response to getting home, this link strengthens, to the point that getting home comes to prompt you to eat a snack automatically, without giving it much prior thought; a habit has formed.

Habits are mentally efficient: the automation of frequent behaviours allows us to conserve the mental resources that we would otherwise use to monitor and control these behaviours, and deploy them on more difficult or novel tasks. Habits are likely to persist over time; because they are automatic and so do not rely on conscious thought, memory or willpower.  This is why there is growing interest, both within and outside of psychology, in the role of ‘habits’ in sustaining our good behaviours.

So where does the magic ’21 days’ figure come from?

We think we have tracked down the source. In the preface to his 1960 book ‘Psycho-cybernetics’, Dr Maxwell Maltz, a plastic surgeon turned psychologist wrote:

It usually requires a minimum of about 21 days to effect any perceptible change in a mental image. Following plastic surgery it takes about 21 days for the average patient to get used to his new face. When an arm or leg is amputated the “phantom limb” persists for about 21 days. People must live in a new house for about three weeks before it begins to “seem like home”. These, and many other commonly observed phenomena tend to show that it requires a minimum of about 21 days for an old mental image to dissolve and a new one to jell.’ (pp xiii-xiv)

How anecdotal evidence from plastic surgery patients came to be generalised so broadly is unclear.  One possibility is that the distinction between the term habituation (which refers to ‘getting used’ to something) and habit formation (which refers to the formation of a response elicited automatically by an associated situation) was lost in translation somewhere along the line. Alternatively, Maltz stated elsewhere that:

‘Our self-image and our habits tend to go together. Change one and you will automatically change the other.’ (p108)

Perhaps readers reasoned that, if self-image takes 21 days to change, and self-image changes necessarily lead to changes in habits, then habit formation must take 21 days. Although ‘21 days’ may perhaps apply to adjustment to plastic surgery, it is unfounded as a basis for habit formation. So, if not 21 days, then, how long does it really take to form a habit?

Researchers from our department have done a more rigorous and valid study of habit formation (Lally, van Jaarsveld, Potts, & Wardle, 2010). Participants performed a self-chosen health-promoting dietary or activity behaviour (e.g. drinking a glass of water) in response to a once-daily cue (e.g. after breakfast), and gave daily self-reports of how automatic (i.e. habitual) the behaviour felt. Participants were tracked for 84 days. Automaticity typically developed indistinct pattern: initial repetitions of the behaviour led to quite large increases in automaticity, but these increases then reduced in size the more often the behaviour was repeated, until automaticity plateaued. Assumed that the point, at which automaticity is highest, is also the point when the habit has formed, it took, on average, 66 days for the habit to form. (To clarify: that’s March 6th for anyone attempting a New Year’s resolution.)

Interestingly, however, there were quite large differences between individuals in how quickly automaticity reached its peak, although everyone repeated their chosen behaviour daily: for one person it took just 18 days, and another did not get there in the 84 days, but was forecast to do so after as long as 254 days.

There was also variation in how strong the habit became: for some people habit strength peaked below the halfway point of the 42-point strength scale and for others it peaked at the very top. It may be that some behaviours are more suited to habit formation – habit strength for simple behaviours (such as drinking a glass of water) peaked quicker than for more complex behaviours (e.g. doing 50 sit-ups) – or that people differ in how quickly they can form habits, and how strong those habits can become.

The bottom line is: stay strong. 21 days is a myth; habit formation typically takes longer than that. The best estimate is 66 days, but it’s unwise to attempt to assign a number to this process. The duration of habit formation is likely to differ depending on who you are and what you are trying to do. As long as you continue doing your new healthy behaviour consistently in a given situation, a habit will form. But you will probably have to persevere beyond January 21st.

Benjamin Gardner and Susanne Meisel




Lally, P., van Jaarsveld, C. H. M., Potts, H. W. W., & Wardle, J. (2010). How are habits formed: Modelling habit formation in the real world. European Journal of Social Psychology, 40, 998-1009. (http://onlinelibrary.wiley.com/doi/10.1002/ejsp.674/abstract)

Maltz, M. (1960) Psycho-cybernetics. NJ: Prentice-Hall.

”Battling against one’s biology”: Inherited behavioural susceptibility to obesity

By Susanne F Meisel, on 30 March 2012

As mentioned in one of our previous blog posts, talking about genes in the context of obesity is often not well received.  Those discounting their role in the development of obesity often argue that, because genes have not substantially changed over the past 200 000 years, whereas obesity levels have only been soaring over the past 20 odd years (where it became possible to mass-produce cheap, tasty food in combination with a decreased need for physical activity), obesity must be due to changes in the environment, and not genetics.

However, using this argument against the heritability of obesity is somewhat flawed, because it ignores that a condition can be dormant over a period of time until the right circumstances bring it to life.  The gardeners among you will know that many plants will adjust their growth according to their surroundings – a plant in a small pot will remain small, whereas a larger pot will allow it to grow.   This, however, does not mean that the plant loses its ability to grow larger in a smaller pot; it merely remains small because its surroundings restrict its growth.  Similarly, genes predisposing to obesity may be present in an environment where little food is available, but without the right ‘medium’ (i.e. food), this is of little consequence.  In the current environment, however, where eating opportunities are plentiful, obesity genes can express their full force.

If obesity was resulting purely from environmental change, all individuals exposed to this change would become overweight.  Yet, this is not the case. In fact, the proportion of lean people has not substantially changed, but large people are becoming even larger.  This suggests that people respond to the food environment differently.  However, undoubtedly, to gain more weight than is healthy, food must not only be available in sufficient quantities, but one must ingest more of it than necessary.  Therefore, researchers started to look at differences in eating behaviours, such as how much we are drawn to food and how quickly we feel full, to see what is going on.

Twins can help to untangle the influence of genes and environment on obesity, because identical twins are 100% genetically identical, whereas non-identical twins only share approximately half of their genes (like normal siblings); both, however, grow up in a very similar environment.  This means that researchers can compare identical twins’ resemblance for weight with that of non-identical twins; if genetically identical twins are more similar in a trait than non-identical twins, it is evidence for genes being responsible for the trait.

Using twins, researchers from our department wanted to see whether genes that influence weight also influence appetite.  If the same genes that influence weight also influence appetite, it suggests that genes influence weight through their effects on appetite – i.e. individuals who inherit more avid appetites might be more susceptible to overeating in the modern food environment, and consequently  more likely to gain excessive weight.  They looked at this in infants, because infants are exclusively milk-fed, which ruled out that other factors such as preference for certain foods would influence the results.   The researchers used questionnaires to ask parents about how fast their twins fed, how easily they got full and how big their appetite was, and related the answers to the babies’ weight.   Because they used a sample of identical and non-identical twins the researchers were able to explore the extent to which appetite is heritable, and the extent to which appetite and weight are caused by the same genes.

They found that identical twins were not only very similar in weight, but shared many more similarities in appetite than non-identical twins, suggesting a strong genetic basis to both appetite and weight.  In addition, the results  showed that a substantial proportion of the genes that are responsible for weight are also responsible for appetite, in line with the idea that genes influence weight through appetite.  These findings lend evidence to the idea that some of us are more likely to overeat in the current environment because of a larger appetite, which is ultimately driven by genes.

These discoveries will hopefully contribute to reducing the stigma that surrounds unhealthy weight gain; because it clearly shows that those struggling with weight are in a sense ‘battling against their biology’.  This of course, does not mean that there is nothing that can be done about it; however, acknowledging these differences as real and designing strategies to ‘outsmart’ one’s genes is crucial if the battle is to be fought successfully.


Article reference: http://www.ajcn.org/content/95/3/633.long


Do you want your kids eating their greens? Then, you better start, too…

By Susanne F Meisel, on 23 February 2012

You don’t need to be Jamie Oliver to figure out what is going on with children’s diets – but his efforts certainly helped to pull the candyfloss from our eyes:  children in England are eating plenty of snacks high in fat, salt and sugar, but only one quarter eats their recommended minimum 5 portions of fruit and vegetables a day.  This can be problematic, because not only could it lead to nutritional deficiencies, but also to disproportionate weight gain.

Unfortunately, it is not the case that children simply ‘outgrow’ their ‘puppy-fat’; the vast majority of overweight children grow into overweight teenagers and potentially obese adults.  This is because people naturally put on about 2 pounds per year as they age (unless they do something about it, of course) – and the higher the ‘starting weight’ is, the higher the chances are that people shift up across the weight spectrum as they get older. Furthermore, people who become overweight or obese early in life are often more severely affected by illnesses linked with an unhealthy weight, such as diabetes, heart disease and some cancers.

This is why it is important to figure out what it is that makes children eat their greens (and all those other healthy fruit and veggies, even if cooking like Jamie isn’t your thing).  It has long been known that many different factors such as inherited taste preferences, family eating habits or the amount of time spent watching TV are important when looking at reasons why children eat (or don’t eat) certain foods; but rarely has research looked at factors related to healthy and unhealthy eating habits at the same time in the same group of families.

In this study, the researchers were interested in the actual foods children in England eat (as opposed to specific nutrients, such as vitamins). The researchers had records of what children and their parents ate from several hundred families, along with information on factors which may influence what they eat.  They decided to look in particular at factors which affected how much fruit, vegetables, unhealthy snacks and sugary drinks children consume; focusing on preschool-aged children – as they are not yet strongly influenced by their peers, and are more dependent on eating what their caregivers provide for them.

Perhaps unsurprisingly, the researchers found that when children liked the taste of fruit and veggies it predicted how much of these they ate.  However, what is more important, they also found that parents’ consumption of either fruit, vegetables, unhealthy snacks or sweetened drinks was a very important indicator of how much children ate of these foods.  This might be not only because caregivers may feed children what they themselves eat, but also because children tend to copy adults’ behaviour – so if mum eats healthily, children will be more likely to want to eat healthily too.  Of course, that is also true for unhealthy eating habits – which is why not having junk foods in the home in the first instance can help.  Because it was mainly mothers who filled out the questionnaires, these results focused only on mothers.

Furthermore, praising children for eating fruit and veggies was a good indicator of how much children ate, and monitoring the unhealthy snacks children eat was linked with them eating less of these and more fruit and vegetables.  The amount of time children spent watching TV was also an indicator of children eating unhealthy snacks and having sweetened drinks, but it had no impact on their consumption of fruit and vegetables.

The research provides a little more evidence on how eating habits are transmitted within a family.  It highlights that different strategies need to be used in order to increase the amount of healthy foods vs. decreasing amounts of unhealthy foods children eat.

So, ultimately, if you want your children to eat their greens, you might not have any choice but to take a bite too and start singing their praises, and if you really want to cut down on their junk intake then get rid of it from within your home and turn off the telly – and at last Jamie will be happy.



Is stress making you gain weight? Think again…

By Susanne F Meisel, on 6 January 2012

If you thought that the stresses of present-picking, turkey-basting and relative-juggling are to blame for weight gain, you are not alone. A Google search for ‘stress and weight gain’ reveals a staggering 32,000,000 sites dealing with the topic. However, researchers from our research group have shown that the effect of stress on weight gain may not be as large as you may have thought.

The body tries to maintain stability by adapting to a change in the environment, a process called homeostasis. Stress can be defined as any external factor, physical or psychological, which threatens to throw the body out of homeostasis. Whether running from a hungry lion, or suffering stage-fright before a speech, the body’s response will be the same: the stressor (lion or stage-fright) will trigger the so called ‘fight-or-flight-response’, which is marked by increased heartbeat, muscle-tension, sweating, dilation of the pupils and the release of the ‘stress-hormones’ adrenalin and cortisol. This response is extremely useful to mobilise resources, help us get through difficult situations and regain homeostasis. However, when we experience the on-going stresses of modern life, such as money-worries, job stress, or social pressures, we begin to feel the strain. Long-term stressors overwhelm the body’s coping system, deplete resources and ultimately lead to exhaustion. It has been thought that weight gain results from the body trying to restore homeostasis by inducing metabolic changes which promote fat storage on the one hand and behaviour changes on the other, for example making less time to be active or reaching for cookies instead of carrots.

Results from studies investigating this topic are mixed – some have found that stress has an effect on weight gain, and others have not. Researchers from our department decided to look at the effect from all these studies overall. Summarizing results of several studies on the same topic to find out the ‘true’ effect is called meta-analysis. The studies that were included in this meta-analysis had to be conducted over a period of time (because these are more accurate than studies that only look at a single time-point), measure weight objectively, and focus on external stressors such as life events, work-or caregiver stress. Fourteen studies from Europe and the USA met the criteria; each ‘stress category’ (life events, work- or caregiver stress) was analysed separately.

Results of the meta-analysis showed that stress is related to weight gain, although the effects were very small. When the researchers looked at the results in more depth, they saw that studies that went on for longer and were of better quality were more likely to show an effect of stress on weight. They also saw that the effect appeared to be stronger in men. It did not matter whether the stressor was related to life or work. Unfortunately, eating behaviour was not assessed, so the researchers could not tell whether it changed under stress.

Although there are not very many studies that looked at the topic over a period of time, and imprecise measurements of stress were often used, the findings are relatively robust because of the way the studies were combined. Finding a stronger link of stress on weight in men complements other findings which show that men have a stronger fight-or-flight response. Overall, however, it can be seen that the effects of stress on weight are much smaller than often made out in the media. Blaming the relatives for a bulging belly might be convenient, but complex issues like weight gain unfortunately have no simple, or convenient, answer.


Source: http://www.nature.com/oby/journal/v19/n4/full/oby2010241a.html

When a little bit of control goes a long way

By Susanne F Meisel, on 31 October 2011

Promoting dieting for weight loss and weight maintenance is often criticized, because of the widely held belief that restricting food intake is the beginning of a slippery slope, leading to overeating and eating disorders.  However, a recent review by our department investigating the literature of dietary restraint shows that this may not be the case.

The idea that restricting food intake would lead to uncontrolled binge eating stems from laboratory studies from the 1970s.  Counter to expectations, people reporting that they were trying to lose weight by eating less (restrained eaters), ate more than unrestrained eaters when offered unhealthy but tasty food after being encouraged to break their diet by drinking a high calorie milkshake.  They also ate more than others after drinking alcohol or when they were upset.  These observations led to the belief that trying to control eating with one’s intellect rather than instinct can lead to less sensitivity to feelings of hunger and fullness, and cause people to overeat when their guard was lowered.  At the same time, research pinpointed dieting as a precursor of eating disorders, such as anorexia nervosa and bulimia nervosa, which further strengthened the lobby against the restriction of food intake.

However, closer examination of the research showed that the methods used to classify people as ‘restrained’ or ‘unrestrained’ eaters may have contributed to the findings.  For example, some of the questions asked to find out whether people restrict their food intake were actually assessing tendencies to eat in an uncontrolled way.  The links between restrictive eating and binge-eating were even less clear when considering the artificial lab setting in which participants were persuaded to break their diet, and then presented with an overwhelming amount of tasty food and told to eat as much as they wanted.

Furthermore, in the current environment, it may well be that a person eats less than desired, but still eats more than would be needed to keep weight stable.  Eating only one chocolate cake is better than eating two, but still, it can hardly be considered beneficial to your health!  This means that measuring food restriction alone may not be such a good indicator of successful weight management.  People who report restricting how much they eat may simply be the ones most likely to overeat.

Support for the positive effects of food restriction comes from real world examples.  In overweight individuals, where overeating is common, restricting food intake is related to lower body weight.  Findings from weight loss studies also show that the people doing best are the ones who vigilantly pay attention to what and how much they eat and don’t binge eat. In fact, evidence from studies with people suffering from binge eating has shown that gaining control over the amount of food eaten is related to fewer binge episodes.

So, how come the myth about the relationship between food restriction and disordered eating behaviour persists? The devil here may be in the detail of how people restrict their food intake. People who are following rigid, rule-based, ‘all-or-nothing’ eating are more likely to react with overeating and disordered eating once their rules are broken than people who take a more flexible approach, limiting rather than totally eliminating certain foods, and compensating for ‘off’ meals at the next meal or with an extra hour at the gym. Identifying oneself as a ‘dieter’ seems to be related to more rigid rules about eating and so may be undermining weight loss efforts.

The key to successful weight management may lie not in restraint per se, but in self-control. The ability to forego immediate rewards in pursuit of higher goals seems to be a skill that, once acquired, is not limited to successful weight management, but extends to other areas of life such as success at work, and better management of time and finances.  Although the capacity to control one’s desires seems to be partly inherited, the good news is that people can also be trained in self-control.  Learning how to control emotions, monitoring and evaluating one’s own  behaviour, setting goals, acquiring more beneficial problem-solving skills and thinking up action plans for resisting temptations have all been shown to enhance self-control.  The view that restraint is always ‘bad’ may need to be revised and the distinction between ‘rigid’ and ‘flexible’ restraint should be given more consideration.

The bottom line is that exercising a little restraint may not only benefit your weight but also your wallet, as long as it does not turn you into a rigid, miserly and overly concerned kill-joy.


Article Reference: Johnson, F., Pratt, M., Wardle, J. (2011). Dietary restraint and self-regulation in eating behavior. Int J Obes (Lond) doi:10.1038/ijo.2011.156.

Tell me about your family and I can tell you about your weight?

By Susanne F Meisel, on 4 October 2011

Mentioning genetics in the context of weight is like treading into a minefield; those who are brave enough to approach the topic need to don their hard hats and be prepared to take hits by followers in the ‘eat-less-and-move-more’ camp. Accusations of laziness, lack of willpower, making excuses and just looking for an easy way out are common responses to the genetic argument of obesity.

However, to ignore genetics when talking about obesity is somewhat confusing when considering how keen people are to attribute skinniness to ‘good genes’, ‘fast metabolism’, and ‘being naturally active’. Nobody seems to notice that skinniness and fatness are two sides of the same coin.

As so often in life, the truth lies somewhere in between. While behaviour is certainly not to be ignored when searching for the root cause of the obesity epidemic, neither should the heritability of body weight. Two recent studies from our research group add evidence to the idea that the predisposition to thinness, as well as to overweight, is transmitted across generations. Researchers used data from the Health Survey for England, which included a large sample of families with children aged 2-15 years to see whether thin children were more likely to have thin parents. Of the thousands of families included in the first study, it was shown that thin children were almost twice as likely to have 2 thin parents.  Furthermore, as parents’ weight decreased, children likewise got progressively lighter.

But, what about the reverse side of the coin – parental weight of children who were overweight? Here, exactly the same pattern was found, but it was even more apparent. Children, who had 2 obese or severely obese parents, were approximately 12 times more likely to be overweight and again the likelihood of obesity gradually decreased with decreased parental body weight. In both studies, findings were unrelated to other factors such as age, sex, social status or ethnicity. Interestingly, the mothers’ weight seemed to be more predictive of a child’s than the father’s, but only among those children that were overweight. For thin children, mothers’ and fathers’ genes appeared to contribute equally to being thin.

Two things are important here. Firstly, weight is governed in part by genetic factors; but, and this is the second important conclusion to take away, there are environmental factors involved that influence a child’s weight – otherwise all children would have had parents that fully resembled their weight status. Influences seem to come especially from the mother’s side, which may be, because the foetus receives nutrients from the maternal diet in the womb and after birth when the infant is breast-fed. In addition, maternal environmental influences may be stronger because the mother is usually in charge of food preparation.

Unfortunately, dietary records of participants were not available, so it was not possible to investigate how diets between underweight and overweight children and their parents differed.

Genes do not always act in the same way; their activity is influenced by the environment. This flexibility allowed our species to adapt well to changing environmental conditions, which made it possible to survive and evolve.  Variation is the key. And this is why it is easier for some than for others to (not) have their cake and eat it, too.



Whitaker KL, Jarvis MJ, Boniface D, Wardle J. Inter-generational transmission of thinness. Archives of Pediatrics and Adolescent Medicine. http://archpedi.ama-assn.org/cgi/content/full/165/10/900

Whitaker KL, Jarvis, MJ, Beeken RJ, Boniface D, Wardle J. Comparing maternal and paternal intergenerational transmission of obesity risk in a large population-based sample. American Journal of Clinical Nutrition. 91, 2010, 1560-1567. http://asn-cdn-remembers.s3.amazonaws.com/f8ee4cfad55bd34900cff3371b9a146d.pdf

Log it to lose it

By Susanne F Meisel, on 26 September 2011

How self-monitoring tools and participation in online support groups assists weight loss


The internet can be a wonderful place, with hours of fun to be had looking at unlimited amounts trivial information, bad adverts and cats doing the craziest things. However, new research by our research group suggests that the Web may have benefits for those looking to shed the pounds and stay fit, too.

Dr Fiona Johnson and colleagues used data collected from a commercial online weight-loss programme (Nutracheck) to see if individuals monitoring their diet and exercise levels using the software more regularly were more likely to lose weight.  The programme is an online platform which helps users track diet and exercise goals in addition to providing weight charting software, information about nutrition and health and an online forum. With over 3500 subscribers’ data to look at, there was enough information to see which techniques worked best and for whom. What the researchers wanted to find out was whether men and women used the programme differently, and whether any particular parts were more effective than others for losing weight.

The main finding was largely unsurprising – the more often people logged into the programme the more weight they lost, demonstrating the benefits of encouraging users to return frequently to online weight loss programmes.  There were also differences between the genders. Using online support forums was a better route to weight loss for women, whereas recording exercise levels seemed to increase success in men. Looking a little deeper in the data reveals yet more interesting patterns. Overweight or obese men and women that used food diaries the most were substantially more likely to lose over 5 % of their body weight (an amount which is likely to have health benefits) than those who logged their food consumption less diligently. Overweight and obese men seemed to benefit particularly from exercise diaries, with the most engaged being the most likely to shed significant amounts of weight.

We all knew it – consistency is the key. Just sticking to actually using the programme you spent your precious money on will help fight the flab. If you are a man, making note of how often and how long you spend exercising and toning your Adonis body appears to be the route to success. And if you are a woman, chatting about the experience of weight loss and dieting will help even more. So what are you waiting for? Stop looking at crazy cats and get logging!



Johnson, F & Wardle, J. (2011) The association between weight loss and engagement with a web-based food and exercise diary in a commercial weight loss programme: A retrospective analysis. International Journal of Behavioural Nutrition and Physical Activity. 8:83 doi:101186/1479-5868-8-83


Susie (susanne.meisel.09@ucl.ac.uk)