The dining table should be more than just a place for eating

A study of Brian Wansink and myself as co-author was published recently. The study shows that the dining environment itself is associated with weight status. It was picked up by several newspapers, such as the Los Angeles Times ('Mealtime rituals might make a difference in obesity, researchers say') and the Daily Mail Online ('Telly tubbies: Eating dinner in front of the TV 'makes you fatter than sharing a meal with family at the table').

Read the Cornell University's Press Release:

'Beyond plate size and calorie and carbohydrate counts, the war against obesity may have a better front – the dinner table. Eating dinner with kin (and without the TV on) is linked to lower body mass, reports a Cornell behavioral economist in the journal Obesity.

Families that eat together frequently – and stay seated at the table until everyone’s finished – have children with lower weights and Body Mass Index (BMI). This is especially strong with boys. Strong, positive socialization skills that dinners foster possibly supplant the need to overeat, explain the researchers. Mothers and fathers who talk meaningfully with children about their day at the dinner table also have lower BMIs.

“The ritual of where one eats and how long one eats seems to be the largest driver,” said Brian Wansink, professor in Cornell’s Dyson School of Applied Economics and Management and director of the Cornell Food and Brand Lab. He co-authored the study with Ellen Van Kleef, assistant professor at Wagening University, the Netherlands.

But families that eat dinner while watching television can turn chubby, as the researchers linked that to higher BMIs. “In fact, eating anywhere other than the kitchen or dining room was related to higher BMIs in both parents and in children,” said Wansink.

“By focusing on family dining rituals, this research departs from the more food-centric approaches. Dinner starts with meal preparation, and while being involved in meal preparation was unrelated to the BMI of young boys, it was positively correlated with the index of young girls,” said Wansink.

“Family meals and their rituals might be an underappreciated battleground to fight obesity.”

The study, “Dinner Rituals that Correlate with Child and Adult BMI,” was published online in Obesity, Oct. 1, and was funded by the Cornell Food and Brand Lab.'

Interview Professor Paul Rozin: Why we have to change people's world if we want them to eat better

Retiring this year, but still busy doing research. Inspired by the way musical pieces often start out slow, build up and then climax, he enthusiastically talks about a new project. 'People come up with a summary judgement of how good a meal is. We are looking at the degree to which an ending is important. You put the best things at the end. People like things that rise', he explains a new study.

In December, I am invited to stay at the Centre For Advanced Studies at the Norwegian Academy of Science and Letters. Every year, this centre hosts three parallel research groups organized around a central theme. One theme of this year is 'The ecology of food perception'.  Researchers from Norway and abroad are invited to work together for several months. Paul Rozin is also invited and I visited him during his stay. He is a professor of psychology at the University of Pennsylvania. Paul Rozin is considered to be one of the most influential researchers on human food choice and particularly known for his work on the meaning of disgust.

We talked about working with Brian Wansink ('We have similar attitudes towards things and we are both outliers'), journals' bias to only publish positive results ('That is ridiculous') and pressure to publish or follow a particular model of how to do research. 'The basis question one should ask is how much the contribution adds to understanding', he writes in his 2009 paper in Perspectives on Psychological Sciences. In this paper, Paul Rozin talks about the value of moving from top-down hypothesis testing as dominant research model in many top psychological journals to research approaches that lead to broader generalizations of interesting phenomena. ''What they do is that they find something with a set of experimental parameters and then instead of saying 'Is this real?', 'Can I change the parameters a bit and is it still there?', they go ahead, they analyse it and they go down. That is what a journal wants', he said. Exploring the large picture of a phenomenon is key according to him; 'Even in the lab, you can vary your parameters. A parameter that you think is not critical, often is in real life'.

We went on to talk about obesity ('We plateaued, I think it is because we now drink more bottled water') and interventions that could help people to eat better. When I asked his opinion on Herman and Polivy's argument that not much progress has been made so far in combatting the obesity problem and that it is probably easier to make the case that things are getting worse, he strongly agrees. 'I think they are right. They are very smart people, they worked on this for decades. I have said that but I do not know whether I said it in print. Nothing has been shown to work except maybe bariatric surgery', he said.

This may seem a pessimistic view, but Paul Rozin has clear ideas about possible solutions. He is a believer of the nudge approach: 'I do not think that we can change people. I think we have to change their world. That is what I think has happened in France. Their world is different, the way their food is presented is different. That is why they have half our obesity rates. I cannot proof that, there are too many variables. That is encouraging, that their environment is so different and they are much thinner.'

Paul Rozin, however, is not yet convinced about the long-term potential of nudging: 'There is no question that it works in the short run. What we do not know is whether nudging will work in the long run. We know that it works over a week, but we don't know whether it works over a year, because there may be compensation in various ways. Doing a year's study will involve a lot of investment. You have to get too many people to support you', he said. An interesting perspective of Professor Paul Rozin; a leading expert you should definitely continue to follow.

3 surprising insights on how food cravings relate to other desires in everyday life

What is harder to resist? Checking your Twitter or Facebook account at work or eating a delicious, but fattening snack when you try to watch your calories? Both are inner conflicts, best described as 'I really want to do this, but I should not'.

In many food studies it is assumed that people have conflicting feelings when being confronted with tempting foods. But is that really the case in everyday life? What type of cravings are felt most strongly? And if people do crave foods, how often are they trying to resist their desire?

Wilhelm Hofmann, Kathlees Vohs and Roy Baummeister recently tried to answer these questions in their Everyday Temptation Study. They gave BlackBerrys to 205 participants and contacted them on 7 random times per day for one week. When they were contacted, they had to indicate what type of desire they experienced within the last 30 minutes, how conflicted they felt about this desire, whether they tried to resist the desire and how successful they were in this. The study included all types of everyday desires, including the desire to eat, drink, have sex, sleep, spend money and use media (such as social media). Here are 3 insights that I found most surprising.

1)   Food is not the hardest desire to resist
People feel some desire about half the time they are awake. In hours, this is about eight hours a day. Almost half of those desires are conflicting at least somewhat with other goals in life.
Interestingly, food is not the hardest desire to resist. It is much more difficult to fight the desire for sleep and fun leisure activitities (such as checking Facebook). These two were considered to be the hardest to resist. Only 23% of all conflicting desires go against some health goals (for example healthy eating or exercise). The majority of reported inner conflicts were related to goals such as saving money, achievements at work or study, social appearance and efficient time use.

In other words, it is harder to resist impulses to spend money, participate in sports, use (social) media and smoke than it is to resist eating.

2)   We spend three hours a day resisting desires
The majority of desires in everyday life are not resisted. We have to eat anyway, so why trying to resist it? When people do try to resist them, they are quite successful in it; in 83% of all inner conflicts, they succeed to not give in. Still, in 17% of all occasions, people do give in. They particularly fail to resist checking e-mail, Facebook, Twitter of other social media when they do not want to do that.

3)   Stop resisting the numerous cravings throughout a day
Besides that we spend about three hours per day resisting desires, we also spend half an hour giving in to desires that we initially resisted. The more often you try to resist a desire, the less willpower is left at the end of the day and the more likely it is that you go for the 'forbidden' food. This confirms the 'muscle model' of willpower, which states that willpower is like a muscle that needs refuel.

So, do not replete your willpower, stop reading this blog post and go back to work.



What is harder to resist; Twitter and Facebook at work or the temptation of an unhealthy snack?

Hofmann W, Baumeister RF, Förster G, & Vohs KD (2012). Everyday temptations: an experience sampling study of desire, conflict, and self-control. Journal of personality and social psychology, 102 (6), 1318-35 PMID: 22149456

Dealing with Big Food: Slow public health response to large food companies' influence

Recently, the world population exceeded 7 billion people. One billion of them is hungry, while at the same time two billion are overweight. This shows we have a huge problem in meeting people's dietary needs. As what people eat is increasingly determined by a few multinational food and beverage companies, this month a new series of articles on the influence of these companies ('Big Food') will appear in PLOS Medicine Magazine. Highly recommendable!

David Stuckler and Marion Nestle start off with their essay on Big Food's problematic influence on the global food system. The authors cite research that shows that the ten largest food companies control over half of all food sales in the United States. Unfortunately, what they successfully sell consists primarily of processed foods enriched in sugar, salt and fat. Frequent consumption of these foods is associated with excess weight and chronic diseases.

The decades-long fight against tobacco has provided us with insights on typical tactics used by industry to undermine public health measures such as taxation and regulation, they state. Basically, that is because food companies aim to maximize profits and not health. They do not like interventions that threaten their profits.

Public health professionals are slow in responding to the threat of Big Food and the authors therefore urge for more strong and conscious choices about how to deal with Big Food's influence. Dealing with the food industry involves more than partnering or waiting for self-regulatory initiatives. It requires a critical approach, recognizing the conflicts of interests that play a key role.

Stuckler and Nestle conclude by stating 'without taking direct and concerted action to expose and regulate the vested interests of Big Food, epidemics of poverty, hunger, and obesity are likely to become more acute'.  A strong plea for action...

Satiety enhancing food development: State of the art in the field of nutrition, food technology, consumer, marketing and technology

Developing foods that keep you feel full for longer is not a matter of simply adding extra fibers, water or air to a food. For many people, the signs of fullness that their body is giving them after eating are easily overridden by the temptations in our environment that trigger to continue eating. Think of the high visibility of delicious foods and large, convenient portion sizes. They all have substantial influence on the amount of food we eat and the resulting satisfaction.

Satiety is a complex interaction of physiological, social and psychological mechanisms.

Food providing enhanced satiety will have to function in the life of people surrounded by cues that stimulate excessive eating. This requires an integrated approach between various food-related disciplines.

This month, our new paper has been published: 'Successful development of satiety enhancing food products: Towards a multidisciplinary agenda of research challenges'. The paper presents the state of the art and key research challenges around satiety enhancings foods in the field of nutrition, food technology, consumer, marketing and communication.

My co-authors are Hans van Trijp, Joost van den borne and Charon Zondervan. Just click on the Critical Reviews in Food Science and Nutrition-paper below to read it full-text.

 

Is there hope for a thinner future?

There is not much progress made in combatting the overweight and obesity epidemic. That is a conclusion drawn in a recent paper of the prominent researchers Peter Herman and Janet Polivy: 'Self-regulation and the obesity epidemic' (Social Issues and Policy Review).  I found it an inspiring paper. Both authors are highly influential and experienced in the field of experimental psychology of eating behaviour and obesity. Because of their outstanding track record, I recommend reading their paper and think about it. Their take home message is not a positive one, however.   

Picture: Rudd Center Image Gallery



The basic premise of the article of Herman and Polivy is that researchers should be sceptical about interventions, both at the individual and societal level. They state that many researchers suggest that progress is being made or just around the corner. But actually, this is not true. Their review of the literature coupled with the decades of  professional experience made them conclude the following: ‘Scrutiny of the statistics, however, suggest that not much progress has been made so far in combatting the problem; in fact, it is probably easier to make the case that things are continuing to get worse’.

The best interventions at an individual level (e.g. clinical interventions) are expensive or impossible to implement on a community-wide basis. Although the authors agree with many scientists that interventions at a societal level (e.g. reshaping of the environment) are needed, they are not optimistic. Basically, many ideas for interventions will not work or even backfire, they argue.



Obesity is a very serious problem. Herman and Polivy stress that it not ok to implement unproven interventions. They warn that scientists should be cautious about applying solutions that turn out to be ineffective as the little trust that the public has in social scientists should not be destroyed.

What do you think? Is there really not much progress made? Is there hope for a thinner future?

Do increased serving bowl sizes influence how much we eat?

It is often stated that that the increasing size of food portions is a strong factor contributing to the incidence of overweight and obesity. Numerous studies have shown it again and again: larger portion sizes, serving devices and packages lead people to eat more, often without them realizing it. In particular, individual serving devices such as plates, spoons and bowl have been shown to influence food intake. However, what has not been shown is whether the most central focus of the dinner table, the main serving bowl, has a similar magnifying effect. When one is eating at home and eating out in buffet restaurants, food is often available in serving bowls from which individual portions are distributed.

This month, the paper 'Serving bowl biases the amount of food served' I wrote together with Mitsuru Shimizu and Brian Wansink came out in the Journal of Nutrition Education and Behavior. This paper reports our study in which we wanted to determine how serving bowls filled with food for many persons influence serving behaviour and consumption. We expected that the larger the size of a multiple-serving bowl, the more people will serve and consume. In the study, 68 participants were randomly assigned to a group serving pasta from a large-sized bowl (almost 7 litre capacity) or a medium-sized bowl (almost 4 litre capacity). When given a large bowl, diners served 77% more pasta compared with the diners serving from the medium-sized bowl. They ate more, even though the food was not rated tastier or otherwise notable different.


Bowl size matters, so fill your largest bowl with salad



We wondered about the reasons for our findings. It could be that more 'social' reasons inhibit an individual from taking too much food from a smaller common bowl. Perhaps people use the size of serving bowl filled with food for multiple persons as an indication of how much they can best serve themselves. It could even seem greedy to take more food from a smaller bowl.

In any case, small increases in food intake may lead to substantial additional caloric intake over a longer time period and even weight gain. Just like larger package sizes, large serving devices seem to suggest to people that large portions are appropriate to consume.

These findings again highlight the role that external cues play in food consumption and show the importance of considering serving bowl size in nutrition education. Maybe our findings can be used to turn bad habits around; just put your salad in bigger bowls.

The six reasons why overweight is a wicked problem

No quick fixes and simple solutions. That is the case with the current overweight and obesity epidemic. You can read this important message in the recently published book 'Tegenwicht. Feiten en fabels over overgewicht', written by Jaap Seidell and Jutka Halbertstadt. The translation of this Dutch title would be something like 'Counterweight. Facts and myths about overweight'.

I really liked reading this book, because it describes in easy-to-read and understandable language the current state of the scientific knowledge on overweight and obesity. What struck me most was that science has not yet come that far in understanding how various factors interact in creating the overweight problem and providing effective solutions. A key reason for that, Seidell argues, is that overweight is a wicked problem. This term was first mentioned in relation to the highly complex problems of social planning, but it can also be applied to overweight and obesity.

Basically, there are six reasons why overweight is a wicked problem:

Reason 1: You know what the problem is, when you have the solution. Since it is hard to define what exactly the problem is, it is difficult to find a solution. This definitely applies to overweight. For example, experts often disagree what the major causes are of overweight: lack of physical activity or overeating? Bad genes or bad eating habits?

Reason 2: The solution process does not have a clear end-point. As Seidell wonders; it is not exactly clear what the purpose is of preventing overweight: halting the rising trends or reducing the number of people with overweight to zero?

Reason 3: Solutions are not right or wrong. All involved stakeholders (such as food companies, authorities, consumers, health professionals) have an opinion about the problem and often disagree. For example, last week we had the No Diet Day (or 'Anti-Diet-day' in the Netherlands). Although the day aims at body weight acceptance, it led to debates about the usefulness of particular diets and the risks of overweight. 

Reason 4: Each wicked problem is unique and new. The involved actors and concrete situations are different. The causes and potential solutions are similarly not the same for different groups of overweight individuals.

Reason 5:  There is no room to experiment. It is impossible to check beforehand whether a particular solution will be effective. Essentially, it is often a matter of critically informed trial and error.

Reason 6: There is no clear set of solutions and there can be many solutions or only one. Solutions are hard to find. As a result, Seidell argues that the overweight and obesity problem requires a holistic solution. For example, schools, food industry, health authorities and consumers should work together in exploring solutions that seem promising. After all, there is a lot at stake: overweight is not just a medical problem, but also a social one. 

Trish Groves likewise argues in the British Medical Journal that obesity seems to be the classic example of a wicked problem. Consequently, we need more innovative and collaborative approaches. I completely agree. Acknowledging that overweight is a wicked problem might help getting a more realistic overview of the problem instead of over-simplistic and one-sided analyses and claims for solutions. It also shows that as researchers we should look across the boundaries of traditional research fields and become more creative in contributing to the search for solutions.

Highlights Obesity 2010 conference San Diego

What is hot in obesity research and policy making? I am here in San Diego to find out at the Obesity conference.

One thing is clear. Obesity is a chronic disease and dieting as a temporary, special way of eating is not going to help people any further. Nothing new, one could say. Studies have shown over and over again that dieting is not such a good idea. However, that has not stopped people from trying. Diet books are among the best sellers in book sales rankings. People see dieting as something that you do for a limited time.

However, presenters at this conference stress it again and again; support should not stop after people lost a considerable amount of weight. Sustained approaches to deal with overweight over a lifetime are needed, according to Van Saxton Hubbard, winner of the Mickey Stunkard Lifetime Achievement Award. 



My poster presentation 'Food Compensation: Do exercise ads change food intake?'