How many total food-and beverage-related decisions do you make in one day? Have a guess!

You reckon more than 15 decisions per day?! Congratulations! You are closer than the average (14.4) of 139 participants who were asked exactly the same question in a study by Wansink and Sobal (2007). However, you might still be far off. Let’s have a closer look at the study.

Being aware of the impact nutrition has on our physical and mental health as well as brain functioning, you might expect people to make well-considered food decisions. Wansink and Sobal (2007) aimed to answer the two following questions:

Are we aware of how many food-related decisions we make?

The results are clear, indicating a large degree of unawareness regarding the number of daily food decisions. The participants underestimated the number of food-and beverage-related decisions in a day by more than 200 decisions. We make an estimated 226.7 food decisions each day. Were you close? The authors conclude that we often engage in mindless eating which results in a lack of control of our food intake. There is a need to increase the awareness of the decisions we make regarding what, when and how much we eat to promote a healthy lifestyle.

These findings raise the question which factors determine our food decisions if we don’t. One potential factor that should be considered is our environment which was addressed in the second question of the study.

Food Choices cartoonAre we aware of the environmental cues that lead us to overeat?

To shed light on the second question the authors analysed data from four studies in which participants were either assigned to the control condition or a so-called exaggerated treatment condition. Environmental factors such as package size, serving bowl and plate size differed for the two conditions. In each study participants in the treatment condition served/prepared/consumed more food than the control group (between 29 and 53 % more). Afterwards the 192 participants of the treatment group were asked “How much did you eat compared to what is typical for you?” Across all four studies 19 % said “less” and 73 % “about the same” as normally. Just 8 % were aware that they consumed more. Afterwards they were informed about the environmental cues and asked a second question: “In this study, you were in a group that was given [a larger bowl]. Those people in your group ate an average of 20%-50% more than those who were instead given [a smaller bowl]. Why do you think you might have eaten more?” Interestingly, 21 % still claimed they did not eat more. 69 % justified the greater food intake with being hungry and 6 % with other reasons. Just 4 % admitted that the environmental cues influenced them.

These findings highlight the unawareness or denial of the influence our environment has on us and our food intake. However, they can be used as a starting point to improve our nutrition. Changing your immediate environment to make it less conducive to overeating can help you improve your health. Start with putting the sweets just a bit further away from you.

Further information on how to make your environment less conducive to overeating you can find in the book “Slim by Design: Mindless Eating Solutions for Everyday Life” by Brian Wansink (

You can also visit Brian Wansink’s website where you find more cartoons – like the one above -amongst other things:

Wansink, B., & Sobal, J. (2007). Mindless eating: The 200 daily food decisions we overlook.

Environment and Behavior, 39(1), 106-123.


What makes some of us more likely to drive over the speed limit, participate in extreme sports or make decisions that can impact health over time? Risk-taking behavior has distinct subtypes (for example disinhibition, sensation seeking, calculated risks, impulsivity) that develop due to the complex interplay of different factors: our lifestyle and environment, our personal susceptibility (genetic and biological variants) and a wide range of psychological effects.

In the study of Strawbridge and colleagues (2018) the goal was to identify genetic determinants of this trait. This approach has the potential to improve our understanding of impulsive behavior across different psychiatric disorders. It can also help later on to explore the possible overlap between mental illnesses and physical health.

„Would you consider yourself a risk taker?” This was the question posed to 116,255 participants, aged 40 to 69, from the UK Biobank project, a large population cohort containing a wide range of sociodemographic and medical information. Roughly one-quarter answered yes, they were the ’risk takers’ group.

A subset of participants took part in a prolonged follow-up occasion as well, where the same question was asked enabling an assessment of response consistency. Reproducibility was quite good, 81% of all participants responded consistently, 13% inconsistently, while in 6% the data was missing.

Genetic loci associated with risk-taking behavior were explored using the genome-wide association study approach. The authors identified one potential locus on chromosome 3 (CADM2) consistently, which was previously implicated in cognitive and executive functions.

Considering the entire genome using the polygenic risk score approach, the authors found, that the genetic variants that make us risk-prone also make us more likely to develop mental illnesses, such as bipolar disorder, schizophrenia, attention-deficit hyperactivity disorder, and post-traumatic stress disorder.

This trait has not only significant positive genetic correlations with a range of mental health disorders, but also with smoking, lifetime cannabis use and body mass index (BMI). The latter implies the possibility that this finding could be followed up in a study exploring the nutritional aspects of impulsivity as well.

Overall, using dimensional approach for traits (from “normal” to pathological) rather than discrete diagnostic categories could be helpful for finding the common ground in the neurobiological underpinnings across psychiatric disorders. From this point of view, risk-taking behavior is also a complex and important phenotype for investigations.

You can find the full research article here.

Strawbridge, R. J., Ward, J., Cullen, B., Tunbridge, E. M., Hartz, S., Bierut, L., Horton, A., Bailey, M. E. S., Graham, N., Ferguson, A., Lyall, D. M., Mackay, D., Pidgeon, L. M., Cavanagh, J., Pell, J. P., O’Donovan, M., Escott-Price, V., Harrison, P. J., & Smith, D. J. (2018). Genome-wide analysis of self-reported risk-taking behaviour and cross-disorder genetic correlations in the UK Biobank cohort. Translational Psychiatry, 8.

This was co-authored by  Tünde Kilencz, a psychologist and research assistant at Semmelweis University, Department of Psychiatry and Psychotherapy in Budapest, Hungary.

Food is addictive. It has been an addiction that has kept mankind alive for thousands of years. Today, hunger is no longer a problem in the developed world; it is quite the opposite. According to the World Health Organization, worldwide obesity has nearly tripled since 1975. Obesity has reached epidemic proportions globally, with at least 2.8 million people dying each year as a result of being overweight or obese.

In order to maximize the nutritional value, humans are hard-wired to prefer foods that have either a high sugar or fat content. The amount of energy obtained from food is measured in kilocalories (kcal) per gram. Fats have the most energy (9 kcal) and carbohydrates (sugars and starches) have the same amount of energy as proteins (4 kcal). However, these nutrients differ in how quickly they supply energy. Sugars and starches have the advantage of being converted into energy faster than fats and protein. Protein is preferentially used for building and repairing different tissues, not as an energy source.

Once a beneficial adaptation of preferring fast digesting or the most energy-rich nutrients, has now become a risk factor for both physical and also mental health (1), making it an inevitable research focus.

In a recent study at the Yale University School of Medicine (2) it was determined that people not only favour fatty or sugary foods, but place the highest value on those that combine both. Participants (tasked to make monetary bids on different food items) were ready to pay the most for cookies, chocolate, cake and other treats that had both high sugar and also fat content. Equally familiar, liked and caloric fatty (e.g., cheese, salami) or sugary foods (e.g., lollipops) were assigned lower values.

Based on surges of activity, brain scans revealed that foods high in both fat and sugar were more rewarding than foods rich in only one category of nutrient.

Unexpectedly, it was also observed that participants were very accurate at estimating the energy density (kcal) of fatty foods, but poor at estimating the energy density of sugar-containing foods.

Once rare, but nowadays common and abundant treats high in both fat and sugar are most rewarding and therefore can very likely contribute to overeating. In addition, it has turned out to be difficult for people to assess the amount of calories in foods with a high sugar content. These findings taken together can help to understand and also hopefully find new treatment options for people struggling with obesity.

  • Hoare E et al (2015) Systematic review of mental health and well-being outcomes following community-based obesity prevention interventions among adolescents. BMJ Open 2015;5:e006586. doi:10.1136/bmjopen-2014-006586
  • DiFeliceantonio et al (2018) Supra-additive effects of combining fat and carbohydrate on food reward. Cell Metabolism 28, 1–12. doi:10.1016/j.cmet.2018.05.018

The reason why I look at impulsive behavior is because mental disorders are the single largest contributors to disease burden in Europe. Impulsivity and compulsivity increase the risk of psychiatric disorders, especially Attention Deficit Hyperactivity Disorder, alcohol and drug abuse disorders, conduct disorder and antisocial disorders (including aggression). The urgency of addressing impulsivity and compulsivity is additionally strongly supported by the fact that these problems increase the risk for mortality.

My name is Yvonne Willemsen and I have started my PhD track at Radboud University in the Netherlands in October 2017. For my project I will assess the association between nutrition, gut microbiota composition and impulsive behavior in toddlers and young adolescents. In the following paragraphs, I will explain the first study that I am currently conducting.

Many previous studies have examined the association between nutrition and executive functions. Executive functions are cognitive processes in the brain that contribute to regulating thoughts and behaviors. Executive functions can be roughly divided into three core functions, namely: inhibitory control, working memory, and cognitive flexibility. Inhibitory control, which can be interpreted as the opposite of impulsivity, is necessary to suppress impulses. It is also an important core function of executive functions, as it supports working memory and cognitive flexibility.  To date, studies have examined the association between nutrition and executive functions in general (1). Whether nutrition is related to inhibitory control specifically (in toddlers and young adolescents) is something that still needs to be investigated.

The next step of my study is to understand how nutrition is associated with inhibitory control. To explain a possible mechanism, we will look at the gut microbiota. The reason why the gut microbiota is a point of interest is because gut microbiota can secrete molecules that may influence brain function, and thus may influence inhibitory control (2). This connection between the gut and the brain is also known as the gut-brain axis. Gut microbiota composition can change according to nutritional intake, and can therefore play a role in the gut brain axis (3). To assess the association between nutrition, gut microbiota and behavior in toddlers and young adolescents, we will use questionnaires and different behavioural measures.

  1. Cohen, J. F. W., Gorski, M. T., Gruber, S. A., Kurdziel, L. B. F. & Rimm, E. B. The effect of healthy dietary consumption on executive cognitive functioning in children and adolescents: a systematic review. Br. J. Nutr. 116, 989–1000 (2016). Link
  2. Rogers, G. B. et al. From gut dysbiosis to altered brain function and mental illness: mechanisms and pathways. Mol. Psychiatry 21, 738–748 (2016). Link
  3. Oriach, C. S., Robertson, R. C., Stanton, C., Cryan, J. F. & Dinan, T. G. Food for thought: The role of nutrition in the microbiota-gut–brain axis. Clin. Nutr. Exp. 6, 25–38 (2016). Link