Ramona Guerrieri

r.Guerrieri@maastrichtuniversity.nl

Both in the United States and in Western Europe the prevalence of overweight and obesity is rising problematically. Although this “obesity epidemic” has many adverse health consequences such as diabetes, heart diseases and some cancers (Flegal, 2005; Hu, 2003), little is known about the causes of the increases in the prevalence of overweight and obesity.

What are potential causes of the obesity epidemic? One factor that is frequently referred to is the changing environment. Sweet and fatty foods have never been more varied, cheaper or more available and they are being offered in increasingly larger portion sizes. Consequently, it becomes very difficult for people to resist palatable and energy-dense foods. It is likely that this will result in a positive energy balance. In its turn this positive energy balance will lead to weight gain.

However, not everyone who is exposed to this obesogenic environment becomes overweight or obese. Some people remain lean despite the temptations in our environment. This is where individual differences come into the picture: a person’s reaction to the environment is moderated by certain traits that they do or do not possess. One such trait is impulsivity. In general, impulsivity is defined as the tendency to think, control and plan insufficiently. In most cases this results in an inaccurate or maladaptive response. Precise behaviours that are considered impulsive are very diverse, but they can be narrowed down to two main aspects of impulsivity: sensitivity to reward and insufficient prepotent response inhibition.

We try to find out whether impulsivity, possibly in combination with exposure to (aspects of) an obesogenic environment, leads to overeating in normal-weight participants. We expect an interaction between impulsivity and variety. More precisely, we expect that highly impulsive people have a difficult time resisting food when it is varied whereas we do not expect this when monotonous food is offered.


Ten percent of my time is reserved for teaching. I mainly fill this time by supervising student’s internships and by tutoring. I tutored for the following courses:

• Artificial Intelligence and Cognitive Science
• Statistics
• Memory
• Learning
• Research: How to do it! (a small group of students plan, execute, analyse and report an experiment under the supervision of a researcher)
• Eating Disorders

Internships that I am willing to supervise:

• Research in which you manipulate the environment (e.g. portion size) and look at the effect of this manipulation on food intake
• Research in which you measure or manipulate (e.g. putting people in an “impulsive mood”, or making them more aware of themselves) a personality trait and in which you measure its effect on food intake
• If a literature search has inspired you, do not hesitate to come by to discuss your proposal!

Guerrieri, R., Nederkoorn, C., Schrooten, M., Martijn, C., & Jansen, A. (2009). Inducing impulsivity leads restrained eaters into overeating, whereas current dieters stick to their diet. Appetite, 53, 93-100.

Guerrieri, R. , (2009). Vechten tegen verleiding: Hoe impulsiviteit bijdraagt aan het overgewichtprobleem. [Fighting temptation: how impulsivity contributes to the problem of overweight and obesity. Psychologie en Gezondheid, 37, 112.

Nederkoorn, C., Guerrieri, R., Havermans, R. C., Roefs, A., & Jansen, A. (2009). The interactive effect of hunger and impulsivity on food intake and purchase in a virtual supermarket. International Journal of Obesity, 33, 905-912.

Nederkoorn, C., Baltus, M., Guerrieri, R., & Wiers, R. (2009). Heavy drinking is associated with deficient response inhibition in women but not in men. Pharmacology, Biochemistry and Behavior, 93, 331-336.

Jansen, A., Nederkoorn, C., van Baak, L., Keirse, C., Guerrieri, R., & Havermans, R. (2009). High-restrained eaters only overeat when they are also impulsive. Behaviour Research and Therapy, 47, 105-110.

Guerrieri, R., Nederkoorn, C., Jansen, A. (2008). The effect of an impulsive personality on overeating and obesity: Current state of affairs. Psychological Topics, 17, 265-286.

Claes, L., Nederkoorn, C., Vandereycken, W., Guerrieri, R., & Vertommen, H. (2006). Impulsiveness and lack of inhibitory control in eating disorders. Eating Behaviors, 7, 196-203.

Geraerts, E., Jelicic, M., Merckelbach, H. & Guerrieri, R. (2004). Het effect van acute stress op het neutraal en emotioneel geheugen. [The effect of acute stress on neutral and emotional memory] Neuropraxis, 8, 54-59.

Guerrieri, R. (2005). Toen de koekjestrommel de fruitschaal verdrong… De toxische omgeving als oorzaak van obesitas. [The toxic environment as a cause of obesity] De Psycholoog, 40, 642-646.

Guerrieri, R., Nederkoorn, C., & Jansen, A. (2007a). How impulsiveness and variety influence food intake in a sample of healthy women. Appetite, 48, 199-122. [Download PDF]

Guerrieri, R., Nederkoorn, C., Stankiewicz, K., Alberts, H., Geschwind, N., Martijn, C., & Jansen, A. (2007b). The influence of trait and induced state impulsivity on food intake in normal-weight healthy women. Appetite, 49, 66-73. [Download PDF]

Guerrieri, R., Nederkoorn, C., & Jansen, A. (2008). The interaction between impulsivity and a varied food environment: its influence on food intake and overweight. International Journal of Obesity, 32, 708-714. [Download PDF]

Jelicic, M., Geraerts, E., Merckelbach, H. & Guerrieri, R. (2004). Acute stress enhances memory for emotional words, but impairs memory for neutral words. International Journal of Neuroscience, 114, 1343-1351. (impact factor: 0.579)

Nederkoorn, C., Guerrieri, R., & Jansen, A. (2006). Leven in luilekkerland. [Living in the land of plenty] De Psycholoog, 41, 10-15.