Roel C.J. Hermans

Alcohol Portrayal on Television Affects Actual Drinking Behaviour

AIMS Alcohol portrayal in movies and commercials is generally positive and might stimulate young people to drink. We tested experimentally whether portrayal of alcohol images in movies and commercials on television promotes actual drinking. METHODS In a naturalistic setting (a bar lab), young adult male pairs watched a movie clip for 1 h with two commercial breaks and were allowed to drink non-alcohol and alcoholic beverages. These participants were randomly assigned to one of four conditions varying on the type of movie (many versus few alcohol portrayals) and commercials (alcohol commercials present or not). RESULTS Participants assigned to the conditions with substantial alcohol exposure in either movies or commercials consume more alcohol than other participants. Those in the condition with alcohol portrayal in movie and commercials drank on average 1.5 glasses more than those in the condition with no alcohol portrayal, within a period of 1 h. CONCLUSIONS This study-for the first time-shows a causal link between exposure to drinking models and alcohol commercials on acute alcohol consumption.

Modeling of palatable food intake in female young adults. Effects of perceived body size

Laboratory taste-test studies have shown that social modeling effects on food intake are powerful. The aim of the present study was to examine the degree to which people model food intake in a more naturalistic eating setting. After completing a cover task, female participants (N=102) spent a 15-min break with a female confederate who ate a large amount or a small amount of M&Ms or no M&Ms at all. Further, the confederate had a slim or (subtly manipulated) normal-weight appearance. Females who were exposed to a confederate who ate much consumed more than those who were confronted with a confederate who ate only a little or nothing at all. Although the manipulation of the confederates appearance had no significant main effect on the amount of food that participants consumed, a significant interaction effect was found, such that the modeling effect of eating was present only in the normal-weight appearance condition. Our findings suggest that normal-weight young women are more inclined to imitate the food intake of a female confederate if they are more similar to the confederate.

Modeling of palatable food intake. The influence of quality of social interaction.

This study investigates the effects of the quality of social interaction on modeling of food intake among young women. A two (confederates food intake: high versus low) by two (confederates sociability: sociable versus unsociable) between-participant factorial design was employed. A total of 100 young women (18-27 years) participated. Findings indicated that young women generally ate more when exposed to a high-intake peer than women exposed to a low-intake peer. However, this modeling effect was only found in the unsociable context. This study underscores the influence of social atmosphere on modeling effects of palatable food intake and suggests that contextual uncertainty or ingratiation strategies may be important in explaining the magnitude of modeling effects.

Effects of social modeling on young women's nutrient-dense food intake

We examined whether a same-sex peers vegetable consumption would predict the number of vegetable pieces eaten by the participant. A total of 116 Dutch women (M age = 20.28; M BMI = 21.68) participated. Their nutrient-dense food intake was measured during a 15-min break between two tasks, consisting of rating television advertisements. Participants consumed more vegetables when exposed to a peer eating a large number of vegetables than when exposed to a peer eating a small number or nothing. These findings suggest that social modeling processes may be relevant to interventions aimed at encouraging young womens nutrient-dense food intake.

Food intake in response to food-cue exposure. Examining the influence of duration of the cue exposure and trait impulsivity

The present study experimentally tested whether the effect of olfactory food-cue exposure on young womens food intake was moderated by the duration of the cue exposure and trait impulsivity. The study employed a 2 (food-cue exposure: smell of baked cookies present vs. no-smell present) by 2 (duration of cue exposure: short-term vs. long-term) between-participants design. Participants were 109 normal-weight young women (mean age=21.6 years) whose food intake was examined during a bogus taste-test. Additional saliva measures were taken during food-cue exposure. Results showed that the duration of the cue exposure did not affect intake. Impulsivity moderated intake, but not saliva flow. Low impulsive females consumed more food when confronted with an olfactory food-cue, whereas high-impulsive females did not eat more after food-cue exposure. Our findings may be explained by the fact that we did not instruct our participants to pay attention to the olfactory food-cue. Results indicate that even people who are normally well controlled are susceptible to the effects of less explicit olfactory food-cues.

Descriptive peer norms, self-control and dietary behaviour in young adults.

There is evidence that perceived peer eating norms can influence dietary behaviour. This cross-sectional study examined whether certain personality traits increase the likelihood that personal eating habits are similar to perceived peer eating habits. We assessed frequency of consumption of sugar-sweetened soda (SSS) and sweet pastries (SP), as well as perceived peer descriptive eating norms for SSS and SP in a group of 1056 young adults. We examined whether individual differences in the need for social acceptance and self-control moderated whether participants were likely to display similar dietary habits to their peers. Perceived peer eating norms for SSS and SP predicted frequency of consumption; believing that one’s peers frequently consumed SSS and SP was associated with increased personal consumption for both. Individuals with low self-control, as opposed to high self-control, were more likely to adhere to peer norms for SP, but not for SSS. Trait social acceptance needs did not significantly moderate similarity between peer norms and personal consumption for either SSS or SP. The extent to which young adults adhere to descriptive peer dietary norms may depend upon self-control, whereby individuals with low self-control are less able to inhibit social influence of descriptive peer norms on dietary behaviour.

Evaluation of a Smart Fork to Decelerate Eating Rate.

Overweight is associated with a range of negative health consequences, such as type 2 diabetes, cardiovascular disease, gastrointestinal disorders, and premature mortality. One means to combat overweight is through encouraging people to eat more slowly. People who eat quickly tend to consume more and have a higher body mass index, whereas people who eat more slowly feel satiated sooner and eat less. Unfortunately, eating rate is difficult to modify, because of its highly automatic nature. In clinical settings, researchers have had some success changing behavior by using devices that deliver feedback in real time. However, existing technologies are either too cumbersome or not engaging enough for use in daily life contexts. Training people to eat more slowly in everyday eating contexts, therefore, requires creative and engaging solutions. This article presents a qualitative evaluation of the feasibility of a smart fork to decelerate eating rate in daily life contexts. Furthermore, we outline the planned research to test the efficacy of this device in both laboratory and community settings.

Imitation of snack food intake among normal-weight and overweight children

This study investigated whether social modeling of palatable food intake might partially be explained by the direct imitation of a peer reaching for snack food and further, assessed the role of the childrens own weight status on their likelihood of imitation during the social interaction. Real-time observations during a 10-min play situation in which 68 participants (27.9% overweight) interacted with normal-weight confederates (instructed peers) were conducted. Childrens imitated and non-imitated responses to the confederates food picking movements were compared using a paired sample t-test. In addition, the pattern of likelihood of imitation was tested using multilevel proportional hazard models in a survival analysis framework. Children were more likely to eat after observing a peer reaching for snack food than without such a cue [t(67) = 5.69, P < 0.0001]. Moreover, findings suggest that children may display different imitation responses during a social interaction based on their weight status (HR = 2.6, P = 0.03, 95% CI = 1.09–6.20). Overweight children were almost twice as likely to imitate, whereas normal-weight children had a smaller chance to imitate at the end of the interaction. Further, the mean difference in the likelihood of imitation suggest that overweight children might be less likely to imitate in the beginning of the interaction than normal-weight children. The findings provide preliminary evidence that childrens imitation food picking movements may partly contribute to social modeling effects on palatable food intake. That is, a peer reaching for food is likely to trigger childrens snack intake. However, the influence of others on food intake is a complex process that might be explained by different theoretical perspectives.

Examining the effects of remote-video confederates on young women's food intake

Ones decisions about eating are at times, largely based on the observations of other peoples eating behavior. Previous studies have shown that modeling of eating is a robust effect. The current research examined the impact of a video remote confederate on young womens food intake. Experiment 1 examined the effect of an eating or non-eating video confederate. Participants (N=77 female undergraduate students, M age=20.29) were exposed to a same-sex video confederate (i.e., a 25 year old woman) who was modeling eating (i.e., 4 winegums; pastille-type sweets) or not eating (i.e. no food visible). Results indicated that participants exposed to the eating confederate did not eat more than participants exposed to the non-eating confederate. Experiment 2 was conducted to address some of the limitations of Experiment 1. In this experiment, participants (N=51, M age=20.43) were exposed to one of three intake conditions: No-eating (i.e. food visible but not consumed), Small portion-size condition (i.e., 8 M&Ms) or Large portion-size condition (i.e., 20 M&Ms). The same video confederate as in Experiment 1 modeled these three conditions. Results indicated that participants did not adjust their intake to that of a video model. The current findings provide preliminary evidence for the assumption that modeling only exists if people have clear indications about how much others have consumed in the same context (as was the case in previous modeling studies). Future research is needed to further examine this proposition.

Facing temptation in the bar: counteracting the effects of self-control failure on young adults' ad libitum alcohol intake

BACKGROUND AND AIMS The self-control strength model suggests that exertion of self-control leads to poorer subsequent self-control performance. Failure of self-control has been suggested as an important underlying mechanism of excessive drinking. This study tested the effects of self-control failure on ad libitum drinking, and the potential moderating role of glucose and self-awareness on this relationship. DESIGN The current research examined in two experiments whether the effects of self-control failure were different for males and females, and whether glucose (experiment 1) and self-awareness (experiment 2) would counteract the effects of self-control failure. A between-participants design with four conditions was employed in each experiment. SETTING A semi-naturalistic drinking setting in the form of a laboratory bar. PARTICIPANTS Undergraduate students recruited at Radboud University Nijmegen, the Netherlands (experiment 1: n = 106; experiment 2: n = 108). MEASUREMENTS The total amount of alcohol consumed during an experimental break (observational data) and questionnaire data on drinking patterns. FINDINGS Self-control failure led to increased levels of drinking in males (P < 0.05), whereas females drank less after being depleted (P < 0.01). Self-awareness, but not glucose, was found to counteract the effects of self-control failure among males (P < 0.05). CONCLUSIONS Self-control failure leads to increased drinking of alcohol in males and decreased levels of drinking alcohol in females. However, increasing self-awareness appears to be a promising strategy in facing the temptation to drink when cognitive resources to inhibit intake are low.