Janneke C.A.H. Giesen

Food liking, food wanting, and sensory-specific satiety

Sensory-specific satiety refers to a temporary decline in pleasure derived from consuming a certain food in comparison to other unconsumed foods. It has been argued that such a reduction may not be limited to food liking but extends to food wanting as well. Animal research suggests that sensory-specific satiety reflects a reduction in both food liking and food wanting and in the present study it was investigated whether this also holds true for humans. Participants had to consume a certain amount of chocolate milk and afterwards approximately half of the participants played a game to obtain more chocolate milk, whereas the other half played a game to obtain crisps. Participants showed a decline in subjective liking of taste and smell of the chocolate milk in comparison to crisps. Furthermore, they showed less motivation (i.e. wanting) to obtain more chocolate milk. It is concluded that sensory-specific satiety in humans reflects a decrease in both food liking and food wanting.

Will work for snack food: the association of BMI and snack reinforcement.

It has been suggested that for overweight and obese individuals high‐calorie foods are more reinforcing than for normal‐weight individuals. It has already been shown that in contrast to sedentary activities, snack food is more reinforcing for obese women, relative to normal‐weight women. However, it is unclear whether overweight/obese individuals are more sensitive to the reinforcing value of food in general or more specifically to the reinforcing value of high‐calorie foods. This was tested in the present study, with overweight/obese and normal‐weight individuals performing a concurrent schedules task, which measures how hard someone is prepared to work for high‐calorie snacks compared to low‐calorie foods (e.g., fruits, vegetables), when both foods are equally liked. By gradually increasing the amount of work required to earn snacks, the relative‐reinforcing value of snacks was determined. As hypothesized, overweight/obese individuals work harder for high‐calorie snacks compared to normal‐weight individuals.

High tax on high energy dense foods and its effects on the purchase of calories in a supermarket. An experiment

The present study examined whether a high tax on high calorie dense foods effectively reduces the purchased calories of high energy dense foods in a web based supermarket, and whether this effect is moderated by budget and weight status. 306 participants purchased groceries in a web based supermarket, with an individualized budget based on what they normally spend. Results showed that relative to the no tax condition, the participants in the tax condition bought less calories. The main reduction was found in high energy dense products and in calories from carbohydrates, but not in calories from fat. BMI and budget did not influence the effectiveness of the tax. The reduction in calories occurred regardless of budget or BMI implying that a food tax may be a beneficial tool, along with other measures, in promoting a diet with fewer calories.

Exploring how calorie information and taxes on high-calorie foods influence lunch decisions

BACKGROUND The potential combined effects of public policy tools-such as calorie information and taxes on highly caloric foods-on purchasing behavior are rarely studied. Furthermore, these tools are rarely studied in the context of individual differences (eg, dietary restraint), which may play a key role in their effectiveness. OBJECTIVE The current study tests the combined effects of providing calorie information and increased taxes on the total number of calories purchased for lunch. Furthermore, these public policy tools were investigated in the context of high- and low-restrained eaters. DESIGN University students (n = 178) had to choose lunch from a menu 3 different times. The prices for the high-calorie foods on the menu increased each time (125% and 150% of base price). In addition, there were 3 between-subject factors: budget (high compared with low), calorie-information (calorie information compared with no calorie information), and dietary restraint. RESULTS Elasticity analyses show a tax × calorie information interaction. A price increase for the high-calorie foods reduced the percentage of calories chosen for lunch but only in the absence of calorie information. CONCLUSIONS A tax of ≥25% on high-calorie foods may decrease the demand for calories and could be a good policy measure to decrease the prevalence of obesity. However, calorie information seems to interfere with the effect of a tax on high-calorie foods.

Weight, gender, and snack appeal

In this study, we hypothesized that overweight/obese persons have an exaggerated approach tendency toward high calorie foods. Testing this hypothesis, a stimulus response compatibility (SRC) task was used to assess approach-avoidance tendencies toward food in both overweight/obese participants (n=42), and normal weight controls (n=46). The SRC task is a reaction time task measuring how fast one approaches and avoids pictures of food and non-foods according to given instructions. It was found that overweight/obese men are slower at avoiding particularly high calorie snack foods. But this does not appear to be the case for overweight/obese women who showed nearly as fast avoidance as approach toward the high calorie food cues. It is concluded that overweight/obese women, rather than men, are ambivalent toward high calorie foods, which is the likely result of high dietary restraint.

Cue reactivity during treatment, and not impulsivity, predicts an initial lapse after treatment in alcohol use disorders

Both cue-elicited craving and impulsivity have been involved in alcohol misuse. However, their role in relapse has not been very clear. In the present study, we ask whether cue-elicited craving, impulsivity, and their interaction term predict a lapse in problem drinkers. Participants (n=20) were former patients of the clinic, U-Center, in the Netherlands, who had completed a six-week alcohol treatment program and had an abstinence goal. While in treatment, they underwent a cue exposure paradigm in a real alcohol-related setting and their trait impulsivity was measured with the Barratt Impulsiveness Scale version 11 (BIS-11). During the follow-up assessment, patients were contacted again and asked about their alcohol drinking behavior during the first three months after the end of the treatment program. It was found that higher craving and lower trait impulsivity levels are associated with a higher probability of a lapse.

Substituting Snacks With Strawberries and Sudokus: Does Restraint Matter?

OBJECTIVE Prior research demonstrates that fruit/vegetables and sedentary activities can serve as substitutes for high-calorie snack foods, when the behavioral costs for obtaining snack food increase. The current study investigated if fruit/vegetables are better substitutes for snacks than sedentary activities are and whether individual differences in dietary restraint play a role in how snacks are being substituted. DESIGN Participants (n = 59) performed a concurrent schedules task, in which fruit/vegetables, sedentary activities, and snacks were simultaneously available. The response requirement for earning snacks increased per trial. Afterward, dietary restraint was measured. MAIN OUTCOME MEASURES The amount of responses for snacks per trial and the amount of points earned for fruit/vegetables and sedentary activity per trial. RESULTS When snacks are harder to obtain, participants increased working for both fruit/vegetables and sedentary activities. No differences were found for dietary restraint in the way snacks were substituted. However, high-restrained participants worked harder for snack foods than low-restrained participants. CONCLUSION Fruit/vegetables and sedentary activities are both equally viable substitutes for high-calorie snacks. High-calorie snacks have a higher reinforcing value for highly restrained eaters.

Changing the default. How to promote healthier food choices

The current environment promotes overeating, hence contributing to the rapid increase in obesity prevalence. To curb the obesity epidemic, it is important that people make healthier food choices. Lately more researchers and health professionals have argued for obesity policy. A public policy tool rising in popularity is ‘nudging’. The goal of nudging is to alter people’s choices without taking any alternatives away. This can be achieved by making small changes in the environment. One example of a nudge is changing the default. Changing the default option can markedly change one’s choice behaviour. Whether this nudge is also effective regarding food choice behaviour is not that clear yet. In an online study, participants were asked to choose a hamburger from a menu. After choosing the hamburger they were randomly divided over three conditions regarding the side dish they received. In the first condition participants received by default a large portion of fries. In the second condition participants received by default a small portion of fries, and in the third condition participants could choose between the two portion sizes. In both the first and second condition participants were given the option to switch to the other portion size. Results showed that especially when hungry, participants choose the side dish that was presented as the default more often. This suggests that a default change may indeed help people make healthier food choices.

Will work less for food: Go/No-Go training decreases the reinforcing value of high-caloric food

Consistently inhibiting responses to palatable food stimuli increases motor suppression for those stimuli and reduces their hedonic value, suggesting a close link between motor inhibition and food reward. The current study aimed to investigate whether GNG training also reduces the motivational, reinforcing value of palatable, high-calorie food. Participants completed either GNG training for high-calorie food or a control task. This was followed by a Concurrent Schedules Task (CST) to measure the reinforcing value of high-calorie food. As hypothesized, participants in the GNG condition showed reduced high-caloric food reinforcement, as indexed by the number of key presses participants were willing to execute to obtain the food, compared to the control condition. This difference between GNG and control, however, was only significant when the response requirement to obtain high-calorie food was high. These results suggest that GNG training not only reduces hedonic food value but also the motivational, reinforcing value of food.

Working for snack food: The role of dietary restraint

The relative reinforcing value of snack food can be studied with a concurrent schedules task. In such a task, participants have the option to work for credits for either snack food or, e.g. fruit and vegetables. By increasing the price of snack food (i.e., the amount of work required for snack credits) one may determine at what point the participant stops working for this option. One factor thought to affect the relative reinforcing value of food is dietary restraint. Restrained eaters are concerned about their weight and, therefore, try to limit their intake of snack foods, but often fail in their attempts to restrict snack consumption. Successful dieting appears to require adherence to a strict set of dieting rules. We hypothesised that without such rules restrained eaters are more prone to work for snack food. Indeed, results show that restrained eaters work harder for snack foods as compared to unrestrained eaters and current dieters.