THE EFFECT OF CALORIE INFORMATION ON FOOD CONSUMPTION
The (over)consumption of calories is one of the most important determinants of the obesity
problem in Europe and the United States. Governments promote the consumption of
healthy alternatives and try to support consumers in making healthy choices, for instance by
the introduction of the Nutritional Labeling and Education Act (NLEA) in the United States .
The NLEA requires manufacturers to provide nutrition information on the packaging of
food products. In a similar vein, the European Commission is working on an updated
version of its regulation on food labeling, issued in December 2006. This regulation defines
specific nutritional profiles which the food industry must comply with in order to bear
nutrition or health claims. Hence, governments want to make sure that consumers get
reliable information on food and eventually make more healthy choices. Despite these
efforts, the obesity problem continues to increase in the United States and Europe.
Jonathan Wilson is a business student at Tilburg University. He has been interested in the
overconsumption of food ever since he has read Brian Wansink’s famous study with the
“bottomless bowls.” For this study, Wansink brought in 60 people for a free lunch and gave
22 ounce bowls of soup to half, while the other half unknowingly got 22 ounce bowls that
automatically refilled as they ate (by an unseen tube under the table). The result: those
eating from the bottomless bowls thought they’d eaten the same amount as people with
regular bowls. They actually consumed 73% more soup. “The lesson is, don’t rely on your
stomach to tell you when you’re full. It can lie,” Wansink reacted to the results of this study.
Together with his thesis supervisor, Donald Driver, Jonathan has developed a series of
studies on the effects of Nutrition Labels on people’s attitudes toward the product, buying
intentions, and the perceived healthiness of food products. The purpose of his latest study
was to determine how the provision of objective calorie information on healthy food items
influences people’s experience of hunger.
Jonathan has developed a first draft of the method section of this study, which is detailed
next. The method section of a paper provides the methods and procedures used in a
The experiment: predictions
We compared hunger ratings between participants who sampled a healthy food item
with calorie information versus participants who sampled a healthy food item
without calorie information versus a “no sample” condition. We predicted that those
who eat a healthy food item in the calorie information condition will subsequently
report that they feel hungrier compared to those who eat a healthy food item in the
no calorie information condition or those who do not eat the sample.
Participants and design. 90 undergraduate students (38 women) from Tilburg
University were randomly assigned to the conditions of a 3 (food sample: healthy
with calorie information vs. healthy without calorie information vs. no-sample)
between-subjects design. The participants ranged in age from 18 to 37, with a median
age of 22. The students received financial compensation (7 €) for their participation.
Procedure and Materials
Participants in the sampling conditions were recruited to participate in a taste test of
a Muesli/granola bar that was unwrapped and contained no identifying information.
Participants in the no-sample condition were invited to participate in a marketing
study rating the appearance of the bar. We asked all the participants in the sampling
conditions to taste a sample of the same bar. In the healthy food item with calorie
information condition, participants read that they were about to taste “a new health
bar containing 78 calories, high levels of vitamins and fiber, and no artificial
sweeteners.” In the healthy food item of vitamins and fiber, and no artificial
sweeteners.” Participants in these conditions then had a 10 gram sample of the bar.
Those in the no-sample condition did not complete the taste test.
Next, in order to assess the strength of the motive to fulfill their appetite, all
participants rated how hungry they were at the present moment (7-point scale; 1 =
not at all hungry, 7 = very hungry). Those in the no-sample condition rated their
hunger but did not complete the taste test beforehand. After providing their hunger
rating, they continued to rate how appealing they thought the bar was.
1. Is the purpose of Jonathan’s study exploratory, descriptive, or is hypothesistesting? Explain your choice.
2. Is Jonathan’s study causal or correlational in nature? Explain your choice.
3. What type of study is Jonathan’s study? Is it a field study, a field experiment, or
a lab experiment? Explain your choice.
4. What research strategy is Jonathan’s study? Explain your choice.
5. Based on your answer to question four, what data collection
method(s)/instruments can Jonathan use? Explain your choice.
6. What is the ‘unit of analysis’ of Jonathan’s study?
7. Is Jonathan’s study cross-sectional or longitudinal in nature?