Portion size: A qualitative study of consumers’ attitudes toward point-of-purchase interventions aimed at portion size

Department of Health Sciences.he EMGO Institute for Health and Care Research, Faculty of Earth and Life Sciences, VU University Amsterdam, De Boelelaan 1085, 1081 HV Amsterdam, The Netherlands.
Health Education Research (Impact Factor: 1.66). 09/2009; 25(1):109-20. DOI: 10.1093/her/cyp051
Source: PubMed
ABSTRACT
This qualitative study assessed consumers' opinions of food portion sizes and their attitudes toward portion-size interventions located in various point-of-purchase settings targeting overweight and obese people. Eight semi-structured focus group discussions were conducted with 49 participants. Constructs from the diffusion of innovations theory were included in the interview guide. Each focus group was recorded and transcribed verbatim. Data were coded and analyzed with Atlas.ti 5.2 using the framework approach. Results showed that many participants thought that portion sizes of various products have increased during the past decades and are larger than acceptable. The majority also indicated that value for money is important when purchasing and that large portion sizes offer more value for money than small portion sizes. Furthermore, many experienced difficulties with self-regulating the consumption of large portion sizes. Among the portion-size interventions that were discussed, participants had most positive attitudes toward a larger availability of portion sizes and pricing strategies, followed by serving-size labeling. In general, reducing package serving sizes as an intervention strategy to control food intake met resistance. The study concludes that consumers consider interventions consisting of a larger variety of available portion sizes, pricing strategies and serving-size labeling as most acceptable to implement.

Full-text

Available from: Willemijn M Vermeer
Portion size: a qualitative study of consumers’
attitudes toward point-of-purchase interventions
aimed at portion size
Willemijn M. Vermeer*, Ingrid H. M. Steenhuis and Jacob C. Seidell
Abstract
This qualitative study assessed consumers’
opinions of food portion sizes and their atti-
tudes toward portion-size interventions located
in various point-of-purchase settings targeting
overweight and obese people. Eight semi-struc-
tured focus group discussions were conducted
with 49 participants. Constructs from the diffu-
sion of innovations theory were included in the
interview guide. Each focus group was recorded
and transcribed verbatim. Data were coded and
analyzed with Atlas.ti 5.2 using the framework
approach. Results showed that many partici-
pants thought that portion sizes of various
products have increased during the past deca-
des and are larger than acceptable. The major-
ity also indicated that value for money is
important when purchasing and that large por-
tion sizes offer more value for money than small
portion sizes. Furthermore, many experienced
difficulties with self-regulating the consumption
of large portion sizes. Among the portion-size
interventions that were discussed, participants
had most positive attitudes toward a larger
availability of portion sizes and pricing strate-
gies, followed by serving-size labeling. In gen-
eral, reducing package serving sizes as an
intervention strategy to control food intake
met resistance. The study concludes that con-
sumers consider interventions consisting of
a larger variety of available portion sizes, pric-
ing strategies and serving-size labeling as most
acceptable to implement.
Introduction
The prevalence of overweight and obese people is
drastically increasing worldwide [1]. One of the
main factors underlying the curren t obesity epi-
demic is an obesogenic environment that promotes
an excessive food intake and discourages physical
activity [2, 3]. Glanz et al. [4] have identified the
consumer nutrition environment as a resear ch pri-
ority in combating the obesity epidemic.
Portion sizes, that is the sizes in which food is
offered and immediately consumed, and consumer
units, that is the entity in which a product is sold, of
energy dense foods have increased during the past
three decades in both the United States and Europe.
Nowadays, portion sizes are in many cases larger
than reference portion sizes as defined by US fed-
eral agencies [5].
Large portion sizes of energy dense food are
problematic because they can lead to increased con-
sumption. There is empirical evidence to support
the position that large portion sizes enhance con-
sumption in the case of amorphous food [6, 7],
prepackaged food [8, 9], prepor tioned units [10]
and even for food with a relatively unfavorably
perceived taste [11]. The increased energy intake
due to larger portions is not adequately compen-
sated for at a later time [12]. The tendency to eat
more when served larger portions has been found
regardless of individual characteristics, such as
Department of Health Sciences and the EMGO Institute for
Health and Care Research, Faculty of Earth and Life
Sciences, VU University Amsterdam, De Boelelaan 1085,
1081 HV Amsterdam, The Netherlands
*Correspondence to: W. M. Vermeer. E-mail:
willemijn.vermeer@falw.vu.nl
HEALTH EDUCATION RESEARCH Vol.25 no.1 2010
Pages 109–120
Advance Access publication 11 September 2009
Ó The Author 2009. Published by Oxford University Press. All rights reserved.
For permissions, please email: journals.permissions@oxfordjournals.org
doi:10.1093/her/cyp051
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Page 1
body mass index (BMI), or a tendency toward di-
etary restraint or disinhibition [7, 8, 10, 12]. One
explanation for increased consumption of large por-
tions is the notion of value for money [9]. A low
price per unit in the case of large portions stimulates
purchase and leads , subsequently to increased con-
sumption of a given product [9].
Portion sizes seem to be a valid starting point for
the development of various environmental interven-
tions directed at the prevention and treatment of obe-
sity. Ledikwe et al. [13] identify a number of
interventions targeted at portion size, including of-
fering consumers a larger variety of portion sizes in
order to give consumers the option to choose smaller
portion sizes than the current standard sizes, reduc-
ing portion sizes in order to counter the trend toward
upsizing food products and labeling serving sizes.
Serving-size labeling identifies the number of recom-
mended servings a package or portion consists of,
combined with caloric information per serving.
Serving-size labeling aims to tackle portion distor-
tion, a phenomenon that can be described as perceiv-
ing large portion sizes as appropriate amounts to eat
at a single eating occasion. Research has shown that
portion distortion unfavorably affects portion sizes
that people select [14]. Serving-size labeling is com-
mon in supermarket food products in some coun-
tries, such as the United States and Australia, but
not in Europe. Furthermore, serving-size labeling
could be expanded to other point-of-purchase set-
tings such as fast-food restaurants, worksite cafete-
rias and recreational settings such as cinemas.
Nielsen and Popkin [15] added to the list of pos-
sible interventions by proposing that portion size
should be controlled using pricing strategies, so as
to prevent pushing consumers toward purchasing
financially more attractive large portions. This can
be done by establishing more proportional prices for
small and large portions instead of value-size pricing
or by offering consumers the possibility to deter-
mine their own portions and pay by weight without
advantaging prices of large quantities.
Although it is assumed that interventions aimed
at portion size can be effective in reducing people ’s
energy intake, to our knowledge no community-
based intervention studies aimed at portion size
are available to date. The feasibility of such inter-
ventions has not been assessed, either. This study
will focus on interventions located in point-of-pur-
chase settings, that is settings where food is sold.
Supermarkets, fast -food restaurants, worksite cafe-
terias and cinemas are point-of-purchase settings
that are taken into account in this study.
The feasibility of point-of-purchase interventions
aimed at portion size depends not only on the will-
ingness of the settings to implement them but also
on the willingness of consumers to accept them.
According to McIlveen [16], consumer attitudes
are important factors in food product development,
and point-of-purchase settings base many corporate
decisions on them. In addition, a longi tudinal study
[17] showed a positive relationship between con-
sumer satisfaction, for example with respec t to the
food that was offered, and company profits in a US
fast-food restaurant chain. A first step in assessing
the feasibility of interventions aimed at portion size
and the purpose of this qualitative study is to reveal,
therefore, what a general group of Dutch consumers
varying in socioeconomic status think of current
portion sizes, their acceptance of interventions
aimed at portion size and under what condition s
they would endorse such interventions.
Methods
Participants and procedure
Focus group discussions were chosen for data col-
lection as they stimulate interaction between partic-
ipants, which enhances the generation of new ideas
[18]. Eight focus groups, with between five and
eight participants in ea ch, were held with a total
of 49 participants in both urban and rural regions
in the Netherlands. Each focus group discussion
lasted for approximately 2 hours. Procedures pro-
posed by Morgan and Krueger [19], for example
concerning participant recruitment and moderation
strategies, guided the organization and moderation
of the focus group discussions.
Before the start of each focus group, parti cipants
were asked to complete a short questionnaire con-
taining questions about their age, sex, profession,
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height and body weight. Participants were recruited
by means of announcements in local newspapers,
on radio, on the Internet, in community centers, in
supermarkets and in libraries. This variety of infor-
mation channels was used in order to reach a broad
audience. The recruitment announcements said that
the focus group discussion topics would be con-
sumer opinions about the food supply in point-of-
purchase settings. People younger than 18 years
and older than 65 years were excluded from partici-
pating. The study results were analyzed on an anon-
ymous basis. This study was deemed exempt by the
VU University Medical Center Institutional Review
Board.
Theoretical framework
According to Rogers [20], an innovation is an idea,
practice or object that is perceived as new by an
individual—consumers, in the case of this
study—or other unit of adoption. Interventions
aimed at portion size can be considered innova-
tions. The diffusion of innovations theory (DOIT)
states that the implementation of an innovation
among the general public is a challenge and is
partly dependent on the attributes of an innovation
[20]. In this study, DOIT was applied to consumer
behavior, which means that we wanted to assess
whether consumers would accept such interven-
tions. The DOIT attributes were discussed in light
of the consumers’ viewpoints regarding their poten-
tial use of portion-size interventions in point-of-
purchase settings. Because consumers, as opposed
to an organization, were the unit of adoption, not all
DOIT attributes were considered relevant. Within
the scope of this study, the following three attrib-
utes were incorporated into the interview guide.
The first attribute was relative advantage, that is
the degree to which an innovation is perceived as
better than the idea it supersedes. The second attri-
bute was complexity, which is the degree to which
an innovation is perceived as difficult to understand
and use, and the third attribute was the time it takes
to use the innovation.
In addition to how participants perceived the
attributes of interventions aimed at portion size, that
is offering a larger variety of portion sizes, portion
size reduction, pricing strategies and serving-size
labeling, barriers that would prevent consumers
making use of portion-size interventions were dis-
cussed during the focus group discussion.
Interview topics
The focus group discussions were conducted in
Dutch and started with participants providing opin-
ions of current portion sizes and their consumption
patterns related to large portion sizes. Subse-
quently, the different portion-size interventions
were discu ssed. For each intervention, participants
expressed their perceptions of its attributes, such as
relative advantages, complexity and time. Lastly,
participants’ opinions regarding portion-size inter-
ventions in general were discussed.
The focus group discussions followed a semi-
structured format and participants were asked to
discuss the different topics and share their opinions.
Each focus group discussion started with a short
introduction. Table I provides an overview of the
interview topics. The discussion was structured
around five topics that were related to portion sizes
and possible interventions. After each topic, the
moderator asked participants if there were any
remaining issues to be discussed. If not, the mod-
erator introduced the next topic.
Data analysis
Focus group discussions were held until data satu-
ration was reached. Data saturation was defined by
a quotation count displaying a list of codes per in-
terview. Subsequently, a percentage was calculated
from the total number of codes that were generated
from all interviews (i.e. 130). The cumulative per-
centages showed that, after the sixth discussion,
almost 80% of the new codes were generated, and
around 95% after the seventh interview. During the
last discussion, no significant new information was
revealed. The method that was used to define data
saturation has been described by Guest et al. [21].
Each focus group was recorded and transcribed
verbatim. The framework approach, which is
especially suitable for policy-relevant qualitative
research, was used to analyze the data [22]. The
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framework approach starts deductively from preset
theoretical background and objectives but also uses
inductive analysis to reflect the original discussions
[22]. The analys is consisted of several phases and
started with familiarization with the data through
reading the transcripts. After that, a thematic frame-
work was identified in two steps:
(i) deductively (by using the intervention attributes
and types of barriers that were determined be-
forehand) and
(ii) inductively (by identifying additional themes
derived from the data).
Next, the quotes were indexed using this the-
matic framework. The last phase in analysis con-
sisted of rearranging the data per theme and
interpreting and summarizing it. Analysis was per-
formed using the software package Atlas.ti version
5.2 (Atlas.ti Scientific Software Development
GmbH, Berlin, Germany).
Results
In total, 49 respondents (11 men and 38 women)
participated in the foc us group discus sions (mean
age = 47.1 years, SD = 12.4, mean BMI = 23.5,
SD = 3.6). Based on self-reported height and body
weight, 64.6% (n = 31) had a normal body weight
(BMI 18.5–24.99), 29.2% (n = 14) were over-
weight (BMI 25.00–29.99) and 6.3% (n =3)were
obese (BMI > 30.00). In the general Dutch popu-
lation, 34.3% are overweight and 11.2% obese
[23].
Occupations were used as an indicator for socio-
economic status. Participants’ occupational level
was measured with the International Socio-Eco-
nomic Index [24]. This index categorizes different
occupations ranging from 10 (low prestige) to 90
(high prestige). The occ upation of each participant
was looked up in this index and coded. In this sam-
ple, scores ranged from 30 to 82 (mean = 56.26,
SD = 13.04) and were considered representative of
the Dutch population.
Table I. Main interview topics
Purchase and consumption patterns related to
portion size
What is your opinion about current portion sizes in different
point-of-purchase settings?
What do you think of the value-for-money ratio between
small and large portions and does value for money guide
your purchasing behavior?
How do you deal with large portion sizes and consumption
units?
Attitudes toward the attributes of point-of-
purchase interventions aimed at portion size
(i.e. a larger variety of portion sizes, reduction
of portion sizes, pricing strategies and
labeling of serving sizes)
What are the (dis)advantages of this intervention and how
important are they? (relative advantage)
Would it be complex to use this intervention and how
important is this? (complexity)
Would it be time consuming to use this intervention and how
important is this? (time)
What factors would prevent you from using this
intervention? (barriers)
What settings are suitable for this intervention?
General opinion of portion-size interventions Would portion-size interventions cater to your personal
needs?
Would portion-size interventions help combating obesity?
Which interventions aimed at portion size would you
suggest?
How do you think that interventions aimed at portion size
should be communicated to the general public?
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Opinions about current portion sizes in
various point-of-purchase settings
In general, participants stated that portion sizes
have increased during the past decades and are, in
their opinions, larger than required. A number of
specific products were mentioned in particular:
candy bars; sweets; soft drinks; potat o chips; pop-
corn and the increased prevalence of all-you-can-
eat restaurants, where people can eat as much as
they want for a fixed price. It was also mentioned
that many companies advertise products with large
portions, suggesting that they are the norm. Partic-
ipants mentioned the following points about con-
sumer units in supermarkets. First, according to the
participants, discount supermarkets sell mainly pre-
packaged and large consumer units that are more
suitable for families than for single- or two-person
households. Second, many consumers noticed that
packages of potato chips, cookies, soft drinks and
ice cream have become larger in the past years.
Furthermore, participants believed that, in restau-
rants, portions sizes are larger than the portions they
serve themselves at home. In addition, participants
noticed that in restaurants, small portions of vegetables
are served compared with the portions of meat. A ma-
jority of the participants thought that in fast-food res-
taurants, portion sizes have increased and are too large.
Some participants stated that there is a choice in portion
size, although they also observed that large portions
offer more value for money than small portions. With
respect to worksite cafeterias, participants were satis-
fied with portion sizes, as in general consumers were
offered the opportunity to define their own portions. At
the cinema, many participants considered the portions
of popcorn as extremely large, although others said that
there is a choice. A last aspect that was mentioned in
relation to portion size was that some participants
experienced portion distortion. One woman said:
I think that sometimes we have lost sense of what
a normal portion size is. Actually, I think that I
don’t know what it is.
Other participants added that large portion sizes
have become the norm and that when they saw di-
etary portion-size recommendations, they seemed
very small to them.
Value for money and portion size
Participants indicated almost unanimously that
large portion sizes usually offer more value for
money than small portion sizes. The fact that in
supermarkets, generic brands are regularly sold in
large consumer units, added to this. Furthe rmore,
most participants indicated that value for money is
quite a strong guide toward buying larger portions.
One woman commented:
Consider McDonalds for instance. There you
have a medium-sized menu and a mega menu,
and the price differences between those meals are
quite small. I don’t have specific information, but
the mega menu is really mega! And I am easily
tempted to choose the mega menu, because the
price difference is small, while. I don’t need
that mega menu at all, but it is tempting to buy
it. Simply because you get more value for your
money.
However, a minority said that their purchase
decisions, sometimes as a result of experience, are
guided by their needs and absolute prices and not
by optimizing value for money. The fact that larger
portions and consumer units of food offer more
value for money seemed to occur to the participants
as a natural economic pattern.
Consumption behavior with respect to large
portion sizes
Three types of reactions can be discerned from the
question of how participants dealt with large por-
tion sizes and consumer units. First, for many par-
ticipants, the amount they ate was guided mainly by
portion size and, to a lesser extent, by an internal
satiety cue. This was especially the case with tasty
products such as potato chips, candies or cookies.
One woman said, for instance:
For me, it [participant is referring to portion size]
makes a difference. So, if I buy a king-size candy
bar, then I finish that king-size candy bar. And
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no, I definitely don’t quit eating before the last
bite, rewrap it and store it in the fridge. And when
I do try that, I end up finishing it ten minutes later
Second, some people expressed difficulties too in
relying on internal satiety cues, but they attempted
to regulate the amount they ate deliberately by de-
termining a certain portion size, and stocking the
remainder. One woman said, for instance:
When we are not at home and our children want
to eat potato chips, each of them takes one bowl.
Then they close the bag with a clip.
Although some people were aware that it is the-
oretically possible to deliberately regulate portion
sizes in this manner, they finished up not doing this,
as one woman illustrated:
I think bags of potato chips are too big. Of course
you can close the bag., but in reality that
doesn’t happen, especially not when the children
are around. I think that when they would de-
crease the bag, you would also finish it, but
you wouldn’t open another one.
Third, some participants said that the amount
they ate uniquely depended on their feelings of sa-
tiety and not on the portion size. A male participant
stated:
Well, I think that I have a built-in alarm clock. I
don’t know what it is. For example, when I
have. let’s say a candy bar, after a while, I just
lose my desire for sweets. Then I am satiated.
For those who indicated that they were guided by
portion size and not by an internal satiety cue, it
seemed that the decisional moment regarding the
amount they ate was ahead of eating. At purchase,
when deciding whether or not to open a package, or
during cooking, participants found it easier to reg-
ulate the amount they ate than once it was served.
Participants stated that not until they had finished
eating, did they realize that a smaller quantity of
food would have been enough. One woman stated:
I never get the feeling that I am full, so I can eat
large quantities. If I would get just a little, it
would be enough, but if I get a lot I finish it just
as easily.
Perceived attributes of portion-size
interventions
This section describes participants’ attitudes toward
the different point-of-purchase interventions aimed
at portion size. An overview is provided in Table II.
A larger availability of portion sizes
Participants’ perceived many relative advantages
with respect to a larger availability of portion sizes.
Participants appreciated having the opportunity to
choose. Another advantage was that less food is
wasted and that the specific needs of different con-
sumers (e.g. men and women) could be catered for.
In addition, some thought that a larger variety of
portion sizes would render them more conscious
about the amount they ate. A disadvantage that par-
ticipants mentioned was that, especially in super-
markets, more package material would be
necessary, which had adverse environmental con-
sequences.
A condition that some participants mentioned was
information provision at the moment of choice in
order to make an informed decision. For instance,
if small, medium and large sizes would be available
in fast-food restaurants, objective and specific infor-
mation about the quantity, such as grams, milliliters
or a displayed example of each portion size, was
desired. According to the participants, suitable set-
tings for a larger variety of portion sizes or consumer
units were fast-food restaurants and supermarkets.
Reducing portion sizes
A theme that emerged from the focus group discus-
sions was that a distinction should be made between
explicit, that is noticeable for consumers and
therefore relatively large, and implicit, that is not
noticeable for consumers and therefore limited por-
tion-size reduct ions. We asked participants what
products and the extent to which they were suitable
for implicit portion-size reduction. Participants
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mentioned pizzas, candy bars and pancakes served
in restaurants. According to some, the portion sizes
of these products could be reduced by 15–30%.
With respect to explicit portion-size reduction of
all availa ble sizes, most respondents were reserved
and perceived disadvantages. Most importantly,
participants were afraid that this intervention would
reduce their control over their food intake. Also,
a substantial proportion of the participants consid-
ered this intervention as paternalistic.
Pricing strategies
Proportional pricing of small and large
portions. According to many, proportional pricing
of small and large portions would be an attractive,
not a paternalistic, intervention. An advantage of
removing value-size pricing of large portions would
be that consumers could choose the portion size
they actually wanted, instead of being directed to-
ward larger quantities. Participants also mentioned
that it would be fairer toward consumers if small
portions were to be more attractively priced.
For large households, on the other hand, propor-
tional pricing of consumer units sold in supermar-
kets would not be attractive. In addition, some
participants distrusted the motives of companies
using pricing strategies. According to these partic-
ipants, the only motive for companies to use pricing
strategies could be to make a profit; otherwise, such
an intervention would not be feasible. Furthermore,
some thought that this pricing strategy would lead
them to buy several small portions instead of one
large portion. Consumers suggested worksite cafe-
terias and fast-food restaurants as suitable settings.
Table II. Perceived attributes of point-of-purchase interventions aimed at portion size
Interventions Relative advantages Relative
disadvantages
Complexity/time Barriers/condition Suitable settings
A larger variety of
portion sizes
Opportunity to
choose; caters to
individual needs; not
paternalistic; less
waste of food
More packaged
material
No consensus Lack of adequate
information
Fast-food
restaurant,
supermarket and
worksite cafeteria
Explicit portion-
size reduction
Counters trend toward
upsizing
Paternalistic;
limitation of
freedom
Not relevant None
Proportional prices Not paternalistic; not
being pushed toward
large portions; fair
Distrusting
corporate motives;
unattractive for
large households;
could lead
consumers to buy
several small
portions
Not relevant Not relevant Worksite cafeteria
and fast-food
restaurant
Possibility to
determine own
portion and pay by
weight
Fair; being in control;
less waste of food
Hygiene and
freshness
Difficult to decide
appropriate
quantity; queues
Supermarket and
worksite cafeteria
Serving-size
labeling
Practical; enhances
consciousness; being
informed at point of
purchase
Risks being
paternalistic;
information that is
not tailored to
consumers’
individual
situations;
confronting
More complex
(only in the
beginning)
Comprehensibility;
position and
readability; tone
should not be to
paternalistic
Supermarket, fast-
food restaurant
and worksite
cafeteria
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Offering consumers the possibility to determine
their portion size and pay per weight. Participants
mentioned a number of relative advantages of of-
fering consumers the possibility to determine their
portion size and pay per weight without discounting
larger quantities, for instance, in supermarkets or
when eating away from home. Those advantages
partly corresponded with the advantages that were
already mentioned for pricing strategi es. In addi-
tion, according to the participants, less food would
be was ted. Lastly, some thought that it would be fun
to determine their own portions and pay by weight.
However, others thought that, when dining out, this
intervention would lead to an unpleasant and un-
sociable dining experience. They preferred to be
served and surprised abo ut the presentation of a dish
when dining out. With respect to supermarkets, es-
pecially, diminished hygiene and freshness wer e
disadvantages that participants mentioned.
For many participants, complexity was an impor-
tant issue. Some thought that it would be difficult to
decide how much food would be an appropriate
quantity, that is to meet their energy requirements.
A last aspect that was mentioned was that this in-
tervention would be time consuming due to longer
queues in point-of-purchase settings.
Participants felt that worksite cafeterias woul d be
appropriate settings for this type of intervention.
Labeling. Some participants would appreciate
serving-size labeling, so as to be informed about
appropriate consumpti on quantities. Another ad-
vantage participants identified was that relevant in-
formation was provided at the moment of making
food purchase decisions. Participants emphasized
the importance of readable and visible presentation
of the labels. A complicating factor according to the
participants was how information could be made
suitable, relevant and correct for different individ-
ual consumers (i.e. the appropriate serving size
depends on the amount of physical activity, age,
sex). Some preferred information about the content
of the foods, rather than about reference quantities.
A number of participants expressed the opinion
that information about serving sizes woul d be pa-
ternalistic and emphasize health too much. In con-
trast, other consumers thought that informing
consumers would leave the ultimate choice to the
consumers and was, therefore, not paternalistic.
With respect to time and complexity, participants
mentioned that in the beginning reading and inter-
preting the serving-size labels would take some ex-
tra time and effort, but that, after a while, consumers
would get used to it. According to the participants,
supermarkets, fast-food restaurants and worksite
cafeterias would be suitable settings for serving-
size labeling. Restaurants were not considered ap-
propriate settings, as going out for dinner should be
enjoyable and not related to health and obesity.
General opinions with respect to
portion-size interventions
Many participan ts supported portion-size interven-
tions not because they perceived them as personally
relevant but because they thought that they would
help combating obesity in the Netherlands. A topic
that emerged during the focus group discussions
was that some asserted that how much one eats is
an individual responsibility and that it would be
paternalistic if the government interfered too much
with this. For instance, one woman stated:
At the market place for instance. At 10 in the
morning you can see people who are just calmly
eating their French fries. Then I think, well of
course you get fat, that’s what you can expect.
The government doesn’t have to deal with that.
Participants who were against gove rnmental in-
terference considered freedom of choice important
and feared more regulation. Others stated that as
a result of marketing and advertising, people have
difficulties in regulating their food intake and that
producers have to take up their responsibility. Some
participants thought that the government has a role
in establishing a balance between commercial inter-
ests and providing a healthy consumer nutrition
environment. Those participants stated that it could
not be expected from companies to self-regulate
portion sizes because the market economy did not
allow them to. Furthermore, some participants
thought that some (paternalistic) interference was
justified by the high societal costs caused by
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obesity. In general, most participants agreed that
consumers have an individual responsibility in reg-
ulating their food intake but that they should be
provided with sufficient information and ch oice.
Interventions suggested by participants
Participants suggested a few possible interventions.
One suggestion was to offer consumers in restau-
rants the possibility to choose their servings of
meat, vegetables and sauce. In this manne r, con-
sumers would have the option to order a large serv-
ing of vegetables and small servings of meat and
potatoes. A second suggestion was offering con-
sumers in restaurants the possibility to obtain
take-out bags with the leftovers, something that is
not customary in the Netherlands. A final sugges-
tion that was given was reducing plate sizes so as to
provide consumers with a visual cue and, therefore,
with a norm toward smaller portions.
Communication of interventions
Participants did not reach a consensus about effec-
tive communication strategies concerning portion-
size interventions. Some stated that it was necessary
to explain the reasons for implem enting portion-
size interventions and that obesity should be men-
tioned in this respect. Others opposed the notion
that, in general, consumers were not health ori-
ented, and communicating health aspects of an in-
tervention would not appeal to them, therefore.
Furthermore, in the eyes of many participants, inter-
ventions aimed at portion size would have adverse
effects on value-for-money perceptions. According
to consumers, therefore, smaller portions should
have lower prices, and communication of interven-
tions aimed at portion size should be guided by
financial arguments and not by health-related ones.
Discussion
From the eight focus groups that were held with
various consumers, the following can be concluded.
First, according to the participants, portion sizes
and consum er units of certain energy dense food
products, for example candy bars, sweets and soft
drinks, have increased and are large r than accept-
able. Second, participants observed that large por-
tion sizes and consumer units have a better value-
for-money ratio than small ones. Third, participants
seemed to experience portion distortion.
With respect to the specific interventions aimed
at portion size, it seems that consumers have a pref-
erence for a larger variety of portion sizes, com-
bined with pricing strategies and serving-size
labeling that does not have a paternalistic tone. Par-
ticipants mentioned many relative advantages and
few complexity and time constraints related to these
three interventions. According to the diffusions of
innovations theory [20], this increases consumers’
receptiveness toward these interventions.
The results, with respect to serving-size labeling,
are in line with a study among 79 American fast-
food restaurant patrons that indicated that 62.1%
somewhat or strongly supported nutrition labeling.
However, in this same study, only 34.2% somewhat
or strongly supported a law affecting prices on
small and large size food portions [25], an interven-
tion that was appreci ated by respondents in our
study. The difference in acceptance of proportional
pricing might be explained by the sample: fast-
food restaurant patrons versus a general group of
consumers.
Furthermore, participants seemed to be aware of
the problem of obesity with which our society is
confronted, which explains why their general atti-
tude toward portion-size interventions was positive.
Yet, in general, participants did not feel personally
confronted with obesity and in need of interven-
tions aimed at portion size. As more than one-third
of the participants were overweight or obese, this is
remarkable. However, this finding can be explained
by previous research showing that one-quarter of
people with a BMI between 25 and 30 underesti-
mate their body weight and perceive their body
weight as healthy [26].
During the focus group discussions, an inte rest-
ing topic with respect to self-regulation of large
portion sizes emerged. Some consumers seemed
to be aware of the fact that large portion sizes of
flavorsome food increases consumption. As a result,
they attempted to regulate their consumption
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beforehand, for example at the point of purchase or
before opening a package, instead of during con-
sumption, which was considered more difficult. An
important opportunity for self-regulation is at the
moment of purchase, therefore, when a choice can
be made for smaller portion sizes or consumer units.
However, self-regulation at the time of purchase is
impeded by value-size pricing that guides consum-
ers toward buying large quanti ties. All in all, self-
regulating consumption is hindered at purchase
through the value-for-money principle and ham-
pered at consumption through large portion sizes
providing consumers with a visual cue and tempta-
tion that is difficult to resist. It should be noted that
consumers tend to perceive ‘value’ as a short-term
attribute. In the long term, a healthy body weight is
of more value to many people than a lower price per
unit for large portion sizes. However, often people’s
choices are guided rather by proximal than distal
considerations. This is one of the biggest challenges
of health-promoting intervent ions in general.
The last important issue that emerged during
nearly every focus group discussion was whether
obesity, and therefore, portion size, was an indi-
vidual, corporate or governmental responsibility.
Participants did not reach full consensus on this
topic. Some felt very strongly that governmental
initiatives with respect to such interventions are
paternalistic. This corresponds with a broad na-
tional and international societal debate concerning
public health policies [27]. Participants who held
this opinion indicated that they woul d perceive cor-
porate initiatives as less paternalistic than legisla-
tive actions. However, when interventions aimed at
portion size were initiated by producers, some par-
ticipants would feel deceived. According to parti-
cipants, it is not lucrative for companies to sell
smaller portions for substantially lower prices.
They were inclined, therefore, to distrust motives
of companies that implement interventions aimed at
portion size. In general, most participants agreed
that consumers have an individual responsibility
for their food intake but that they should be pro-
vided with sufficient information and choice.
A limitation of this study was the recruitment of
participants, which is likely to have led to a self-
selection of participants who were interested in issues
related to food supply and eating behavior. Neverthe-
less, this study has provided important insights in
consumers’ opinions about current portion sizes,
their perceived attributes and acceptance of several
point-of-purchase interventions aimed at portion size
and conditions for implementation in different point-
of-purchase settings. As this study was limited to
point-of-purchase-based interventions, an interesting
question is which portion-size interventions in home
settings would be feasible and effective.
This study focused on the consumer perspective
with respect to portion-size interventions. Insights
from this study can be used by policymakers and
companies to develop a more portion-size friendly
environment. Althoug h companies base their poli-
cies in large part on consumer research, it is also
important to consider the possibilities, barriers and
inclination of various point-of-purchase settings
specifically, in order to adopt and implement inter-
ventions aimed at portion size. This has been done
in another study [28], from which it was concluded
that point-of-purchase settings considered offering
a larger variety of portion sizes, serving-size label-
ing and, to a lesser extent, pricing strategies as most
feasible to implement.
The current study, combined with the study on
the point-of-purchase perspective, provide impor-
tant insi ghts into the feasibility of implementing
interventions targeted at portion size. However, lit-
tle is currently known about their effectiveness. As
far as we know, no studies are available on the
effectiveness of offering a larger variety of portion
sizes. With respect to pricing strategies, one study
showed that pricing strategies related to portion size
did not affect food intake [29], whereas the results
of another study showed that pricing strategies are
potentially effective among people who are over-
weight [30]. With respect to serving-size labeling,
several types of labeling are possible. For instance,
labeling could be used in supermarkets to help con-
sumers select appropriate packages or to provide
them wi th information about reference serving
quantities. Labeling could also be put in place set-
tings where fast food is sold and where a large size
portfolio is usually available. Ready-to-eat meals
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could be labeled with reference portion sizes. So
far, only two experimental studies [31, 32] have
assessed the effectiveness of serving-size labeling
on food intake, with both studies yielding mixed
results.
In conclusion, environmental interventions
aimed at portion size that are, in the eyes of con-
sumers, most acceptable to implement, are a larger
variety of portion sizes, pricing strategies and serv-
ing-size labeling. Furthermore, communication
strategies with respect to these interventions should
be carefully developed. Finally, futur e research
should focus on portion-size interventions in home
settings and on the effectiveness of portion-size
interventions.
Funding
ZonMw (the Netherlands Organization for Health
Research and Development) (61300033).
Acknowledgements
We would like to thank Steffie Nooy, Lubke van‘t
Hul and Reineke Horbach for their help with the
organization and moderation of the focus group
discussions.
Conflict of interest statement
None declared.
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  • Source
    • "schools, restaurants) or pricing strategies are also suggested (Steenhuis et al., 2009). For some foods, recommended serving sizes on food labels are acceptable interventions for consumers (Vermeer et al., 2010) and might be a reliable guide for portion size determination. In the meal planning phase it can also be helpful for consumers to use smaller plates when serving foods and to leave leftovers in the kitchen (Wansink, 2010). "
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    Full-text · Article · Oct 2015 · Critical reviews in food science and nutrition
  • Source
    • "Several large-scale observational studies show that humans plan the amount of food that they are going to eat in advance of eating.17, 18, 19 This appears to be the case irrespective of the type of meal, (breakfast, lunch or dinner) and it reflects a general tendency either to ‘plate clean' or at least to be unsurprised by the amount remaining at the end of a meal.20 Meal planning has been observed under natural conditions in a restaurant21 and it is also evident in comprehensive and detailed qualitative analyses of consumers' interactions with food portions.22 "
    [Show abstract] [Hide abstract] ABSTRACT: It is widely accepted that meal size is governed by psychological and physiological processes that generate fullness towards the end of a meal. However, observations of natural eating behaviour suggest that this preoccupation with within-meal events may be misplaced and that the role of immediate post-ingestive feedback (for example, gastric stretch) has been overstated. This review considers the proposition that the locus of control is more likely to be expressed in decisions about portion size, before a meal begins. Consistent with this idea, we have discovered that people are extremely adept at estimating the 'expected satiety' and 'expected satiation' of different foods. These expectations are learned over time and they are highly correlated with the number of calories that end up on our plate. Indeed, across a range of foods, the large variation in expected satiety/satiation may be a more important determinant of meal size than relatively subtle differences in palatability. Building on related advances, it would also appear that memory for portion size has an important role in generating satiety after a meal has been consumed. Together, these findings expose the importance of planning and episodic memory in the control of appetite and food intake in humans.
    Full-text · Article · Jul 2014 · International journal of obesity (2005)
  • Source
    • "In this context, Herman and Polivy (2005) concluded that the jury was still out as there is a desire for value for money that was likely to lead to smaller portions being unacceptable. Supporting this view, Vermeer et al. (2010) used focus groups to establish views concerning the portion size of food items. There was a general perception that the portion size of many items had increased to a level where they were larger than was acceptable. "
    [Show abstract] [Hide abstract] ABSTRACT: ABSTRACT There is increasing evidence that the portion sizes of many foods have increased and in a laboratory at least this increases the amount eaten. The conclusions are, however, limited by the complexity of the phenomenon. There is a need to consider meals freely chosen over a prolonged period when a range of foods of different energy densities are available. A range of factors will influence the size of the portion size chosen: amongst others packaging, labeling, advertising and the unit size rather than portion size of the food item. The way portion size interacts with the multitude of factors that determine food intake needs to be established. In particular the role portion size on energy intake should be examined as many confounding variables exist and we must be clear that it is portion size that is the major problem. If the approach is to make a practical contribution then methods of changing portion sizes will need to be developed. This may prove to be a problem in a free market, as it is to be expected that customers will resist the introduction of smaller portion sizes, given that value for money is an important motivator.
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