Title: Understanding consumer acceptance of intervention strategies for healthy food choices: a qualitative study

Transcription

1 Author's response to reviews Title: Understanding consumer acceptance of intervention strategies for healthy food choices: a qualitative study Authors: Colin Bos (colin.bos@wur.nl) Ivo A. Van der Lans (ivo.vanderlans@wur.nl) Frank J. Van Rijnsoever (f.j.vanrijnsoever@uu.nl) Hans C. M. Van Trijp (hans.vantrijp@wur.nl) Version: 4 Date: 8 October 2013 Author's response to reviews: see over

2 Changelog Following the comments of the reviewers, the manuscript has been revised. A point-by-point response to the concerns is hereby provided. Comments by Mario Mazzocchi (minor essential revisions): There is a literature on surveys trying to elicit support for obesity/healthy eating policies, which I think is relevant to the objectives of the paper. These studies rely on quantitative approaches, but I feel the present study contributes by providing a more structured insight on the determinants of acceptance. The authors could mention consistencies and inconsistencies between these quantitative studies and their findings. Thank you for this comment and the useful references. In the introduction, we changed the sentence from However, little research has been directed towards gaining this knowledge within the food domain [17]. into Within the food domain, a number of surveys have found that beliefs about the causes of obesity affect support for obesity prevention policies [17-19]. However, a structured insight into consumers perceptions of interventions is lacking [20]. The present study aims to fill this gap by exploring not only consumer acceptance, but also the perceived effectiveness and the perceived fairness of intervention strategies for low-calorie food choices. In the discussion we mention consistencies: These findings agree with Chambers and Traill [35], who found that the support for policy interventions was greatest when the responsibility for food choice was also attributed to factors beyond individual control. However, we now also refer to the study of Barry about obesity metaphors and we slightly changed the rest of the sentence: These findings agree with Chambers and Traill [35] and Barry et al. [17], who

3 found that the support for obesity prevention policies was greatest when causes for obesity rates were attributed to factors beyond individual control. Another element which would deserve some discussion is the generalizability of the results to other cultures. That is a very valid point. After reading the EATWELL reports we added a paragraph to the discussion on the generalizability of our results: The results merely reflect the viewpoints of a sample of Dutch consumers who varied with regard to age, gender, and income. It is possible that variations in political and cultural circumstances lead to different levels of acceptance as well as other mechanisms underlying acceptance. For instance, Mazzocchi et al. [43] found differing levels of acceptance of obesity prevention policies across five European countries, presumably due to the familiarity with specific policies. However, with respect to the mechanisms underlying acceptance, we think that the concepts that we identified are quite generalizable, particularly because these also underlie acceptance of interventions in non-food domains [23]. I have two concerns about aspects which are usually considered in quantitative surveys. Social desirability bias: To what extent the views expressed by participants in such an environment actually reflect their 'private' views, i.e. the views they would express in a political referendum? Was any countermeasure taken to consider such a potential bias? We understand your concerns regarding the social desirability bias. As with all research in social sciences, social desirability potentially influences the legitimacy of participants responses. We took measures to counteract this potential bias by inviting participants to be honest, and

4 explicitly explain this at the beginning of the discussions. Therefore we added to the procedure section After a short introduction, the interviewer explicitly invited and encouraged participants to voice their personal opinions and stressed that there were no correct or wrong answers.. Looking at all the different viewpoints and fruitful exchanges of arguments that emerged during the discussions, we think that social desirability did not play a major role in participants answers. We therefore supplemented They particularly appreciated the opportunity to voice their own opinions and to discuss public health issues with each other. with Therefore, there is little reason to believe that social desirability influenced the legitimacy of participants responses. at the end of the procedures section. I have two concerns about aspects which are usually considered in quantitative surveys. Monetary incentives: Were the respondents informed about the monetary incentive prior to selection? To what extent does this affect the representativeness of the study, even in qualitative term? The authors state that participants were selected with an eye to income heterogeneity, is it safe to assume that the monetary incentives did not introduce a selection bias? Because participants were recruited from a panel that is maintained by an agency, they were aware of the fact that they would receive a monetary incentive. This agency uses standard compensations for participation in research. To make this clear, we added: Participants were recruited through an agency, which uses its own panel and we changed Participants received monetary compensation for their participation into For their participation, participants received the standard monetary compensation, according to the recruitment agency s policy. We hope this makes the procedure of recruitment clear enough to take away any concerns.

5 I am aware that qualitative methods elicit answers from respondents rather than leading them through questions, but I am surprised that the 'responsibility' dimension does not cover the issue of self-control (and lack of) in generating obesity and driving food choices. Has this been mentioned during the interviews or focus groups at any stage? If not, why do the authors think this aspect has not emerged? Thank you for this insightful finding. After reading the transcripts again, we found that no direct references were made to self-control. We did find some indirect references to self-control, such as: I think it s about your own mentality. These indirect references were made during the short introductory part (responsibility for food choices) of the focus groups. We think that the issue of self-control did not come up much after that because of the present study s emphasis on perceptions of intervention strategies rather than causes of obesity. What is an effective policy? One enabling consumers to make informed (even if unhealthy) choices or one lowering the caloric intakes? Within the framework presented in this paper, my feeling is that an explicit definition of effectiveness (towards lowering caloric intakes) has been assumed. If this is the case, such definition (and how it has been communicated to participants) might be included in the discussion, namely in the Section "Procedure". I note that the discussion on acceptance was led by an explicit statement on lowering calorie intakes, thus - even if no explicit statement was made in the focus groups - I presume participants continued to assume that the policy goal was the same when discussing effectiveness. We can see that this could be confusing when rereading our paragraphs about the procedure. We indeed defined effective as: leading to low-calorie choices. To make this more clear, we added the sentence: For these parts the main questions were Do you think the archetypical

6 interventions will lead you to make low-calorie food choices? and Do you think the archetypical interventions are a fair way to stimulate you to make low-calorie food choices?, respectively. We hope this makes it more clear. More in general, this study has (necessarily) limited its scope to consumer choices in terms of caloric intake, while the biology and policy on healthy eating does stress many other dimensions, like fat content, fruit and vegetable intakes, salt, etc. To what extent - given the participants response do the authors think that the single focus on calories is sufficient to elicit consumer acceptance of interventions? The authors observe that participants tend to see substitution within the same food category (a finding which is common in the economics literature), but is it possible that such result is led by the initial definition of the issue, rather than a more general discussion about the characteristics of a healthy diet? Good question. We don t know whether the focus on calories (and substitution within product groups) is sufficient to elicit acceptance of interventions for everyone. That said, we have no reason to think that the concepts we found (perceived effectiveness and fairness) are not applicable to other situations (for instance substitution between product groups). To illustrate this, we added to the discussion: This study limited its scope to acceptance of interventions for consumer choices in terms of caloric value. It would be extremely useful to see whether consumers perceptions are construed similarly when talking about interventions that target other product characteristics, e.g. increased fruit consumption or decreased salt consumption. Similar to the expected generalizability of the concepts underlying acceptance across cultures, we expect them to be generalizable to acceptance of interventions aimed at other nutritional characteristics as well. We hope that this sufficiently addresses the point you made.

7 The authors state that several participants reassessed their acceptance of fiscal measures. However, according to the study logical order (if reflected by the paper structure?) this immediately follows the discussion on the intrusiveness of policies and freedom of choices. I wonder whether one would get the same modification if the discussion on intrusiveness were introduced at the beginning of the focus group, then finish with the discussion on rising obesity and the role of environment. In other words, I am arguing that the method followed in qualitative research might be 'leading' to some results rather than others. Is this the case? If not, how can the authors demonstrate that these reassessment are independent from the order of topics debated in the food groups? And that the procedure has no influence on these? Good point. We added to the discussion: One can argue that the order of the different parts of the discussions led to modifications in participants ratings of acceptance. Because this sequence was not varied, potential biases, particularly order effects [44] and belief overkill [45], can t be ruled out. Looking at participants argumentations for their ratings, we have little reason to believe that these side effects indeed surfaced and compromised the legitimacy of participants responses. Furthermore, the specific order was employed to prevent that discussions on effectiveness and fairness of interventions would influence the initial rating and discussion on acceptance. This enabled us to see whether statements about effectiveness and fairness would surface spontaneously, like they did. (discretionary revisions) Attributions of obesity are the main driver of acceptance, which makes the framework in Figure 1 quite appropriate. However, I wonder whether other aspects may be considered relevant.

8 Thank you for indicating the appropriateness of the figure. One other aspect that can be considered relevant is familiarity with interventions. We therefore included this in the discussion (see the answer to your 2 nd point). "Fairness of encouragement versus discouragement of choices" I found this part of the study extremely interesting. It raises a point which has been rarely discussed in the literature, i.e. potential asymmetric response to incentives versus "punishments". It is not entirely clear to me what is the final synthesis of the findings under this section. The woman advocating "positive" designs of intervention, and the formerly obese man advocating taxes indicate major heterogeneity in response. After rereading the section, we agree that the synthesis could be more clear. Therefore we changed Figure 4 illustrates that the majority of participants perceived interventions that encourage low-calorie choices to be fairer than those that discourage high-calorie choices (1 st, 3 rd, and 5 th versus the 2 nd, 4 th, and 6 th ). When asked to account for this finding, a woman claimed: into Figure 2c indicates that perceptions of fairness not only varied across interventions, but also within interventions. Overall, encouraging strategies were rated slightly more fair than the discouraging counterparts (1 st, 3 rd, and 5 th versus the 2 nd, 4 th, and 6 th ). When asked to account for the preference of encouraging strategies, a woman claimed: and to accentuate the contrasting opinions we changed When elaborating on the perceived fairness of both encouraging and discouraging interventions, participants also commented on the perceived effectiveness of such interventions. Into In contrast, proponents of discouraging interventions often pointed at the effectiveness of discouragement to illustrate why they thought these interventions were fair. We hope that this makes the synthesis more clear.

9 Perceived liberty, autonomy, and privacy of food choice: It might be worth to anticipate in the introduction to this paper that this aspect is also dealt with in the research. This is a valid point. We tried to incorporate your point in the introduction, without compromising the flow of the text. As you can see in the response to your 1 st point, we tried to address this point by making the aim of our study more clear. We changed The aim of the present study is to explore beliefs that influence consumer acceptance of intervention strategies for low-calorie food choices. Into The present study aims to fill this gap by exploring not only consumer acceptance, but also the perceived effectiveness and the perceived fairness of intervention strategies for low-calorie food choices. Comments by Marianne Promberger (major compulsory revisions) The main major revision concerns the figures. I don't think they are useful in their current form and should be improved. Of interest to the reader seems mainly (a) to assess relative acceptance of the different interventions, (b) to compare acceptance ratings with fairness and effectiveness ratings, and possibly (c) see whether acceptance increased or decreased between the 1st and 2 nd rating. (For example, you ask readers to compare Figures 2 and 5 to assess (c), which is really impossible). My suggestion would be to include all ratings into 1 figure, to aid with (b) and reduce clutter. Stacked barcharts with segments of "accept" "neutral" "don't accept" would also improve legibility. Then, you might consider sorting bars by how well the intervention was accepted. I think you could also drop the bars showing the 2nd acceptance

10 rating, given that these did not change much. If you think showing where they did change is important, hen you need to make this better visible, eg by showing bars with the net rating changes. All figures: If the intervention "restricted promotion of highcalorie foods" has eight ratings less, then it is inappropriate to include them in the same figure that leads to comparisons across interventions. You could use percent. It would be better to drop the figure footnote explaining the categorization and include this information in the figure. If you do not sort by level of acceptance, this should be very easy by grouping bars. Otherwise, I'm not sure whether this information is needed at all. Thank you for the comment. We can see that the situation with the figures is not optimal. We tried to make a version with stacked bars, like you suggested. However, we feel that this was not optimal as well, because comparisons between interventions perceived effectiveness and fairness are difficult to see. Therefore we opted for the solution to keep the figures and put them on one page. This way (a) is satisfied, and also (b) is satisfied (although not as optimal as your suggestion). Due to the relatively low number of participants we think absolute numbers are more informative than percentages. To address your concern on the differences in ratings of acceptance (c), we took your advice and we made a figure with the net rating changes and deleted the figure with the second ratings of acceptance. Again, thank you for suggesting to make a figure with the net rating changes. This makes figure 2d much more helpful for the reader. The text accompanying the figures is as follows: Figure 2. An overview of participants ratings of: acceptability (a), perceived effectiveness (b), and perceived fairness (c) of interventions. Differences between the first and second ratings of acceptance are depicted in (d). * Restricting promotion of high-calorie foods was added after the interviews and therefore has eight ratings less. We hope that by structuring the figures this way, your concerns are adequately addressed.

11 There seems to not have been a test for inter-coder agreement. This is okay but limits the strength of your findings wherever you make claims about counts of statements. Please try to drop these, and add it to the discussion as a limitation. Maybe an example of this, I would think that in section 3.4, the last example of undesired effects of the food industry "gaming" the system relates more to effectiveness than to fairness. Please add that this might be the case. This is a valid point. We agree that the lack of inter-coder agreement limits the strength of the claims that can be made about the counts of statements. Therefore we looked at the statements we made about Table 4. We agree that some of these statements go beyond the limitations of our coding procedure. These will be addressed in your following remarks. Despite the limitations, we would like to keep the table in the article. We have two reasons for this. 1: it gives an informative overview of when (during which part) certain statements were given, which indicates the relations between the constructs. For example, it shows that statements about effectiveness and fairness frequently came up during the discussions about acceptability. 2: even though the counts have limited strength, it does give an indication about how frequent statements about a particular belief were given. We hope that we elaborated enough on the importance of the table to convince you to accept the table. Section 2.1, first para, 2nd and 3rd sentence. I don't see how summing the quotes can illustrate the preceding sentence, assuming quotes include statements such as "I think this is effective" as well as "I think this is not effective". I don't think the statements in these sentences are supported by the data shown in Table 4.

12 Thank you for this comment. Like we stated above, we agree that the counts have limited strength because of the lack of inter-coder agreement. Therefore we removed the statement that the table illustrates the preceding sentence. Section 4, first para, 2nd sentence. "Table 4 indicates...": I don't see that Table 4 indicates this at all. For sure, it does not speak to causation, but I have trouble even seeing a correlations in these numbers. Please explain better, or drop this claim. For the same reason, we again agree with you on this point and therefore we dropped the claim. (minor essential revisions) Background section: Please define the term "consumer" in this context, or think whether it is appropriate in this context. For food, healthy or unhealthy, there are certainly consumers, but it your method and findings are of interest regarding health interventions in general, which may affect some parts of the population (patients, smokers), but where you'd also be interested in how well these interventions are accepted by everyone else, i.e., by citizens. Thank you for this point. To address this concern and to make it more clear what we mean by it, we added a part to the introduction: The term consumer acceptance is used throughout the article because the interventions of interest target food choice (consumption) behaviour. It is important to note that the present study s method allowed for assessing these interventions from a consumer point of view as well as from a broader, social perspective. We hope that adding this section brings clarity. If not, we gladly hear your suggestions.

13 Background, 2nd para, 3rd sentence, "... reinforces effects of physical activity on weight status": citation supporting this claim? (or drop) We agree with the comment. The citation supporting this claim is the same as the sentence preceding it. We therefore changed the sentence from Limiting calorie intake directly affects weight status and also reinforces the effects of physical activity on weight status. into Limiting calorie intake directly affects weight status and also adds to the impact of physical activity on weight status [5]. Background > Consumer acceptance of intervention strategies, 1 st para, citation [13]: I don't see why this citation is placed here. After reading the sentence and the cited article again, we agree. We therefore removed the citation. Discussion, 4th para, 1st sentence: Remove "influence" and rephrase; your study does not support a statement about causation. We agree with your point. Therefore we changed the sentence from In addition, the perceived responsibility for food choice influenced the acceptance of interventions. To In addition, the perceived responsibility for food choice was related to the acceptance of interventions. Following this comment, we also adjusted the sentences that used the word influence in the Abstract. Discussion, 4th para, 2nd sentence: "... study participants... their..."

14 Thank you for spotting this error. We changed While all study participants acknowledged a personal responsibility for his or her food choice into While all study participants acknowledged a personal responsibility for their food choice Discussion > Conclusions, 2nd para, 2nd sentence: replace "domain-specific" with "from other domains", adjust sentence as needed. Again, thank you for spotting this error. We changed the sentence from First, it confirms domain-specific research on beliefs that influence consumer acceptance of interventions for the food domain. Second, and most important, it identifies the underlying aspects of these beliefs specifically for food choice interventions. into First, it confirms research on the beliefs that influence acceptance of interventions from other domains. Second, and most important, it identifies the underlying aspects of these beliefs specifically for food choice interventions. I would add to the discussion how representative your sample was, or how this would matter (maybe I overlooked it). Sample characteristics were given in the methods section: Selection of participants aimed at a sufficiently heterogeneous sample in terms of gender, age and income level (Table 1). To address your comment, we added a section to the discussion. This section also addresses a point from the other reviewer, therefore you can find it on the second page of the change log. As you write, acceptance, perceptions of effectiveness, and perceptions of fairness aligned very closely in your study. This could be belief overkill, the tendency to distort beliefs so that they

15 point in the same direction for decision making (Baron, 2009; Jervis, 1976). Please add this to your discussion. Thank you for this remark. Although the perceptions do align to some degree, there are also differences. Especially when looking at the perceived effectiveness and the perceived fairness, these differences become apparent. In response to your and the other reviewer s remarks, we added a section to the discussion which you can find on page 6 of this changelog. (discretionary revisions) Background > Consumer acceptance of intervention strategies: I don't see why this needs an extra sub-heading. We agree that the sub-heading is redundant. We therefore removed it from the manuscript. Theoretical framework > Types of intervention strategies, 3 rd sentence: This sounds as if Rothschild is juxtaposed with the previous citations, while it is singled out from them. I would drop "however" and write "Among them, Rothschild's..." Thank you for this nuance. We changed the sentence from Rothschild s social marketing framework, however, allows for the exploration of both policy and non-policy oriented intervention strategies. in Among them, Rothschild s social marketing framework allows for the exploration of both policy and non-policy oriented intervention strategies. Discussion, 4th para, 3rd sentence: I don't understand this sentence, "Participants who...". I suggest you rephrase. (On reading the next sentence, I now get it. I think it would be better expressed more specifically, avoiding the term "stakeholders." Something like: ",... they did not agree how much others, such as the government or food companies, were also responsible.

16 Those who thought such third parties were also responsible were more likely to show acceptance...") Thank you for pointing out that the sentence was not clear. We changed the sentence from While all study participants acknowledged a personal responsibility for his or her food choice, they did not reach consensus on the degree of additional responsibility of other stakeholders. Participants who perceived the responsibility for food choice to be shared with other stakeholders expressed greater acceptance of interventions. into While all study participants acknowledged a personal responsibility for their food choice, they did not agree on how much others, particularly the government and food companies, were also responsible. Those who thought such third parties were also responsible were more likely to show acceptance of interventions. We hope it is more clear now. Discussion, 5th para: I agree, and it would be interesting to see what happens when participants become aware of the evidence. In Promberger et al (2012), we found that many respondents who did not like financial incentives for overweight people and smokers were willing to accept them if they were stated to be effective. Thank you for the suggestion. We added It would be interesting to see what happens when evidence for effectiveness is provided, especially because positive statements regarding effectiveness seem to increase acceptance of interventions [38]. to the paragraph I think your article ends rather weak. What would be the benefit of a segmentation study? You could give reasons. I would argue that more interesting is whether the underlying beliefs are

17 supported by evidence, and if not, whether participants would change their minds when presented with the evidence. Also, what does this mean for policy making? Can people be convinced? Should they, or are their concerns important and something that policy makers should listen to more closely? In particular, I think the finding that effectiveness seems to be seen to improve acceptance is a promising aspect of your findings, especially as it sometimes seems to override less tangible ideas about personal responsibility for food choice. In retrospect, we agree that the article could end stronger. We therefore changed A segmentation study that includes these items would therefore provide essential information for the targeting of interventions. into Logical next steps would be to segment people based on how they perceive specific interventions and to explore how these people should be approached to increase acceptance. This will enable us to see whether providing evidence for actual effectiveness of interventions will increase the perceived effectiveness and subsequently the acceptance of interventions. On behalf of all the authors, I would like to thank both reviewers for reading the manuscript and for giving us the opportunity to improve the article. The comments were very helpful and we did our best to address them adequately. Kind regards, Colin Bos