1. Introduction
Halo effects, or “health halos”, have been used to describe the illusion that occurs when a product is perceived as healthy overall, based on the presence of a few salient traits rather than on an evaluation of the characteristics of the product in its entirety [
1]. For example, products with reduced fat claims are often seen as healthy, even when they contain high levels of sugar and calories [
2,
3]. Perceiving food as healthy can lead to increased consumption of the product, and to decreased guilt when doing so [
4,
5]. Perceived healthiness can also affect subsequent food choices and food intake, as the consumption of a food perceived as healthy can influence people to consume more food later [
6]. Even the mere presence of foods perceived as healthy as an option can lead individuals to choose to eat more indulgent foods instead [
7].
Though research is limited, particular characteristics of product names and titles have been shown to influence perceptions of healthfulness, leading to perceived health halos [
5,
8,
9]. A study of health halo effects from protein-labeled bars found that products with “protein” in their product title led consumers to perceive the product as being more healthful compared to the control bar that did not have “protein” in its title [
8]. To expand upon this research and extend it to other types of protein-labeled products, the present study takes advantage of a natural experiment to explore whether a cereal product with the word “protein” in its name elicits the same type of healthfulness perceptions from consumers, leading to a health halo for products that may not be particularly healthy.
For many consumers, the focus is on individual nutrients, either within one food or from their diet as a whole [
10]. This, in conjunction with health halos, leads to people overlooking the less healthful characteristics of food products, like increased calories, sugar, and/or fat, in favor of more healthful ingredients, such as fiber or vitamins, which may then result in unhealthy food choices [
9,
11,
12].
Protein is a nutrient that is often a focus for consumers as they search for ways to improve their health through diet, which also frequently results in health halos [
10]. Evidence suggests that consumers know little about protein, but perceive it to be healthier than other nutrients [
13]. The average intake of protein by most Americans reaches or exceeds recommendations [
14]. However, surveys have shown that 71% of people do not know how much protein they need [
15], and 60% of consumers are actively trying to increase their protein intake [
16].
1.1. Cereal and Protein Claims
Understanding health halos related to protein in cereals is of particular importance. Ready-to-eat cereals are consumed by nearly nine-in-ten Americans [
17], and 96% of American consumers purchase a box of cereal during every trip to the grocery store [
18], making the potential influence of health halos associated with protein in these products substantial. Cereal by itself is often considered to be a healthy choice, particularly when fortified with ingredients perceived as healthful [
11,
19,
20].
Manufacturers began to market cereals featuring protein to keep up with consumers’ growing preferences for “healthier” foods, and to directly compete with other breakfast options, including eggs and Greek yogurt, seen by consumers as high in protein [
21]. Through the use of the online product database Label Insight, our data (February 2021) showed that approximately 20% of cereal and breakfast foods now contain protein claims [
22]. These products can be profitable, as consumers are willing to pay more for cereal with protein [
23].
Kellogg’s, one of the most frequently purchased cereal brands [
23], introduced a “Protein Plus” line of their Special K breakfast cereals in 2012 [
24]. Since its initial introduction, several varieties of this Special K Protein cereal (SK-PRO) have been sold in grocery stores alongside its original Special K counterpart (SK-ORIG), inviting comparisons between the two products. We hypothesize that compared to SK-ORIG, SK-PRO will be perceived as healthier.
1.2. Front-of-Package Nutrition Information: Facts Up Front
Halo effects can lead to consumers focusing on particular nutrients while perhaps ignoring others. Though a lack of attention to nutrition information by a large portion of consumers is well-documented [
25,
26], studies show that consumers are more likely to view FOP nutrition information than they are to view the Nutrition Facts Panel (NFP) on the side or back of the packaging [
12,
27,
28]. Therefore, the current work also examines the impact of consumer attention to FOP nutrition information with respect to protein and other nutrients.
Facts Up Front (FUF) labels are used by food manufacturers to take select nutrition information from the NFP present on the side or back of the package and to highlight it on the FOP [
29,
30]. The FUF is designed to provide a concise, easy-to-read summary of some of the nutrients from the NFP, usually including the product’s calorie content and the “nutrients to limit” per serving (e.g., saturated fat, sugar, and sodium). The calories and nutrients in the FUF label are typically displayed in a bubble-like graphic, displayed in a top or bottom corner of the package, with the serving size displayed above or below these “bubbles” [
29]. See
Figure 1.
In a survey of consumer awareness of FUF labels, ready-to-eat cereal products were most frequently recalled as containing FUF labels [
31]. However, the effects of FUF labels on consumer understanding of the nutrient contents of food appear to be mixed. One study that examined consumer nutrient knowledge based on viewing different label conditions found that those who viewed a FUF label scored a higher percentage of correct answers on quizzes that assessed their knowledge of nutrient levels between foods [
32]. However, when asked to estimate the level of nutrients in food products, those viewing the FUF were more likely to underestimate the levels of fat and sugars, and to overestimate fiber and protein, compared to the control and other FOP label groups [
32].
While FUF labels may invite nutrient comparisons between products, they are not always based on consistent serving sizes. The serving size of SK-PRO is listed as ¾ cup, while for SK-ORIG, it is 1¼ cup, making it difficult for consumers to compare nutrient contents across the two products. To make this potential for misunderstanding clearer, the nutrition information shown on the FOP for each product is listed in
Table 1, as well as the same nutrients after equalizing the serving size to one cup. For example, if one were quickly looking at the FUF, without taking notice of the serving sizes, it would appear that SK-ORIG has more calories than SK-PRO (150 calories vs. 120 calories, respectively). However, when the serving sizes of both cereals are equalized, SK-PRO has 160 calories while SK-ORIG has 120 calories per cup. When the serving sizes are based on one cup, SK-PRO contains not just more protein than SK-ORIG, but more of all of the nutrients in the FUF, including more than twice the amount of sugars and 11% more sodium. Because most Americans do not need to increase their intakes of protein, but do need to reduce the amounts of sugar and sodium they consume [
14], SK-PRO isn’t necessarily a “healthier” alternative than SK-ORIG. We examine attention to these variations in serving sizes and hypothesize that most participants will be unaware of the differences. Because of the potential for consumers to misinterpret the FUF, we compare the responses of participants who say they looked at the information listed in the FUF with those who say they did not.
1.3. Influence of Front-of-Package Nutrition Claims and Purchase Intentions
FOP nutrition claims have also been shown to influence purchase intentions [
33]. For example, Verrill et al. [
12] demonstrated that a FOP declaration of vitamin fortification (i.e., “Good Source of Calcium and Vitamin D!”) led to increased perceptions of healthfulness and greater purchase intentions. Similarly, the presence of various nutrient content claims on three different products (i.e., yogurt, lasagna, and cereal) influenced study participants to view the product as healthier and to increase purchase intentions [
28]. Because purchase intentions can predict actual purchase behaviors [
34,
35,
36], examining them in the context of FOP label claims is valuable.
In this study, we examine whether the FUF label showing less healthful qualities such as sugar and saturated fat is overshadowed by the other more healthful FOP claims, such as protein and fiber. We hypothesize that the SK-PRO cereal will lead to increased perceptions of healthfulness and nutritiousness compared to SK-ORIG. Overall, the main objective of the present study is to examine the effect of a protein label on the perceived nutrient qualities and health benefits of the cereal products. Specifically, we hypothesize that SK-PRO will be perceived as containing more healthful ingredients and fewer less healthful ingredients compared to SK-ORIG. Additionally, we hypothesize that participants, particularly women, will perceive SK-PRO cereal as possessing more health benefits compared to SK-ORIG. We also posit that the presence of a protein label will decrease the perceived tastiness and increase purchase intentions of the cereal. An additional objective of the present research is to investigate consumer attention to and use of FUF labels. In line with the previous research outlined above, we believe attention to these FUF labels will be lacking and will not assist the participants in their ability to answer questions about the nutritional content of each cereal. Lastly, we hypothesize that the presence of FOP claims for protein will lead to increased purchase intentions.
2. Materials and Methods
Study participants were recruited from multiple online panels through a market research and online survey software company Qualtrics (
www.qualtrics.com (accessed on 20 July 2020)), using quota sampling to reflect the demographics of the population based on 2010 U.S. Census data. Selected panel members (
n = 8516) were invited to participate in the study via an email invitation, with 4410 of those invited panelists clicking on the link. The final sample included 1022 participants who fully completed the survey and passed attention check questions.
The questionnaire was administered over a 3-week period in August 2018, using the Qualtrics platform. Participants gave informed consent via an online form. The experimental protocol was approved by the Institutional Review Board at Rutgers University (#E15-329). The survey instrument can be found in the
Supplementary Materials (S1).
The study was designed to assess consumer perceptions and purchase intentions for two cereals: Special K Original (SK-ORIG), and Special K Protein (SK-Protein). Images of the front of the product packaging of the cereals on the market shelves at the time of the experiment were chosen to represent real-world conditions (See
Figure 1 for product stimuli). To control for order effects, the participants viewed the two cereals in random order. In each condition, the participants were first shown an image of the front of the cereal box, followed by corresponding questions about product familiarity, perceived healthfulness, perceived taste, and purchase intention. Participants were then shown the images of the two cereals side-by-side and asked comparative questions about the dependent measures. To reduce participant fatigue and improve survey flow, page breaks were inserted periodically. Corresponding product images were shown after each page break.
Overall, participants were shown images of each product five times. Participants could view the product images while responding to all individual product and comparative questions. However, to prevent them simply looking up the answers, product images displaying the FUF labels were intentionally not visible to the participants when they were asked questions about nutrient amounts and serving sizes. Participants could also not go back to look at the product images. The NFP containing information about nutrients not in the FUF, including total fat, total carbohydrates, and dietary fiber, was never shown to the participants.
This study investigated the impact of a FOP protein claim on multiple health-related outcome measures. Perceived healthfulness, nutritiousness, and tastiness of the control and protein cereals were measured, as well as purchase intentions. Each was measured using 5-point scales (e.g., “How healthy is this product?” with responses ranging from 1 (not healthy at all) to 5 (extremely healthy). Paired samples t-tests were performed to determine the differences in the measures between the two products.
Perceived comparative product attributes were measured using 10 items. Participants were asked “Per serving, which of the two products likely has more… (Your best guess is fine)”, for the following: protein, sugar, calories, fiber, whole grains, sodium, Vitamin A, Vitamin D, folic acid, and raisins. Neither product contained raisins. The response option of “No difference” was also available. The items were analyzed as separate dependent variables.
Participants indicated which cereal product was more likely to help them achieve seven health goals: live longer, lose weight, build muscle, feel stronger, stay healthy, have stronger bones, and have a healthier digestive system. None of these health benefits or claims were explicitly displayed on either product. The response options of “No difference” and “I don’t know” were also present. These items were analyzed as separate dependent variables.
Participants chose which cereal they would be more likely to purchase, and which is likely to cost more for the same size package. Willingness to pay was also assessed with the Likert scale question “In comparison to Special K Original, how much more or less would you be willing to pay for Special K Protein?” with responses ranging from 1 (much more) to 7 (much less).
Attention to the FUF nutrition information on the front of the packages was then measured with two items. Participants rated their agreement with the statement “I looked at the nutrition facts information on the front of the boxes to compare them.” Responses were recorded on a Likert scale, ranging from 1 (strongly agree) to 5 (strongly disagree). The choice task asked participants to choose which of the two cereal products had the bigger serving size, with the response options of “No difference” and “I don’t know” also available.
Hypotheses and analyses were specified prior to data collection. All data analyses were conducted using SPSS (Version 26; IBM: Armonk, NY, USA, 2019). Frequencies illustrate to which of the two cereals the participants were more likely to attribute specific nutrients. Multinomial logistic regressions were performed to examine the relationship between participants’ sex and perceived health benefits. Using descriptive statistics, we determined which cereal product was chosen more frequently for the health attribute and nutrient comparison questions. Multinomial logistic regressions were used to examine the relationship between looking at the FUF information and perceived health attributes.
4. Discussion
Overall, participants in this study perceived SK-PRO to be healthier and more nutritious, though less tasty, than SK-ORIG. Participants also incorrectly attributed health benefits more frequently to the protein-labeled cereal, even though no health benefit claims appeared on the product packaging. Although the protein content declaration of SK-PRO is factually correct, the perception that it is healthier and more nutritious than the original product without a protein claim suggests the existence of a misleading health halo associated with SK-PRO’s protein content. Such health halos may lead consumers to purchase and to pay more for products that they believe offer illusory health benefits, yet may add additional calories, sugars, sodium, and fats to their diets.
That participants perceived SK-PRO to be healthier and less tasty than SK-ORIG is consistent with current literature. Foods with healthier names or descriptions implying that they are healthier are often perceived as being less tasty than their less-healthful counterparts, although this can vary by participant characteristics, such as diet status and food pleasure orientation [
5,
37,
38].
Also consistent with the literature is the seeming inattention to the less healthful ingredients displayed in the FUF, in favor of healthful ingredients [
39]. One study examined how a product with FUF labels that displayed both less healthful nutrients, such as saturated fat, and healthful nutrients, such as potassium, were perceived as being more healthful than a product that had only healthful ingredients in the FUF. Additionally, Miller et al. [
40] found that although participants did pay attention to the FUFs on two cereal packages, the ability to choose the healthier cereal was low, which is also demonstrated in our results.
Most participants did perceive no differences between cereals with respect to the content of most nutrients displayed. However, of those who did perceive differences, SK-ORIG was chosen as having more of the less healthful nutrients, such as sugar and sodium, while they more frequently chose SK-PRO as having more of the healthful nutrients, such as protein, fiber, folic acid, and Vitamin D.
The percentage of participants who reported viewing the FUF is also consistent with previous studies [
27]. However, the inaccuracies in participant responses when asked to indicate nutrient amounts and serving sizes reveal their lack of attention to this FUF information. Those who reported looking at the FUF were generally more accurate in indicating which product had more of certain nutrients per serving but were inaccurate in their perception of which cereal had a bigger serving size. These participants were also less likely to choose “no difference” in nutrient amounts between products, likely because the FUF labels make it obvious that there were differences in the products’ nutritional makeups.
Even though the majority of participants reported that they looked at the FUF, many fewer correctly chose SK-ORIG as having the bigger serving size. This may be because the participants simply did not look closely at the serving sizes located at the top of the FUF graphic, and instead paid closer attention to the nutrient amounts in the main “bubbles” portion of the graphic. Additionally, the intentional unavailability of the product images to participants during questions regarding nutrient amounts allowed us to observe the possibility of a recall bias. As demonstrated here, a biased recall of information may have contributed to the increased perceptions of health for SK-PRO, in which the inability to recall the correct nutrient amount information led participants to rely on other cognitive biases, such as the halo effect.
Although the FOP of SK-ORIG highlighted that it was “Made with Folic Acid, B vitamins and Iron” and “Powering your strength” (albeit in small lettering), only about 5% of the participants believed that SK-ORIG would be more likely than SK-PRO to help them feel stronger (5.6%) and build muscle (4.7%). In contrast, 43.3% thought that SK-PRO would be more likely than SK-ORIG to help them feel stronger, and 54% thought it would help them build muscles. This suggests that the participants consider protein-enriched foods to be functional foods, providing a health benefit beyond their basic nutritional value.
Many participants also attributed other health benefits to the SK-PRO cereal, such as having a healthier digestive system and stronger bones, though these benefits are not associated with protein. This is consistent with the literature, where, when asked to name a food or nutrient that they consider beneficial for a health issue they experience, such as cardiovascular problems, weight loss, and lack of energy, participants most frequently cited protein [
41]. This suggests that participants may be aware of some health benefits associated with protein but lack the knowledge of how these benefits apply to their own diets and lifestyles. This is consistent with studies showing that consumers often possess attribute-related knowledge for high-protein and other functional foods, but lack knowledge about the health consequences of consuming them [
42]. These results do not align with those of a study of European consumers, which found that people were quite knowledgeable about the function of protein in the body, though the older study participants were skeptical about products that had increased protein content and their effects on health [
43]. In contrast, our results seem to portray a misunderstanding or confusion about the role of protein in the body, with many participants indicating that SK-PRO would be more likely to affect health benefits, such as help them live longer or have stronger bones than SK-ORIG.
It is possible that some of the falsely attributed health benefits may be the result of other FOP information on the cereal boxes. For example, although dietary fiber content did not appear on the FOP of either product, the SK-PRO cereal noted that it was made with whole grains, perhaps suggesting to participants that it was fiber-rich, and thus promoted a healthier digestive system. Additionally, for all the questions about comparative health benefits between cereals, more than 10% of participants chose “I don’t know.” This highlights a lack of nutrition, food, and health literacy that exists among many consumers, which can be problematic for food choice and decisions that can impact health [
44,
45].
Many participants reported that SK-PRO would not taste as good as SK-ORIG but said they would be more likely to purchase SK-PRO and would pay the same or more for it. Our results are aligned with the Unhealthy = Tasty Intuition first defined by Raghunathan, Naylor, and Hoyer [
37], in which perceived healthiness and tastiness are inversely related. This may be explained by research that has found that consumers are willing to pay a premium for functional foods or products with health claims [
46,
47]. Additional research should further explore the relationship between perceived health, tastiness, and willingness to pay.
These increased purchase intentions for SK-PRO may also translate into real-world shopping behaviors. One study found that intentions are more highly correlated with actual purchases for specific, existing products, rather than with new and broadly categorized products, such as generic mock cereals that are often used in studies [
34]. Our study utilized two existing cereal products with which many participants were familiar. Thus, the results from this study demonstrate that a protein label on cereal may lead to increased purchase intentions, which could translate to actual purchase behavior in a real-world setting, complementing purely experimental manipulations.