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Abstract

Objective

Social media influencers frequently post “What I Eat in a Day” (WIEIAD) vlogs, shaping dietary perceptions and behaviors among young audiences. There is concern that these videos contribute to negative outcomes, such as disordered eating and unhealthy social comparisons. While prior research largely focuses on the effects of short-form content (e.g., from TikTok), this study examines the impact of long-form WIEIAD videos on perceptions about the content creators and nutrition-related behaviors, and measures behavior by asking participants to select an apple or cookie after watching a WIEIAD video.

Methods

Using a 2 × 2 experimental design (N = 289), participants viewed WIEIAD YouTube videos varying in the presence and absence of sponsorship (i.e., either a service or product) and physical health benefits of the diet.

Results

Results indicate that sponsorship increased perceptions of influencer trustworthiness and attractiveness but decreased authenticity and parasocial interaction. Additionally, exposure to sponsored content increased the likelihood of selecting a cookie, supporting media priming effects in nutrition behavior. However, disclosure of physical health benefits did not influence snack choice. There was also a relationship between intentions to change diet and opting out of the snack.

Conclusions

These findings raise important considerations for digital health communication, influencer regulation, and content literacy interventions aimed at mitigating the negative health effects of social comparison and commercial nutrition messaging online.

Keywords

Influencer nutrition nutrition behavior social media sponsorship

Introduction

Social media influencers have a significant following on platforms like Instagram, YouTube, or TikTok, and use their online presence to shape opinions, promote products, or share content that resonates with their audience.¹ Influencers commonly focus on creating content in the health and wellness sector, oftentimes creating “What I Eat in a Day” (WIEIAD) vlogs, or food diaries² that emerged in the 2010's chronicling what individuals consume on any given day.³ The food diary trend is popular across a variety of platforms; there are approximately 2 M tagged posts with the hashtag #whatieatinaday on TikTok as of January 2025. Due to their popularity, there is widespread discussion among researchers and in the popular press about the impact of these videos. Researchers suggest that WIEIAD content circulates misinformation.⁴ However, some scholarship suggests that these videos can be used for health promotion and positive sustained behavior change.⁵ The press highlights concerns that such content can lead to self-comparison and negative body image, particularly affecting young people struggling with eating disorders.⁶ Others suggest that WIEIAD vlogs foster toxic diet culture.⁷ A primary goal of the current study is therefore to investigate WIEIAD influencer content and understand how this trend impacts young women's health-related beliefs and behaviors.

Despite widespread claims about the potential impact of WIEIAD content, most research on this trend to date is descriptive.^2,8,9 For example, Pfender et al. (2023) conducted a content analysis of 83 YouTube WIEIAD vlogs to understand dominant messages in these videos. Additionally, our team uncovered only one experiment testing the impact of WIEIAD on body image and behavioral intentions,¹⁰ in addition to one experimental study that examined the impact of trending influencer health content.¹¹

WIEIAD studies have three main limitations that the current study addresses. First, prior research typically measures only behavioral intentions,^10–12 whereas we assess actual nutrition behaviors after exposure. Second, most experiments focus on short-form content,¹³ but we examine long-form YouTube videos, which allow influencers more time to build parasocial connections and authenticity.^14–16 Third, prior research emphasizes calorie-focused content^2,10 yet most WIEIAD YouTube videos do not highlight calories.² We therefore investigate how factors like credibility, sponsorship, and physical health benefit disclosures shape audience perceptions and behaviors.

The present study employs a 2 × 2 factorial design to test the effects of WIEIAD videos containing sponsorship and physical health benefits on behavior (i.e., healthy vs unhealthy snack nutrition behavior). Grounded in impression-related theories (i.e., source credibility theory, self-presentation theory) and expectancy value theory, this experiment contributes to a body of research that questions if WIEIAD videos are harmful for young consumers.

Features of WIEIAD content

Previous research on WIEIAD messaging suggests that sponsorship and discussing the benefits of following the influencer's dietary choices are two common features of this content.² Sponsorship is a type of influencer marketing where creators are paid to promote a brand or product¹⁷ using their personal opinions and experiences to maintain authenticity while earning income.¹⁸ Nearly 30% of influencer WIEIAD YouTube content is sponsored and 60% contains messages suggesting that there is physical health benefits associated with the food in the video.² What follows is an explanation of the two theoretical frameworks that ground these types of message features.

Sponsorship and self-presentation theory

Authenticity and sponsorship are central to influencer marketing and can be understood through Goffman's self-presentation theory.¹⁹ Followers evaluate sponsored content based on the perceived alignment between the influencer's presented and genuine self.²⁰ Demonstrations of relatability, personal experience, and tailored messaging increase authenticity,^21,22 while overly promotional or nontransparent messages can seem intrusive or inauthentic.²³ Most research focuses on behavioral intentions,^11,24 but in the context of WIEIAD videos, authentic health-focused sponsorship may encourage viewers to select healthier foods, whereas sponsorship that feels forced or purely promotional may undermine authenticity and reduce the likelihood of healthier choices.

RQ1: How will exposure to sponsorship WIEIAD vlogs be related to snack choice?

Physical health benefits and expectancy value theory

Research indicates that influencer marketing often emphasizes the positive expectations associated with adopting a product or behavior.^25,26 Grounded in expectancy-value theory, health decisions are shaped by two factors: probability judgments and value judgments.^27,28 Probability judgments involve assessing the likelihood of positive or negative outcomes from a behavior, while value judgments pertain to the perceived utility or importance of those outcomes. Studies suggest that when individuals perceive both high probability and value in positive outcomes, they are more likely to change their behavior.²⁷

In the context of health influencers, modeling and promoting positive health behaviors or attitudes has become a prominent trend in the literature.^12,29 Influencers often showcase positive health expectations, such as psychological or physical benefits of certain behaviors, to enhance their perceived credibility and authenticity^2,30 and attract brand partnerships. By illustrating the benefits of their health practices, such as dietary choices, influencers may encourage followers to adopt similar behaviors.

H1: Exposure to vlogs with physical health benefits is related to engaging in a healthier snack (i.e., apple).

Source credibility theory and WIEAD message features

Source credibility theory emphasizes the importance of a communicator's perceived trustworthiness, expertise, and attractiveness in shaping message persuasiveness.³¹ Trustworthiness and expertise influence health message effectiveness and behavioral intentions,³² and examining the three dimensions separately is beneficial.^1,33 Expertise increasingly relies on personal experience rather than formal credentials.³⁴ For example, influencers who share insights from their own diets can attract loyal followers.³⁴ At the same time, DeAndrea and Vendemia (2016) found that audiences tend to view communicators with ties to health organizations or pharmaceutical companies less favorably, suggesting that such affiliations can reduce perceived authenticity.³⁵ Trustworthiness reflects transparency and consistency, such as being open about personal experiences or aligning content with endorsed products.³⁴ Sponsorship often reduces trust.^1,36 However, non-sponsored or health-benefit-focused content can enhance it.^22,34 Updated literature on attractiveness now includes aesthetics, identity, and alignment with audience values.³⁴ In WIEIAD content, showing the benefits of a diet for glowing skin, energy, or a fit physique can increase perceived attractiveness and credibility,³⁷ but sponsorship may undermine it by signaling inauthenticity.³⁴

Self-presentation theory and WIEAD message features

Self-presentation theory emphasizes how individuals strategically curate their behaviors and messages to shape how others perceive them.¹⁹ In the context of influencers, self-presentation often involves managing impressions to appear authentic and relatable to their audience. Authenticity, distinct from source credibility, focuses on relational and affective dimensions, such as perceived realism, wishful identification, parasocial interaction, and creativity, rather than solely on persuasion or information exchange.^21,22

Authenticity is central to influencer-audience relationships, as followers value perceived realism and sincerity.³⁸ Similarity fosters authenticity, with audiences trusting and engaging more with influencers who share their values or lifestyles.^13,39 Sponsorship can undermine this, as overtly promotional content may reduce perceived similarity and trust,^24,40 but highlighting diet benefits can strengthen perceived similarity by aligning with audiences’ health goals.¹³

Wishful identification, a key outcome of self-presentation theory and authenticity, refers to aspiring to emulate others’ behaviors or lifestyles.⁴¹ By highlighting benefits like energy, weight management, or well-being, influencers position themselves as health-conscious role models.¹³ However, overly promotional or insincere sponsorship can reduce authenticity and weaken this aspirational connection.^40,42

Parasocial interaction, or a one-time engagement with a media figure, can create the illusion of a close relationship.^43,44 It enhances emotional engagement, trust, and intentions to adopt health behaviors,⁴⁵ deepening over time through exposure and self-disclosure.^44,46 Sharing personal health information strengthens authenticity and parasocial bonds,⁴⁷ and highlighting diet benefits in WIEIAD content can increase credibility and relatability.³⁴ Sponsorships, however, may reduce authenticity and weaken these connections.¹³ Together, these variables create a framework for understanding how self-presentation contributes to the perception of authenticity and its relational effects. Based on the theoretical frameworks of source credibility theory and self-presentation theory in relation to WIEIAD message features (i.e., sponsorship and physical health benefits), we pose the following hypotheses and research questions:

H2: Sponsored vlogs will be negatively associated with (a) perceived influencer credibility, including perceived trustworthiness, expertise, attractiveness, (b) perceived similarity, (c) authenticity, (d) wishful identification, and (e) parasocial interaction.

H3: Vlogs that mention physical health benefits will be positively associated with (a) perceived influencer credibility, including perceived trustworthiness, expertise, attractiveness, (b) perceived similarity, (c) authenticity, (d) wishful identification, and (e) parasocial interaction.

RQ2: How does the interaction of sponsorship and physical health benefits relate to snack choice?

RQ3: How does the interaction of sponsorship and physical health benefits relate to (a) perceived influencer credibility, including perceived trustworthiness, expertise, attractiveness, (b) perceived similarity, (c) authenticity, (d) wishful identification, and (e) parasocial interaction?

Impressions and nutrition-related behavior

Impressions of influencer food vlogs have been shown to impact behavioral intentions, such as purchase intentions⁴⁸ and intent to diet.¹⁰ However, little food diary research has investigated how impressions of influencers relate to behavior, the direct outcome of behavioral intention.⁴⁹ There is a link between source credibility, including trustworthiness, expertise, and attractiveness, as well as perceived authenticity and similarity, behavioral intentions, and consuming influencer content.^1,13,22,39 If perceived source credibility, authenticity, and similarity are high, followers may be more likely to engage in a healthier snack choice, such as an apple, because they trust the influencer's expertise, view them as genuine, and see them as relatable. When viewers believe an influencer is knowledgeable about nutrition and genuinely follows the dietary choices they promote, they may be likely to model their behavior accordingly.⁵⁰ Thus, we pose the following research question:

RQ4: How do perceptions of influencer credibility—specifically trustworthiness, expertise, and attractiveness— and perceived authenticity and similarity relate to women's snack choices, particularly in terms of healthier or less healthy options?

Wishful identification and parasocial interactions with influencers are other facets of the psychological and relational aspects of impression formation that relate to behavioral intentions.⁵¹ Like source credibility and authenticity, most research on wishful identification and parasocial interaction in an influencer dietary context falls short of understanding exposure and only investigates behavioral intentions.⁵² If individuals strongly identify with an influencer or feel a parasocial bond, they may be more likely to emulate their eating behaviors.⁵⁰

RQ5: How do wishful identification and parasocial interaction relate to women's snack choices, particularly in terms of healthier or less healthy options?

There has been growing research on the impact of WIEAD vlogs, particularly in shaping viewers’ behavioral intentions related to diet and body image. Drivas et al. (2024) found that exposure to high-calorie diet videos on TikTok increased young adults’ intentions to diet, potentially as a psychological response to distance themselves from the depicted eating behaviors.

RQ6: How does intention to alter diet or replicate the influencer's meals relate to snack choice?

Methods

Using a 2 × 2 between-subjects design, the experiment manipulated sponsorship (present vs absent) and physical expectancies from the diet discussed (present vs absent) in the “What I Eat in a Day” YouTube video, which were identified from a previous content analysis.² After viewing the YouTube video, we asked to select a “thumbs up” or “thumbs down” emotion to capture social media likes or dislikes of the video, comment on the video, complete a battery of questions, and finally, select a snack. Experimental conditions included sponsorship present/expectancies present, sponsorship present/expectancies absent, sponsorship absent/expectancies present, sponsorship absent/expectancies absent. Figure 1 provides a conceptual model. Figure 2 represents the theoretical model.

Figure 1.

Conceptual model.

Figure 2.

Theoretical model.

Procedure and experimental design

We selected videos from a previous content analysis on WIEIAD YouTube videos posted from October 2021 to October 2022, that contained the titles “what I eat in a day” or “full day of eating” and were posted by influencers (>20 K subscribers).² The videos were primarily created by female influencers (86.7%) without medical or nutrition-related credentials (97.6%).² Nearly one-third (28.9%) contained a sponsorship disclosure and 59.0% contained discussion of physical benefits resulting from their diets.² Only 10.8% mentioned calories.²

In the content analysis, two coders reached high intercoder reliability (AC1 = 1) on the codebook including sponsorship (present vs absent) and physical expectancies (present vs absent). We coded sponsorship present if the content creator stated that a food company sponsored something they ate in their WIEIAD video. We coded physical expectancies present if the content creator stated that a positive physical outcome would result from their diet, such as “I add collagen to my smoothies because it improves my skin.” Based on these codes, we randomly selected two videos to fit each of the four conditions from Pfender et al.'s (2023) sample to use in the current study, resulting in eight total videos. We excluded male content creators because there were so few, allowing the researchers to control for content creator sex. We randomly assigned participants to one of the four conditions (N = 8 videos) and then they randomly received one of two videos. Videos selected for this experiment were an average of 13:42 min (SD = 3:33). To ensure consistency in time spent watching the video, each condition had a shorter video and a longer video. Shorter videos ranged from 8:49–11:33 min. Longer videos ranged from 15:48–18:35 min.

The experiment took place in the Communication Department lab at a mid-Atlantic university. Participants signed up for the study online. In the lab, participants watched the YouTube video, completed the survey, and engaged in a nutrition behavior. We conducted the study in a lab because YouTube videos are long form content and can be taxing on attention span. Participating in a quiet, focused, and monitored environment could increase participants’ attention to the videos. After they finished watching the YouTube video and answering questions, prior to exiting the lab, we asked participants to select a snack, which could be found in a separate room in the lab and hidden when participants arrived for the study. Participants were not aware that their choice of snack was part of the experiment. The researchers recorded snack choices, which included cookies (e.g., oreo, chips ahoy) and apples (e.g., red, green). We obtained IRB approval from the sponsoring institution and all participants provided informed consent before participating in the study (IRB approval number: 2169803-1).

Sample

The sample was recruited from the undergraduate student SONA pool in the Communication Department. Students were offered course credit as designated by their instructor for completion of the study. An a priori power analysis, conducted in G power, indicated that the study needed a sample of at least 280 people (70 per condition) to detect small-size effects in a 2 × 2 factorial design. The final sample consisted of n = 289 undergraduate students. We recruited female participants only because they are most likely to watch female content creators. Most participants rated their health as moderate (M = 4.51, SD = 1.34) and their current diet somewhat healthy (M = 4.44, SD = 1.28). Participant demographics can be found in Table 1.

Table 1.

Participant demographics.

		% (n)
Age		M = 19.52, SD = 1.42
Race
	White	86.8% (250)
	Black	4.8% (14)
	Asian	3.1% (9)
	Multiracial	2.4% (7)
	Other	2.4% (7)
	American Indian or Native Alaskan	.4% (1)
Ethnicity
	Hispanic	11% (32)
Height in inches		M = 64.5, SD = 3.00
Weight in pounds		M = 136.1, SD = 22.6
BMI		M = 23.0, SD = 4.03
Dietary habits
	Nut allergies	10.3% (19)
	Dairy free	9.8% (18)
	Fruit allergies	5.9% (11)
	Vegetarian	4.9% (9)
	Pescatarian	3.3% (6)
	Kosher	2.2% (4)
	Lactose intolerance	2.2% (4)
	Seafood allergies	1.6% (3)
	Soy free	1.6% (3)
	Red food coloring allergy	.5% (1)
	Vegan	.5% (1)

Measurement

Social media use. We measured social media use in four ways. First, participants responded to, “How many days a week do you do any of the below activities?” with responses ranging from 0 = no days to 7 = every day. Example activities included “using social media in the 15 min before you go to sleep” and “using social media when eating dinner” (M = 6.07, SD = 1.58).⁵³ Next, we asked participants, “How often do you watch “What I Eat in a Day” content on social media?” with answers ranging from 0 = never to 4 = always (i.e., every time you open social media) (M = 2.56, SD = .92). After that, participants responded to, “How often do you seek out “What I Eat in a Day” content on social media?” with options ranging from 0 = never to 4 = always (M = 2.07, SD = .94). Finally, we asked participants if they had ever seen content from the person in the video they watched or follow them (0 = no, 1 = yes). Most participants did not follow the influencer (n = 282, 97.2%). Additionally, we asked participants if they had ever seen the creators in the YouTube videos they watched for the experiment. Most participants (97.5%, n = 275) selected, “I have never seen any of this creator's content.” Few selected 2.5% (n = 7), “I’ve seen their content, but I’m not a regular viewer.”

Source credibility. We measured source credibility using Ohanian's (1990) three-factor source credibility measure, including perceived trustworthiness, expertise, and attractiveness, using a 7-point semantic differential scale.³¹ There was high reliability for trustworthiness (M = 2.95, SD = 1.15; a = .92), expertise (M = 3.13, SD = 1.17; a = .89), and attractiveness (M = 2.82, SD = 1.01; a = .82).

Authenticity. Authenticity was assessed using Moulard et al.'s (2015) celebrity authenticity scale.⁵⁴ Previous influencer research only uses three out of the nineteen items from Moulard et al.'s (2015) scale and reports high reliability (a = .96).⁵⁵ Similar to Lee and Johnson (2022), the current study used three items from Moulard et al.'s (2015) authenticity scale.^54,55 The scale included the following three items: “she is genuine,” “she seems real to me,” and “she is authentic,” with a 7-point scale where 1 = strongly disagree and 7 = strongly agree. Reliability for the three authenticity items was high (M = 5.34, SD = 1.23; a = .90).

Parasocial interaction. We adapted a parasocial interaction scale.⁵⁶ For example, we changed “I look forward to watching this character on his or her next episode” to “I look forward to watching this person's content.” Additionally, we changed “I miss seeing this character when he or she is not on TV” to “I'd miss seeing this person if I didn't follow them.” We used seven items, and reliability was high (M = 3.83, SD = 1.09; a = .86).

Wishful identification. We adapted wishful identification from Hoffner's (1996) wishful identification scale (3 items).⁴¹ Items included, “I wish my diet was like the person's in this video,” “This person is the sort of person I want to be like myself,” and “I wish I could be more like this person.” Reliability was high (M = 4.55, SD = 1.42; a = .87).

Similarity. We adapted perceived similarity from McCroskey et al.'s (2006) background homophily scale.⁵⁷ Six bipolar items included, “This person's background is/is not similar to mine.” Reliability was good (M = 3.69, SD = 1.00; a = .87).

Intention. Behavioral intention was measured using two items on a 7-point scale, where 1 = strongly disagree and 7 = strongly agree. Participants received the prompt, “Please respond to the following items about your plans for your nutrition in the next 2 weeks.” Items included, “I intend to make changes to my current diet within the next 2 weeks,” (M = 4.34, SD = 1.56) and “I intend to replicate some of the meals or snacks in the video within the next 2 weeks” (M = 3.40, SD = 1.69).

Snack choice. We measured behavior when participants exited the study. The researcher verbally told participants, “Please help yourself to a snack on your way out. Thank you for participating in the study.” The researcher recorded participants’ snack choices in one of three ways: “cookie,” “apple,” or “no snack.” The unhealthy option included cookies, such as Oreos or Chips Ahoy. The healthier option included apples. We offered a variety of apple types. Cookie served as the referent because cookies are a common default or “typical” snack choice, so using them as the referent aligns with participants’ habitual behaviors.

Statistical analysis

Descriptive statistics, correlations, and regressions were calculated to understand the relationships between the independent and dependent variables. The main analysis was conducted using two path analysis models with the gsem command in STATA 19.0. In the first path analysis, the independent variables included the experimental video conditions: sponsorship (sponsored vs. non-sponsored), physical benefits messaging (present vs. absent), and the interaction between sponsorship and physical benefits. Mediating variables included participants’ impressions of the influencers, such as perceived expertise, trustworthiness, and attractiveness. The dependent variable was participants’ nutrition behavior, operationalized as their selection among an apple, cookie, or neither. In the second path analysis, we added BMI as a moderating variable to explore the direct effect of sponsorship and physical benefits on nutrition behavior.

Both path analysis models were specified to estimate both direct and indirect effects of the independent variables on nutrition behavior through influencer impressions. Covariances among mediator error terms were included to account for shared variance between impressions of the influencer. Multinomial logistic regression was used within the gsem framework to model the categorical dependent variable.

Results

Manipulation check

Two items served to check the experimental conditions previously identified by two coders in a content analysis.² Participants who viewed a sponsored video were significantly more likely to recognize that the video was sponsored (M = 5.36, SD = 1.84) compared to those who viewed a non-sponsored video (M = 2.56, SD = 1.48), t(280) = -14.06, p < .001. This suggests that participants were able to discern sponsorship when it was explicitly presented in the video, indicating a heightened ability to identify commercial intent in the content.

Similarly, participants who viewed a benefits-focused video were significantly more likely to report that the influencer mentioned physical health benefits (M = 5.39, SD = 1.48) compared to those who did not view a benefits-focused video (M = 3.61, SD = 1.79), t(280) = −9.10, p < .001. These findings suggest that messages emphasizing specific physical health benefits, such as dietary advantages, are effectively noticed and retained by viewers.

Research questions and hypotheses

The goal of this study was to assess how different aspects of the videos are associated with snack choice. The following hypotheses and research questions investigate these relationships. Relationships between video conditions (i.e., sponsorship, physical health benefits, interaction) and snack choices as well as impressions and snack choices can be found in Table 2. Relationships between video conditions (i.e., sponsorship, physical health benefits, interaction) and impressions can be found in Table 3.

Table 2.

Direct effects of sponsorship, health benefits, and influencer impressions on snack choice.

	Apple	No Snack
	b(se)	b(se)
Sponsorship	.56(.77)	−.75(.38)*
Physical health benefits	1.12(.77)	−.02(.39)
Sponsorship X Physical health benefits	−1.02(1.01)	.95(.54)
Trustworthiness	.15(.32)	−.06(.18)
Expertise	.15(.32)	−.00(.15)
Attractiveness	−.32(.27)	.09(.15)
Similarity	−.47(.28)	.46(.16)***
Authenticity	.37(.29)	−.08(.16)
Wishful identification	.09(.21)	−.05(.22)
Parasocial interaction	.08(.33)	−.28(.18)
Intention to change diet	.07(.18)	.26(.11)**
Intention to replicate influencer meals	−.17(.18)	−.05(.10)

Note: Total N = 289. Coefficients are unstandardized. ***p < .001, ** p < .01, *p < .05. Snack choice referent is a cookie.

Table 3.

Direct effects of sponsorship and health benefits on influencer impressions.

	Trustworthiness	Expertise	Attractiveness	Similarity	Authenticity	Wishful identification	Parasocial interaction	Intention to change diet	Intention to replicate influencer meals
	b(se)	b(se)	b(se)	b(se)	b(se)	b(se)	b(se)	b(se)	b(se)
Sponsorship	.45(.19)**	.15(.19)	51(.16)**	−.19(.17)	−.47(.20)*	−.07(.23)	−.38(.18)*	−.11(.26)	.13(.28)
Physical health benefits	.08(.19)	−.64(.19)***	.17(.16)	−.26(.17)	−.38(.20)	.00(.24)	−.22(.18)	−.25(.26)	−.01(.28)
Sponsorship X Physical health benefits	.06(.27)	.50(.27)	−.84(.23)***	.02(.24)	.18(.28)	.03(.34)	.26(.26)	.24(.37)	−.32(.37)

Note: Total N = 289. Coefficients are unstandardized. ***p < .001, ** p < .01, *p < .05.

Sponsorship, physical health benefits, and snack choice

The first research question asked how exposure to sponsored WIEIAD vlogs is related to snack choice. Those who saw a sponsored video were more likely to select a snack. Sponsorship was not associated with selecting an apple. The first hypothesis expected that exposure to vlogs that stated physical health benefits of the diet would be related to participants selecting a healthier snack choice. Disclosure of physical health benefits was not associated with any snack choice. Specifically, influencer disclosure of physical health benefits was not associated with selecting an apple or selecting neither, compared to those who selected a cookie. Physical health benefits did not have an impact on snack choice. We also investigated the interaction of physical health benefits and sponsorship on snack choice. Research question two asked how the interaction of sponsored vlogs containing physical health benefits impacts snack choice. Compared to those who selected the cookie, the interaction of sponsorship and physical health benefits was not related to selecting an apple or not selecting a snack. This indicates that the combined effect of sponsorship and physical health benefits did not influence participants’ likelihood of choosing the apple or skipping a snack, relative to choosing the cookie.

Sponsorship and impressions

Hypothesis two expected a negative relationship between sponsored vlogs and impressions of the influencer (e.g., expertise, wishful identification). Sponsorship was positively associated with trustworthiness and attractiveness and negatively associated with parasocial interaction and authenticity. In other words, when participants saw a sponsored video, they viewed the influencer as more trustworthy and attractive. However, sponsorship was not associated with wishful identification or similarity. Sponsored messages did not increase perceptions of wanting to be like the influencer or perceived similarity. Sponsorship was not associated with intentions to change their current diet or replicate the influencer's meals. As such, sponsored messages were not related to behavioral intentions.

Physical health benefits and impressions

Hypothesis three expected to find a positive relationship between vlogs containing a statement about physical health benefits and stronger impressions of the influencer. Disclosure of physical health benefits was negatively associated with expertise. When influencers disclosed physical health benefits related to their diet, participants viewed them as having less expertise. Benefits were not associated with trustworthiness, attractiveness, similarity, authenticity, wishful identification, or parasocial interaction. Benefits were not associated with intentions to change their current diet or replicate the influencer's meals. Overall, these findings suggest that while highlighting physical health benefits may reduce perceived expertise, it does not appear to be associated with other perceptions of the influencer or participants’ nutrition-related intentions.

Interaction and impressions

The third research questions asked how the interaction of sponsorship and physical health benefits is related to influencer credibility, similarity, authenticity, wishful identification, and parasocial interaction. The interaction was not associated with trustworthiness, expertise, similarity, authenticity, wishful identification, or parasocial interaction. The interaction was negatively associated with attractiveness. Influencers who presented a sponsored message and disclosure of their diet's physical health benefits were viewed as less attractive. Combining sponsorship with health-benefit disclosures may reduce perceived attractiveness, but does not appear to influence other perceptions of the influencer or participants’ nutrition-related intentions.

Influencer impressions and snack choice

The fourth research question asked how influencer credibility, authenticity, and similarity inform women's choices between healthier and less healthy snacks. Compared to those who selected a cookie, trustworthiness, expertise, attractiveness, similarity, and authenticity were not related to selecting an apple. Compared to those who selected a cookie, trustworthiness, expertise, attractiveness, and authenticity were not associated with not selecting a snack. However, greater perceived similarly was associated with not selecting a snack. In other words, when viewers felt more similar to the influencer, they were more likely to opt out of a snack.

Wishful identification, parasocial interaction, and snack choice

The fifth research question asked how wishful identification and parasocial interaction relate to women's snack choice, particularly in terms of healthier or less healthy options. Compared to those who selected the cookie, wishful identification and parasocial interaction were not associated with selecting the apple. Additionally, compared to those who selected the cookie, wishful identification and parasocial interaction were not associated with selecting no snack. This finding suggests that the psychological factors, such as wanting to be like the influencer and feeling a one-sided connection with the influencer, did not influence participants’ likelihood of selecting any of the presented snacks.

Behavioral intentions and snack choice

The sixth research question asked how intention to alter diet or replicate the influencer's meals related to snack choice. Compared to those who selected the cookie, those with a greater intention to change their diet selected no snack, but there was no relationship between intending to replicate the influencer's meals and not selecting a snack. Additionally, there was no relationship between intentions to change their diet or replicate the influencer's meals and selecting an apple, compared to selecting a cookie. Overall, these results suggest that participants’ intentions to change their diet, rather than their intentions to replicate the influencer's meals, were associated with opting out of consumption, but neither intention influenced the choice of an apple over a cookie.

Direct effects of BMI as a moderator

Compared to selecting an apple, BMI was positively associated with not selecting the apple or the cookie. This pattern held in both sponsorship conditions. When the message was not sponsored, higher BMI was associated with a greater likelihood of selecting neither the apple nor the cookie (b = .11, se = .04, p = .007). When the message was sponsored, the relationship was similar, such that higher BMI was associated with opting out of a snack selection (b = .07, se = .04, p = .05). The nutrition behavior of people with a higher BMI involves opting out of a snack in the current experiment and this relationship does not vary based on whether a sponsored message is present.

Discussion

The prevalence of influencer WIEIAD content on social media resulted in concerns about its role in proliferating misinformation,⁴ triggering self-comparison and negative body image,⁶ and contributing to toxic diet culture in content consumers.⁷ Investigating these concerns, the current experiment assesses the effects of sponsorship and physical expectancies in WIEIAD content on audience behavioral intentions, behavior, and perceptions of influencers. Our results demonstrate that sponsorship increases perceptions of influencer trustworthiness and attractiveness. However, sponsorship decreases perceptions of authenticity and parasocial interaction, while simultaneously increasing the likelihood of selecting a snack. Together, neither sponsorship nor diet benefit messaging led to the selection of a healthier snack, and those with intentions to change their diet were more likely to opt out of eating. Generally, results show that perceptions of influencers impacted participant snack choice, rather than the messaging present in the video. Three key findings emerged related to the effects of WIEIAD content, including: the effect of sponsorship on influencer perceptions, effect of sponsorship on nutrition behavior, and association between intention and nutrition behavior.

Our first key finding suggests a complex relationship between sponsorship presence and perceptions of influencers. Sponsored content led to higher ratings of influencer trustworthiness and attractiveness. Despite these positive evaluations, sponsored content was also found to negatively affect ratings of authenticity and parasocial interaction. Although some research finds a positive association between trustworthiness and authenticity,¹³ sponsorship has typically been negatively associated with perceptions of authenticity.^24,40 Through the process of image transfer,⁵⁸ perceptions of a brand can be transferred to the influencer or celebrity who is engaging in an endorsement. Image transfer involves an associative link, where one's evaluation of a brand's credibility or attractiveness carries over to the evaluation of the influencer endorsing the brand. In the case of WIEIAD, it is possible that the brands shown in sponsored content were perceived as trustworthy and attractive, which through the process of image transfer, increased these ratings in the influencers endorsing these brands. Although the image transfer of sponsored content may increase feelings of trust and perceptions of attractiveness, these features of influencer credibility did not impact perceptions of authenticity nor were they associated with parasocial interaction.

Our second key finding assessed the impact of sponsorship in WIEIAD content on snack selection, contributing to the gap in literature linking sponsored content to behavior. Participants who viewed a sponsored video were found to be more likely to take a cookie compared to those who did not see a sponsored video. This suggests that influencer advertising in WIEIAD was successful in altering nutrition behavior, through the process of media priming. Media priming occurs when a stimulus is presented in a media context, triggering cognitive activation and ensuing behaviors in response to the stimulus.⁵⁹ Some explanations of media priming position it as subconscious, heuristic processing, occurring in contexts where audiences are less aware of the target outcome or effect.⁶⁰ Thus, the backstage self-presentation style used in WIEAD content may serve as an optimal environment for heuristic priming via sponsorship; the expectation that this content shows the private, informal life of the influencer may ‘lower the guard’ of viewers’ central or deliberative processing⁶⁰ or reactance, while priming them for branded food and consumption. It is important to note that the snacks available to participants were not the same foods present in WIEIAD sponsored content, however all foods were popular brands. Ultimately, sponsorship may serve as heuristic for brands, resulting in activation or heightened salience of brands, and the resulting behavior of choosing a branded food.

Finally, study results demonstrate a significant association between participant's behavioral intention and nutrition behavior. Participants with a greater intention to change their diet were more likely not to select a snack than to select a cookie after watching the WIEIAD video, which is in line with a large body of research validating intention as an effective predictor for behavior.⁴⁹ Generally, intention to change diet was associated with consumption reduction or avoidance of consumption. Thus, individuals with intention to change their diet, when exposed to WIEIAD content, may be susceptible to engage in reduced consumption. When considering populations vulnerable to consumption reduction intentions, such as those diagnosed with anorexia nervosa or other clinical eating disorders, the limited effects of content exposure on nutrition behaviors may be a viable concern.

From a practical application perspective, findings suggest that sponsored content may impact one-shot nutrition behaviors through the process of media priming, and in the context of backstage influencer content. For brands considering sponsorships with influencers, WIEIAD video formats may be an effective vehicle for brand-related persuasion and driving nutrition behaviors. However, due to the impacts of sponsored content in reducing authenticity and parasocial relationships with influencers, whether sponsored content would drive long-term health behaviors and brand affiliation is uncertain. As most media consumption involves repeated and varying exposure, examining longitudinal effects of WIEIAD content is an important next step for future research. In relation to the association between intention and not selecting a cookie or apple, health practitioners treating and educating patients on nutrition may consider addressing the contents of one's media diet, including WIEIAD content, as an important factor influencing one's diet. Finally, the rise of WIEIAD videos and trends like #SkinnyTok on platforms such as TikTok and YouTube has intensified concerns about the influence of social media on disordered eating behaviors, particularly among adolescents and young adults.⁶¹ While platforms have implemented measures to curb harmful content, such as banning specific hashtags and redirecting searches to support resources, users often circumvent these restrictions through coded language and alternative spellings, allowing pro-eating disorder content to persist.⁶¹ Given the findings about opting out of snacks and the current SkinnyTok trends, there is a necessity for comprehensive influencer regulation and digital health policies that address the proliferation of harmful content related to eating disorders.

Limitations and future directions

This study has several limitations that serve as areas for future research. First, the sample consisted exclusively of undergraduate female students from a single mid-Atlantic university, limiting the generalizability of the findings. Future research should consider a more diverse sample, including participants from different age groups, educational backgrounds, and geographic locations to enhance external validity. Next, the study used pre-existing WIEIAD videos selected from a prior content analysis, which ensured ecological validity but limited experimental control over video content. While videos were carefully chosen to fit the experimental conditions, variations in production quality, influencer persona, and engagement styles may have occurred. Third, the experimental setting may not fully replicate the naturalistic environment in which individuals typically consume social media content. Watching videos in a lab setting with potential monitoring may influence attention and engagement differently than viewing content in a personal, relaxed environment. Future research could employ field experiments or use eye-tracking and physiological measures to assess real-time engagement with social media content. Fourth, the social media exposure question asked participants if they “always” seek out WIEIAD content, which could be further clarified. We cannot be sure if participants indicated if they always seek out WIEIAD content or if they seek it out every time they are on social media.

While the snack choice measure provides an innovative behavioral outcome, the available food options (cookies vs. apples) may not fully capture the range of dietary behaviors influenced by WIEIAD videos. Additionally, some participants had restrictions and couldn’t select the cookie (e.g., 2.7% were gluten free). Future research could examine longer-term dietary choices or employ ecological momentary assessments (EMA) to track real-world eating behaviors post-exposure. Finally, while this study focused on sponsorship and physical expectancies, additional message features, such as emotional appeals, influencer credibility, and audience engagement (e.g., likes and comments), warrant further investigation. Exploring these elements can provide a more comprehensive understanding of how WIEIAD videos influence viewer perceptions and behaviors.

Conclusion

This study expands our understanding of how long-form “What I Eat in a Day” videos influence dietary perceptions and behaviors, addressing gaps in prior research focused on short-form content. Findings suggest that sponsorship increases perceptions of influencer trustworthiness and attractiveness but decreases authenticity and parasocial interaction, while also increasing the likelihood of selecting a cookie. However, neither sponsorship nor diet benefit messaging influenced the selection of a healthier snack choice, and those with intentions to change their diet were more likely to opt out of eating. These results highlight the complex ways WIEIAD digital content may shape nutrition behaviors. Future research should examine the long-term effects of WIEIAD exposure and explore how influencer characteristics shape dietary outcomes to inform public health efforts.

Footnotes

ORCID iD

Emily J Pfender

Ethical approval

The work described has not been published previously.

The article is not under consideration for publication elsewhere.

The article's publication is approved by all authors and tacitly or explicitly by the responsible authorities where the work was carried out.

We received Human Subjects approval from the University of Delaware to do this research (IRB approval #: 2169803-1).

Contributions

Emily Pfender – study lead and project manager, conceptualization, data collection, data analysis, write initial and final drafts

Claire Wanzer – data collection, write initial draft

Katelynn Kuijpers - data collection, reviewed initial and final drafts

Amy Bleakley – conceptualization, data analysis, editing and reviewing final manuscript.

Funding

The authors received no financial support for the research, authorship, and/or publication of this article.

Declaration of conflicting interests

The authors declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Data availability

Data are available from the first author upon request.

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Your media diet is impacting your actual diet: The effects of influencer “What I Eat in a Day” YouTube videos on influencer perceptions and nutrition behaviors

Abstract

Objective

Methods

Results

Conclusions

Keywords

Introduction

Features of WIEIAD content

Sponsorship and self-presentation theory

Physical health benefits and expectancy value theory

Source credibility theory and WIEAD message features

Self-presentation theory and WIEAD message features

Impressions and nutrition-related behavior

Methods

Procedure and experimental design

Sample

Measurement

Statistical analysis

Results

Manipulation check

Research questions and hypotheses

Sponsorship, physical health benefits, and snack choice

Sponsorship and impressions

Physical health benefits and impressions

Interaction and impressions

Influencer impressions and snack choice

Wishful identification, parasocial interaction, and snack choice

Behavioral intentions and snack choice

Direct effects of BMI as a moderator

Discussion

Limitations and future directions

Conclusion

Footnotes

ORCID iD

Ethical approval

Contributions

Funding

Declaration of conflicting interests

Data availability

References