The Effect of Periodic Email Prompts on Participant Engagement With a Behavior Change mHealth App: Longitudinal Study.

BACKGROUND: Following the need for the prevention of noncommunicable diseases, mobile health (mHealth) apps are increasingly used for promoting lifestyle behavior changes. Although mHealth apps have the potential to reach all population segments, providing accessible and personalized services, their effectiveness is often limited by low participant engagement and high attrition rates. OBJECTIVE: This study concerns a large-scale, open-access mHealth app, based in the Netherlands, focused on improving the lifestyle behaviors of its participants. The study examines whether periodic email prompts increased participant engagement with the mHealth app and how this effect evolved over time. Points gained from the activities in the app were used as an objective measure of participant engagement with the program. The activities considered were physical workouts tracked through the mHealth app and interactions with the web-based coach. METHODS: The data analyzed covered 22,797 unique participants over a period of 78 weeks. A hidden Markov model (HMM) was used for disentangling the overtime effects of periodic email prompts on participant engagement with the mHealth app. The HMM accounted for transitions between latent activity states, which generated the observed measure of points received in a week. RESULTS: The HMM indicated that, on average, 70% (15,958/22,797) of the participants were in the inactivity state, gaining 0 points in total per week; 18% (4103/22,797) of the participants were in the average activity state, gaining 27 points per week; and 12% (2736/22,797) of the participants were in the high activity state, gaining 182 points per week. Receiving and opening a generic email was associated with a 3 percentage point increase in the likelihood of becoming active in that week, compared with the weeks when no email was received. Examining detailed email categories revealed that the participants were more likely to increase their activity level following emails that were in line with the program's goal, such as emails regarding health campaigns, while being resistant to emails that deviated from the program's goal, such as emails regarding special deals. CONCLUSIONS: Participant engagement with a behavior change mHealth app can be positively influenced by email prompts, albeit to a limited extent. Given the relatively low costs associated with emails and the high population reach that mHealth apps can achieve, such instruments can be a cost-effective means of increasing participant engagement in the stride toward improving program effectiveness.

Adoption of the Website and Mobile App of a Preventive Health Program Across Neighborhoods With Different Socioeconomic Conditions in the Netherlands: Longitudinal Study.

BACKGROUND: Socioeconomic disparities in the adoption of preventive health programs represent a well-known challenge, with programs delivered via the web serving as a potential solution. The preventive health program examined in this study is a large-scale, open-access web-based platform operating in the Netherlands, which aims to improve the health behaviors and wellness of its participants. OBJECTIVE: This study aims to examine the differences in the adoption of the website and mobile app of a web-based preventive health program across socioeconomic groups. METHODS: The 83,466 participants in this longitudinal, nonexperimental study were individuals who had signed up for the health program between July 2012 and September 2019. The rate of program adoption per delivery means was estimated using the Prentice, Williams, and Peterson Gap-Time model, with the measure of neighborhood socioeconomic status (NSES) used to distinguish between population segments with different socioeconomic characteristics. Registration to the health program was voluntary and free, and not within a controlled study setting, allowing the observation of the true rate of adoption. RESULTS: The estimation results indicate that program adoption across socioeconomic groups varies depending on the program's delivery means. For the website, higher NSES groups have a higher likelihood of program adoption compared with the lowest NSES group (hazard ratio 1.03, 95% CI 1.01-1.05). For the mobile app, the opposite holds: higher NSES groups have a lower likelihood of program adoption compared with the lowest NSES group (hazard ratio 0.94, 95% CI 0.91-0.97). CONCLUSIONS: Promoting preventive health programs using mobile apps can help to increase program adoption among the lowest socioeconomic segments. Given the increasing use of mobile phones among disadvantaged population groups, structuring future health interventions to include mobile apps as means of delivery can support the stride toward diminishing health disparities.

Can graphic warning labels reduce the consumption of meat?

The classification of red meat as "probably carcinogenic" and processed meat as "carcinogenic" was followed by pleas to place warning labels, akin to those used for tobacco products, onto meat products. These labels educate people about the health risks associated with the target behavior and are typically accompanied by graphic imagery that elicits disgust (e.g., a picture of blackened lungs). Although the emotion of disgust has been shown to be an effective tool to affect consumer attitudes toward meat, it remains unclear whether such graphic warning labels that recruit disgust would also affect people's intentions to reduce their meat consumption. Two experiments reveal that graphic warning labels, by recruiting disgust, can increase people's intention to reduce their current levels of meat consumption. However, by eliciting disgust, graphic warning labels can simultaneously trigger reactance: graphic images can make people feel they are being manipulated, thereby ironically decreasing meat-reduction intentions. In a final experiment, we aimed to circumvent reactance by providing disgusting information under the guise of trivia, thereby avoiding the perception that the disgusting information was meant to manipulate. Via this route, disgust becomes a potent tool to influence consumers' intentions to consume meat. Ethical concerns are discussed.

No Way, That's Gross! How Public Exposure Therapy Can Overcome Disgust Preventing Consumer Adoption of Sustainable Food Alternatives.

Two prominently discussed sustainable food alternatives-lab-meat and edible insects-elicit disgust among consumers, thereby preventing acceptance. While providing prospective consumers with more information on, for instance, the environmental benefits of lab-meat has shown some success in increasing consumer acceptance, we argue that the disgust response-the main barrier to the societal acceptance of these foods-is not addressed. This is, we argue, because disgust is not the result of misperceptions (e.g., edible insects carry diseases) and thus unlikely to be overcome by information alone. Building on the latest insights into the social origins of disgust, this manuscript reviews an alternative strategy to foster the broader acceptance of sustainable food alternatives that currently elicit disgust. Specifically, we explain why and how public exposure could be a promising avenue for marketers to reduce consumers' disgust response and thus increase the acceptance of sustainable food alternatives.

Propelling pride to promote healthy food choices among entity and incremental theorists.

Past research suggests that people's beliefs about the malleability of their body weight influence their motivation to engage in healthful behaviors: people who perceive their body weight as fixed (entity theorists) engage less in healthful behaviors than people who perceive their body weight as changeable (incremental theorists). Accordingly, current health interventions frequently aim at shifting entity theorists' beliefs about the malleability of their body weight. Instead of trying to change these beliefs, we test whether the elicitation of pride from past achievements can serve as an intervention to promote healthful behaviors among entity theorists. In addition, we contrast the effect of pride recall among entity theorists with the effect among incremental theorists. Specifically, we find that entity theorists chose healthier behaviors upon the recall of pride related and unrelated to the health domain - the source of pride does not seem to matter. For incremental theorists, however, the source of pride does matter. While health-related pride led them to persist in making healthy food choices, health-unrelated pride instilled reward-seeking behavior among incremental theorists. Prompting health-related pride might be a viable motivational tool to promote healthy food choices, as it is beneficial for entity theorists without thwarting the motivation of incremental theorists.

Losses tune differently than gains: how gains and losses shape attentional scope and influence goal pursuit.

Research on the asymmetric effect of negative versus positive affective states (induced by gains or losses) on scope of attention, both at a perceptual and a conceptual level, is abundant. However, little is known about the moderating effect of anticipating gains or losses versus actually experiencing them and about any downstream consequences of these effects on goal-directed behaviour. In two studies, we show that gains versus losses induce qualitatively different processes. In Experiment 1, we demonstrate that the anticipation of monetary gains results in a narrowing of attentional scope, while experiencing gains broadens the scope of attention. We find the reverse pattern concerning monetary losses - while anticipation of monetary losses results in broadening of attentional scope, the actual experience of losses results in narrowing of attentional scope. Additionally, Experiment 2 replicates these findings and shows how differential attentional tuning as a function of the anticipation versus experience of gains versus losses modulates priming-induced goal-directed behaviour.

A packaged mindset: How elongated packages induce healthy mindsets.

Product packaging is an important instrument for marketers to draw consumer attention to specific product information and influence product perceptions. The purpose of this research is to investigate whether exposure to a product's packaging can also activate specific mindsets that, once activated, alter consumers' food perceptions. The results of three experiments demonstrate that elongated containers activate a health mindset that influences both consumers' perception of the packaged food product but also their health perceptions of subsequently encountered food. Specifically, foods in elongated containers lead consumers to think of concepts related to healthiness, which have differentiable effects on subsequent healthy and unhealthy food products.

Stop spoon dosing: milliliter instructions reduce inclination to spoon dosing.

BACKGROUND: Does the use of teaspoon units in dose recommendations on Drug Facts panels of liquid medicine lead to dosing errors and could any such errors be reduced if millimeter units were used instead? FINDINGS: Participants given dosing instructions in teaspoon units were twice as likely to choose a kitchen teaspoon as those given instructions in milliliter units (31.3 vs. 15.4%). CONCLUSION: Our results suggest that spoon usage--and the inherent risk of dosage errors--could be reduced by more than 50% simply by changing the units of measurement given in dosing instructions.

Larger bowl size increases the amount of cereal children request, consume, and waste.

OBJECTIVE: To examine whether larger bowls bias children toward requesting more food from the adults who serve them. STUDY DESIGN: Study 1 was a between-subject design involving 69 preschool-age children who were randomized to receive either a small (8 oz) or large (16 oz) cereal bowl and were asked to tell researchers how much cereal they wanted for a morning snack. Study 2 was a within-subject design involving 18 school-age children at a summer camp who were given a small (8 oz) cereal bowl on one day and a large (16 oz) cereal bowl on another day and asked by a cafeteria server how much cereal and milk they wanted for breakfast. Hidden scales measured how much cereal and milk were served, consumed, and wasted. Body mass index was calculated at the end of the study. RESULTS: In study 1, the young children requested almost twice as much cereal to eat when presented with the larger bowl compared with the smaller bowl. In study 2, the older children consumed 52% more and wasted 26% more when served in the larger bowl. CONCLUSION: A step toward potentially reducing overeating and waste would be for parents and adult caregivers to use smaller bowls for serving food to children.

Portion size me: plate-size induced consumption norms and win-win solutions for reducing food intake and waste.

Research on the self-serving of food has empirically ignored the role that visual consumption norms play in determining how much food we serve on different sized dinnerware. We contend that dinnerware provides a visual anchor of an appropriate fill-level, which in turn, serves as a consumption norm (Study 1). The trouble with these dinnerware-suggested consumption norms is that they vary directly with dinnerware size--Study 2 shows Chinese buffet diners with large plates served 52% more, ate 45% more, and wasted 135% more food than those with smaller plates. Moreover, education does not appear effective in reducing such biases. Even a 60-min, interactive, multimedia warning on the dangers of using large plates had seemingly no impact on 209 health conference attendees, who subsequently served nearly twice as much food when given a large buffet plate 2 hr later (Study 3). These findings suggest that people may have a visual plate-fill level--perhaps 70% full--that they anchor on when determining the appropriate consumption norm and serving themselves. Study 4 suggests that the Delboeuf illusion offers an explanation why people do not fully adjust away from this fill-level anchor and continue to be biased across a large range of dishware sizes. These findings have surprisingly wide-ranging win-win implications for the welfare of consumers as well as for food service managers, restaurateurs, packaged goods managers, and public policy officials.

Extraverted children are more biased by bowl sizes than introverts.

Extraverted children are hypothesized to be most at risk for over-serving and overeating due to environmental cues--such as the size of dinnerware. A within-subject field study of elementary school students found that extraverted children served themselves 33.1% more cereal in larger bowls (16-oz) than in smaller (12-oz) bowls, whereas introverted children were unaffected by bowl size (+5.6%, ns). However, when children were asked by adults how much cereal they wanted to eat, both extraverted and introverted children requested more cereal when given a large versus small bowl. Insofar as extraverted children appear to be more biased by environmental cues, this pilot study suggests different serving styles are recommended for parents and other caregivers. They should serve extraverts, but allow introverts to serve themselves. Still, since the average child still served 23.2% more when serving themselves than when served by an adult, it might be best for caregivers to do the serving whenever possible--especially for extraverted children.

Fast food restaurant lighting and music can reduce calorie intake and increase satisfaction.

Recent research shows that environmental cues such as lighting and music strongly bias the eating behavior of diners in laboratory situations. This study examines whether changing the atmosphere of a fast food restaurant would change how much patrons ate. The results indicated that softening the lighting and music led people to eat less, to rate the food as more enjoyable, and to spend just as much. In contrast to hypothesized U-shaped curves (people who spend longer eat more), this suggests a more relaxed environment increases satisfaction and decreases consumption.

How negative experiences shape long-term food preferences. Fifty years from the World War II combat front.

How does a person's first experience with a foreign or unfamiliar food shape their long-term preference and behavior toward that food? To investigate this, 493 American veterans of World War II were surveyed about their preference for Japanese and Chinese food. Pacific veterans who experienced high levels of combat had a stronger dislike for these Asian foods than those Pacific veterans experiencing lower levels of combat. Consistent with expectations, combat experience for European veterans had no impact on their preference for Asian food. The situation in which one is initially exposed to an unfamiliar food may long continue to shape preferences.

Ice cream illusions bowls, spoons, and self-served portion sizes.

BACKGROUND: Because people eat most of what they serve themselves, any contextual cues that lead them to over-serve should lead them to over-eat. In building on the size-contrast illusion, this research examines whether the size of a bowl or serving spoon unknowingly biases how much a person serves and eats. METHODS: The 2 x 2 between-subjects design involved 85 nutrition experts who were attending an ice cream social to celebrate the success of a colleague in 2002. They were randomly given either a smaller (17 oz) or a larger (34 oz) bowl and either a smaller (2 oz) or larger (3 oz) ice cream scoop. After serving themselves, they completed a brief survey as their ice cream was weighed. The analysis was conducted in 2003. RESULTS: Even when nutrition experts were given a larger bowl, they served themselves 31.0% more (6.25 vs 4.77 oz, F(1, 80) = 8.05, p < 0.01) without being aware of it. Their servings increased by 14.5% when they were given a larger serving spoon (5.77 vs 5.04 oz, F(1, 80)=2.70, p = 0.10). CONCLUSIONS: People could try using the size of their bowls and possibly serving spoons to help them better control how much they consume. Those interested in losing weight should use smaller bowls and spoons, while those needing to gain weight--such as the undernourished or aged--could be encouraged to use larger ones. Epidemiologic implications are discussed.

Shape of glass and amount of alcohol poured: comparative study of effect of practice and concentration.

OBJECTIVE: To determine whether people pour different amounts into short, wide glasses than into tall, slender ones. DESIGN: College students practised pouring alcohol into a standard glass before pouring into larger glasses; bartenders poured alcohol for four mixed drinks either with no instructions or after being told to take their time. SETTING: University town and large city, United States. PARTICIPANTS: 198 college students and 86 bartenders. MAIN OUTCOME MEASURES: Volume of alcohol poured into short, wide and tall, slender glasses. RESULTS: Aiming to pour a "shot" of alcohol (1.5 ounces, 44.3 ml), both students and bartenders poured more into short, wide glasses than into tall slender glasses (46.1 ml v 44.7 ml and 54.6 ml v 46.4 ml, respectively). Practice reduced the tendency to overpour, but not for short, wide glasses. Despite an average of six years of experience, bartenders poured 20.5% more into short, wide glasses than tall, slender ones; paying careful attention reduced but did not eliminate the effect. CONCLUSIONS: To avoid overpouring, use tall, narrow glasses or ones on which the alcohol level is premarked. To avoid underestimating the amount of alcohol consumed, studies using self reports of standard drinks should ask about the shape of the glass.