"You started working out to get a flat stomach and a fat a$$": A content analysis of fitspiration videos on TikTok.

Fitspiration presents idealised bodies to viewers, emphasising a fit ideal to women and a muscular ideal to men. Previous content analyses have focused on images from Instagram, with research yet to examine video content on TikTok or verify the accuracy of the diet and exercise information posted by fitness influencers. This content analysis examined 200 videos from popular TikTok fitspiration hashtags (fitness, fitspo, gymtok, fittok). Two independent coders used a standardised codebook containing definitions and examples for coding. Overall, 78 % of videos showed only women, and 10 % of videos showed only men. Videos of women included both fit and thin idealised bodies, whole body and specific body part objectification, harmful themes, and promoted appearance-related reasons for exercise more frequently than videos containing men. Videos of men included muscular idealised bodies and objectification through face obscurity (excluding the face from view) more frequently than videos of women. Most videos were posted by fitness influencers, and 60 % of videos presented incorrect or harmful information. Findings suggest that fitspiration TikTok content contains characteristics known to negatively impact body image and highlights gendered differences in content themes. Further investigation is required on the promotion of appearance reasons to exercise, and the credibility of information and content creators.

The role of cognitive biases involving selective interrogation of taste-based information in sugar-sweetened beverage consumption.

BACKGROUND AND OBJECTIVES: Consumption of sugar-sweetened beverages (SSBs) is a global public health issue. Consequently, there is strong interest in advancing understanding of the cognitive mechanisms that underpin excessive SSB consumption. This work proposes that selective interrogation of taste-based characteristics (e.g., flavour), rather than health-based characteristics (e.g., sugar content), of beverages is associated with greater SSB choice and consumption. METHODS: To evaluate this novel hypothesis, undergraduate students (n = 210) were recruited to complete self-report measures of SSB consumption, motivation and success in reducing SSB consumption and unhealthy eating more broadly, as well as a novel selective interrogation assessment task. This task provided participants with the opportunity to selectively interrogate taste-based and health-based characteristics of various mystery beverages. RESULTS: Results supported the hypothesis that greater selective interrogation of taste-based characteristics, rather than health-based characteristics, of beverages is associated with greater SSB choice and consumption. Additionally, results revealed that greater selective interrogation of taste-based characteristics was associated with decreased motivation to reduce SSB consumption and decreased motivation and success to reduce unhealthy consumption more broadly. LIMITATIONS: The current study did not evaluate whether selective interrogation of taste-based characteristics of beverages predicted actual SSB consumption. CONCLUSION: These findings provide novel evidence for the potential role of selective interrogation of taste-based characteristics of beverages in SSB choice and consumption. An important implication of these findings is that in order for interventions focusing on front-of-package nutrition labels to be effective in reducing unhealthy consumption, it is necessary that individuals are selectively interrogating this 'health-based' information.

A circadian-informed lighting intervention accelerates circadian adjustment to a night work schedule in a submarine lighting environment.

STUDY OBJECTIVE: Night work has detrimental impacts on sleep and performance, primarily due to misalignment between sleep-wake schedules and underlying circadian rhythms. This study tested whether circadian-informed lighting accelerated circadian phase delay, and thus adjustment to night work, compared to blue-depleted standard lighting under simulated submariner work conditions. METHODS: Nineteen healthy sleepers (12 males; mean±SD aged 29 ±10 y) participated in two separate 8-day visits approximately one month apart to receive, in random order, circadian-informed lighting (blue-enriched and dim, blue-depleted lighting at specific times) and standard lighting (dim, blue-depleted lighting). After an adaptation night (day 1), salivary dim light melatonin onset (DLMO) assessment was undertaken from 18:00-02:00 on days 2-3. During days 3-7, participants completed simulated night work from 00:00-08:00 and a sleep period from 10:00-19:00. Post-condition DLMO assessment occurred from 21:00-13:00 on days 7-8. Ingestible capsules continuously sampled temperature to estimate daily core body temperature minimum (Tmin) time. Tmin and DLMO circadian delays were compared between conditions using mixed effects models. RESULTS: There were significant condition-by-day interactions in Tmin and DLMO delays (both p<0.001). After four simulated night shifts, circadian-informed lighting produced a mean [95%CI] 4.3 [3.3 to 5.4] h greater delay in Tmin timing and a 4.2 [3 to 5.6] h greater delay in DLMO timing compared to standard lighting. CONCLUSIONS: Circadian-informed lighting accelerates adjustment to shiftwork in a simulated submariner work environment. Circadian lighting interventions warrant consideration in any dimly lit and blue-depleted work environments where circadian adjustment is relevant to help enhance human performance, safety, and health.

Effects of traffic light labelling and increased healthy range on beverage choices from vending machines.

OBJECTIVE: To test whether traffic light labels and an increased range of healthy beverages, individually and in combination, can increase healthy beverage choices from vending machines. DESIGN: Two studies (n 558, 420) tested whether the provision of traffic light labels (green, amber and red) and an increased range of healthy beverages (from 20 % to 50 % green options), individually and in combination, could increase healthy beverage choices from a digital vending machine display. The studies used a between-subjects experimental design, and a hypothetical beverage choice, a limitation when considering real-world applicability. SETTING: Both studies utilised an online Qualtrics survey that featured a digital vending machine display. PARTICIPANTS: Both studies (n 558, 420) consisted of university students from Flinders University and individuals from a survey recruitment service. RESULTS: Featuring traffic lights did not significantly influence beverage choices (P = 0·074), while increasing the healthy range (P = 0·003, OR = 3·27), and the combination of both, did significantly increase healthier beverage choices (P < 0·001, OR = 4·83). CONCLUSIONS: The results suggest that the traffic light system and increased healthy range are not maximally effective when used on their own, and benefit greatly when combined, to increase healthy beverage choices. It was suggested that the provision of traffic light labels supplied the necessary nutritional information, and the increased healthy range offered greater opportunity to act in accordance with that information. In so doing, the present findings offer a promising pathway for reducing unhealthy beverage consumption.

Effectiveness of visual nudges for encouraging healthier beverage choices from vending machines.

ISSUES ADDRESSED: Research suggests visual nudging techniques can subtly encourage healthier consumption. Two experiments explored the effect of four visual primes for nudging drink choices from a vending machine display. METHODS: Participants (17-25 years) were randomly assigned to view vending machine advertising posters containing pictorial nudges of water, soft drink, general health (runner), or a text-only control, for nudging vending machine choices. Participants then selected an item from a vending machine display containing drinks only (Experiment 1; n = 164), or both drinks and snack foods (Experiment 2, n = 684). RESULTS: In both experiments, nudging condition predicted beverage choice. Specifically, the water image nudged healthier beverage choices in both experiments. However, there was no effect on food choice in Experiment 2. Furthermore, in both experiments, liking and habitual consumption of chosen items were also significant predictors of choice, but condition predicted beverage choice over and above these. CONCLUSION: A water prime may be an effective means of encouraging healthier beverage choices in a vending machine environment. SO WHAT?: Findings have the potential to inform strategies for encouraging healthier beverage choices from vending machine environments.

I'll have what She's having (but not what They're having): The moderating role of group membership in the effect of social norms on food choice in an online environment.

The modern food-rich environment has contributed to the rise of unhealthy diets linked to noncommunicable diseases. Previous in-person research has found that the effect of social norms on food intake is greater when set by a perceived in-group member relative to an out-group member. Given recent increased social media use, we investigated whether this effect of group membership extends to food choices and to normative information presented remotely online. Participants (N = 179 female university students, 18-32 years) viewed a Facebook page pertaining to either their university (in-group) or a rival university (out-group). They were presented with either a healthy or an unhealthy norm via a post in which a student discussed their order at a café on the relevant campus. Food choice was assessed through an online menu where participants were asked to order one main, side, and dessert dish. As predicted, participants who viewed the healthy norm ordered a higher percentage of healthy items (especially in the desserts category) relative to those who viewed the unhealthy norm. However, this effect was significant only for those in the in-group condition; there was no such pattern for participants in the out-group condition. These findings provide insight into the role of group membership in the effect of social norms, and have practical implications regarding the design of identity-based social media health campaigns to promote healthier eating behaviours.

Tripolar concentric ring electrodes for capturing localised electroencephalography signals during sleep.

By design, tripolar concentric ring electrodes (TCRE) provide more focal brain activity signals than conventional electroencephalography (EEG) electrodes placed further apart. This study compared spectral characteristics and rates of data loss to noisy epochs with TCRE versus conventional EEG signals recorded during sleep. A total of 20 healthy sleepers (12 females; mean [standard deviation] age 27.8 [9.6] years) underwent a 9-h sleep study. Participants were set up for polysomnography recording with TCRE to assess brain activity from 18 sites and conventional electrodes for EEG, eyes, and muscle movement. A fast Fourier transform using multitaper-based estimation was applied in 5-s epochs to scored sleep. Odds ratios with Bonferroni-adjusted 95% confidence intervals were calculated to determine the proportional differences in the number of noisy epochs between electrode types. Relative power was compared in frequency bands throughout sleep. Linear mixed models showed significant main effects of signal type (p < 0.001) and sleep stage (p < 0.001) on relative spectral power in each power band, with lower relative spectral power across all stages in TCRE versus EEG in alpha, beta, sigma, and theta activity, and greater delta power in all stages. Scalp topography plots showed distinct beta activation in the right parietal lobe with TCRE versus EEG. EEG showed higher rates of noisy epochs compared to TCRE (1.3% versus 0.8%, p < 0.001). TCRE signals showed marked differences in brain activity compared to EEG, consistent with more focal measurements and region-specific differences during sleep. TCRE may be useful for evaluating regional differences in brain activity with reduced muscle artefact compared to conventional EEG.

A pre-post evaluation of the impact of the Embrace Kids film on children's and adults' body image and self-compassion.

Given the prevalence of body dissatisfaction among young people, which tends to persist into adulthood, a need exists for large-scale interventions that address this problem. Film has been identified as a resource that is well-suited to large-scale dissemination, which can achieve broad impact and reach. Embrace Kids, a film aimed at improving young people's body image, is one such resource. To evaluate the film's impact on body image, 55 children (M = 10.59, SD = 1.49) and 47 adults (M = 43.75, SD = 8.54) were recruited from the Australian general public to complete a brief survey before and after viewing the film. After viewing the film, significant increases in state body appreciation, state functionality appreciation and state self-compassion were reported for children (d = 0.46 - 0.61) and adults (d = 0.88 - 1.08). They supported the safety of the film by indicating that it did not make them more concerned about their appearance. Findings provide initial support for the film as a scalable intervention that can be safely task-shifted to non-professional audiences. Future research directions include comparing the effect of Embrace Kids against a control film, and testing the longitudinal impact of the film on trait body image.

My mother, sisters, and I: Investigating the role of female family members in body dissatisfaction and disordered eating behaviours among young Middle-Eastern women.

The global rise in body dissatisfaction and disordered eating concerns is apparent; however, limited research in Middle-Eastern populations gives an incomplete understanding of these concerns. The present study recruited 377 young women aged 18 to 25 years from the Middle-East for an online survey to determine how female family members may contribute to body dissatisfaction and disordered eating behaviours. Guided by the Tripartite Influence Model, we investigated the relationships between appearance pressures and fat talk, from mothers and sister(s), in predicting body dissatisfaction, and in turn, disordered eating symptomatology (restriction and bulimia), as mediated by appearance comparisons and internalisation of the thin-ideal. Overall, greater appearance pressures and fat talk from mothers and sister(s) were associated with body dissatisfaction and disordered eating symptomatology. Greater reported closeness in mother-daughter relationships, but not sister relationships, was associated with less perceived appearance pressure and fat talk by mothers, and lower appearance comparisons, body dissatisfaction and bulimia symptomatology. Finally, participants perceived greater appearance pressure from their mothers than their sister(s), but there was no difference in their perceived levels of fat talk. Findings demonstrate the applicability of a subsection of the Tripartite Influence Model in a non-Western and understudied population, namely in young Middle-Eastern women.

The role of decision-making and impulsivity in beverage consumption.

Soft drink and alcohol consumption have become significant public health issues. This study aimed to explore the mediating role of decision-making processes in the relationship between trait impulsivity and calorie dense beverage consumption. Participants comprised a community sample of 300 adults (aged 19-75). They completed self-report measures assessing impulsivity (SUPPS-P), reward sensitivity (RST-PQ), and participated in decision-making tasks related to risk propensity (BART), short-term strategy preference (IGT), and delay discounting rate. Beverage consumption was calculated using the BEVQ-15. Impulsivity was conceptualised within the framework of the two-factor model as consisting of rash impulsivity and reward sensitivity. Both facets of impulsivity were positively associated with both alcohol and soft drink consumption, and each independently predicted consumption of these beverages. Additionally, there was a significant interaction between rash impulsivity and reward sensitivity on soft drink consumption. Importantly, there were significant indirect effects of both rash impulsivity and reward sensitivity on soft drink consumption via delay discounting. The results support the logic of the two-factor model of impulsivity in the prediction of consumption of unhealthy beverages. Furthermore, the mediating role of delay discounting supports the hypothesis that personality traits can pass through to behaviour via decision-making processes. Further research should extend these findings to other consumption domains in both clinical and non-clinical populations.

The effectiveness of Go/No-Go and Stop-Signal training in reducing food consumption and choice: A systematic review and meta-analysis.

The Go/No-Go and Stop-Signal tasks have been used to reduce excess food intake via repeated pairing of food cues with response inhibition. A meta analysis of 32 studies was conducted to determine whether, and under which conditions, the Go/No-Go and Stop-Signal training tasks are effective in reducing food consumption or choice. Moderators included task parameters (e.g., number of sessions, stop signal), sample differences (e.g., age, weight), and the measure of food consumption or choice. Overall, there was a small effect for Go/No-Go and Stop-Signal training in reducing food consumption or choice, g = -0.21, CI95 = [-0.31, -0.11], p < .001, with this holding individually only for a single session of the Go/No-Go Task, g = -0.31, CI95 = [-0.45, -0.18], p < .001. Comprehensive investigation of the impact of varying moderators indicated that the effect for Go/No-Go training was robust. Nevertheless, there was significant variation in the specific parameters of the task. Overall, the present meta-analysis extends previous findings by providing comprehensive evidence that the Go/No-Go Task is effective in reducing food consumption and choice, as well as providing optimal parameter recommendations for the task.

Estimating vigilance from the pre-work shift sleep using an under-mattress sleep sensor.

Predicting vigilance impairment in high-risk shift work occupations is critical to help to reduce workplace errors and accidents. Current methods rely on multi-night, often manually entered, sleep data. This study developed a machine learning model for predicting vigilance errors based on a single prior sleep period, derived from an under-mattress sensor. Twenty-four healthy volunteers (mean [SD] age = 27.6 [9.5] years, 12 male) attended the laboratory on two separate occasions, 1 month apart, to compare wake performance and sleep under two different lighting conditions. Each condition occurred over an 8 day protocol comprising a baseline sleep opportunity from 10 p.m. to 7 a.m., a 27 h wake period, then daytime sleep opportunities from 10 a.m. to 7 p.m. on days 3-7. From 12 a.m. to 8 a.m. on each of days 4-7, participants completed simulated night shifts that included six 10 min psychomotor vigilance task (PVT) trials per shift. Sleep was assessed using an under-mattress sensor. Using extra-trees machine learning models, PVT performance (reaction times <500 ms, reaction, and lapses) during each night shift was predicted based on the preceding daytime sleep. The final extra-trees model demonstrated moderate accuracy for predicting PVT performance, with standard errors (RMSE) of 19.9 ms (reaction time, 359 [41.6]ms), 0.42 reactions/s (reaction speed, 2.5 [0.6] reactions/s), and 7.2 (lapses, 10.5 [12.3]). The model also correctly classified 84% of trials containing ≥5 lapses (Matthews correlation coefficient = 0.59, F1 = 0.83). Model performance is comparable to current fatigue prediction models that rely upon self-report or manually entered data. This efficient approach may help to manage fatigue and safety in non-standard work schedules.

Digging into digital buffets: A systematic review of eating-related social media content and its relationship with body image and eating behaviours.

Recently, researchers have started investigating the influence of eating-focused social media content on viewers' body image and eating behaviour. The current systematic review collates the evidence for the relationship between exposure to eating-related social media content and people's body image, disordered eating, food consumption, and eating-related opinions. Following PRISMA guidelines, searches were conducted on five databases (i.e., Medline, PsycINFO, Web of Science, Scopus, and ProQuest), resulting in 38 eligible studies that examined the link between eating-related content and body image, eating behaviour and/or viewers' perceptions. Evidence showed positive relationships between exposure to certain material on social media (e.g., fast-food advertisements, clean eating, eating videos) and body image concerns, disordered eating, and consumption of, or a willingness to consume the foods seen on social media; however, studies that focused on 'healthy food' content showed no such link. Viewers expressed mixed feelings towards content such as nutrition information and mukbang videos which record hosts eating a large amount of food. Future research would benefit from a consistent measure of exposure to different eating-related content. There is also a need for more experimental research to examine the impact of watching different types of eating videos on body image, disordered eating, and food consumption.

Delayed melatonin circadian timing, lower melatonin output, and sleep disruptions in myopic, or short-sighted, children.

STUDY OBJECTIVES: This study investigated the differences in melatonin circadian timing and output, sleep characteristics, and cognitive function in myopic and non-myopic (or emmetropic) children, aged 8-15 years. METHODS: Twenty-six myopes (refractive error [mean ±â€…standard error mean] -2.06 ±â€…0.23 diopters) and 19 emmetropes (-0.06 ±â€…0.04 diopters), aged 11.74 ±â€…2.31 years were recruited. Circadian timing was assessed using salivary dim-light melatonin onset (DLMO), collected half-hourly for 7 hours, beginning 5 hours before and finishing 2 hours after individual average sleep onset in a sleep laboratory. Nocturnal melatonin output was assessed via aMT6s levels from urine voids collected from 05:30 pm to 8:00 am the following morning. Actigraphy-derived objective sleep timing were acquired for a week prior to the sleep laboratory visit. Cognitive assessments of sustained attention (using psychomotor vigilance task [PVT]) and working memory (using digit spans) were performed on the night of sleep laboratory. RESULTS: Myopic children (9:07 pm ±â€…14 minutes) exhibited a DLMO phase-delay of 1 hour 8 minutes compared to emmetropes (7:59 pm ±â€…13 minutes), p = 0.002. aMT6s melatonin levels were significantly lower among myopes (18.70 ±â€…2.38) than emmetropes (32.35 ±â€…6.93, p = 0.001). Myopes also exhibited significantly delayed sleep onset, delayed wake-up time, poor and reduced sleep, and more evening-type diurnal preference than emmetropes (all p < 0.05). Finally, myopes showed a slower reaction time in the PVT (p < 0.05), but not digit span tasks at night. CONCLUSIONS: These findings suggest a potential association between circadian rhythm dysfunction and myopia in children.

Self-regulation profiles in addictive behaviors among adolescents: A transdiagnostic approach.

Dual-pathway models suggest that poor self-regulation (immature regulatory combined with strong reactive processes) is an important factor underlying addictive behaviors among adolescents. This study examined whether there are different self-regulation profiles among community adolescents, and how these profiles are related to the presence, severity and comorbidity of different addictive behaviors. A community sample of 341 adolescents (54.5% female; 13-17 years) was recruited. Participants self-reported on regulatory (inhibitory control) and reactive (reward and punishment sensitivity) processes, as well as on different addictive behaviors (binge eating, tobacco-, cannabis- and alcohol use, gaming, gambling and pathological buying). A model-based clustering analysis found evidence for three meaningful profiles: 'impulsive/under-controlled', 'anxious' and 'protective'. The 'impulsive/under-controlled' profile was characterized by the highest prevalence and severity of cannabis use and the most severe alcohol use. The 'impulsive/under-controlled' and 'protective' profiles demonstrated the highest prevalence and severity of tobacco use, whereas the 'impulsive/under-controlled' and 'anxious' profiles showed the highest binge eating scores. Adolescents who reported more than three types of addictive behaviors generally belonged to the 'impulsive/under-controlled' profile. The profiles did not differ for gaming, gambling and pathological buying. The 'impulsive/under-controlled' profile emerged as the most vulnerable profile in the context of addictive behaviors (especially for binge eating and substance use).

Enhancing body image in motherhood: A randomised controlled trial of Expand Your Horizon among mothers of young children.

Motherhood can increase vulnerability to body dissatisfaction, but positive body image interventions may mitigate this. Expand Your Horizon (Alleva et al., 2015), an online writing intervention, enhances functionality appreciation, an aspect of positive body image. The intervention's demonstrated efficacy and focus on body functionality indicate its potential use among mothers. However, its original 3-session format may be unfeasible for mothers alongside other commitments. Thus, we tested the impact of a single 15-minute Expand Your Horizon session on state body appreciation and functionality appreciation. Mothers (N = 143) of 0-10-year-olds were randomly allocated to either the intervention group, or an active control group. State body appreciation and functionality appreciation were assessed pre- and post-intervention. Trait self-compassion was tested as a potential moderator. Participants who completed Expand Your Horizon reported greater state body appreciation and functionality appreciation post-intervention than those in the control group. Self-compassion moderated the intervention's effect on state functionality appreciation, with effects strongest for those with lower levels of self-compassion. Overall, findings support the intervention's suitability for mothers, particularly those with low self-compassion. Practical implications include possibly tailoring Expand Your Horizon and similar interventions to benefit all mothers. Future research directions include longitudinal and qualitative designs, and extension to other specific populations.

The effect of spatial separation on food and drink choices from an online menu.

Emerging research suggests that modifying the presentation context of healthy food items can subtly 'nudge' individuals to make healthier choices. The present study aimed to investigate the effect of spatial separation between high and low nutritional value items on food and drink choices from an online fast-food menu. Participants (N = 210 women) were presented with one of three pictorial menus in which high nutritional value food and drink items were presented spatially mixed, grouped, or separate from low nutritional value items. Participants were asked to make one selection from each menu category (a main, drink, and dessert), and then completed a measure of dietary restraint. Overall, there was no main effect of menu condition. However, dietary restraint status moderated the effect of menu condition on healthy choices. In particular, women who scored low (but not those who scored high) on dietary restraint were positively influenced by the experimental manipulation, making approximately 14 % healthier selections when high nutritional value items were presented separately from low nutritional value items. This was principally the case for desserts, and to a lesser extent drinks. The findings have practical implications for the design of online fast-food menus to promote healthier food and drink selections.

The mother-daughter-sister triad: The role of female family members in predicting body image and eating behaviour in young women.

Familial influence, specifically from mothers and sisters, may impact the development of body dissatisfaction and disordered eating in young women. Guided by the Tripartite Influence Model, the present study recruited 422 young Australian women for a survey to determine how appearance pressures and fat talk, exhibited by mothers and sisters, and mediational mechanisms (comparisons and internalisation), are associated with body dissatisfaction, and in turn, disordered eating symptomatology. We also explored differences in perceived ratings of mother versus sister appearance pressures and fat talk. Findings were in the hypothesised directions. Greater appearance pressures and fat talk from mothers and sisters was associated with greater body dissatisfaction, restriction and bulimic behaviours. Furthermore, appearance pressures from mothers and sisters was related to young women's likelihood of engaging in appearance comparisons and thin-ideal internalisation, which was associated with body dissatisfaction, and in turn, disordered eating symptomatology. Finally, participants perceived more appearance pressures from their mothers than their sisters, and perceived their mothers to exhibit greater fat talk than their sisters. The findings extend previous research in an important and novel way by investigating individual agents of female familial influence in addition to the role of fat talk in predicting body dissatisfaction and disordered eating.

A micro-randomized pilot study to examine the impact of just-in-time nudging on after-dinner snacking in adults with type 2 diabetes: A study protocol.

AIM: To determine whether a digital nudge soon after dinner reduces after-dinner snacking events as measured objectively by continuous glucose monitoring (CGM) in patients with type 2 diabetes (T2D). METHODS: This is a single-site micro-randomized trial (MRT). People with T2D, aged 18-75 years, managed with diet or a stable dose of oral antidiabetic medications for at least 3 months, and who habitual snack after dinner at least 3 nights per week, will be recruited. Picto-graphic nudges were designed by mixed research methods. After a 2-week lead-in phase to determine eligibility and snacking behaviours by a CGM detection algorithm developed by the investigators, participants will be micro-randomized daily (1:1) to a second 2-week period to either a picto-graphic nudge delivered-in-time (Intui Research) or no nudge. During lead-in and MRT phases, 24-hour glucose will be measured by CGM, sleep will be tracked by an under-mattress sleep sensor, and dinner timing will be captured daily by photographing the evening meal. RESULTS: The primary outcome is the difference in the incremental area under the CGM curve between nudging and non-nudging days during the period from 90 minutes after dinner until 04:00 AM. Secondary outcomes include the effect of baseline characteristics on treatment, and comparisons of glucose peaks and time-in-range between nudging and non-nudging days. The feasibility of 'just-in-time' messaging and nudge acceptability will be evaluated, along with the analysis of sleep quality measures and their night-to-night variability. CONCLUSIONS: This study will provide preliminary evidence of the impact of appropriately timed digital nudges on 24 -hour intertitial glucose levels resulting from altered after-dinner snacking in people with T2D. An exploratory sleep substudy will provide evidence of a bidirectional relationship between after-dinner snacking behaviour, glycaemia and sleep. Ultimately, this study will allow for the design of a future confirmatory study of the potential for digital nudging to improve health related behaviours and health outcomes.

Vending machine backgrounds: nudging healthier beverage choices.

Soft drink overconsumption is a growing public health concern. The present research investigated whether priming nudges could decrease soft drink choices from a vending machine. We compared the effect of six vending machine wraps (Mount Franklin ™ logo, Coca-Cola™ logo, picture of water, picture of soft drink, blue, red) on beverage choice against a black (control) computerised vending machine display. In two studies, young adult participants (17 - 25 years) were recruited from [removed for blind review] (Study 1, n = 142, Study 2, n = 232). Participants were randomly allocated to choose a beverage from one of the wrap conditions. They also rated how much the beverage was liked and how often it was consumed (Study 1), or rated the refreshing value, healthiness, taste, and energy of each beverage in the vending machine (Study 2). We predicted that wraps referencing water would produce healthier choices and those referencing soft drink would result in unhealthier choices. Contrary to these predictions, the type of vending machine wrap did not significantly influence beverage choice in Study 1. However, viewing the black vending machine wrap resulted in significantly more caffeine-based selections in Study 2. Other significant predictors of the choice of beverage were how often the beverages were consumed and how much they were liked (Study 1), as well as their perceptions of the taste, healthiness and refreshing value (Study 2). The finding that the black vending machine produced more caffeine-based beverage choices demonstrates, in principle, that color-based priming nudges could influence beverage choices.