Does exposure to socially endorsed food images on social media influence food intake?

Social norms can influence the consumption of high and low energy-dense (HED/LED) snack foods. Such norms could be communicated via social media, however, there is little experimental research investigating this possibility. This laboratory study aimed to investigate the acute effect of socially endorsed social media posts on participants' eating behaviour. Healthy women students (n = 169; mean age = 20.9; mean BMI = 23.3) were assigned to either a HED, LED or control condition, where they viewed three types of images (HED foods, LED foods and interior design as control), but only one type was socially endorsed (e.g. in the control condition, only interior design images were socially endorsed). Participants completed questionnaires and were also provided a snack buffet of grapes and cookies. One-way ANOVA revealed a significant main effect of condition on participants' relative consumption of grapes (percentage of grapes consumed out of total food intake), for both grams and calories consumed (both ps < .05). Follow-up t-tests revealed that participants consumed a larger proportion of grapes (grams and calories) in the LED condition vs HED condition (all ps < .05), and a larger proportion of calories from grapes in the LED compared to control condition (p < .05). These findings suggest that exposure to socially endorsed images of LED food on social media could nudge people to consume more of, and derive more calories from these foods in place of HED foods. Further research is required to examine the potential application of these findings.

Do perceived norms of social media users' eating habits and preferences predict our own food consumption and BMI?

In laboratory studies, exposure to social norm messages conveying the typical eating behaviour of others has influenced participants' own consumption of food. Given the widespread use of social media, it is plausible that we are implicitly exposed to norms in our wider social circles, and that these influence our eating behaviour, and potentially, Body Mass Index (BMI). This study examined whether four perceived norms (perceived descriptive, injunctive, liking and frequency norms) about Facebook users' eating habits and preferences predicted participants' own food consumption and BMI. In a cross-sectional survey, men and women university students (n = 369; mean age = 22.1 years; mean BMI = 23.7) were asked to report their perceptions of Facebook users' consumption of, and preferences for, fruit, vegetables, energy-dense snacks and sugar sweetened beverages (SSBs), their own consumption of and preferences for these foods, and their BMI. Multiple linear regression revealed that perceived descriptive norms and perceived frequency norms about Facebook users' fruit and vegetable consumption were significant positive predictors of participants' own fruit and vegetable consumption (both ps < .01). Conversely, perceived injunctive norms about Facebook users' energy-dense snack and SSB consumption were significant positive predictors of participants' own snack and SSB consumption (both ps < .05). However, perceived norms did not significantly predict BMI (all ps > .05). These findings suggest that perceived norms concerning actual consumption (descriptive and frequency) and norms related to approval (injunctive) may guide consumption of low and high energy-dense foods and beverages differently. Further work is required to establish whether these perceived norms also affect dietary behaviour over time.

Can social media be used to increase fruit and vegetable consumption? A pilot intervention study.

Background: Exposure to social norms about fruit and vegetable intake has been shown to increase individuals' consumption of these foods. Further, exposure to socially endorsed 'healthy' food posts can increase consumption of low energy-dense (LED), relative to high energy-dense (HED) foods. The current pilot study aimed to investigate whether exposure to healthy eating (vs. control) social media accounts can shift normative perceptions about what others eat, eating intentions and self-reported food consumption. Methods: In a 2 (condition) × 2 (type of food consumed) mixed factorial design, 52 male and female students were asked to follow either healthy eating (intervention) or interior design (control) Instagram accounts over a two-week period. Baseline and post-intervention measures assessed normative perceptions of Instagram users' consumption of fruit and vegetables (LED foods), and energy dense snacks and sugar sweetened beverages (HED foods). Participants' intentions to consume, and self-reported consumption of these foods, were also measured. Results: There were no significant changes in perceptions about what others eat, or participants' own eating intentions (ps > 0.05). However, the intervention increased participants' self-reported consumption of LED foods by 1.37 servings (per day) and decreased consumption of HED foods by 0.81 items (per day), compared to the control condition (ps < 0.05). Conclusions: This novel pilot study demonstrates that a social norm-based social media intervention can successfully encourage healthier eating, with a large effect after two weeks. Certain social media platforms may therefore provide a viable tool for nudging healthy eating. Future work will aim to replicate these findings in a larger and more diverse sample.

Which components of behavioral weight management programs are essential for weight loss in people living with obesity? A rapid review of systematic reviews.

The optimal treatment and organization of care for people with obesity is one of the greatest challenges facing today's health services. While surgery and pharmacotherapy offer effective treatment options for some people with obesity, behavioral interventions are important to support long-term behavioral change. However, little is known about the most effective components of behavioral interventions, and this is especially the case for people with complex or severe obesity (i.e. body mass index [BMI] > 35 kg/m2). Accordingly, the current rapid review aimed to identify which behavior change techniques (BCTs) are effective for weight loss in adults with (severe) obesity. A secondary aim was to review the effects of BCTs on dietary behaviors and physical activity, and psychological outcomes, recognizing that behavioral interventions commonly target these. A search of Scopus, Ovid Medline, and Web of Science resulted in 1227 results, with 22 reviews eligible for inclusion. The most commonly reported BCTs were self-monitoring and goal setting, but these had variable effects on weight in adults with obesity. Combining these BCTs with other self-regulatory techniques led to increased weight loss. Further, for adults with severe obesity, so-called 'nudge' techniques and self-regulatory techniques were associated with greater weight loss. Three reviews also found that while self-monitoring increased physical activity, behavioral commitments increased changes to dietary behaviors. BCTs were not associated with psychological well-being. The review confirms that behavioral interventions have an impact in weight management, including for individuals with more complex or severe obesity, but highlights the need for further investigation of their use within clinical settings.

Development of a group-based behaviour change intervention for people with severe obesity informed by the social identity approach to health.

INTRODUCTION: Interventions to support behaviour change in people living with chronic health conditions increasingly use patient groups as the mode of delivery, but these are often designed without consideration of the group processes that can shape intervention outcomes. This article outlines a new approach to designing group-based behaviour change interventions that prioritizes recipients' shared social identity as group members in facilitating the adoption of established behaviour change techniques (BCTs). The approach is illustrated through an example drawn from research focused on people living with severe obesity. METHODS: A prioritization process was undertaken in collaboration with stakeholders, including behaviour change experts, clinicians, and a former patient to develop an evidence-based, group intervention informed by the social identity approach to health. Three phases of development are reported: (1) identification of the health problem; (2) delineation of intervention mechanisms and operationalization of BCTs for group delivery and (3) intervention manualization. The fourth phase, intervention testing and optimization, is reported elsewhere. RESULTS: A group-based behaviour change intervention was developed, consisting of 12 group sessions and 3 one-to-one consultations. The intervention aimed to support the development of shared social identity among recipients, alongside the delivery of evidence-based BCTs, to improve the likelihood of successful intervention and health outcomes among people living with severe obesity. CONCLUSIONS: A manualized intervention, informed by the social identity approach to health, was systematically designed with input from stakeholders. The development approach employed can inform the design of behavioural interventions in other health contexts where group-based delivery is planned.

A group-based behavioural intervention for weight management (PROGROUP) versus usual care in adults with severe obesity: a feasibility randomised controlled trial protocol.

BACKGROUND: Approximately 15 million people in the UK live with obesity, around 5 million of whom have severe obesity (body mass index (BMI) ≥35kg/m2). Having severe obesity markedly compromises health, well-being and quality of life, and substantially reduces life expectancy. These adverse outcomes are prevented or ameliorated by weight loss, for which sustained behavioural change is the cornerstone of treatment. Although NHS specialist 'Tier 3' Weight Management Services (T3WMS) support people with severe obesity, using individual and group-based treatment, the current evidence on optimal intervention design and outcomes is limited. Due to heterogeneity of severe obesity, there is a need to tailor treatment to address individual needs. Despite this heterogeneity, there are good reasons to suspect that a structured group-based behavioural intervention may be more effective and cost-effective for the treatment of severe obesity compared to usual care. The aims of this study are to test the feasibility of establishing and delivering a multi-centre randomised controlled clinical trial to compare a group-based behavioural intervention versus usual care in people with severe obesity. METHODS: This feasibility randomised controlled study is a partially clustered multi-centre trial of PROGROUP (a novel group-based behavioural intervention) versus usual care. Adults ≥18 years of age who have been newly referred to and accepted by NHS T3WMS will be eligible if they have a BMI ≥40, or ≥35 kg/m2 with comorbidity, are suitable for group-based care and are willing to be randomised. Exclusion criteria are participation in another weight management study, planned bariatric surgery during the trial, and unwillingness or inability to attend group sessions. Outcome assessors will be blinded to treatment allocation and success of blinding will be evaluated. Clinical measures will be collected at baseline, 6 and 12 months post-randomisation. Secondary outcome measures will be self-reported and collected remotely. Process and economic evaluations will be conducted. DISCUSSION: This randomised feasibility study has been designed to test all the required research procedures and additionally explore three key issues; the feasibility of implementing a complex trial at participating NHS T3WMS, training the multidisciplinary healthcare teams in a standard intervention, and the acceptability of a group intervention for these particularly complex patients. TRIAL REGISTRATION: ISRCTN number 22088800.