S188 (cooked meals, snacks, cold drinks, sandwiches). Generalised linear mixed models controlled for cafeteria usage and time trends, with random effects for worksite. Results. Feasibility and Acceptability: Changes to pre-packaged products were mostly adhered to across sites, but changes to cooked meals were only implemented at sites where menus were preplanned. Very few customer surveys were completed, suggesting 78% either favoured or did not object to the intervention remaining in place post-study. Impact: The average effect of the intervention across all sites was a reduction of 6.9% (95%CI: -11.7%,-1.7%, p=0.044) in energy purchased from targeted food categories. At the level of individual sites, energy purchased from targeted categories was significantly reduced in two sites (-10.7% (95%CI: -18.1% to -2.6%, p=0.046); -18.4% (95%CI: 26.9% to -8.8%, p=0.013)), while no significant differences were seen in the other four sites. Conclusions. Increasing the proportion of healthier food options in worksite cafeterias can reduce energy purchased. Impact varied by site, perhaps relating to degree of implementation, food categories targeted (e.g. cooked meals) or site characteristics. Further work should try to establish reasons for this differential impact, and thereby the most effective ways of implementing this promising intervention. CORRESPONDING AUTHOR: Rachel Pechey, University of Cambridge, rachel.pechey@medschl.cam.ac.uk
O33.2 INTERVENTION TO SUBSTITUTE SUGAR-SWEETENED BEVERAGES FOR HEALTHIER ALTERNATIVES Elizaveta Novoradovskaya1, Monica Yee2, Gaby Judah2, Barbara Mullan1, Lina Johansson2 1. Curtin University - Australia 2. Imperial College London – United Kingdom Obesity and diseases associated with it, such as diabetes and cancer, are on the increase globally. While cases of obesity are multifaceted, one of the contributors is the increased consumption of energy dense nutrient poor food, including sugar-sweetened beverages (SSB). One strategy that has been shown to successfully lead to behaviour change in habitual behaviours, such as this, is implementation intentions, where SSB consumption is substituted with an alternative behaviour, such as drinking water. However, as SSB have a hedonic component, substituting them with diet drinks may result in larger behaviour change. The aim of the current study was to develop an online implementation intention based intervention to substitute SSB consumption for diet drinks or water consumption. Methods: Participants (n=136) were randomly assigned to one of two intervention conditions. They were asked to develop implementation intentions for consuming diet drinks in the first condition and water in the second condition. Measures of consumption of SSB, diet drinks and water, along with habit strength and hedonic reward were taken at baseline and after two months. Results: Both groups significantly decreased SSB consumption (λ = 0.31, F(1, 134) = 294.55, p < 0.001, ηp2= 0.69) and SSB habit strength (λ = 0.57, F(1, 134) = 102.08, p < 0.001, ηp2= 0.43), however, no group differences were observed (λ = 1.00, F(1, 134) = 0.02, p = 0.88, ηp2 = 0.0002). Diet drink (t (56) = 6.17, p < 0.01, d = 0.82) and water (t (78) = 2.07, p = 0.04, d = 0.23) habit strengths increased, with the former experiencing the larger increase. SSB consumption and diet drink habit strength were not associated (r = 0.11, n = 57, p = 0.4), with drinking water habit strength showing association with SSB consumption (r = 0.23, n = 79, p = 0.04). Hedonism did not differ between diet drink and water consumption (t(134) = 1.80, p = 0.07, d = 0.31). Conclusions: The results of the current study demonstrated that a simple implementation intention intervention can be successful in reducing SSB consumption and habit strength and substituting it with consumption of diet drink or water and future research can build on this promising start. CORRESPONDING AUTHOR: Elizaveta Novoradovskaya, Curtin University, elizaveta.novoradovskaya@postgrad.curtin.edu.au
Int.J. Behav. Med. (2018) 25 (Suppl 1):S1–S219 O33.3 A SCHOOL-BASED GAMIFICATION STRATEGY TO REDUCE OBESITY: RESULTS FROM A PILOT STUDY Sebastián Peña1, Macarena Carranza2, Pau Espinoza2, Valeska Müller2, Ricardo Cerda3, Pedro Zitko3, Andrea Cortinez4, Nicolás Loira5, Cristobal Cuadrado6 1 National Institute for Health and Welfare - Finland 2 Municipality of Santiago – Chile 3 University of Chile – Chile 4 Pontifical Catholic University – Chile 5 Independent – Chile 6 University of Chile – Chile School-based interventions have shown mixed results. Most studies have lacked enough statistical power and have been carried out in North America and Europe. Multidimensional interventions have often used education to address nutrition and physical activity, without structural components and weak community participation. In this study, we report the results of the gamification strategy and effectiveness of a pilot study in Santiago de Chile. Methods: The Juntos Santiago cluster-randomized trial uses a gamification strategy (i.e. elements of a game, points, levels and rewards) with a strong community participation component. Participants of the pilot study were 381 children in 5th and 6th grade of three schools in Santiago selected by convenience. Children voted their enrolment and collectively chose the activity reward they were playing for. The intervention consisted of a healthy snacks challenge and a steps challenge. The reward for the pilot was a fun day at the City swimming pool. The primary outcome was change in BMI zscore and waist circumference. Results: Of enrolled students, 88% was examined at baseline and followup. Unhealthy snacks brought from home reduced by 6.5 percentage points. Data from steps challenge was not available due to encryption of activity trackers. We observed statistically significant reductions in zBMI (-0.09) and waist circumference (-0.79 cms). No difference was observed for BMI. Systolic blood pressure reduced on average 5.19 mmHg and diastolic blood pressure increased by 1.48 mmHg. The latter changes are likely due to equipment change. Results of the 2018 trial in 4000 participants will also be presented. The trial in 2018 will incorporate a points system and structural rewards (improvements in school infrastructure for physical activity and nutrition). Conclusions: Despite the short duration of the pilot study, results are promising. The gamification strategy appears to foster community engagement and motivation. Attention should be given to data extraction and quality assurance prior the beginning of the trial in 2018. CORRESPONDING AUTHOR: Sebastian Peña, National Institute for Health and Welfare, sebastian.pena.fajuri@thl.fi
O33.4 DEVELOPING THE LOGIC MODEL OF CHANGE FOR A HEALTH P R O M O T I O N I N T E RV E N T I O N A I M I N G T O R E D U C E SOCIOECONOMIC DIFFERENCES IN PRESCHOOLERS’ HEALTH BEHAVIORS AND WELLBEING- THE DAGIS STUDY Carola Ray1, Riikka Kaukonen1, Elviira Lehto1, Henna Vepsäläinen2, Reetta Lehto1, Nina Sajaniemi3, Maijaliisa Erkkola4, Eva Roos1 1 Folkhälsan Research Center – Finland 2 Department of Food and Environmental Sciences, University of Helsinki – Finland 3 Division of Early Education, University of Helsinki – Finland 4 Department of Food and Environmental Sciences, University of Helsinki – Finland Socioeconomic status (SES) differences in children’s energy balancerelated behaviors (EBRBs) exist already at preschool age. When planning health promotion interventions targeting all, it is important to pay special attention to those who most need it. The aim is to present the process of