Does additional support provided through e-mail or SMS in a Web-based Social Marketing program improve children’s food consumption? A Randomized Controlled Trial

BACKGROUND: The FAN Social Marketing program was developed to improve dietary and physical activity habits of families with children in Ticino, Switzerland. The aim of this study was to examine if the effects of the program on children’s food intake differed by intervention group. METHODS: Effects of the FAN program were tested through a Randomized Controlled Trial. The program lasted 8 weeks, during which participants received tailored communication about nutrition and physical activity. Families were randomly allocated to one of three groups, where the parent received the intervention by the Web (G1), Web + e-mail (G2) or Web + SMS (G3). Children in all groups received tailored print letters by post. Children’s food consumption was assessed at baseline and immediate post intervention using a 7-day food diary. Generalized linear mixed models with child as a random effect and with time, treatment group, and the time by treatment interaction as fixed effects were used to test the impact of the intervention. RESULTS: Analyses were conducted with a sample of 608 children. After participating in FAN the marginal means of daily consumption of fruit changed from 0.95 to 1.12 in G1, from 0.82 to 0.94 in G2, and from 0.93 to 1.18 in G3. The margins of the daily consumption of sweets decreased in each group (1.67 to 1.56 in G1, 1.71 to 1.49 in G2, and 1.72 to 1.62 in G3). The change in vegetable consumption observed from pre to post intervention in G3 (from 1.13 to 1.21) was significantly different from that observed in G1 (from 1.21 to 1.17). CONCLUSIONS: A well-designed Web-based Social Marketing intervention complemented with print letters can help improve children’s consumption of water, fruit, soft drinks, and sweets. The use of SMS to support greater behavior change, in addition to Web-based communication, resulted only in a small significant positive change for vegetables, while the use of e-mail in addition to Web did not result in any significant difference. TRIAL REGISTRATION: The trial was retrospectively registered in the ISRCTN registry (ID ISRCTN48730279). ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1186/s12937-018-0334-1) contains supplementary material, which is available to authorized users.