Unhealthy eating is a major risk factor for chronic disease. However, many current strategies to promote healthy eating are not sustainable over the longer-term. More cost-effective wide-reaching initiatives are urgently needed. Mobile health (mHealth) interventions, delivered via mobile devices, could provide a solution. This systematic review summarized the evidence on the effect of mHealth interventions for promoting healthy eating in adults. A comprehensive systematic search of five scientific databases was conducted using methods adapted from the Cochrane Handbook. Eligible studies were randomized controlled trials (RCTs), published up to 1 July 2016, which examined healthy eating interventions delivered via mobile device. Of 879 articles identified, 84 full text articles were potentially eligible and further assessed, and 23 included. Narrative review results indicated small positive effects of mHealth interventions on healthy eating (5/8 trials) and weight loss (5/13 trials). However, the current evidence base is insufficient (studies are of poor quality) to determine conclusive positive effects. More rigorous RCTs with longer-term (>6months) follow-up are warranted to determine if effects are maintained