We conducted a systematic review to determine if the use of nutrition apps resulted in improved outcomes, including knowledge and behavior, among healthy adults. Using app(s), cellular phone, iPads, mobile phone, mobile telephone, smart phone, mobile and mHealth as search terms with diet, food and nutrition as qualifiers we searched PubMed, CINAHL (January 2008-October 2013) and Web of Science (January 2008-January 2014). Inclusion criteria were peer-reviewed randomized controlled trials, non-controlled trials, and cohort studies published in English that used apps to increase nutrition knowledge or improve behavior related to nutrition. Studies that were descriptive, did not include apps, focused on app development, app satisfaction app feasibility, text messaging, or digital photography were excluded. We evaluated article quality using the Academy of Nutrition and Dietetics Evidence Analysis Manual. Data was extracted for knowledge, behavior and weight change. Our initial search identified 12,010 titles from PubMed, 260 from CINAHL and 4762 from Web of Science; of these, only four articles met all search criteria. Positive quality ratings were given to three articles; only one reported knowledge outcomes (non-significant). All four articles evaluated weight loss and suggested an advantage to using nutrition apps. Behavioral changes in reviewed studies included increased adherence to diet monitoring (p < 0.001) and decreased effort to continue diet without app (p = 0.024). Few studies, however, have explored the use of nutrition apps as supportive educational interventions. Most apps focus on weight loss with inconsistent outcomes. We conclude that using apps for education needs additional research which includes behavior theory within the app and improved study design.