Mobile health apps: An assessment of needs, perceptions, usability, and efficacy in changing dietary choices

•We explored mHealth apps as dietary self-monitoring tools to improve food choices.•MyFitnessPal was reported to be easy to use.•MyFitnessPal helped users change their diet and advance toward their health goals.•Although the intake of sugary foods was significantly reduced, overall weight was not.•Participants who wanted to lose ≥5 kg lost a significant amount of weight.