Table 1.

Qualitative studies and randomized controlled trials of smartphone applications for promoting healthy diet and nutrition.

Study	Sample	Design	Results	Limitations
Vandelanotte et al. [6]	30 middle-aged men in Australia	Focus groups	The men supported use of the Internet to improve and self-monitor dietary behaviors and physical activity provided the website-delivered interventions were quick and easy to use. Smartphones were more acceptable than regular mobile phones.
Robinson et al. [7]	12 overweight and obese volunteers who were university staff members	Non-randomized 4-week trial	The participants self-reported that the app raised their awareness of what they were eating and that it was easy to use.	Non-randomized design, small sample size
Morrison et al. [8]	13 adult volunteers	Mixed-methods design	The POWER Tracker app was associated with an increase in awareness of participants’ food intake (P=0.04) and physical activity goals (P=0.03).	Small sample size, short duration of trial
Gasser et al. [9]	40 volunteers (20 per group)	4-week randomized trial that compared smartphone app to a Web-based app	The smartphone group had a more regular usage pattern than the Web-based group. No significant differences in nutrition goals or physical activity goals were observed across groups.	Small sample size
Wharton et al. [10]	47 volunteers	8-week randomized controlled trial with three groups: smartphone app (n= 19), paper-based (n=15), and memo (n=13)	All three groups lost weight. Smartphone app (Lose It!) users recorded dietary data more consistently than the paper-based group but not the memo group.	Small sample size
Allen et al. [3]	68 obese adults (mean age 45 years, 78% female, 49% African American	Randomized controlled trial with four groups: 1) intensive counseling, 2) intensive counseling plus smartphone, 3) less intensive counseling plus smartphone, and 4) smartphone app only	Participants in the intensive counseling plus self- monitoring smartphone group tended to lose more weight than the other groups (5.4 kg and 3.3 kg, respectively).
Martin et al. [11]	40 adult volunteers	Randomized controlled trial with SmartLoss smartphone group (n=20) and a health education control group (n=20)	Weight loss was greater in the SmartLoss group compared with the health education group (P<0.001).	Small sample size
Carter et al. [12]	128 overweight volunteers	6-month randomized controlled trial with three groups: My Meal Mate smartphone app, website group, and diary group	Mean weight change at 6 months was −4.6 kg (95% CI −6.2 to −3.0) for the smartphone app group, −2.9 kg (95% CI −4.7 to −1.1) for the diary group, and −1.3 kg (95% CI −2.7 to 0.1) for the website group. The change in BMI at 6 months was −1.6 kg/m² (95% CI −2.2 to −1.1) for the smartphone group, −1.0 kg/m² (95% CI −1.6 to − 0.4) for the diary group, and −0.5 kg/m² (95% CI − 0.9 to 0.0) for the website group. Change in body fat was −1.3% (95% CI −1.7 to −0.8) for the smartphone group, −0.9% (95% CI −1.5 to −0.4) for the diary group, and −0.5% (95% CI −0.9 to 0.0) for the website group.
Duncan et al. [13]	301male volunteers in Queensland,	9-month randomized controlled trial (the ManUP Study) that compared web- and mobile phone-based intervention with a print- based intervention	Participants reported an increased number of minutes and sessions of physical activity at three months and 9. Overall dietary behaviors improved at 3 months and 9 months. The proportion of participants in both groups consuming high-fiber bread and low-fat milk increased at 3 months.
Turner- McGrievay and Tate [14]	96 volunteers	6-month randomized controlled trial [Mobile Pounds Off Digitally (POD) Study] with two groups: podcast only group and podcast+mobile	At six months, weight loss did not differ between the two groups (P = 0.98. Podcast+Mobile participants were 3.5 times more likely than the Podcast group to use an app to monitor diet (P = 0.01), whereas most Podcast participants reported using the Web or paper. The number of podcasts participants reported downloading over the 6- month period was moderately correlated with weight loss in both the Podcast+Mobile (P = 0.001) and the Podcast (P < 0.001) groups.
Turner- McGrievey et al. [15]	96 volunteers	Post hoc analysis of data from Mobile POD Study	Adjusting for randomized group and demographics, smartphone app users self- monitored exercise more frequently over the 6- month study and reported greater intentional physical activity than non-app users (P<0.01). App users also had a lower BMI at six months than non-users (p=0.02), and consumed less energy than paper journal users (P=0.01).
Rabbi et al. [16]	17 volunteers	Randomized controlled trial that compared personalized suggestions from the MyBehavior smartphone app with nonpersonalized suggestions from a smartphone	Between- group differences in consumption of lower-calorie foods were not significant (P=0.15). Over the course of the trial, however, MyBehavior users walked more than the control group (P=0.05).	Small sample size