Development, validation and use of a smartphone application for weight loss

Background
The effective treatment of overweight and obesity is challenging. A smartphone application which allows self monitoring of diet and activity could give an opportunity to
deliver a weight management intervention.
Methods
Multiple methods have been employed. A scoping review was conducted to explore the evidence for portable handheld electronic devices and weight loss and a smartphone application, ‘My Meal Mate’ (MMM) has been developed. MMM has a theoretical basis and has been informed by focus group research. A validation study compared the diet measures captured on MMM to a reference measure and MMM was
piloted in a 6 month, 3-armed randomised trial with a sample of 128 overweight/obese adults.
Results
The literature review found no studies to date of a stand-alone smartphone app for weight loss. In the validation study, energy (kcal) recorded on MMM correlated well
with 24 hour diet recalls. Day 1: r=0.77 (95% CI: 0.62-0.86) and had a small mean difference (Day 1: -16 (95% CI: -132 to 100) kcals/d (MMM-recall). Bland Altman analysis showed wide limits of agreement between the methods (+/-2SD -824 to 791kcals/d on day 1). From the pilot trial, frequency of use was statistically significantly higher in the MMM group with a median 82 (IQR: 28, 172) days of diet recorded compared to 15 (IQR: 7, 45) days in the website group and 18 (IQR: 0, 37) days in the diary group (p=<0.001). MMM was rated higher in terms of convenience and comfort of use in social settings. Mean weight change was −4.6kg (95%CI: −6.2 to −3.0) in the MMM group after 6 months (using intention to treat analysis).
Conclusion
MMM has potential as a dietary assessment tool and is an acceptable and feasible intervention. The weight loss seen in the pilot trial is promising and a full trial of MMM
is warranted.