Use of mobile phones as a tool for weight loss: a systematic review.

We conducted a systematic review of the literature on the use of mobile phones for weight loss. A total of 43 studies were identified on obese or overweight adults, aged 18 years or over. After review, ten articles met the inclusion criteria. There were 19-534 participants per study. Participants were from European, Asian and North American regions. The mean body mass index (BMI) of the subjects varied from 22 to 36 kg/m(2). Two studies used text messaging or multimedia messaging. All the other studies used mobile-phone apps or web-based programmes that could be accessed from mobile phones as a part of a weight-loss intervention or for evaluating their potential for use and their acceptance. Most studies lasted 2-4 months and the maximum duration was 1 year. All but two studies showed reductions in the participants' bodyweight, BMI, waist circumference and body fat in the various interventions. There appeared to be a proportional relationship between weight loss and programme use. The programmes most benefited those who took a pro-active approach to everyday problems. Frequent self-recording of weight seemed to be important, as was the personalisation of the intervention (counselling and individualized feedback). Finally, a social support system acted as a motivational tool.