Effects of Mobile Application-based Lifestyle Counselling on Body Weight Loss in Obese Subjects

The aim of the trial is to study the effect of a mobile application-based lifestyle change program on body weight loss in adult subjects with obesity. The main focus is to motivate and support beneficial lifestyle changes targeting long-term weight management. This study comprises two randomly assigned study arms: mobile application-based lifestyle change program and "waiting-list" control. The mobile application-based lifestyle change program consists of twice a week content for the first 6 months, continuing with less frequent contents for the following 6 months (the length of intervention 12 months). The "waiting-list" control group will receive mobile application-based lifestyle change program after 6 months followed by intervention for 12 months. The main aim is to demonstrate that the users of mobile application-based lifestyle change program lose more weight than controls at 6 month timepoint and weight loss is maintained for 18 months (6 months after the end of mobile application-based lifestyle change program use). Weight is measured and blood samples (lipids, glucose and metabolic syndrome measures) are collected at 0, 6, 12, and 18 months. The mobile application-based counselling contains aspects of cognitive behavior therapy and persuasive system design and consists of twice a week reminders, tasks, self-monitoring, and reflection. The main outcome is the decrease in body weight. Secondary outcomes are changes in eating behavior, psychological factors, components of metabolic syndrome (waist circumference, plasma lipid and glucose values, blood pressure), and calculated scores of metabolic condition and adiposity.