title: Quantified-Self for Obesity: Physical Activity Behaviour Sensing to Improve Health Outcomes.
abstract: Physical activity levels in bariatric patients have not been well documented, despite their importance in maintaining weight loss following surgery. This study investigated the feasibility of tracking physical activity using a smartphone app with minimal user interaction. Thus far, we have obtained good quality data from 255 patients at various points in their weight loss journey. Preliminary analyses indicate little change in physical activity levels following surgery with pre-surgery patients reaching an average of 16 minutes per day and post-surgery patients achieving a daily average of 21 minutes. Further analyses using machine-learning techniques will be conducted to determine whether physical activity is a critical factor in distinguishing between successful and unsuccessful weight loss outcomes and in the resolution of comorbid conditions in patients with similar clinical profiles.
authors.affiliation: Department of Surgery, Cancer and Investigative Medicine, Imperial College London.
authors.forename: David
authors.initials: D
authors.lastname: Taylor
authors.affiliation: Department of Surgery, Cancer and Investigative Medicine, Imperial College London.
authors.forename: Jennifer
authors.initials: J
authors.lastname: Murphy
authors.affiliation: Department of Surgery, Cancer and Investigative Medicine, Imperial College London.
authors.forename: Mian
authors.initials: M
authors.lastname: Ahmad
authors.affiliation: Division of Diabetes, Endocrinology, and Metabolism, Imperial College London.
authors.forename: Sanjay
authors.initials: S
authors.lastname: Purkayastha
authors.affiliation: Department of Investigative Medicine, Imperial College London.
authors.forename: Samantha
authors.initials: S
authors.lastname: Scholtz
authors.affiliation: Wireless Health Institute, University of California, Los Angeles.
authors.forename: Ramin
authors.initials: R
authors.lastname: Ramezani
authors.affiliation: Behavioural Science Group, Warwick Business School, University of Warwick.
authors.forename: Ivaylo
authors.initials: I
authors.lastname: Vlaev
authors.affiliation: Division of Diabetes, Endocrinology, and Metabolism, Imperial College London.
authors.forename: Alexandra I F
authors.initials: AI
authors.lastname: Blakemore
authors.affiliation: Department of Investigative Medicine, Imperial College London.
authors.forename: Ara
authors.initials: A
authors.lastname: Darzi
mesh_terms: D056044:Actigraphy / Q000295:instrumentation* / Q000379:methods; D000328:Adult; D050110:Bariatric Surgery / Q000534:rehabilitation*; D015444:Exercise; D005081:Exercise Therapy / Q000379:methods; D005260:Female; D006801:Humans; D008297:Male; D009765:Obesity / Q000175:diagnosis / Q000517:prevention & control*; D063868:Patient Outcome Assessment; D012648:Self Care / Q000295:instrumentation* / Q000379:methods; D000068997:Smartphone; D016896:Treatment Outcome