Feasibility randomized controlled trial of ImpulsePal: smartphone app–based weight management intervention to reduce impulsive eating in overweight adults

Research output: Contribution to journalArticle


  • Samantha Barbara van Beurden
  • Jane Rebecca Smith
  • Natalia Sophie Lawrence
  • Charles Abraham
  • Colin Greaves

Colleges, School and Institutes


Background: Obesity remains a key global health priority. Impulsive processes driving eating behaviour can often undermine peoples’ attempts to lose weight and maintain weight loss. ImpulsePal is a theory-driven (dual-process), evidence-informed, and person-centred smartphone app intervention designed to help people manage impulsive processes that prompt unhealthy eating to facilitate dietary change and weight loss.

Objective: This study aimed to (a) assess the feasibility of trial procedures for evaluation of the ImpulsePal intervention, (b) estimate standard deviations of outcomes, and (c) assess usability of, and satisfaction with, ImpulsePal.

Methods: We conducted an individually randomised parallel two-arm non-blinded feasibility trial. Eligibility criteria included: being ≥16 years old, having a Body Mass Index of ≥25kg/m2, and access to an android-based device. Weight was measured (as the proposed primary outcome for a full-scale trial) at baseline, 1-month and 3-months of follow-up. Participants were randomised in a 2:1 allocation ratio to the ImpulsePal intervention or a waiting list control group. A nested action-research study allowed for data-driven refinement of the intervention across two cycles of feedback.

Results: 179 participants were screened for eligibility and 58 were randomised to the intervention group and 30 to the control group. Data were available for 74 (84%) participants at 1 month and 67 (76%) participants at 3 months. The intervention group (n=43) lost 1.03 kg (95% CI 0.33 to 1.74), more than controls (n=26) at one month, and 1.01kg (95% CI -0.45 to 2.47) more than controls (n=43, n=24 respectively) at three months. Feedback suggested changes to intervention design were required to (a) improve receipt and understanding of instructions, and (b) facilitate further engagement with the app and its strategies.

Conclusions: The evaluation methods are feasible and initial findings suggest that addressing impulsive processes may be helpful for those wishing to lose weight. The intervention is acceptable and satisfactory to users.

Clinical Trial: Retrospectively registered with the ISRCTN (ref: ISRCTN14886370)


Original languageEnglish
Article numbere11586
Number of pages19
JournalJMIR Formative Research
Issue number2
Publication statusPublished - 30 Apr 2019


  • weight loss, mHealth, digital behavior change, obesity, dual-process