Planning to lose weight: randomized controlled trial of an implementation intention prompt to enhance weight reduction among overweight and obese women

Health Psychol. 2007 Jul;26(4):507-12. doi: 10.1037/0278-6133.26.4.507.


Objective: The trial investigates the effects of augmenting an established weight-reduction intervention with implementation intention prompts.

Design: Fifty-five overweight or obese women (ages 18 to 76 years; body mass index from 25.28 to 48.33) enrolled in a commercial weight reduction program were randomly assigned to either an implementation intention prompt or a control condition. Data were collected twice, with a time gap of 2 months.

Main outcome measures: The primary outcome was participants' change in weight and body mass index from preintervention to follow-up.

Results: Repeated measures analysis of variance revealed a significant Time = Condition interaction: On average, implementation intention prompt participants lost 4.2 kg (95% confidence interval = 3.19, 5.07), whereas control participants lost 2.1 kg (95% confidence interval = 1.11, 3.09). The change in frequency of planning mediated the effects of the intervention on weight and body mass index change.

Conclusion: Among obese or overweight women participating in a commercial weight loss program, those who learn to form implementation intentions can achieve greater weight reduction. Planning facilitation is a key mechanism explaining enhanced weight loss generated by implementation intention formation.

Publication types

  • Comparative Study
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Body Mass Index
  • Control Groups
  • Diet, Reducing / methods
  • Female
  • Follow-Up Studies
  • Health Behavior
  • Health Promotion / methods*
  • Humans
  • Intention*
  • Middle Aged
  • Motor Activity
  • Nutritional Status
  • Obesity / diet therapy*
  • Planning Techniques
  • Psychotherapy, Group / methods
  • Social Support
  • Surveys and Questionnaires
  • Weight Loss*