Combining self-affirmation with implementation intentions to promote fruit and vegetable consumption.
OBJECTIVE
The current study tested whether self-affirmation in the context of a threatening health message helps promote a health behavior (fruit and vegetable consumption) over a 3-month period, and whether adding a manipulation to support the translation of intentions into behavior (an implementation intentions induction) enhances the impact of self-affirmation.


METHODS
Participants (N = 332, 71% women) reported their baseline consumption and were randomly assigned to condition in a 2 (self-affirmation: yes, no) × 2 (implementation intentions: formed, not formed) between-subjects factorial design. They completed a self-affirmation/control task and then read a health communication advising eating at least 5 portions of fruit and vegetables daily. Next participants reported intentions for behavior change, after which they formed/did not form relevant implementation intentions. Consumption was measured again 7 days and 3 months postintervention.


RESULTS
Self-affirmed (vs. nonaffirmed) participants reported eating more fruit and vegetables at both follow-ups. Forming (vs. not forming) implementation intentions was also beneficial for consumption. At 7 days, there was also a significant self-affirmation × implementation intentions interaction: consumption was highest when self-affirmed participants also formed implementation intentions.


CONCLUSIONS
The present study offers new evidence concerning the impact and durability of self-affirmation on health behaviors and the role of implementation intentions in enhancing the impact of self-affirmation.
Department of Psychology, University of Sheffield.
Peter R
PR
Harris
Department of Psychology, University of Sheffield.
Irina
I
Brearley
Department of Psychology, University of Sheffield.
Paschal
P
Sheeran
Department of Oncology, University of Sheffield.
Margo
M
Barker
National Cancer Institute.
William M P
WM
Klein
Department of Psychology, Carnegie Mellon University.
J David
JD
Creswell
Department of Psychology, University of Pittsburgh.
John M
JM
Levine
School of Psychology, University of Sussex.
Rod
R
Bond
D000293:Adolescent; D000328:Adult; D004435:Eating / Q000523:psychology*; D005260:Female; D005500:Follow-Up Studies; D005638:Fruit; D006293:Health Promotion / Q000379:methods*; D006801:Humans; D033182:Intention; D008297:Male; D008875:Middle Aged; D012649:Self Concept; D014675:Vegetables; D055815:Young Adult