Timing of dietary change in response to a telephone counseling intervention: evidence from the WHEL study.

OBJECTIVE

Little is known about temporal patterns of diet change within interventions, nor about predictors of early and sustained successful change. Social-cognitive theory asserts that early successes in achieving behavior change increase self-efficacy, leading to longer-term success.

DESIGN

The authors conducted exploratory cluster analyses using dietary data from the first month of the telephone counseling intervention of the Women's Healthy Eating and Living (WHEL) Study.

MAIN OUTCOME MEASURE

Change in dietary pattern at three early intervention timepoints.

RESULTS

Three clusters were identified: Cluster 1 (25%) was close to meeting study goals at baseline, but still made major changes; Cluster 2 (49%) and Cluster 3 (26%) were not achieving study goals at baseline, but Cluster 2 made substantial immediate changes, while Cluster 3 changed their diet more gradually. Baseline demographic and behavioral variables were associated with cluster membership; however, the strongest predictors of cluster were self-efficacy, motivation, and approaches to study goals. Cluster membership predicted dietary pattern at 12 months.

CONCLUSION

These data suggest that a one-on-one telephone counseling intervention that is intensive in the early weeks may maximize the level of change achieved in a study.