The Drop it at Last Study: Six-Month Results of a Phone-Based Weight Loss Trial

Abstract

Purpose.

To address the translational research question regarding the optimal intervention “dose” to produce the most cost-effective rate of weight loss, we conducted the Drop It At Last (DIAL) study.

Design.

DIAL is a 6-month pilot randomized trial to examine the efficacy of phone-based weight loss programs with varying levels of treatment contact (10 vs. 20 sessions) in comparison to self-directed treatment.

Setting.

Participants were recruited from the community via mailings and advertisement.

Subjects.

Participants were 63 adults with a body mass index between 30 and 39 kg/m².

Intervention.

Participants received a standard set of print materials and were randomized to either: (1) self-directed treatment; (2) 10 phone coaching sessions; or (3) 20 phone coaching sessions.

Measures.

Measured height, weight, and psychosocial and weight-related self-monitoring measures were collected at baseline and follow-up.

Analysis.

General linear models were used to examine 6-month treatment group differences in weight loss and in psychosocial and behavioral measures.

Results.

Weight losses were – 2.3, – 3.2, and – 4.9 kg in the self-directed, 10-session, and 20-session groups, respectively (p < .21). Participants who completed 10 or more sessions lost more weight (– 5.1 kg) compared to those completed four or fewer sessions (– .3 kg, p < .04).

Conclusion.

Phone-based weight loss program participation is associated with modest weight loss. The optimal dose and timing of intervention warrant further study.