Objective: The Keep It Off trial evaluated the efficacy of a phone- and mail-based weight loss maintenance intervention among adults who have recently lost weight.
Methods: Four hundred nineteen adults who had recently lost ? 10% of their body weight were randomized to the “Guided” or “Self-Directed” intervention. Guided participants received a 10 session workbook, 10 biweekly phone coaching calls, eight monthly and six bimonthly calls, and bimonthly weight graphs and tailored letters based on self-reported weights. Self-Directed participants received the same workbook and two coaching calls. Primary outcomes are weight change and maintenance (regain of < 2.5% of baseline body weight) at six, 12, 18, and 24 month follow-up.
Results: Mixed model repeated-measures analysis examining weight change revealed a significant time by treatment group interaction (F = 8.91, p < 0.035). Guided participants regained significantly less weight than Self-Directed participants at 12, 18, and 24 months. The odds of 24 month maintenance were 1.59 (95% CI: 1.04 - 2.41, p=0.03) times greater in the Guided than in the Self-Directed group.
Conclusions: A sustained, supportive phone- and mail-based intervention is effective in promoting weight loss maintenance relative to a brief intervention for participants who have recently lost weight.