Key Determinants of Weight Loss Trajectory Across Different Periods of a Behavioral Weight Loss Intervention

Abstract

OBJECTIVE: This longitudinal study aims to identify the key factors influencing the weight loss trajectory during a 24-week intervention and their relevance at different stages of the treatment. METHODS: We studied 1252 participants (age 18-65 years) of a cognitive behavioral program to lose weight. Body weight was measured weekly, and a range of variables at baseline and throughout the treatment period were assessed. Linear regression analyses were conducted to understand the factors involved in the weight loss trajectory across three treatment periods (0-6, 7-12, 13-24 weeks). RESULTS: The rate of weight loss progressively decreased from the 1st to the 3rd period (770-198 g/week). During the 1st period, the recent history of the individual, including baseline metabolic status, dietary habits, and motivation, was the highest-ranked determinant. In the 2nd period, the sole predictor was the long-term personal history of obesity, that is, the duration of the individual's lifetime spent with overweight/obesity. In the 3rd period, emotional eating behaviors and related barriers emerged as the two highest-ranked determinants of reduced rate of weight loss. CONCLUSIONS: Findings suggest targeted interventions that address the specific challenges of each period of weight loss interventions. As treatment progresses, strategies focused on emotional-related behaviors may be crucial for sustaining weight loss. TRIAL REGISTRATION: ClinicalTrials.gov identifier NCT02829619.