Trajectories of Weight Change and Predictors Over 18-Month Weight Loss Treatment.
Obesity research has typically focused on weight change patterns using the whole sample in randomized clinical trials (RCTs), ignoring subsets of individuals with varying weight change trajectories (e.g., continuing to lose, or maintaining weight). The purpose was to explore possible trajectories of weight change and their associated predictors.



We conducted a secondary analysis of data from two RCTs using standard behavioral treatment for weight loss. Group-based trajectory modeling was used to identify distinct classes of percent weight change trajectories over 18 months.



The sample (N = 338) was primarily female (85.2%), White (73.7 %), 45.7 ± 9.0 years old, with 15.6 ± 2.8 years of education. Three trajectory groups were identified: good responders (>15% weight loss), fair responders (5%-10% weight loss), and poor responders (<5% weight loss). The good responders had a significantly larger decrease in perceived Barriers to Healthy Eating subscale scores than the fair and poor responders (p < .01). Compared to the poor responders, there was a significant decrease in fat gram intake in the good responders (p = .01).



Good responders differed from poor responders in decreasing their perceived barriers to healthy eating (e.g., managing emotions, social support, and daily mechanics of adopting a healthy diet) and reducing fat intake. Good responders differed from fair responders in perceived barriers to healthy eating.



Clinicians need to focus on how we can assist those who are being unsuccessful in adopting some of the behaviors observed among those who have experienced successful weight loss and maintainers.
Assistant Professor, Boston College, Connell School of Nursing, Chestnut Hill, MA, USA.
Yaguang
Y
Zheng
Professor; Director, Center for Research and Evaluation, University of Pittsburgh School of Nursing, Health & Community Systems, and Departments of Biostatistics and Epidemiology in the Graduate School of Public Health, Pittsburgh, PA, USA.
Susan M
SM
Sereika
Assistant Professor, University of Pittsburgh School of Nursing, Health Promotion & Development, Pittsburgh, PA, USA.
Cynthia A
CA
Danford
Assistant Professor, University of Pittsburgh School of Nursing, Acute & Tertiary Care, Pittsburgh, PA, USA.
Christopher C
CC
Imes
PhD Candidate, University of Pittsburgh, School of Social Work, Pittsburgh, PA, USA.
Rachel Woodson
RW
Goode
Clinical Research Coordinator, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA.
Juliet
J
Mancino
Professor, University of Pittsburgh School of Nursing, Health & Community Systems and Department of Epidemiology in the Graduate School of Public Health, Pittsburgh, PA, USA.
Lora E
LE
Burke
D000328:Adult; D000072001:Diet, Healthy / Q000523:psychology; D004644:Emotions; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000628:therapy*; D012944:Social Support; D016896:Treatment Outcome; D015431:Weight Loss
Obesity; trajectory; weight change