Factors Associated with Achievement of Clinically Significant Weight Loss by Women in a National Nonprofit Weight Loss Program

BACKGROUND: Clinically significant weight loss (CSWL) is ≥5% of initial weight. The purpose of the study is to determine factors associated with women achieving CSWL in Take Off Pounds Sensibly (TOPS), a national, nonprofit weight loss program. METHODS: This is a retrospective analysis of 48,674 females who joined TOPS from 2005 to 2011 and had a birth date in the database. Predictors of CSWL were evaluated using log-binomial regression and adjusted relative risks [99% CI] for participant age, initial weight, number of members per chapter, and chapter age. RESULTS: Older women were more likely to achieve CSWL, with women ≥70 years 1.23 (1.18, 1.28) times more likely to achieve CSWL compared to women 18 to <45 years. Women who weighed 113 to <136 kg and ≥136 kg were 1.06 (1.02, 1.10) and 1.07 (1.02, 1.14) times more likely to achieve CSWL compared to women <80 kg, respectively. Women in chapters with 25 to