Background: The use and effectiveness of tobacco quitlines by weight is still unknown.
Purpose: This study aims to determine if baseline weight is associated with treatment engagement, cessation, or weight gain following quitline treatment.
Methods: Quitline participants (n = 595) were surveyed at baseline, 3 and 6 months.
Results: Baseline weight was not associated with treatment engagement. In unadjusted analyses, overweight smokers reported higher quit rates and were more likely to gain weight after quitting than obese or normal weight smokers. At 3 months, 40 % of overweight vs. 25 % of normal weight or obese smokers quit smoking (p = 0.01); 42 % of overweight, 32 % of normal weight, and 33 % of obese quitters gained weight (p = 0.05). After adjusting for covariates, weight was not significantly related to cessation (approaching significance at 6 months, p = 0.06) or weight gain.
Conclusions: In the first quitline study of this kind, we found no consistent patterns of association between baseline weight and treatment engagement, cessation, or weight gain.