The study aims to randomize 400 participants to 1 of 3 arms: a) a weight stability intervention prior to smoking cessation (Group 1); b) a weight loss intervention prior to smoking cessation (Group 2); or c) a self-guided weight management prior to cessation (Group 3) and to determine the efficacy of the interventions on preventing weight gain at 12 month follow-up. All 3 conditions receive a highly efficacious behavioral smoking cessation program and 6 months of varenicline pharmacotherapy (ChantixTM), the most efficacious medication for smoking cessation.

While smoking cessation leads to significant improvements in mortality and morbidity, weight gain post-cessation partially attenuates this benefit. Furthermore, concerns about postcessation weight gain are common and are often cited as a reason to delay cessation attempts. In addition, postcessation weight gain is associated with smoking relapse. Thus, although the health benefits of smoking cessation outweigh the negative impact of weight gain, ideally there would be intervention "packages" that would not require that people choose between smoking cessation and nontrivial weight gain. Thus, in the proposed study, the investigators will determine whether two very promising methods of reducing postcessation weight gain, namely a weight stability intervention (based on the evidence-based Small Changes intervention) versus a weight loss intervention (based on the evidence-based Look AHEAD intensive lifestyle intervention) followed by a smoking cessation intervention are efficacious for reducing postcessation weight gain. The investigators will randomize 400 smokers to one of three arms: a) a weight stability intervention prior to cessation (Group 1); b) a weight loss intervention prior to cessation (Group 2), or c) a self-guided intervention prior to cessation (Group 3) and to determine the efficacy of the interventions on preventing weight gain at 12 month follow-up. All three conditions receive a highly efficacious in-person smoking cessation behavioral intervention and six months of Varenicline (ChantixTM) pharmacotherapy. Those participants randomized to the Group 1 and Group 2 conditions will receive monthly booster weight management sessions, after completing the behavioral smoking cessation intervention. The primary outcomes will be weight change and smoking cessation at 12 month follow-up. In addition, the investigators will gather process data on mediators of treatment outcome via measures of treatment engagement (e.g., session attendance, varenicline utilization). The investigators will be able to determine whether a weight stability intervention or a weight loss intervention is efficacious in reducing post-cessation weight gain. The intervention results, if successful, could be disseminated and make a significant contribution towards curtailing obesity in this vulnerable population.

Inclusion Criteria:

• Participants must wish to quit smoking in the next 30 days
• Have smoked 5 or more cigarettes a day for at least 1 year
• Participants must be 18 years or older as the safety and efficacy of varenicline therapy has not been established for pediatric patients
• Participants must have a BMI of 22 kg/m2 or greater, as it would not be recommended to have those who are underweight or the lower end of the normal BMI range attempt a 5% weight loss (if assigned to the Group 2 condition)
• Participants must have access to a telephone and daily access to email, if using a cell phone, participants must be willing to use their cell phone minutes for weekly phone interventions
• Participants must have the ability to understand consent process in English
• If female and of childbearing age, participant must have a negative pregnancy test and must agree to use contraception during participation in the study
• All participants must be willing to be randomized to the study conditions and wait eight weeks prior to beginning smoking cessation (during which they will participate in the weight management intervention to which they are assigned).
• Participants must have BP < 150/95 and a heart rate of >40 beats per minute and <120 beats per minute.

Exclusion Criteria:

• Participants must not have a known contraindication, allergy or hypersensitivity to varenicline therapy
• Participants must not currently (in the previous 30 days) be participating in other behavioral or pharmacologic weight or smoking cessation interventions
• Participants must not have had weight loss surgery (hx of gastric bypass, stomach stapling or banding)
• Participants must not have lost > or equal to10 lbs in the past 6 months
• Participants must not be taking a medication that impacts weight
• Participants must not have used an investigational drug within the last 30 days
• Participants must not have current suicidal thoughts or have a lifetime history of a suicide attempt as defined by the Columbia-Suicide Severity Rating Scale (C-SSRS)
• Participants must not self-report a history of psychosis, bipolar disorder, or anorexia nervosa
• Participants must not have self-reported current alcohol abuse or illicit substance use
• Participants must not have kidney or liver disease, unstable cardiovascular conditions, HIV, or history of cancer in last 5 years
• Participants must not have another member of their household already participating in this study
• Participants must not be currently pregnant or lactating or planning to become pregnant in the next 12 months, or have been pregnant within the last 6 months
• Weight limit of 385 pounds

It is anticipated that a cleaned data set of study-specific data will be provided within two years following the termination of the study for the data archive and this data set would be made public. Confidentiality of individual participants would be maintained with all releases of data. The final study analytical database would be processed according to HIPAA definitions for public data sharing. Documentation would be provided along with the data sharing file that includes but is not limited to: data dictionary, data code book, valid variable ranges (where provided), the protocol, procedure and operational manuals, intervention manual or programs and any electronic versions of any paper forms that were used in data collection.

Two years following the termination of the study

Upon reasonable request to the principal investigator, Rebecca Krukowski

12 months

Consistent with the typical definition