RecruitingBehavioural interventionThe Effects of Treating Insomnia on Behavioral Weight Loss Outcomes in Survivors of Breast CancerThe investigators propose a randomized controlled clinical trial in 250 women with a history of early stage breast cancer who are overweight or obese with insomnia to test whether a brief, cognitive-behavioral intervention for insomnia (CBT-I) prior to behavioral weight loss (CBT-I+BWL) is superior to a sleep education control (EDU) condition followed by behavioral weight loss (EDU+BWL). The investigators will measure outcomes at baseline, 8 weeks (after completing CBT-I or EDU and prior to BWL), and at 3, 6, and 12 months.