Adaptive Nutrition and Exercise Weight Loss (A-NEW) Study

Inclusion Criteria: * Female, at least 3 months after completion of local therapy (e.g. surgery, radiation), and if applicable, adjuvant chemotherapy * Diagnosed within 10 years with histologically-confirmed ductal carcinoma in situ (DCIS) or stage I-III invasive carcinoma of the breast * Up to date with recommended screening mammography within one year * Current BMI ≥ 30 kg/m2 or BMI 27.0-29.9 kg/m2 with hypertension, non-insulin dependent diabetes or hyperlipidemia; and weight ≤ 400 lbs * Eastern Cooperative Oncology Group (ECOG) performance status 0-1 * Willingness to change diet, physical activity, track behaviors, engage in weekly and monthly contacts and visit, and take chronic weight loss medication * Able to read and write the English language without assistance and daily access to the e-mail and/or smartphone * Patient is aware of her diagnosis, understands the study regimen, its requirements, risks, and discomforts, and is able and willing to sign an informed consent form. Exclusion Criteria: * Serious/uncontrolled medical condition at the discretion of the Protocol Chair/designee likely to hinder accurate measurement of weight or any condition for which weight loss is contraindicated or would affect adipokine and inflammatory markers (e.g. active malignancy, end stage renal disease on dialysis, cirrhosis, autoimmune disease, adrenal disease, uncontrolled hypertension, seizure disorder, and history of bariatric surgery) * Pregnant or nursing within past 6 months, or plans to become pregnant in the next year * Currently enrolled or planning to enroll in a weight loss program (e.g. Weight Watchers, Jenny Craig, Nutrisystem and Medifast) or to take a chronic weight loss medication. * Diabetes on insulin or sulfonylureas within the past 3 months * Unstable psychiatric disorder or bulimia/anorexia nervosa * Alcohol, nicotine or substance abuse; or undergoing abrupt discontinuation of alcohol, benzodiazepine, barbiturate or anti-epileptic drug * Use of the following medications are excluded: * Monoamine oxidase (MAO) inhibitors (must be \>14 days from discontinuation) * Thyroid medication use unless on stable doses for at least the past 3 months * Buproprion containing products or opiate agonists (must be \>14 days from discontinuation) * Medications that cause weight loss (e.g., lorcaserin, phentermine, orlistat, Qsymia, Contrave) within the past 3 months * Medications that are likely to cause weight gain or prevent weight loss (e.g., corticosteroids, lithium, olanzapine, risperidone, clozapine, oral contraceptive pills, hormone replacement therapy) within the past 3 months. NOTE: An exception to this is that SSRI's and SNRI's are allowed if participant has been on stable doses for at least 3 months (if discontinued, a washout of 2 weeks from prior selective serotonin reuptake inhibitor (SSRI)/Serotonin-norepinephrine reuptake inhibitor (SNRI) use is required). * Medications that may affect adipokine or inflammatory markers (e.g., metformin, glitazones, steroids, angiotensin converting enzyme (ACE) inhibitors, beta blockers and statins) unless on stable doses ≥3 months prior to registration (if discontinued, a washout of 2 weeks from prior use is required). Concurrent NSAIDs are allowed if use is limited to \<3 times per week; chronic NSAIDs are permitted on study only if use has been ≥3 times per week for at least 3 months prior to registration and is expected to continue.