Dementia and Diabetes Prevention Program

Inclusion Criteria: * Sedentary (as per the Telephone Assessment of Physical Activity) * Poor diet (as per the MIND Diet Screener) * Cognitive function: absence of significant cognitive impairment as per the modified Telephone Interview for Cognitive Status (TICSm; age-, education-, and race-adjusted TICSm \>32) * Lives in a region where the DDPP interventions will be delivered * Does not plan to travel outside of the home geographic area for more than 3 months over the course of the study * Free of physical disabilities that preclude participation in the study * Willing to complete all study-related activities for 32 weeks * Willing to be randomized to either lifestyle intervention group Exclusion Criteria: * Age \<60 * Body Mass Index (BMI) \>40 * Any significant neurologic disease, including any form of dementia, Parkinson's disease, Huntington's disease, normal pressure hydrocephalus, brain tumor, progressive supranuclear palsy, seizure disorder, subdural hematoma, multiple sclerosis, or history of significant head trauma with persistent neurologic sequelae or known structural brain abnormalities * History of major depression within the last 12 months * History of bipolar disorder or schizophrenia as per Diagnostic and Statistical Manual of Mental Disorders (DSM) V criteria * History of alcohol or substance abuse or dependence within the past 2 years, as per DSM V criteria * Use of psychoactive medications within the last 3 months including tricyclic antidepressants, antipsychotics, mood-stabilizing psychotropic agents (e.g., lithium salts), psychostimulants, opiate analgesics, antiparkinsonian medications, anticonvulsant medications (except gabapentin and pregabalin for non-seizure indications), systemic corticosteroids, or medications with significant central anticholinergic activity; in the absence of major depression, stable dose use of selective serotonin reuptake inhibitors or serotonin and norepinephrine reuptake inhibitors are allowed * Health profiles that would jeopardize their safety to participate: (Screen failures will be referred immediately to a physician for medical examination): (1) Myocardial infarction or symptoms of unstable coronary artery disease (e.g., angina) in the last six months, (2) Uncontrolled hypertension within the past 6 months, (3) Morbid obesity (BMI\<40), (4) History of clinically-evident stroke, (5) Clinically-significant infection within the past 30 days, (6) Significant pain or musculoskeletal disorder limiting the ability to participate safely, or (7) Clinically significant * Past or current use of insulin to treat type 2 diabetes * Serious diabetic event within 6 months of enrollment * Lung disease requiring either regular use of corticosteroids or the use of supplemental oxygen (inhaled steroids for asthma is permissible) * Renal disease * Clinically significant abnormalities in laboratory blood tests as per judgment of the Study Physician * History within the last 2 years of treatment for primary or recurrent malignant disease, excluding non-melanoma skin cancers, resected cutaneous squamous cell carcinoma in situ, basal cell carcinoma, cervical carcinoma in situ, or in situ prostate cancer with normal prostate-specific antigen post-treatment * History of hip fracture, joint replacement, or spinal surgery in the last 6 months * Currently receiving physical therapy or cardiopulmonary rehabilitation * History of a malabsorptive bariatric procedure (gastric bypass, biliopancreatic diversion); other bariatric procedures involving restriction (i.e., sleeve, band) are not exclusionary * For women: currently pregnant, pregnant within the past 6 months, or planning to become pregnant within the next 6 months * Currently incarcerated * Receiving hospice care * Adults unable to provide consent for participation * PI/Study Physician discretion regarding appropriateness of participation or concern about intervention adherence