Early vs. Late Time Restricted Eating vs. Daily Caloric Restriction (Time2Eat)

Inclusion Criteria: Adult males and females with a BMI of 27-45 kg/m2 Age, 18-65 years old Passing medical and physical screening, and analysis of blood and urine screening samples Typical eating duration >12 hours per day (assessed by questionnaires) Own a smartphone No plans to relocate within the next 12 months Capable and willing to give informed consent, understand exclusion criteria, and accept the randomized group assignment. Have a primary care physician (or are willing to establish care with a primary care physician prior to study enrollment) to address medical issues which may arise during screening or study procedures/interventions. Exclusion Criteria: Pregnancy or lactation for women (women who are >6 months postpartum with no plans of becoming pregnant in the next year and who are not currently lactating can be included; oral contraceptives will be allowed if medication has been consistent for the prior 6 months) Weight loss >5kg in past 3 months for any reason except post-partum weight loss, weight gain >5kg in past 3 months requires assessment by PI to determine reason for weight gain and if it is appropriate for the subject to participate in the study Weight loss of >50 lbs in past 3 years for any reason except post-partum weight loss Presence or history of any metabolic or chronic health problems which would affect appetite, food intake, energy metabolism, or ability to optimally participate in the exercise component including: CVD, peripheral vascular disease, cerebrovascular disease, significant cardiac arrhythmias or cardiac valve disease, diabetes, uncontrolled hyper- or hypothyroidism, uncontrolled hypertension, cancer (within the last 5 years, except skin cancer or other cancers considered cured with excellent prognosis), HIV infection, significant gastrointestinal disorders (described below), significant pulmonary disorders (described below), significant renal, musculoskeletal, neurologic, hematologic, or psychiatric disease. Significant gastrointestinal disorders including: chronic malabsorptive conditions, peptic ulcer disease, Crohn's disease, Ulcerative Colitis, chronic diarrhea, or active gallbladder disease. Significant pulmonary disorders including: chronic obstructive pulmonary disease (COPD), interstitial lung disease, cystic fibrosis, or uncontrolled asthma. Symptoms suggestive of CVD: chest pain, shortness of breath at rest or with mild exertion, syncope. Taking medications affecting weight or energy intake/energy expenditure in the last 6 months, including weight loss medications, antipsychotic drugs or other medications as determined by the study physician Having abnormal blood chemistry (eGFR<45mL/min, AST or ALT >3 times the upper limit of normal) or as deemed significant by the study physician Being considered unsafe to participate as determined by the study physician Previous obesity treatment with surgery or weight loss device, except: (1) liposuction and/or abdominoplasty if performed > 1 year before screening, (2) lap banding if the band has been removed > 1 year before screening, (3) intragastric balloon if the balloon has been removed > 1 year before screening (4) duodenal-jejunal bypass sleeve, if the sleeve has been removed > 1 year before screening or 5) AspireAssist or other endoscopically placed weight loss device if the device has been removed > 1 year before screening. Being a smoker or having been a smoker in the 3 months prior to their screening visit Working night shifts Typical wake time earlier than 6AM Night eating syndrome (at least 25% of food intake is consumed after the evening meal and/or at least two episodes of nocturnal eating per week) as assessed with meal pattern assessment questionnaire History of clinically diagnosed eating disorders including anorexia nervosa, bulimia, binge eating disorder. Score >20 on the EATS-26 or pattern of response on the QEWP-5 suggestive of possible binge eating disorder or bulimia will require further assessment by the Study MD to determine if it is appropriate for the subject to participate in the study. Current alcohol or substance abuse (assessed with CAGE-AID questionnaire (48)) Current severe depression or history of severe depression within the previous year, based on DSM-IV-TR criteria for Major Depressive Episode. Score > 18 on BDI will require further assessment by the Study MD to determine if it is appropriate for the subject to participate in the study.