Inclusion Criteria:  Age ≥ 18 years old BMI ≥ 25kg/m^2 Consume ≥ 5 servings red meat per week Active duty military and Department of Defense (DoD) Beneficiaries with active Tricare insurance Willing and able to adopt a vegan or standard omnivorous diet for 4 weeks Willing and able to track meal patterns, nutritional intake, exercise activity, and adverse events for 13 weeks Willing and able to come to David Grant USAF Medical Center for 4 blood draws Able to receive weekly emails and receive and prepare meal kits  Exclusion Criteria:  Currently on a vegetarian, vegan, or food-group restricted diet Currently taking or planning to initiate medications or supplements that significantly affect TMAO levels, carnitine, choline, or gut microbiome (Systemic antibiotics, antifungals, antivirals, antiparasitic, corticosteroids, methotrexate, cytokines, or immunosuppressive cytotoxic agents, laxatives, proton pump inhibitors, resveratrol, meldonium, or metformin) Currently consuming the following ≥ 2 times per week: probiotics/prebiotics, probiotic enhanced foods (eg. enhanced yogurt, kefir, kombucha), or energy drinks, multivitamins, or supplements with choline, carnitine, or betaine (Acceptable to consume: non-probiotic enhanced yogurts, energy drinks and multivitamins without choline, carnitine, or betaine) Participants will have the option to delay study start if they express interest in the study and have permanently discontinued one of the excluded diet, medication, or supplement listed previously within the past 4 weeks (minimum 4 week time between discontinuation of excluded item and study start) Clinically significant or unstable cardiovascular, gastrointestinal, hepatic, or renal disease states defined as requiring on-going changes to medication or medical management Consumption of smoking or chewing tobacco, or other nicotine-containing products for >1 day per week Consumption of >14 alcohol drinks per week Pregnant, breastfeeding, or plan to become pregnant