Tiny study to test how Ultra-Processed foods affect weight and health

Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.

Inclusion Criteria: * Overweight or obesity (BMI 25-50 kg/m2) * Willingness to accept group assignment and provide outcome measures * Premenopausal (women only) * Be able to communicate (oral and written) in English * Be able to provide informed consent Exclusion Criteria: * Recent weight loss (≥10 pounds in the last six months) * On a regimen of medications (weight loss or otherwise) that can affect weight or diabetes outcomes for less than 3 months (GLP1 medications allowed if weight stable and on stable dose for \>=3 months) * Given birth within the past year or is currently pregnant or breastfeeding * Past bariatric surgery (\<10 years) - all types * Disease/condition that is life threatening or can interfere with or be aggravated by weight change * Dementia, psychiatric illness, or substance abuse that may interfere with adherence * Current or history of a clinically diagnosed eating disorder, including anorexia nervosa or bulimia nervosa * Type 1 or type 2 diabetes * Uncontrolled gastrointestinal disorders including chronic malabsorptive conditions, peptic ulcer disease, Crohn's disease, chronic diarrhea or active gallbladder disease * Current cancer or cancer treatment, or a history of cancer or cancer treatment within the last 3 years. Exceptions include 1) successfully resected non-melanoma carcinoma of the skin, 2) basal or squamous cell skin cancer, 3) stage 0 non-invasive carcinoma of the cervix, 4) stage 0 non-invasive prostate cancer * History of kidney or liver disease or malnutrition that in investigator judgment should exclude participation * Hemoglobinopathy that interferes with measurement of HbA1c * Class II or higher congestive heart failure * Unstable heart disease * Blood pressure ≥160/100 mm Hg * Thyroid disease for which the participant is untreated or has had treatment changed within the last 6 weeks. * Unwilling to stop alcohol intake during study participation * Current smoker or other type of tobacco user (chewing tobacco, vaping, etc.) * Any other condition or factor which in the opinion of the study physician or investigator makes it inadvisable for the candidate to participate in the trial