Effect of Ultra-processed Versus Unprocessed Diets on Energy Metabolism

* INCLUSION CRITERIA: In order to be eligible to participate in this study, an individual must meet all of the following criteria: * Provision of signed and dated informed consent form * Adults age 18-60 years, male and female * Weight stable (\< +/- 5 % body weight change over past 6 months) as determined by volunteer report * Body mass index (BMI) \> =20 kg/m2 * Body weight \> = 53 kg * Able to complete daily bouts of stationary cycling at a moderate rate and intensity with a HR equal to or greater than 0.3(SqrRoot) (220-age-HRrest)+HRrest but not exceeding 0.4(SqrRoot) (220-age-HRrest)+HRrest and no signs of arrhythmia * Willingness to comply with all study procedures and Lifestyle Considerations for the duration of the study per the discretion of the PI. EXCLUSION CRITERIA: An individual who meets any of the following criteria will be excluded from participation in this study: * Evidence of diseases or conditions that may influence appetite (e.g., cancer, diabetes, alterations of smell or taste post COVID-19), or other conditions at the discretion of the PI and/or study team). * Taking prescription medications or other drugs that may influence appetite (including, but not limited to, diet/weight-loss medication or other medications at the discretion of the PI and/or study team) * Positive pregnancy test or lactation as determined by volunteer report (women only) * Participating in a regular exercise program (\> 2h/week of vigorous activity) as determined by volunteer report * Hematocrit \< 37% (women only) * Hematocrit \< 40% (men only) * Caffeine consumption \> 300 mg/day as determined by volunteer report * Alcohol consumption \> 3 drinks per day for men or \> 2 drinks per day for women as determined by volunteer report * Regular use of tobacco (smoking or chewing), amphetamines, cocaine, heroin, or marijuana over past 6 months as determined by volunteer report. Subjects may also be excluded based on a urine drug test. * Psychological conditions as determined by volunteer report such as (but not limited to) eating disorders, depression, bipolar disorders, that would be incompatible with safe and successful participation in this study, as determined by investigators * Volunteers with strict dietary concerns (e.g. vegetarian or kosher diet, food allergies) or a reported dislike of a significant fraction of the study foods * Volunteers unwilling or unable to give informed consent