The Effect of Processing on Food Reward (PFR)

The minimally processed diets of our ancestors have been rapidly replaced by UPFs driving poor diet to become the leading risk factor for preventable death globally. Hence, it is essential to understand what properties of UPF are driving their overconsumption to reduce diet-related mortality. To address this gap in knowledge this proposal will test: If UPFs have a greater post meal metabolic response when compared to MPFs an essential signal for food reward Through the use of an auction task paradigm if UPFs overvalued and if this value is differentially encoded in the brain This study is a fully cross-over design in that each participant receives all conditions and therefore serves as their own control. All orders of foods will be counterbalanced. Although participants cannot be blinded to the conditions as they must be aware of the foods they are eating, they will not be made aware that the key manipulation is food processing. On different days participants will come to the lab and consume a meal containing either minimally or ultra-processed foods as determined by the widely used NOVA (not an acronym) scale. These conditions will be consumed in a whole room metabolic chamber allowing for simultaneous measurement of multiple metabolic responses (glucose, insulin, and metabolic rate). These measures will be collected for 45 min before consumption of the meal (baseline) and for 3 hours after consumption (post-prandial). All participants will also undergo a Becker-Degroot-Marschak auction paradigm that consists of foods that are either minimally or Ultra-processed in the MRI scanner. Food value will be measure in participants' willingness to pay for each food and Neural responses will be measured during presentation of the food cues.

In a whole room metabolic chamber participants will consume a ~300 kcal meal consisting of ultra-processed foods as determined by the widely used NOVA scale. The whole room metabolic chamber will allow for collection of simultaneous measurement of multiple metabolic responses (glucose, insulin, and metabolic rate). Measures will be collected for 45 min before consumption of the meal (baseline) and for 3 hours after consumption (post-prandial).

In a whole room metabolic chamber participants will consume a ~300 kcal meal consisting of ultra-processed foods as determined by the widely used NOVA scale. The whole room metabolic chamber will allow for collection of simultaneous measurement of multiple metabolic responses (glucose, insulin, and metabolic rate). Measures will be collected for 45 min before consumption of the meal (baseline) and for 3 hours after consumption (post-prandial).

In a whole room metabolic chamber participants will consume a ~300 kcal meal consisting of ultra-processed foods as determined by the widely used NOVA scale. The whole room metabolic chamber will allow for collection of simultaneous measurement of multiple metabolic responses (glucose, insulin, and metabolic rate). Measures will be collected for 45 min before consumption of the meal (baseline) and for 3 hours after consumption (post-prandial).

In a whole room metabolic chamber participants will consume a ~300 kcal meal consisting of minimally processed foods as determined by the widely used NOVA scale. The whole room metabolic chamber will allow for collection of simultaneous measurement of multiple metabolic responses (glucose, insulin, and metabolic rate). Measures will be collected for 45 min before consumption of the meal (baseline) and for 3 hours after consumption (post-prandial).

In a whole room metabolic chamber participants will consume a ~300 kcal meal consisting of minimally processed foods as determined by the widely used NOVA scale. The whole room metabolic chamber will allow for collection of simultaneous measurement of multiple metabolic responses (glucose, insulin, and metabolic rate). Measures will be collected for 45 min before consumption of the meal (baseline) and for 3 hours after consumption (post-prandial).

In a whole room metabolic chamber participants will consume a ~300 kcal meal consisting of minimally processed foods as determined by the widely used NOVA scale. The whole room metabolic chamber will allow for collection of simultaneous measurement of multiple metabolic responses (glucose, insulin, and metabolic rate). Measures will be collected for 45 min before consumption of the meal (baseline) and for 3 hours after consumption (post-prandial).

A meal containing ultra-processed foods derived from the picture set used in the Becker-Degroot-Marschak auction paradigm.

a meal containing minimally processed foods derived from the picture set used in the Becker-Degroot-Marschak auction paradigm.

Blood glucose concentration will be assessed at baseline and at set time points for 3 hours after consumption of each condition on different days.

Blood insulin concentration will be assessed at baseline and at set time points for 3 hours after consumption of each condition on different days.

Whole room indirect calorimetry will be used to determine energy expenditure at baseline (for 45 minutes) and for 3 hours after consumption of each condition on different days.

Whole room indirect calorimetry will be used to determine respiratory exchange ratio at baseline (for 45 minutes) and for 3 hours after consumption of each condition on different days.

Whole room indirect calorimetry will be used to determine substrate oxidation at baseline (for 45 minutes) and for 3 hours after consumption of each condition on different days.

A food picture set of 28 that are matched on 23 visual, perceptual, and nutritional properties but vary on degree of NOVA food processing level will be used in a Becker-Degroot-Marschak auction paradigm to assess participants' brain reward response for each food.

Inclusion Criteria: BMI between 18.5-24.9 kg/m2 Not pregnant or planning to become pregnant during study participation Residing in the Roanoke area and/or willing/able to attend sessions at the Fralin Biomedical Research Institute Able to speak and write in English Participants must be able to see a computer display clearly with or without vision correction (eyeglasses, contacts). Exclusion Criteria: Claustrophobia (this would make lying in an MRI scanner or indirect calorimetry canopy very uncomfortable). 2. History of head injury resulting in loss of consciousness for more than 10 minutes 3. Current or past diagnosis of diabetes or metabolic disorder (thyroid disease, etc.) 4. Contraindications to MRI: Individuals with pacemaker, aneurysm clips, neurostimulators, cochlear implants, metal in eyes, steel worker, or other implants. 5. History of alcohol or drug dependence 6. Active neurologic disorder 8. Diagnosed eating disorder 9. Food allergies or restrictive diet