Biobehavioral Reward Responses Associated With Consumption of Nutritionally Diverse Ultra-Processed Foods

Overview

The changing food environment, with increasingly abundant ultra-processed food (UPF) options, may directly contribute to rising rates of obesity, though it is unknown which ingredients in UPF elevate their reinforcing nature in a way that may lead to overconsumption. The proposed study is the first to systematically examine differences in the rewarding characteristics of and physiological and metabolic responses to UPFs that are high in fat, refined carbohydrates (like sugar), or both. Understanding the biobehavioral underpinnings that enhance the reinforcing potential of ingredients in UPF (e.g., fat vs. refined carbohydrates) can inform novel intervention targets for the treatment of overeating and obesity.

Detailed description

The abundance of ultra-processed foods (UPFs) in our environment has led to excessive calorie intake and been cited as perpetuating the obesity epidemic. UPFs do not exist in nature and are created to maximize palatability through the additions of fat, refined carbohydrates (RC), and/or sodium (e.g., chocolate, potato chips). Emerging research suggests UPFs may be reinforcing akin to rewarding substances like alcohol. However, empirical investigation of which ingredients in UPFs directly motivate overeating is in its nascent stages. This study will be the first to combine biological and behavioral methods used in addiction research with assessments of food reward, to delineate the mechanisms by which fat and RC drive UPF reinforcement and influence future consumption.

Individuals (n=50) with obesity will be recruited for the current study. Participants will attend four appointments (order randomized/counterbalanced) and will consume a snack consisting of 1) UPF high in fat + RC (UPF+FRC), 2) UPF high in fat (UPF+F), 3) UPF high in RC (UPF+RC), or 4) minimally processed foods (MPF). At each assessment, subjective experiences and metabolic responses will be assessed before and up to 120 minutes after consumption of each snack. An ad-libitum eating period for each food condition will follow to evaluate associations of metabolic/behavioral responses with subsequent intake. For five days after each appointment, participants will use ecological momentary assessment (EMA) to assess subjective experiences and real-world reported consumption of UPF+FRC, UPF+F, UPF+RC, and MPF.

Interventions

• Other Intake of nutritionally diverse ultra-processed foods
  All participants will attend four food consumption assessment visits where, at each visit, they will be asked to consume a standardized snack portion of: 1) ultra-processed foods (UPFs) high in both fat and refined carbohydrates (UPF+FRC), 2) UPF high in fat (UPF+F), 3) UPF high in refined carbohydrates (white flour, sugar) (UPF+RC), or 4) minimally processed foods. The order of the four food consumption assessment visits will be randomized and counterbalanced across participants, who will each

Primary outcome measures

• Subjective reward responses to food intake (in lab) [Time frame: 10 minutes before intake of test snack, during, and 30-, 60-, 90-, and 120 minutes after intake of the test snack.]
• Subjective reward responses to food intake (EMA) [Time frame: EMA surveys administered over 5 days following each food consumption assessment (20 total days of EMA data)]
• Ad libitum consumption [Time frame: 2 hours after test snack intake at each food consumption assessment.]
• Daily calorie intake (EMA) [Time frame: EMA surveys administered over 5 days following each food consumption assessment (20 total days of EMA data)]
• Consumption of UPFs and MPFs (EMA) [Time frame: EMA surveys administered over 5 days following each food consumption assessment (20 total days of EMA data)]

Secondary outcome measures (3)

• Changes in heart rate in response to food intake [Time frame: 10 minutes before intake of test snack, during, and 30-, 60-, 90-, and 120 minutes after intake of the test snack.]
• Salivation responses to food intake [Time frame: 10 minutes before intake of test snack, during, and 30-, 60-, 90-, and 120 minutes after intake of the test snack.]
• Magnitude of metabolic responses to food intake [Time frame: 10 minutes before intake of test snack, during, and 30-, 60-, 90-, and 120 minutes after intake of the test snack.]

Eligibility criteria

Inclusion Criteria Men and women Age 18-65 years BMI ≥ 30 kg/m2 Endorse liking the foods included in the compulsory test snacks at a 6 on a scale from 1-10 No history of severe psychiatric illness; current mild to moderate severity of depression, anxiety, or binge eating disorder, determined by the behavioral evaluation and the screening measures will be included Live in the greater Springfield, Oregon area and are willing/able to participate in six in-person assessments Can access and are willing/able to use a smartphone

Exclusion Criteria Medical condition that may limit consumption of compulsory test snack foods or impact metabolic responses to food consumption Type I or II diabetes (HbA1c > 6.5 based on blood test) Uncontrolled hypertension (blood pressure ≥ 140/90 mm Hg) Cardiovascular event (e.g., stroke, myocardial infarction) in the last 12 months Individuals with dietary allergies of aversions to the test snack foods Individuals taking medications that may influence the metabolic responses of interest (e.g., metformin) Individuals who are actively pursuing weight loss or have lost ≥ 5% of their initial weight in the last 6 months Severe symptoms of mood, anxiety, and any severity of thought disorders Severe binge eating disorder or full criteria bulimia Persons with active substance-use disorders Current, active suicidal ideation, and/or a suicide attempt within the past year History of bariatric surgery Women who are nursing, pregnant, or planning to become pregnant in the next three months Self-report current diagnosis of a transferrable blood condition (including HIV, hepatitis B, hepatitis C, or syphilis) Self-report prior history of being dizzy or anxious during blood draws and/or technician not being able to find a vein.

Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.

Healthy volunteers: No

Study design

Allocation

Randomized

Model

Crossover

Masking

Open label

Primary purpose

Other

Study locations

United States · 1 center

• Drexel University — Philadelphia

Identifiers

NCT: NCT05437809 · K23DK129825

Primary sources (government registries)

• ClinicalTrials.gov (US NIH)

View this study on ClinicalTrials.gov ↗