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

Study Overview
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Brief Summary
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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
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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.

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

Conditions
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Obesity, Overeating, Food Addiction

Intervention / Treatment
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* Other: Intake of nutritionally diverse ultra-processed foods


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: 18 to 65 years old BMI ≥ 30 kg/m2 Endorse liking the test snack foods at a 6 on a 1-10 scale Live in the greater Philadelphia area and are willing/able to participate in six in-person assessments Can access and are willing/able to use a smartphone Able to give consent Exclusion Criteria: Unable to fluently speak, write, and read English BMI below 30 kg/m2 Self-report dietary allergies or aversions to the test snack foods Current diagnosis of type 1 or 2 diabetes (HbA1c > 6.5; will be confirmed by blood test at baseline) or self-reported diagnosis of hypertension Self-report a cardiovascular event (e.g., stroke, myocardial infarction) in the last 12 months Self-report current use of medications that may influence the metabolic responses of interest or inhibit appetite (e.g., metformin, liraglutide) Self-report a loss of ≥ 5% of their body weight in the last 6 months, as this may influence their food choices Self-report severe symptoms of mood (Beck Depression Inventory score ≥ 29), anxiety, and any severity of thought disorders Self-report severe binge eating disorder or full criteria bulimia nervosa Self-report active substance-use disorders Self-report current, active suicidal ideation, and/or a suicide attempt in the past year (will be referred to psychiatric treatment facilities in the greater Philadelphia area) Self-report a history of bariatric surgery Self-report current involvement in weight loss treatment or self-directed weight loss attempt Women who are nursing, pregnant, or planning to become pregnant in the next 3 months Does not have access or are not willing to use a smartphone

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 65 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Other
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Other: Adults with obesity<br>All participants (n=50 adults with obesity) will complete each of the four food consumption appointments (order of the four appointments will be randomized/counterbalanced). | Other: Intake of nutritionally diverse ultra-processed foods<br>* 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 consume all the test snacks across the four appointments.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Subjective reward responses to food intake (in lab) | Indicators of subjective reward (craving, palatability, hedonic hunger, and mood) will be assessed by participants' self-reports before, during, and after consumption of the test snack at each of the four food consumption appointments. Each facet of subjective reward will be assessed by 100-point visual analog scales ranging from 0-100. | 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) | Indicators of subjective reward (craving, palatability, hedonic hunger, and mood) will be assessed by participants' self-reports in EMA surveys. Each facet of subjective reward will be assessed by 100-point visual analog scales ranging from 0-100. | EMA surveys administered over 5 days following each food consumption assessment (20 total days of EMA data) | 
| Ad libitum consumption | Total number of calories consumed from the test snack food during a 15-minute eating period. Calories will calculated by measuring bowls containing the test snacks before and after participant consumption on a digital scale accurate to 0.01 grams. The difference in grams will be converted into the calories that the participant ate. | 2 hours after test snack intake at each food consumption assessment. | 
| Daily calorie intake (EMA) | Calorie intake will be derived from participants' self-reported food consumption in EMA surveys. | EMA surveys administered over 5 days following each food consumption assessment (20 total days of EMA data) | 
| Consumption of UPFs and MPFs (EMA) | Trained study staff will calculate the percentage of participants' daily calories from the four food categories (UPF+FRC, UPF+F, UPF+RC, MPF) based on participants' self-reported food consumption in EMA surveys. | EMA surveys administered over 5 days following each food consumption assessment (20 total days of EMA data) | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Changes in heart rate in response to food intake | Manually measured by counting the radial pulse for 15 seconds (timed using a digital stopwatch). | 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 | Participants will spit into a plastic cup for 1 minute and the weight of their saliva will be measured in grams using a digital food scale accurate to 0.01 grams. | 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 | Serial blood draws will be conducted before, during, and after test snack consumption. Samples will be assayed for glucose, insulin, ghrelin, and leptin levels. | 10 minutes before intake of test snack, during, and 30-, 60-, 90-, and 120 minutes after intake of the test snack. | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Ultra-processed foods, Food reward