The goal of this pilot study is to test the feasibility of assessing how biological factors and chemical properties of sugars may influence metabolism and food reward in humans. The main questions it aims to answer are: • Can differences in appetitive responses and neural activations to sucrose (table sugar) and its chemical components (glucose and fructose) be measured and quantified? This study is a crossover design, meaning every participant will complete every condition. Participants will consume beverages containing sucrose, glucose, or fructose, which are each novelly flavored, 6 times within a week. During one of the consumption times, energy expenditure, carbohydrate oxidation, and blood glucose will be measured in the lab before and for 2 hours after consumption. After participants have consumed each condition, they will undergo a tasting task in the MRI scanner, neural responses to receipt of the beverages are measured.
Prior studies in humans indicate that while energy expenditure response is similar after consumption of equal amounts of fructose, glucose, and sucrose (a dimer of glucose + fructose), carbohydrate oxidation and blood glucose responses differ. Elevated carbohydrate oxidation responses appear to be driven by the presence of fructose, and elevated blood glucose responses appear to be driven by the presence of glucose. Prior work also suggests that post-ingestive signals of glucose availability, measure specifically as blood glucose levels, intestinal glucose transporter activity, and carbohydrate oxidation rate, are all associated with elevated brain response to calorie-predictive flavor cues and reward learning of these flavor cues. However, in animal models, glucose has been shown to repeatedly and reliably condition these calorie-predictive learning responses, but fructose does not. Human work has indicated that oxidation of glucose is critical for these responses. Thus, it is unclear what roles fructose and glucose each play in conditioning reward responses and flavor-calorie learning. We hypothesize that fructose plays a synergistic role in enhancing flavor-calorie learning without itself conditioning the reward response.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
BASIC_SCIENCE
Masking
SINGLE
Enrollment
7
Participants will consume flavored beverage solutions containing 110 calories of sucrose in 6 exposure sessions within 1 week. One exposure session will include pre- and post-consumption blood draws and indirect calorimetry measurements inside a metabolic chamber over a 2-hour period. The other 5 exposure sessions will occur at specified times outside the laboratory sessions. Subjective ratings of internal state (i.e., hunger, fullness, and thirst) will be collected throughout each exposure. Subjective ratings of liking and wanting of each beverage will also be assessed.
Participants will consume flavored beverage solutions containing 110 calories of glucose in 6 exposure sessions within 1 week. One exposure session will include pre- and post-consumption blood draws and indirect calorimetry measurements inside a metabolic chamber over a 2-hour period. The other 5 exposure sessions will occur at specified times outside the laboratory sessions. Subjective ratings of internal state (i.e., hunger, fullness, and thirst) will be collected throughout each exposure. Subjective ratings of liking and wanting of each beverage will also be assessed.
Participants will consume flavored beverage solutions containing 110 calories of fructose in 6 exposure sessions within 1 week. One exposure session will include pre- and post-consumption blood draws and indirect calorimetry measurements inside a metabolic chamber over a 2-hour period. The other 5 exposure sessions will occur at specified times outside the laboratory sessions. Subjective ratings of internal state (i.e., hunger, fullness, and thirst) will be collected throughout each exposure. Subjective ratings of liking and wanting of each beverage will also be assessed.
Fralin Biomedical Research Institute at Virginia Tech Carilion
Roanoke, Virginia, United States
Change in Preference- Subjective Liking Ratings for Each Beverage on a Scale
Subjective ratings of liking of flavors used in the intervention will be assessed at baseline and after the intervention. The generalized Labeled Magnitude Scale will be used. The scale is anchored by descriptors of "Most Disliked Sensation Imaginable" and "Most Liked Sensation Imaginable" at the lower and upper ends, respectively. The score is determined by the place on the scale participants select (range of scale is 0-100). An increase in score from baseline to post-intervention indicates an increase in liking.
Time frame: Immediately after informed consent and in the post-test session approximately 5 weeks later
Post-Test Measure of Preference- Subjective Wanting Ratings for Each Beverage on a Scale
Subjective ratings of liking of flavors used in the intervention will be assessed at baseline and after the intervention. A Visual Analog Scale will be used. Participants select a place on the line that corresponds with their subjective rating, and the score is determined by the place selected (range of scores is 0-100). The line is anchored by polar opposite descriptors ("Do not want at all" and "Want very much"). An increase in score from baseline to post-intervention indicates and increase in wanting.
Time frame: At the end of study; approximately 5 weeks after first session
Post-Test Measure of Preference - Wanting (ad Libitum Intake): The Amount Consumed of Each Beverage is Reported as the Outcome
Ad libitum intake will be used as a measure of wanting in a post-test session. Participants will be provided each beverage used during the intervention and asked to drink as much or as little of them as they would like over a 30-minute period.
Time frame: At the end of study; approximately 5 weeks after first session
Post-Test Measure of Preference- Wanting (Forced Choice): Number of Participants Who Chose Each Indicated Beverage
Forced choice will be used as a measure of wanting in a post-test session. Participants will be provided each of the beverages used during the intervention and asked to choose 1 to take home with them.
Time frame: At the end of study; approximately 5 weeks after first session
Blood Oxygen Level-dependent (BOLD) Response to Beverages
In a post-test session, functional magnetic resonance imaging (fMRI) scans were performed while beverages (without calories) used during the intervention and a tasteless solution are delivered through a custom manifold fitted to a head coil and connected to a pump system that allows precisely timed and measured delivery of liquids. Participants receive the glucose, sucrose, fructose, and tasteless (control) solutions 18 times each over the course of 2 runs. Contrasts of interest are the blood oxygen level-dependent (BOLD) response of glucose+\>tasteless solution, sucrose\>tasteless solution, and fructose\>tasteless deliveries. Parameter estimates for these contrasts are extracted and reported. A positive outcome reflects greater whole-brain BOLD response for the sugar condition compared with a tasteless solution.
Time frame: At the end of study; approximately 5 weeks after first session
Blood Glucose Response to Beverages
Blood glucose will be assessed at baseline and at set time points for 2 hours after consumption of intervention beverages (baseline, 5-, 20-, 40-, 60-, 90-, and 120-minutes after drink consumption)in one exposure session. Area under the curve is calculated using these time points and reported as the outcome measure.
Time frame: Each week for 3 weeks during the study
Energy Expenditure in Response to Beverages
Indirect calorimetry will be used to determine energy expenditure at baseline and for 120 minutes after consumption of condition beverages in an exposure session. Area under the curve is calculated as a change from baseline energy expenditure using minute-by-minute resolution across 120 minutes and reported as the outcome measure.
Time frame: Each week for 3 weeks during the study
This platform is for informational purposes only and does not constitute medical advice. Always consult a qualified healthcare professional.