The Role of Altered Nutrient Partitioning in Food Reward
Condition: Overweight and Obesity
MeSH terms: Overweight
Study type: Interventional

Summary: 
      Obesity remains a public health epidemic despite substantial advances in treatment strategies
      and therapies in the last decade. Effective strategies to support maintenance of improved
      metabolic health and reduced body weight are still needed.

      Signals from the gut to the brain are important in regulating metabolism and energy balance
      and have been linked with food reward and preference in metabolically healthy individuals
      with normal body mass index. In particular, post-ingestive signaling related to glucose
      metabolism has been linked with food reward and preference. However, not much is known about
      how these gut and brain signals interact to influence eating behaviors in states of obesity
      or altered metabolic health. In addition, evidence in rodent models and human studies
      indicates obesity is associated with a blunted brain response to foods compared with normal
      body weight. However, whether altered nutrient utilization, termed metabolic inflexibility,
      influences the relationship between obesity and food reward has yet to be studied.

      The overall objective of this proof-of-concept pilot study is to assess the feasibility of
      measuring reward response following a flavor-nutrient conditioning paradigm across the normal
      to obese body mass index (BMI) range and in states of altered metabolic health. The aims of
      this study are: 1) to determine whether differences in reinforcement learning/flavor-nutrient
      conditioning of carbohydrate can be measured across the body mass index range; and 2) to
      determine the feasibility of assessing metabolic flexibility and whether a relationship
      between metabolic flexibility and calorie-predictive reward can be detected.
    


Intervention name(s): Conditioned Stimulus + (CS+): Flavored beverage solution with 75 calories of sucrose; Conditioned Stimulus - (CS-): Flavored beverage solution with sweetness-matched sucralose; High-Fat Test Meal Inside a Metabolic Chamber; High-Carbohydrate Test Meal Inside a Metabolic Chamber
Intervention type(s): Other; Other; Other; Other
Intervention description(s): Participants will consume flavored beverage solutions containing 75 calories of sucrose in 6 exposure sessions within 1 week. One exposure session will include pre- and post-consumption blood draws over a 2-hour period, and one exposure session will include indirect calorimetry measurement pre- and post-consumption. The other 4 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 sweetened with sucralose to match the sweetness of 75 calories of sucrose in 6 exposure sessions within 1 week. One exposure session will include pre- and post-consumption blood draws over a 2-hour period, and one exposure session will include indirect calorimetry measurement pre- and post-consumption. The other 4 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.; A high-fat test meal (60% fat, 20% carbohydrate) will be provided after a 1-hour baseline measurement of substrate oxidation during a 6-hour metabolic chamber stay. Postprandial substrate oxidation will be measured for 5 hours.; A high-carbohydrate test meal (60% carbohydrate, 20% fat) will be provided after a 1-hour baseline measurement of substrate oxidation during a 6-hour metabolic chamber stay. Postprandial substrate oxidation will be measured for 5 hours.
Intervention MeSH terms: Pharmaceutical Solutions
Allocation: Randomized
Intervention model: Crossover Assignment
Masking: Single (Participant)
Primary purpose: Other