Yale Study

The aim of this study is to test the hypothesis that orosensation influences carbohydrate metabolism (as measured by resting energy expenditure (REE)) and regional cerebral blood flow (CBF) by regulating gastric emptying (GE). Preliminary data from another laboratory show that when the sweetness of a flavored beverage is too strong or too weak for a given carbohydrate load (i.e. "mismatched"), REE and GE are decreased compared to isocaloric beverages where sweetness and calories are appropriately "matched".

The objective of the study is to test the hypothesis that the correspondence between orosensation of sweetness and postoral sensation of calories influences REE, CBF and GE.

The study design is a 2x2 factorial within participants double blind design, with the factors sweetness and calories (sweet and high caloric, low sweet and low caloric, sweet and low caloric (mismatched), and low sweet and high caloric (mismatched))

The study population consists of 15 healthy, normal weight (BMI 18.525 kg/m2), volunteers, between the age of 18 and 35y. Calories are manipulated with nonsweet polymer maltodextrin content at two levels: 75 and 150 kcal. Sweetness is

manipulated with sucralose at 2 levels: equivalent to sweetness of a 75 kcal or 150 kcal beverage sweetened with sucrose. This yields four combinations. The drinks also have a commercial flavoring.
Primary study parameters/outcome of the study:

1. Change in resting energy expenditure in kcal/day

2. Change in gastric emptying rate in mm3/min

3. Change in cerebral blood flow in mL/100 g·min

the correspondence between orosensation of sweetness and post-oral sensation of calories influences resting energy expenditure, cerebral blood flow and gastric emptying, and more specifically that the “not sweet enough” beverage, that contains more calories than expected based on the sweetness, leads to a decreased REE, regional CBF in the food reward network and rate of GE compared to the isocaloric “appropriately sweet” beverage.

baseline and 0 - 35 minutes of data collection

sucralose sweetened beverages containing maltodextrin