The goal of this study is to test the hypothesis that repeated consumption of artificial sweetener reduces sweet taste intensity.

Significant controversy surrounds the possibility that consumption of artificial sweeteners (AFS) leads to weight gain. Some studies have found correlations between AFS use and weight gain and/or diabetes [1-4] while others have indicated that AFSs may aid in weight loss [5] or have no effects on body mass index (BMI) [6]. In rats, exposure to AFS leads to reduced chow intake following a sweet preload [7, 8], higher body weight [9, 10] and increased glucose responses and decreased GLP1 release following an oral glucose tolerance test [11] compared to exposure to caloric sweeteners. Given that the five FDA approved AFSs are found in thousands of foods [12] this marks a clear and significant gap in knowledge. Our preliminary data demonstrate a 3-fold decrease in sweet taste sensitivity following consumption of a beverage sweetened with two packets of Splenda for just 10 days. These data provide strong evidence that repeated exposure to sucralose reduces perception of sweet taste intensity, most likely by down-regulation of the sweet taste receptor. Therefore, it is imperative that we gain a greater understanding of the consequences of AFS use, since alterations in sweet taste perception that occur in response to AFS exposure may promote weight gain.

Inclusion Criteria:

• Healthy
• Fluent in English

Exclusion Criteria:

• History of oral nerve damage,
• presence of known taste or smell disorder,
• food allergies or sensitivities (for example nuts, lactose, artificial sweeteners),
• history of CNS disease,
• diabetes,
• history of DSM-IV major psychiatric disorder, including alcohol and substance abuse, chronic use of medication that may affect taste,
• conditions that may interfere with gustatory or olfactory perception (colds, seasonal allergies, recent smoking history),
• aberrant stimulus ratings,
• contra-indication for fMRI,
• uncomfortable swallowing in supine position.