Functional MRI of the responses of the human hypothalamus to sweet taste and calories
van Osch M, de Graaf C, Stafleu A, van der Grond J, Smeets P
Leiden University Medical Center, University Medical Center Utrecht
Evidence exists that caloric beverages do not elicit appropriate anticipatory physiologic responses. This leads to excessive energy intake. We investigated the effects of sweet taste and calories on the fMRI signal in the hypothalamus and on blood glucose and insulin concentrations. Five men were scanned four times for 37 min. After 7 min they ingested one of four stimuli: water, a glucose, an aspartame (sweet taste) or a maltodextrin solution (nonsweet carbohydrate). We found that only glucose triggered a prolonged signal decrease. Our findings suggest that both sweet taste and energy content are required for a hypothalamic response.