Description
Humans are biologically predisposed to like and prefer sweet tastes and foods for the energy content and nutritional value of sugar. However, due to the abundance and accessibility of sweet foods, having a higher preference for sweet tastes, and particularly for foods that are high in both sugar and fat, can have negative health implications including increased risk for obesity. Although sweet tastes are generally considered pleasant, the development of preferences and intake of sweet foods varies across individuals and the relationship between liking, preference, and intake is rather complex. Sucrose is a sweet tastant that is commonly used in psychophysical studies of taste and hedonic evaluation. Although sucrose is often considered a pleasant stimulus, there is some evidence to suggest the existence of an inverted U-shaped relationship between pleasantness ratings and concentration in a significant proportion of the population, such that the hedonic value of sucrose increases as the intensity or concentration of sucrose increases up to a certain point, then decreases as the intensity increases further. However, this Ushaped relationship is not universal, and some individuals demonstrate a consistent increase in hedonic response with increasing intensity. Moreover, although the findings are mixed, some research suggests that the degree to which individuals demonstrate liking for sweet tastes such as sucrose is explained in part by their sensitivity to the bitterness of the chemicals 6-n-propylthiouracil (PROP) and phenylthiocarbamide (PTC). The present study aimed to investigate differences in psychophysical responses to sweet (and fat) tastes between young likers and non-likers of sucrose by examining the effects of sucrose concentration, sucrose liker status, PROP/PTC taster status, and gender on reported pleasantness ratings and perceived sweetness intensity ratings for sucrose solutions in various backgrounds. Participants included 40 younger adults; 20 were classified as sucrose likers, and 20 were classified as sucrose non-likers using previously established methods of classification. Within each group, 10 participants were male and 10 were female. Participants were administered taste solutions consisting of varying concentrations of sucrose in different backgrounds and instructed to provide pleasantness and intensity ratings of each using the generalized Labeled Magnitude Scale (gLMS). Analyses of covariance (ANCOVA) with repeated measures were conducted to investigate the effects of sucrose concentration, sucrose liker status, PROP/PTC taster status, and gender on reported pleasantness ratings and perceived sweetness intensity ratings for sucrose solutions in various backgrounds. In general, results suggested that in young adults, hedonic response to sucrose in distilled water and fat backgrounds varied as a function of sucrose concentration, sucrose liker status, and gender. Assessing sweet-fat taste perception in young likers versus non-likers of sucrose is important because it addresses a variety of factors that might influence the onset and development of particular dietary behaviors associated with weight gain and increased risk for obesity.
