Some aspects of human experience are universally regarded as pleasant, and the experience of sweetness is a classic example.

Our individual behaviors toward sweets and our underlying reasons for consuming sweets are complex therefore, an extensive understanding of the sweet tooth will assist us in tailoring nutritional advice. Additionally, the taste of sweet may be sought for its pleasurable and soothing properties, and thus may be consumed irrespective of the nutritional consequences. Other variables help shape our behavior toward eating sweets and determine how many calories we consume from them, such as differences in our ability to digest sugars. The amount of calories we consume from sweet substances may play a role in the regulation of our body weight and overall nutritional status. Bitter perception is related to sweet perception in humans, and these two sensory systems share some common features.

Understanding sweetness also expands our understanding of bitterness. For instance, recent studies in mice demonstrate that DNA sequence variants in a sweet taste receptor gene have an effect on sweet preference and intake, and so it is possible that genetic differences among individuals may play a role in the human sweet tooth. There are several facets of the human sweet tooth, and several academic disciplines, such as genetics, nutrition, and psychology, that contribute to our understanding of this trait. In the box labeled 'Consequences' we list the physical and psychological effects of eating sweets. The box labeled 'Modifiers' denotes those methods used to modify or change our attitudes and behaviors toward sweets. Individual variables that may influence these determinants are listed in the box under the heading 'Variables'. The aspects that determine how humans respond to sweets are listed in the box labeled 'Determinants'. The determinants and consequences of the sweet tooth. However, sweet perception varies even in the same individual over time, and therefore a well-conceived model of the sweet tooth must be able to account for this observation and a broad range of other variables (Figure (Figure1 1). The term 'sweet tooth' has been coined to describe people who 'prefer' sweets, implying that these individuals differ from those who 'do not prefer' sweets. Several variables are good predictors of how well sweets are liked, such as age ( e.g., children are more avid consumers than are adults). The reasons for these individual differences are largely unknown, but the explanation for these differences could have important public health consequences. However, although there is a strong desire on the part of humans to seek and ingest sweet foods and drinks, it would be inaccurate to view the liking and enjoyment of sweetness and sweeteners as uniform across people and populations. The human appetite for refined sugar and for sweet foods and drinks has been so strong that it has influenced the course of human history, and the recent and sharp rise in the consumption of sugar may be unprecedented. The sense of taste gives us important information about the nature and quality of food, and of all the basic taste qualities, sweetness is the most universally liked. Future studies will be designed to understand how a genetic preference for sweet food and drink might contribute to the development of dental caries. Overall, people differ in their ability to perceive the basic tastes, and particular constellations of genes and experience may drive some people, but not others, toward a caries-inducing sweet diet. Children who are genetically more sensitive to bitter compounds report that very sweet solutions are more pleasant and they prefer sweet carbonated beverages more than milk, relative to less bitter-sensitive peers.

We also find a relationship between sweet and bitter perception. Our studies demonstrate that there are two sweet receptor genes (TAS1R2 and TAS1R3), and alleles of one of the two genes predict the avidity with which some mammals drink sweet solutions. We have used genetic and molecular techniques in humans, rats, mice, cats and primates to understand the origins of sweet taste perception. The focus of my group's research is to understand why some people have a sweet tooth and others do not. Although sugar or sweetened foods are generally among the most preferred choices, not everyone likes sugar, especially at high concentrations.

Humans love the taste of sugar and the word 'sweet' is used to describe not only this basic taste quality but also something that is desirable or pleasurable, e.g., la dolce vita.

Sweet tooth