Sweetness is classically recognized as one of the five “basic tastes” detected by the sensory receptors present in the oral cavity. Research of past decades suggests that liking for sweetness is innate and influenced by cultural and personal preferences.
Sweetness increases the palatability of numerous foods and beverages, and stimulates intake. In order to allow consumers to enjoy the palatable sweet taste of their favourite foods and beverages without the energy load of sugars, a number of low calorie sweeteners have been developed in the last decades. These ingredients have a very high sweetening power compared to sugars, so that they can be used in minute amounts to confer the desired level of sweetness to foods and drinks, while contributing very little or no energy at all to the final product.
Appetite for sweetness from early life to adulthood
Research suggests that liking for sweetness is expressed even before birth. A few hours after birth, and before the first feeding experience, the human newborn responds to the perception of a sweet solution by a characteristic “gusto-facial response”. Experts believe that the innate acceptance of sweet stimuli and rejection of bitter ones have developed through natural evolution and constitute an adaptive advantage, preparing the young to spontaneously accept sources of energy and to reject potentially toxic bitter substances.
Figure: Infant facial expressions
While all humans express the same response to sweetness immediately after birth, the liking for sweet products will change with time and become highly idiosyncratic. Studies of taste preferences in infants show that an individual’s preferences develop rapidly in the first year of life. The attractiveness of sweet products remains high but other taste dimensions are progressively accepted. At one year of age, the human infant has already developed an individual hierarchy of likes and dislikes.
Throughout childhood, sweetness remains highly attractive: the two main features determining acceptance of a food by a young child are familiarity and sweetness. In parallel with the acquisition of various food likes, the liking for sweetness spontaneously decreases during growth. In adolescents, the preferred intensity of sweetness is lower than in younger children, and it is lower in adults than in adolescents. The strong appetite for sweet foods in young individuals is viewed as a response to the high demands of energy for growth, a hypothesis consistent with the preferences for higher concentrations of sucrose observed in adolescents with greater rates of linear growth.
This was also confirmed in a study published in 2017 by Bobowski and Mennella, which adds to the body of evidence that children have a higher preference for sweet taste overall than adults, for both sugar and low calorie sweeteners. An important finding of this study is that there were no significant relationships between body mass index (BMI) and most preferred level of sucrose or low calorie sweeteners, regardless of age, meaning that there was no difference between obese and non-obese children or adults, indicating that there is no direct link between preference for sweetness and body weight status.
An appetite for sweetness is present in most adults, although large inter-individual differences exist in both the preferred level of sweetness in familiar products and in the range of foods and drinks that are consumed sweet.