Rejection thresholds for sweetness reduction in a model drink predict dietary sugar intake
Mei Peng, Rachel Ginieis, Sashie Abeywickrema, Jessica C. McCormack, John Prescott
Abstract
Links between individual sweetness perception and sugar intake have been previously explored, with highly contrasting results. The current study aimed to test individual-based rejection thresholds (RjTs) to ascending and descending sucrose concentrations in a model drink, and to evaluate potential links between these measures and sugar intake behaviour in real life. Sixty-three participants (final N=43 [f=29]; 20±5 years) each undertook three sensory testing sessions and completed a 4-day weighed food records. Each individual was tested for their Sweet Liker status, detection thresholds to sucrose, RjTs to 5 descending and 5 ascending sucrose concentrations in an orange-flavoured drink, as well as sugar intake in daily diet and from sweetened beverages. The results demonstrate that RjTs can be estimated an individual level. With each participant completing 4 replications of the RjT task, data from over 88% of participants produced a reasonable individual-based psychometric function. Intriguingly, descending, but not ascending, RjTs were positively correlated with sweet liking (r=0.43, p<0.01), and acted as a significant predictor of both overall dietary sugar intakes (R2=0.10, F(4,38)=2.23, p=0.050) and sugar intakes from sweetened beverages (R2=0.21, F(4,38)=3.73, p=0.012). While sweet likers (SL) and dislikers (SD) had comparable ascending RjTs (acceptance for sugar addition), they differed substantially in terms of descending RjTs (p=0.002; acceptance for sugar reduction), with SL rejecting samples having >47% sugar reduction (47g/L), and SD rejecting samples with >68% reduction (28g/L). Overall, these findings suggest that descending RjTs is a useful measure for detecting a sensory-diet relationship, and should be considered for research informing sugar reduction targets and facilitating policies on product reformulation.