Figure 1.

Hierarchical cluster analysis identified three sucrose sweet liking phenotypes based on sweet liking response using a 15 cm visual analog scale; however, patterns differed between habitual and curtailed nights. After the habitual night, cluster 1 (n = 25), cluster 2 (n = 6), and cluster 3 (n = 9) demonstrated the fundamental phenotypes of sweet liking. After the curtailed night, cluster 1 (n = 28) and cluster 3 (n = 8) retained the familiar fundamental patterns of liking; whereas, cluster 2 (n = 4) had a distorted pattern.