Comparison of 150-mm versus 100-mm visual analogue scales in free living adult subjects

The aim of this study was to verify whether appetite sensation scores obtained from 150-mm visual analogue scales (VAS) can be compared to those obtained from 100-mm scales. On one occasion, using a within-subject design, 25 participants (mean age: 42.2 ± 13.3 years, mean body mass index: 22.9 ± 2.3 kg/m2) recorded their appetite sensations before lunch, and at five additional time points during the postprandial period. At each time point, both VAS (150 mm and 100 mm) were used to record desire to eat, hunger, fullness, satiety, and prospective food consumption. The VAS in the same booklet were completed immediately one after the other in a randomized order to eliminate the order effect. We observed that the immediate, successive completion of questionnaires varying in length resulted in no significant difference in appetite markers, with a strong linear relationship between the two tools (r from 0.80 to 0.98, P < 0.01). We conclude that VAS scores obtained from 150-mm to 100-mm length scales are interchangeable, both before and in response to a meal.