Both longer oral sensory exposure to and higher intensity of saltiness decrease ad libitum food intake in healthy normal-weight men

Orosensory exposure to sweetness has been shown to be important in satiation, whereas the effect of exposure to a salty taste on satiation is not known. The primary objective was to investigate the effect of orosensory exposure time to and intensity of saltiness in soup on ad libitum intake. The secondary objective was to investigate the effect of intensity on bite size. Fifty-five healthy men consumed ad libitum from both a low-salt (LS) and a high-salt (HS) creamy tomato soup in 2 exposure time conditions ("long" and "short") and a free condition ("free"). Bites were administered and controlled via a pump. In the long condition, bites of 5 g were administered in 2 s at intervals of 5 s (exposure time: 24 s/min). In the short condition, bites of 15 g were administered in 3 s at intervals of 15 s (exposure time: 12 s/min). The eating rate was equal in the long and short conditions (60 g/min). In the free condition, participants adjusted their bite sizes at intervals of 15 s. The short condition resulted in ~34% higher ad libitum intake compared to the long condition (P < 0.001); there was no interaction with intensity. Ad libitum intake of HS soup was ~9% lower than LS soup (P < 0.001). The free condition showed that HS soup was consumed with smaller bite sizes during the first half of the intake period (P < 0.05). Longer orosensory exposure and higher saltiness intensity both decreased food intake, although orosensory exposure had more impact than intensity. Prolonging the orosensory exposure per food unit may be helpful to reduce food intake.