Effect of bite size and oral processing time of a semisolid food on satiation

Background: Food texture plays an important role in food intake regulation. In previous studies we showed a clear effect of viscosity on ad libitum food intake and found indications that eating rate, bite size, and oral processing time (OPT) could play a role. Objective: The objective was to determine the effect of bite size and OPT of a food on satiation, defined as ad libitum food intake. Design: Twenty-two healthy subjects participated in all 7 test conditions. Bite sizes were free or fixed to small bite sizes (˜5 g) or large bite sizes (˜15 g). OPT was free (only in combination with free bite size) or fixed to 3 or 9 s. Subjects consumed chocolate custard through a tube, which was connected to a peristaltic pump. Sound signals indicated OPT duration. Results: Subjects consumed significantly more when bite sizes were large than when they were small (bite size effect: P <0.0001) and when OPT was 3 s rather than 9 s (OPT effect: P = 0.008). Under small bite size conditions, mean (6SD) ad libitum intakes were 3826 197 g (3-s OPT) and 313 ± 170 g (9-s OPT). Under large bite size conditions, ad libitum intakes were much higher: 476 ± 176 g (3-s OPT) and 432 ± 163 g (9-s OPT). Intakes during the free bite size conditions were 462 ± 211 g (free OPT), 455 ± 197 g (3-s OPT), and 443 ± 202 g (9-s OPT). Conclusion: This study shows that greater oral sensory exposure to a product, by eating with small bite sizes rather than with large bite sizes and increasing OPT, significantly decreases food intake