Small food texture modifications can be used to change oral processing behaviour and to control ad libitum food intake

Little is known whether small modifications of food texture are sufficient to influence satiation. This study used four iso-caloric yogurts differing in viscosity (low/high) and granola particle size (small/large) to investigate the influence of small texture modifications on oral processing behaviour, eating rate and ad libitum intake. Yogurt viscosity differed by a factor of 1.57x to 1.81x. Granola particle size was 6 mm and 12 mm (2-fold difference). Granola particle concentration based on weight was constant (15% w/w). Oral processing behaviour was quantified by video recording consumers eating yogurt ad libitum (n = 104). Ratings for appetite, liking and product familiarity were also quantified. A decrease in yogurt viscosity significantly decreased spoon size, number of chews per spoon and oral exposure time per spoon but did not significantly affect eating rate and ad libitum intake. A decrease in granola particle size from 12 mm to 6 mm at constant weight concentration significantly increased number of chews per spoon and decreased spoon size, eating rate and ad libitum intake without affecting liking. The differences in eating rate and ad libitum intake between yogurts containing small and large granola particles were 5 g/min (7%) and 17 g (5%), respectively. We suggest that the volume of granola particles added to the yogurt and not the size of particles per se was the driver of oral processing behaviour. We conclude that relatively small modifications in yogurt texture, especially granola particle size, are sufficient to change oral processing behaviour and ad libitum intake. These findings demonstrate that small texture modifications of foods, such as the size of granola particles added to yogurt, can be used to modulate eating rate and food intake within a meal.