Writing in Food Quality and Preference, they investigated whether altering the number of sips per gram and oral transit time per gram for a model food (soup) contributed to alterations in ad libitum intake of the food in consumers.
Led by Dr Dieuwerke Bolhuis from Wageningen University in the Netherlands, the research team noted previous suggestions that higher eating rates may leads to a higher food intake, possibly through shorter orosensory exposure to food - suggesting that the underlying mechanisms of how these factors that influence eating rate (number of sips/bits and oral transit time) could be modified and thus affect satiation and energy intake.
The results of the study revealed that both a higher number of sips per gram food and longer oral transit time per gram food independently reduced food intake by 22% and 8%, respectively.
"Higher number of sips and longer oral transit time per gram food resulted in reduced food intake, where the number of sips showed the greatest effect," explained Bolhuis and her colleagues. "In addition, a higher number of sips per gram food, thus smaller sips, led to faster increase in fullness per consumed gram food."
"This means that reducing the sip size is probably more effective in reducing food intake than only prolonging the oral transit time," they suggested.
Bolhuis and her team added that advice to consume with smaller sips or bites, and to prolong the oral transit time, may be helpful in body weight management.
"Moreover, designing foods that will be consumed with small sips or bites and long oral transit times may also be an effective tool to reduce food intake," they said.
Study details
Bolhuis and her colleagues tested the separate effects of total sips and oral transit time in two investigations. In the first, 56 healthy male subjects consumed soup where the number of sips and oral transit time differed by a factor three respectively: 6.7 vs. 20 sips/100 g, and 20 vs. 60 s/100 g (2 × 2 cross-over design). Eating rate of 60 g/min was kept constant.
In the second study, the effects of number of sips and oral transit time (equal as in study 1) on the total magnitude of orosensory exposure per gram soup were measured by time intensity functions by 22 different healthy subjects.
A higher number of sips and longer oral transit time reduced ad libitum intake by 22% and 8%, respectively - with higher number of sips leading to faster increases in fullness per gram of food, said the team.
Higher number of sips and longer oral transit time both also increased the orosensory exposure per gram food, they added.
Source: Food Quality and Preference
Volume 32, Part C, March 2014, Pages 234–240, doi: 10.1016/j.foodqual.2013.10.001
"Both a higher number of sips and a longer oral transit time reduce ad libitum intake"
Authors: Dieuwerke P. Bolhuis, Catriona M.M. Lakemond, Rene A. de Wijk, et al