Eating rate, oral processing, gastric emptying and appetite in older adults: Investigations of food intake and food form

Oral processing behaviours are known to impact on expected fullness, energy intake and post-meal satiety . For older adults, slower eating may be detrimental to meeting adequate calorie and protein needs but necessary to ensure comfortable and safe swallowing . Mastication is known to impact on the particle size of the food, the smaller the particle size, the faster it will be to emptying from the stomach, making it also easier to digest and absorb the nutrients. People with greater salivary flow rates have been shown to require fewer chewing cycles and less time in the mouth. Dentition problems and reduced muscle strength, alongside reduced salivary flow, can hinder food intake for many older people requiring them to chew for a longer period of time before swallowing. The likely consequences of this, are slower eating rates and reduced food intake.

We hypothesise that manipulating foods to enhance saliva flow and aid mastication will increase eating rate and food intake in older adults.

The project aims to:

(1) Assess the extent of oral processing of food on food intake in older adults

(2) Explore the impact of manipulation of food form and food presentation on oral processing and food intake.

Study 1 will evaluate the effect of dentition, eating rate and oral processing on subjective satiety in older adults (aged >70 years of age).

Study 2 will evaluate difference in food form and the impact on oral processing and food intake.

Study 3 will evaluate the addition of foods that have the potential to stimulate saliva production. This may make eating easier for older adults and decrease the time required in the mouth to ensure sufficient softness of food for swallowing, hence increasing eating rate.