Salivation to the Sight and Thought of Food: A New Measure of Appetite*

TLDR

The study examined whether salivation in response to food images could serve as an objective appetite measure. Salivation was recorded with cotton dental rolls before and during exposure to familiar foods. Salivation increased consistently when subjects viewed or imagined palatable food, varied with deprivation and palatability, correlated strongly with hunger (r = 0.75) and food appeal (r = 0.46), was reduced when food was not expected, and thus appears to be a useful objective appetite indicator.

Abstract

Salivary response to the sight of food was studied to determine its value as a quantitative and objective measure of appetite. Salivation was measured by a simple technique using cotton dental rolls, before and during exposure to familiar foods. Increases in salivation occurred regularly when subjects looked at or thought of palatable food. The amount of salivation varied significantly and meaningfully with manipulated deprivation and palatability, and was correlated with subjects' ratings of hunger (r = 0.75) and appeal of the food stimuli (r = 0.46), indicating that the measure reflects appetite by several criteria. Salivary responses to food stimuli were found to be attenuated when subjects did not expect to eat the food. This method, because it employs an involuntary response, should prove a useful addition to other indices of hunger in studies of food regulation.