Physiological signals measured by food- and time-specific expected satiety

The most sensitive of the highly correlated ratings of appetite we introduced in the mid-1970s was used to measure the satiating after-effects of ingesting carbohydrates and fats absorbed at different rates. A postprandial satiation process lowers the amount wanted of a food that the individual might eat at that stage between meals. This actual appetite at a specified time after the tested meal was subtracted from the appetite at that time as predicted at the end of the meal from past experience of meals on those foods in those amounts. Any difference between actual and expected state of satiety for a food at a particular time measures a ‘surprise’ effect of the experimental meal. In accord with the theory that many chemo-specific satiety signals are generated only during absorption, slowly digested bean starch suppressed appetite later than glucose or grain starch did and emulsified fat induced a ‘surprise’ satiety state earlier than did oil, which is liable to be retained in the stomach. Somatic, social and sensory influences on ingestive behaviour can only be measured by controlling one or more of the stimuli active at a particular moment and measuring the disposition to consume a mouthful of a specified material in that transient context.