Methodological studies on single meal food intake characteristics in normal weight and obese men and women

The eating behaviour of 19 normal weight males, 19 obese males, 19 normal weight females and 19 obese females was measured by means of VIKTOR, our version of the universal eating monitor. The total food intake, the duration of consumption, the rate of consumption, the relative rate of consumption and the subjective motivation to eat were measured during five homogenous lunch meals to analyse how these variables were related to body weight or to sex. Furthermore, the stability of the eating characteristics over the five eating occasions were tested with pre-defined criteria of stability. The predictive validity of the variables measuring subjective motivation to eat and forthcoming food intake was also tested.

Men ate more food than women; normal weight men by eating for a longer time and obese men by eating faster. Females did not slow down the eating rate towards the end of the meals as much as males did. The obese subjects described themselves as having less motivation to eat prior to meals than normal weight subjects.

Total stability, i.e. both relative and absolute stability, for all subjects was present for the eating variables intake of food and eating rate. Of the variables measuring subjective motivation to eat (desire to eat, hunger, fullness and prospective consumption) on visual analogue scales, only the variables desire to eat and prospective consumption predicted forthcoming food intake.