The impact of a mental work on food preferences, eating behavior traits and satiety efficiency

Sedentary lifestyles, which are partly due to the type of labor being performed, have contributed to the increased prevalence of obesity. In general, labor in a modern context solicits mental work, which has been shown to promote overeating and altered satiety efficiency. The aim of this study was to evaluate the impact of knowledge-based work on food preferences, eating behaviors traits and appetite sensations. The relationship between these effects and the morphological profile was also assessed. A cross-over experimental design was used in this study for which 35 healthy adults (22 men and 13 women (mean age: 24±3years)), were recruited. The participants were randomly assigned the one of the two following conditions: mental work (reading a document and writing a summary of 350 words with the use of a computer) or control (rest in seated position). Each condition lasted 45min, and was followed by a standardized ad libitum buffet-type meal. Measurements included anthropometric variables, ad libitum food intake, appetite sensations before and after each condition, and satiety quotient, a marker of satiety efficiency in response to the meal. Eating behavior traits were also evaluated using the Three-Factor Eating Questionnaire (TFEQ). Eating behaviors (restriction, disinhibition) were not associated with the energy intake in both conditions and in both genders. Women appeared to have a higher energy intake after the mental work condition (p<0.05), which was accompanied by an increased carbohydrate intake (p<0.05). Moreover, participants with the highest waist circumference had lower satiety efficiency (r=0.43, p<0.05) in response to mental work. These results suggest that increased energy intake in response to knowledge-based work is associated with food preference and an altered satiety efficiency in women and individuals with higher waist circumference.