Thinking hard makes you hungry.....so you eat more. Yet thinking hard doesn't burn calories. So if you are going to think hard then eat, well you better do something to burn the calories that you are going to add.
WHAT IS ALREADY KNOWN ABOUT THIS SUBJECT:
Achievement of a stressful mental task leads to increased energy intake over a short period of time. Given that mental work does not increase energy expenditure, a positive energy balance is observed.
WHAT THIS STUDY ADDS:
The single fact of waiting and relaxing after mental work does not reduce energy intake. Thirty minutes of physical activity performed at moderate/high intensity between mental work and a meal is enough to create a energy deficit compare to a situation where the meal directly follows mental work.
Although energy expenditure during mental work is not higher than energy expenditure at rest, a stressful mental task is related to an increase in energy intake. It is suggested that mental work produces physiological changes, thereby influencing food intake.
Because physical activity can influence hunger, the aim of the study was to determine if the introduction of an active pause could counteract the negative effects of mental work on energy intake and energy balance.
Twelve male students, of normal weight, between 15 and 20 years old were evaluated. All subjects participated in three different sessions realized in a randomized order: (i) without pause = relaxation/mental work/meal; (ii) relaxation pause = mental work/relaxation/meal; and (iii) exercise pause = mental work/exercise/meal. Energy expenditure was measured with indirect calorimetry, energy intake was measured with a cold buffet-type meal of 40 items, and appetite-related sensations were measured with visual analogue scales. The effect of introducing an active pause in energy intake and energy balance was studied.
The introduction of an active pause did not influence energy intake; although, higher appetite-related sensations were observed (16-26 mm on a 150-mm scale; P < 0.05). After accounting for the energy expenditure related to physical activity, a lower energy balance was measured for the exercise pause visit compared with the visit without a pause (-1137 kJ; P < 0.05).
This study indicates that being active between mental work and a meal could represent a strategy to create a negative energy balance following mental work via an increased energy expenditure and a maintenance of energy intake. Globally, these results could help individuals attain and/or maintain a healthy body weight in a context where mental work is omnipresent.