None listed
Conditions
Brief summary
Background: Overweight and obesity are major health problems in Australia, with 61% of the population being either overweight or obese. Individuals, low in self-control, consume greater amounts of unhealthy food and are more likely to be overweight. Executive function training, an intervention technique designed to increase self-control and consequently decrease unhealthy food consumption, has demonstrated moderate success. However, researchers employing this technique have not focused on the mechanisms underlying the effect of training. Objectives: To conduct an executive function training intervention to determine whether training buffers against self-control ‘depletion’ effects and results in less unhealthy eating behaviour. Methods: Participants will either complete an executive function training paradigm or an inert version of training, followed by a self-control depletion task or a non-depleting task, and finally a taste test. Expected Findings: Those who receive training will eat less unhealthy food after the depletion task compared to those who did not receive training.
Interventions
A 2 (executive function training/placebo training) x 2 (depletion/no depletion) factorial design will be used to test whether executive function training buffers against the negative effects of depletion on eating behaviour. Therefore, there will be four conditions: 1) executive function training followed by depletion; 2) executive function training followed by no depletion; 3) placebo training followed by depletion; 4) placebo training followed by no depletion.
Following this, behaviour will
A 2 (executive function training/placebo training) x 2 (depletion/no depletion) factorial design will be used to test whether executive function training buffers against the negative effects of depletion on eating behaviour. Therefore, there will be four conditions: 1) executive function training followed by depletion; 2) executive function training followed by no depletion; 3) placebo training followed by depletion; 4) placebo training followed by no depletion. Following this, behaviour will be measured via a 'taste-test'. Participants will be informed that they are completing an unrelated experiment in which they have to rate a new flavour of a particular snack food (e.g. chocolate). Participants will be left alone with a bowl of the snack food and asked to rate this food on several properties such as taste and texture. They will be informed that they can eat as much or as little as they like in order to rate the food. The amount that the participant consumes will serve as the dependent variable. An interaction between training condition and depletion condition is expected, such that participants who received executive function training will not demonstrate a depletion effect compared to those who did not receive training. The intervention will be administered in a laboratory setting, in a single session, by a psychologist. The training/placebo tasks and the depletion/no depletion tasks are computerised, and will therefore be administered using a computer. The training/placebo task will take approximately 10 minutes, while the depletion/no depletion task will take 5 minutes. Details on executive function training task: A stop-signal task that has been modified to include unhealthy food stimuli will be employed to train executive function, specifically inhibitory control. Participants in the training condition will be required to categorise images of unhealthy food and neutral items, and refrain from responding when presented with a signal. These signals will only be paired with unhealthy food stimuli. In this way, participants will learn to associate a stop response with unhealthy food stimuli. Details of depletion task: Participants will be required to complete a writing task in which they will be asked to compose a paragraph describing a recent event without using words that contain the letters 'a' or 'n'. As words such as these are quite frequent, the task is expected to be quite difficult and result in a depletion effect.
Sponsors
Curtin University
Study design
Allocation
Randomised controlled trial
Intervention model
Factorial
Primary purpose
Treatment
Masking
Blinded (masking used) (Subject, Caregiver)
Eligibility
Sex/Gender
All
Age
18 Years to 60 Years
Healthy volunteers
Yes
Inclusion criteria
Individuals will only be asked to express interest in the study if they describe themselves as motivated to eat healthily but unsuccessful. They will indicate on a 7 point scale how motivated they are to eat healthily, and how (un)successful they perceive themselves to be. If they score above 5 (high motivation/low success) on both items they will be invited to join the study.
Exclusion criteria
Dietary allergies or restrictions Past or present diagnosis of an eating disorder
Outcome results
None listed