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Trial registered on ANZCTR

Registration number
Ethics application status
Date submitted
Date registered
Date last updated
Type of registration
Retrospectively registered

Titles & IDs
Public title
Training restraint to increase healthy food consumption
Scientific title
Inhibitory control training to reduce consumption in obese adolescents and adults
Secondary ID [1] 288605 0
Nil Known
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Obesity 297748 0
Overweight 297749 0
Condition category
Condition code
Mental Health 297930 297930 0 0
Studies of normal psychology, cognitive function and behaviour
Diet and Nutrition 297956 297956 0 0

Study type
Description of intervention(s) / exposure
The intervention is based on cognitive training. It does not involve pharmacological agents. Participants are randomly assigned to a Control or Training condition, based on a random permutation calculator (http://www.randomizer.org).

Participants in the Training condition are required to utilize the NoGo training app once a day to play 10 games, taking about 1 minute per game. Training is completed at a time and place convenient to the participant. The NoGo app requires participants to press buttons to select images of healthy foods (e.g. fruit, vegetables and activities) as quickly and accurately as possible and not press to select less healthy choices (e.g. hamburgers, chips, cupcakes, etc). Training will take place for 10 minutes per day over a 14 day period, which equates to a total training time of 140 minutes over 2 weeks.

Adherence is monitored by the training application, which records the task performance data and training date/time. The research team will monitor training rate and contact participant if the rate is too slow.

Intervention code [1] 294000 0
Comparator / control treatment
The control arm involves no treatment. The wait-list control group will not complete any training during the 2 week study period.
Control group

Primary outcome [1] 297448 0
Healthy Eating Quiz

The Healthy Eating Quiz is a food frequency questionnaire containing 70 items relating to the frequency of healthy food consumption over the past 7 days, rated on a Likert Scale from ‘Never’ to ‘5 or more times a week’. It also asks about water consumption each day (less than 4 glasses per day/more than 4 glasses a day) and how frequently sauces and spreads are used (never/once a week or more). It includes 8 subgroups; fruit, vegetables, meat proteins and vegetarian proteins, grains, water, dairy, and extras (i.e. sauces and spreads). Participants were asked to rate approximately how many serves of items within these food groups they had consumed in the past week. Food frequency questionnaires are widely used to assess eating habits.
Timepoint [1] 297448 0
Pre-intervention and 2 weeks post-intervention commencement
Primary outcome [2] 297449 0
Food Consumption Test

The Food Consumption Test was used to examine immediate changes in food consumption following the ICT. It was based on the bogus taste tests used in previous research, but without the associated element of deception. Participants were informed that they would receive a refreshment break during the session in which snacks would be offered, and that they could eat as little or as much as they liked. Participants were presented with four bowls containing snack-sized portions of 2 healthy (156 g of unsalted nuts and 216 g of grapes) and 2 unhealthy food options (60 g of plain potato chips and 161 g of chocolate candies, M&Ms). While nuts and grapes are still high calorie choices, these foods were chosen as they represent “real world” choices that participants would be faced with. For example, while grapes are still high in sugar, they are high in natural sugar and are non-processed. Thus they represent a healthier choice than M&Ms (which are processed and high in sugar and saturated fat) for individuals when craving a convenient, sweet snack food. Food was presented for 10 minutes whilst the experimenter cleaned equipment used previously in the experimental session, facing away from participants. After the participant left the lab, the food was weighed, consumption was recorded, and the number of calories consumed was calculated. Before completing the FCT, participants were asked covertly (questions were embedded in a larger general health questionnaire) to rate their current levels of hunger and food craving to account for differences in the food consumption test results between conditions.
Timepoint [2] 297449 0
Pre-intervention and 2 weeks post-intervention commencement
Primary outcome [3] 297450 0
Three Factor Eating Questionnaire (TFEQ)

Participants completed the 51 item TFEQ which contained a combination of true/false questions (e.g., “Sometimes when I start eating, I just can’t seem to stop”) and items rated on a 4-point Likert scale (e.g., “How frequently do you avoid ‘stocking up’ on tempting foods?” Rated: not at all/slightly/moderately/almost always). The TFEQ contains three subscales- cognitive restraint, disinhibition, and hunger, measuring the ability to resist foods, and overcome internal and external food cues. The TFEQ has been widely used in overweight and obese populations, and is psychometrically valid in obese and non-obese populations.

Timepoint [3] 297450 0
Pre-intervention and 2 weeks post-intervention commencement
Secondary outcome [1] 321076 0
Go/Nogo task

Two auditory Go/Nogo tasks that varied in reaction time deadline (RTD) were used to assess general IC ability. Tones were presented at 1100 and 2000 Hz for 200 ms, with an inter-stimulus interval (ISI) of either 2500 (longer RTD) or 1250 ms (shorter RTD). These specific time intervals were pilot tested for this study in an adult population. Shorter RTDs increase task demands by inducing rapid responding to Go stimuli making the inhibition of motor responses on infrequent ‘Nogo’ trials more difficult and increases the likelihood of errors. As a result, this study used two separate tasks with varying task demands (‘longer RTD’ and ‘shorter RTD’) to better assess potential effects of the ICT training. Tasks were created in Presentation Version 11, and tones were presented at 60 dB binaurally though Sennheiser HD201 headphones. Participants were required to press a response button on a game controller upon presentation of the frequent ‘Go’ tone (70% of presented stimuli), and to withhold response upon presentation of the infrequent ‘Nogo’ tone. Participants completed 10 practice trials to ensure they understood task instructions, and then completed 100 trials, taking approximately 2.5 minutes to complete. Assignment of each tone as Go/Nogo, and the order of tasks, was counterbalanced across sessions and participants. This task was used to assess how the IC training affected general IC ability, but used a different medium (auditory rather than visual) to reduce practice effects and make comparison to the control group more equal.
Timepoint [1] 321076 0
Pre-intervention and 2 weeks post-intervention commencement

Key inclusion criteria
Participants were required to be over 13 years of age, have a BMI over 25, and possess an iOS device in order to access the training app.
Minimum age
13 Years
Maximum age
No limit
Both males and females
Can healthy volunteers participate?
Key exclusion criteria
Participants were excluded if they did not complete both experimental sessions, or failed to play more than 90 training games. Participants were excluded if they had any clinical neurological disorder, and non-normal hearing and vision.

Study design
Purpose of the study
Allocation to intervention
Randomised controlled trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
Allocation involved contacting the holder of the allocation schedule (SJ) who did not take part in recruitment or data collection.
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Participants were assigned to Control or Training condition based on a random permutation calculator (http://www.randomizer.org).
Masking / blinding
Open (masking not used)
Who is / are masked / blinded?

Intervention assignment
Other design features
Not Applicable
Type of endpoint(s)
Statistical methods / analysis
A strong effect size (o.80) was expected as a recent meta-analysis shows optimal effects are achieved with Go-Nogo training tasks using stimuli tailored to the specific behaviour. The expectation for increased effect size is due to these factors, as well as the increased duration of training (14 sessions). A power analysis using Gpower indicated that a total sample
of 6o participants would be needed to detect large effects (d=0.80) with 90% power using a t test between means with alpha at .05.

One way Analyses of Variance (ANOVAs) were used to assess baseline differences between Training and Control conditions, and to assess NOGO training app performance data.

Additionally, Time (1, 2) x Condition (Waitlist, Training) mixed design ANOVAs were used to assess the FCT, HEQ, and TFEQ, with planned follow-up analysis splitting data by Condition and assessing the impact of Time. ERP latency analysis was restricted to the frontal midline location (Fz), as the N2 and P3 components showed a frontal maximum. Go and Nogo ERP data was subject to a Condition x Time x Stimulus (Go, Nogo) x RTD (Longer, Shorter) mixed factorial ANOVA. ERP amplitude analyses included an additional Lateral (Left, Midline, Right) factor. Planned contrasts within the Lateral factor compared the right and left hemispheres. Here we focus on interactions between Time and Condition, and Time x Condition x Laterality for ERP amplitude analysis. Alpha level was set to .05 for all analysis.

Recruitment status
Date of first participant enrolment
Date of last participant enrolment
Date of last data collection
Sample size
Accrual to date
Recruitment in Australia
Recruitment state(s)
Recruitment postcode(s) [1] 12787 0
2522 - University Of Wollongong
Recruitment postcode(s) [2] 12788 0
2500 - Wollongong

Funding & Sponsors
Funding source category [1] 292951 0
Commercial sector/Industry
Name [1] 292951 0
Neurocognitive Solutions Pty Ltd
Address [1] 292951 0
PO Box 913
Taylors Road
Norfolk Island 2899 Australia
Country [1] 292951 0
Primary sponsor type
University of Wollongong
Northfields Avenue
Wollongong, NSW 2522
Secondary sponsor category [1] 291722 0
Name [1] 291722 0
Address [1] 291722 0
Country [1] 291722 0

Ethics approval
Ethics application status
Ethics committee name [1] 294457 0
University of Wollongong and Illawarra Shoalhaven Local Health District Health and Medical Human Research Ethics Committee
Ethics committee address [1] 294457 0
Northfields Avenue
Wollongong NSW 2522
Ethics committee country [1] 294457 0
Date submitted for ethics approval [1] 294457 0
Approval date [1] 294457 0
Ethics approval number [1] 294457 0

Brief summary
The project aims to investigate the efficacy of computerised inhibitory control training on unhealthy food consumption in obese adolescents and adults. Outcome measures will include consumption of various food types, attitudes towards food, and electrophysiological indices of approach/avoidance during exposure to food stimuli. Training will involve daily sessions playing an iOS app designed to reduce responses to unhealthy food, while encouraging responses to healthy foods. Using a waitlist control design the study will test both the efficacy of the app, and the viability of the intense training schedule.
Trial website
Trial related presentations / publications
Public notes

Principal investigator
Name 63802 0
A/Prof Stuart Johnstone
Address 63802 0
School of Psychology
University of Wollongong
Wollongong NSW 2522
Country 63802 0
Phone 63802 0
Fax 63802 0
Email 63802 0
Contact person for public queries
Name 63803 0
A/Prof Stuart Johnstone
Address 63803 0
School of Psychology
University of Wollongong
Wollongong NSW 2522
Country 63803 0
Phone 63803 0
Fax 63803 0
Email 63803 0
Contact person for scientific queries
Name 63804 0
A/Prof Stuart Johnstone
Address 63804 0
School of Psychology
University of Wollongong
Wollongong NSW 2522
Country 63804 0
Phone 63804 0
Fax 63804 0
Email 63804 0

No information has been provided regarding IPD availability
Summary results
Have study results been published in a peer-reviewed journal?
Other publications
Have study results been made publicly available in another format?
Results – basic reporting
Results – plain English summary