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Trial registered on ANZCTR


Registration number
ACTRN12616001531404
Ethics application status
Approved
Date submitted
1/11/2016
Date registered
7/11/2016
Date last updated
7/11/2016
Type of registration
Retrospectively registered

Titles & IDs
Public title
Fasting and its effect on Cognitive Function
Scientific title
The effect of caloric restriction and fasting on cognitive performance, satiety levels and fatigue in healthy adult females
Secondary ID [1] 290440 0
None
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Weight Loss 300795 0
overweight / obesity 300839 0
Cognitive function 300840 0
Condition category
Condition code
Diet and Nutrition 300621 300621 0 0
Obesity
Mental Health 300665 300665 0 0
Studies of normal psychology, cognitive function and behaviour

Intervention/exposure
Study type
Interventional
Description of intervention(s) / exposure
In this randomised crossover design, adult women will complete three experimental days at the CSIRO Cognitive Laboratory in Adelaide, South Australia. Two days will utilise a Caloric Restriction Condition protocol. In both of these conditions, participants will consume a total of ~500 kcal throughout the testing. Two different patterns of delivery will permit the investigation of overall caloric restriction as well as meal timing on the relevant outcomes. In addition to their energy kcal allowance, participants are provided with ~100 kcal of caloric-neutral vegetable snacks (cucumber, celery & capsicum) for ad-lib consumption and to assist with any intestinal discomfort. The washout between each testing day is 1 week (7-days).

Bulking - Participants will consume a total allowance of ~500 kcal in the form of two liquid meal replacement shakes delivered at 9am and 11am respectively. Participants may only consume water throughout the day.

Extended Distribution - Participants will consume a total allowance of ~500 kcal in the form of one Liquid Meal Replacement at 9am, and two snack bars consumed at 12pm and 3pm respectively. Participants may only consume water throughout the day.
Intervention code [1] 296285 0
Lifestyle
Intervention code [2] 296324 0
Treatment: Other
Comparator / control treatment
Fasting - Participants will not be permitted to consume any kcal other than the ~100 kcal of caloric-neutral vegetable snacks (cucumber, celery & capsicum) for ad-lib consumption to assist with any intestinal discomfort. Participants may only consume water throughout the day.
Control group
Active

Outcomes
Primary outcome [1] 300031 0
Cognitive Function: captured as mean performance on the CSIRO Computerised Fatigue Battery (CFB). The CFB consists of three tasks (Psychomotor Vigilance Task, Interference Task & Arithmetic Task) in each set, with three sets performed per assessment
Timepoint [1] 300031 0
Baseline (0; 8:30am), +1.5, +3.5, +5.5, +7.5 hours
Primary outcome [2] 300032 0
Cognitive Fatigue: captured as intra-individual variability estimates (e.g., Standard Deviation of Reaction Times, Coefficient of Variation of Reaction Times) during performance on the CSIRO Computerised Fatigue Battery (CFB). The CFB consists of three tasks (Psychomotor Vigilance Task, Interference Task & Arithmetic Task) in each set, with three sets performed per assessment
Timepoint [2] 300032 0
Baseline (0; 8:30am), +1.5, +3.5, +5.5, +7.5 hours
Primary outcome [3] 300033 0
Subjective Fatigue: Measured with a modified Activation-Deactivation Adjective Check List VAS instrument
Timepoint [3] 300033 0
Baseline (0; 8:30am), +1.5, +3.5, +5.5, +7.5 hours
Secondary outcome [1] 328866 0
Blood Glucose: Determined via use of a lancing device and blood glucose meter
Timepoint [1] 328866 0
Baseline (0; 8:30am), +1.5, +2.5, +3.5, +4.5, +5.5, +6.5, +7.5 hours
Secondary outcome [2] 328867 0
Satiety & Food Cravings Questionnaire
Timepoint [2] 328867 0
Baseline (0; 8:30am), +1.5, +2.5, +3.5, +4.5, +5.5, +6.5, +7.5 hours

Eligibility
Key inclusion criteria
Self-reported cognitively healthy participants
Able to undertake a computerised battery
Not currently using a fasting regime for weight management or weight loss
Minimum age
20 Years
Maximum age
50 Years
Gender
Females
Can healthy volunteers participate?
Yes
Key exclusion criteria
Smoker
BMI >30
History of mood disorder (e.g., Depression or Anxiety)
Neurological Disease (e.g., Dementia)
Uncontrolled Hypertension
Diabetes (both types)
Lactose intolerant
Coeliac Disease
Nut/Seed allergy

Study design
Purpose of the study
Treatment
Allocation to intervention
Randomised controlled trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Masking / blinding
Who is / are masked / blinded?



Intervention assignment
Other design features
Phase
Type of endpoint(s)
Statistical methods / analysis

Recruitment
Recruitment status
Active, not recruiting
Date of first participant enrolment
Anticipated
Actual
Date of last participant enrolment
Anticipated
Actual
Date of last data collection
Anticipated
Actual
Sample size
Target
Accrual to date
Final
Recruitment in Australia
Recruitment state(s)
SA

Funding & Sponsors
Funding source category [1] 294847 0
Government body
Name [1] 294847 0
CSIRO
Address [1] 294847 0
Gate 13, Kintore Avenue, Adelaide, SA 5000
Country [1] 294847 0
Australia
Primary sponsor type
Government body
Name
CSIRO
Address
Gate 13, Kintore Avenue, Adelaide, SA 5000
Country
Australia
Secondary sponsor category [1] 293686 0
None
Name [1] 293686 0
Address [1] 293686 0
Country [1] 293686 0

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 296232 0
CSIRO Health and Medical Human Research Ethics Committee (CHM HREC) Low Risk Review Panel
Ethics committee address [1] 296232 0
c/o Dr Anneliese Spinks
Ecosciences Precinct,
41 Boggo Road, Dutton Park QLD 4102
Ethics committee country [1] 296232 0
Australia
Date submitted for ethics approval [1] 296232 0
29/08/2016
Approval date [1] 296232 0
02/09/2016
Ethics approval number [1] 296232 0
LR 16/2016

Summary
Brief summary
Fasting may have benefits for weight loss, the acute effects of this on cognitive function and mental fatigue throughout fasting days are not well understood. Some studies have shown negative impacts of fasting including slower psychomotor speed, slower reaction times, reduced memory capacity, reduced working memory function, and poorer inhibition and reasoning skills. These deficits have the potential to impact negatively on activities including driving, and functioning within the workforce more generally. Ultimately these negative effects may impact on retention in these weight loss programs due to potentially unwanted side-effects, thus moderating their impact on health outcomes resulting from sustained weight loss.

A current trend in weight loss programs is to avoid true fasting days and instead, incorporate extreme Caloric Restriction days. One current approach, known as the 5:2 intermittent fasting method, recommends a total caloric intake allowance of ~2100kj/day (500 kcal) for women, and ~2500kj/day (600kcal) for men on two days out of every seven (i.e., two days per week). Despite suggestions in the literature that intermittent fasting (including caloric restriction) improves metabolic markers in young women and in those with diabetes, to date, little is known about the impact of caloric restriction on cognitive function, fatigue and satiety. In particular, there has been limited exploration about how best to distribute the permissible restricted calories across the day. The timing of energy consumption is likely an important factor that could alter any potentially negative effects of caloric restriction on cognitive function and fatigue, particularly in the context of carbohydrates.

This study will explore the impact of different nutrient intake timing during caloric restriction days on cognitive performance, fatigue, satiety and blood glucose.

In light of literature showing negative effects of fasting on cognitive function, our hypotheses are as follows:
1) Fasting will result in poorer cognitive function and enhanced fatigue compared to both of the caloric restriction arms (Bulking and Extended Distribution)
2) Extended Distribution of calories will result in less fatigue throughout the afternoon assessments compared to Bulking
3) Fasting will lead to significantly higher subjective ratings of fatigue and satiety compared to both caloric restriction conditions
4) Fasting will result in significantly lower blood glucose readings compared to both caloric restriction conditions
Trial website
Trial related presentations / publications
Public notes

Contacts
Principal investigator
Name 70098 0
Dr Ian Zajac
Address 70098 0
CSIRO, PO Box 10041, Adelaide BC, SA, 5000
Country 70098 0
Australia
Phone 70098 0
+61 8 8303 8875
Fax 70098 0
Email 70098 0
ian.zajac@csiro.au
Contact person for public queries
Name 70099 0
Dr Ian Zajac
Address 70099 0
CSIRO, PO Box 10041, Adelaide BC, SA, 5000
Country 70099 0
Australia
Phone 70099 0
+61 8 8303 8875
Fax 70099 0
Email 70099 0
ian.zajac@csiro.au
Contact person for scientific queries
Name 70100 0
Dr Ian Zajac
Address 70100 0
CSIRO, PO Box 10041, Adelaide BC, SA, 5000
Country 70100 0
Australia
Phone 70100 0
+61 8 8303 8875
Fax 70100 0
Email 70100 0
ian.zajac@csiro.au

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