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Effects of Periodic Fasting Versus Daily Energy Restriction on Metabolic Health (PREFER)

This study is currently recruiting participants. (see Contacts and Locations)
Verified May 2014 by University of Adelaide
Information provided by (Responsible Party):
A/Prof Leonie Heilbronn, University of Adelaide Identifier:
First received: January 15, 2013
Last updated: May 6, 2014
Last verified: May 2014

The aim of this study is to examine whether periodic fasting improves markers of diabetes risk and cardiovascular health, and will compare this to the effects observed with daily dieting by energy restriction, and also with no change in energy intake.

It is hypothesized that periodic fasting, with or without weight loss, will be as effective as daily energy restriction to improve markers of metabolic health and energy metabolism.

Condition Intervention
Insulin Resistance
Other: Periodic fasting
Other: Energy restriction
Other: Energy balance diet

Study Type: Interventional
Study Design: Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Open Label
Primary Purpose: Basic Science
Official Title: Effects of Periodic Fasting Versus Daily Energy Restriction on Metabolic Health

Resource links provided by NLM:

Further study details as provided by University of Adelaide:

Primary Outcome Measures:
  • Insulin sensitivity [ Time Frame: 8 weeks ] [ Designated as safety issue: No ]
    assessed by hyperinsulinemic euglycemic clamp

Secondary Outcome Measures:
  • Plasma hormones and adipokines [ Time Frame: 8 weeks ] [ Designated as safety issue: No ]
  • Cognitive function, hunger, and mood [ Time Frame: 8 weeks ] [ Designated as safety issue: No ]
  • Oxidative stress, stress resistance, and lipid metabolism [ Time Frame: 8 weeks ] [ Designated as safety issue: No ]
  • Energy expenditure [ Time Frame: 8 weeks ] [ Designated as safety issue: No ]
    resting energy expenditure, and total daily energy expenditure

Estimated Enrollment: 100
Study Start Date: January 2013
Estimated Study Completion Date: December 2016
Estimated Primary Completion Date: December 2015 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Experimental: Daily energy restriction
25% reduction in daily energy intake
Other: Energy restriction
Active Comparator: Energy balance diet
Diet provides 100% of energy requirements and is designed to achieve weight stability
Other: Energy balance diet
Experimental: Periodic fasting with weight loss
Fast 3 days per week, and consume 1.5 times usual amount of food on other days
Other: Periodic fasting Other: Energy restriction
Experimental: Periodic fasting without weight loss
Fast 3 days per week, and consume double usual amount of food on other days
Other: Periodic fasting Other: Energy balance diet


Ages Eligible for Study:   35 Years to 70 Years
Genders Eligible for Study:   Female
Accepts Healthy Volunteers:   Yes

Inclusion Criteria:

  • Body mass index (BMI) between 25 and 35 kg/m2
  • weight stable (<5% fluctuation in body weight for the 6 months prior to study entry)

Exclusion Criteria:

  • history of cardiovascular disease, diabetes, major psychiatric disorders, and eating disorders
  • use of prescribed or non-prescribed medications with may affect energy metabolism, gastrointestinal function, body weight, or appetite
  • recent weight changes in 3 months prior to study entry
  • uncontrolled asthma, current fever, upper respiratory infections
  • individuals who regularly perform high intensity exercise (>2 sessions per week)
  • pregnancy, lactation (breast feeding), women who are planning to become pregnant
  • current intake of >140g of alcohol per week
  • current smoker of cigarettes/cigars/marijuana
  • current intake of any illicit substance
  • experience claustrophobia in confined spaces
  • has donated blood within the past 3 months
  • unable to comprehend the study protocol
  • experiences migraines
  Contacts and Locations
Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below. For general information, see Learn About Clinical Studies.

Please refer to this study by its identifier: NCT01769976

Australia, South Australia
Royal Adelaide Hospital Recruiting
Adelaide, South Australia, Australia, 5005
Contact: Leonie Heilbronn, PhD   
Principal Investigator: Leonie Heilbronn         
Sponsors and Collaborators
University of Adelaide
Principal Investigator: Leonie Heilbronn University of Adelaide
  More Information

No publications provided

Responsible Party: A/Prof Leonie Heilbronn, Associate Professor, University of Adelaide Identifier: NCT01769976     History of Changes
Other Study ID Numbers: APP1023401
Study First Received: January 15, 2013
Last Updated: May 6, 2014
Health Authority: Australia: National Health and Medical Research Council

Additional relevant MeSH terms:
Insulin Resistance
Glucose Metabolism Disorders
Metabolic Diseases processed this record on November 20, 2014