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Effects of Time of Sleep Restriction in Obesity

This study has been completed.
ClinicalTrials.gov Identifier:
First Posted: December 14, 2010
Last Update Posted: August 18, 2014
The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details.
Associacao Fundo de Incentivo a Psicofarmcologia
Centro de Estudos em Sonolência e Acidentes
Information provided by (Responsible Party):
Iona Zalcman Zimberg, Federal University of São Paulo
The purpose of this study is to determine the effect of different time of sleep restriction on control of food intake and metabolism of obese and normal subjects.

Obesity Sleep Restriction Appetite Regulation Eating

Study Type: Observational
Study Design: Observational Model: Case-Crossover
Time Perspective: Cross-Sectional
Official Title: Effect os Sleep Restriction on Control of Food Intake and Metabolism of Obese Subjects

Further study details as provided by Iona Zalcman Zimberg, Federal University of São Paulo:

Primary Outcome Measures:
  • Appetite regulating hormones and stress hormones [ Time Frame: Measured every hour over the course of 24 hours on day 3 ]
    Hormones are sampled from blood

Secondary Outcome Measures:
  • Hunger and satiety [ Time Frame: Measured every 4 hour over the course of 12 hours on day 2 and 3 ]
    Hunger and saciety are measured using visual analogue scales before and after breakfast, lunch and dinner meal

  • Food intake [ Time Frame: measured each meal ]
    The meal will be weighted before and after the breakfast, lunch and dinner. Energy and nutrient intake are assessed from the amount of the meal consumed.

Enrollment: 20
Study Start Date: February 2009
Study Completion Date: June 2012
Primary Completion Date: September 2011 (Final data collection date for primary outcome measure)
BMI > 30kg/m2
Normal weight
BMI between 19 and 24,9kg/m2

Detailed Description:

The reduction of sleep time has now become a common habit, driven by the demands and opportunities of modern society. Some studies have suggested that sleep restriction would be an important factor in predisposing to obesity. However studies of sleep restriction in obese individuals have not yet been conducted. Still, the time of sleep restriction varies greatly between studies, making it difficult to compare results.

The investigators aim to recruit 20 young adults, 10 obese and 10 normal weight individuals. The study will be conducted as a randomized, crossover study with three conditions. Each participant will be subjected to reduction of the beginning of sleep (from 3-7h), reduction of the end of sleep (from 23-3h), and normal sleep (from 23-7h), in random order, for three consecutive nights.

In each condition, subjects will stay for 4 days in the laboratory. Three control meals will be offered. Visual analogue scales will be applied before and after each meal to assess hunger and appetite for different food categories. Blood samples will be collected hourly during 24 hours.


Information from the National Library of Medicine

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Ages Eligible for Study:   20 Years to 35 Years   (Adult)
Sexes Eligible for Study:   Male
Accepts Healthy Volunteers:   Yes
Sampling Method:   Non-Probability Sample
Study Population
primary care clinic, community sample, residents of the city of Sao Paulo

Inclusion Criteria:

  • obese (BMI>30) and normal weight (BMI between 19 and 24,9)
  • regular time of sleep between 6.5 and 8 hours

Exclusion Criteria:

  • self-reported sleep problems (Pittsburgh Sleep Quality Index score >5);
  • Obstructive sleep apnea (AHI > 5 in polysomnography)
  • night work;
  • variable sleep habits or habitual daytime naps;
  • regular physical exercise (>3 hours/week);
  • excessive intake of alcohol (>7 drinks/week);
  • excessive intake of caffeine (>300 mg/day);
  • smoking;
  • substance abuse;
  • use of prescription medications or over-the-counter drugs affecting sleep or metabolism;
  • chronic diseases (e.g. cancer, asthma, back pain, thyroid disease, heart disease, diabetes, etc.)
  • history of neurological, medical or sleep disorders;
  • trans-meridian travelling the last month;
  • chronotype: extreme morning or extreme evening
  • unable to comply with the protocol.
  Contacts and Locations
Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT01259895

Centro de Estudos em Psicobiologia e Exercicio (CEPE)
Sao Paulo, Brazil, 04020-060
Sponsors and Collaborators
Federal University of São Paulo
Associacao Fundo de Incentivo a Psicofarmcologia
Centro de Estudos em Sonolência e Acidentes
Principal Investigator: Marco Tulio de Mello, PhD Federal University of São Paulo
  More Information

Additional Information:
Responsible Party: Iona Zalcman Zimberg, PhD student, Federal University of São Paulo
ClinicalTrials.gov Identifier: NCT01259895     History of Changes
Other Study ID Numbers: CEPE18
FAPESP2008/09565-2 ( Other Grant/Funding Number: FAPESP )
First Submitted: December 13, 2010
First Posted: December 14, 2010
Last Update Posted: August 18, 2014
Last Verified: August 2014

Additional relevant MeSH terms:
Nutrition Disorders
Body Weight
Signs and Symptoms