Effects of Time of Sleep Restriction in Obesity

The recruitment status of this study is unknown because the information has not been verified recently.
Verified December 2010 by Federal University of São Paulo.
Recruitment status was  Recruiting
Associacao Fundo de Incentivo a Psicofarmcologia
Centro de Estudos em Sonolência e Acidentes
Information provided by:
Federal University of São Paulo
ClinicalTrials.gov Identifier:
First received: December 13, 2010
Last updated: June 22, 2011
Last verified: December 2010

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.

Sleep Restriction
Appetite Regulation

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

Resource links provided by NLM:

Further study details as provided by 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 ] [ Designated as safety issue: No ]
    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 ] [ Designated as safety issue: No ]
    Hunger and saciety are measured using visual analogue scales before and after breakfast, lunch and dinner meal

  • Food intake [ Time Frame: measured each meal ] [ Designated as safety issue: No ]
    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.

Estimated Enrollment: 20
Study Start Date: February 2009
Estimated Study Completion Date: April 2012
Estimated 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.


Ages Eligible for Study:   20 Years to 35 Years
Genders 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
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Please refer to this study by its ClinicalTrials.gov identifier: NCT01259895

Centro de Estudos em Psicobiologia e Exercicio (CEPE) Recruiting
Sao Paulo, Brazil, 04020-060
Contact: Iona Zimberg    (+5511)55720177    iona@psicobio.epm.br   
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:
No publications provided

Responsible Party: Ioná Zimberg, UNIFESP
ClinicalTrials.gov Identifier: NCT01259895     History of Changes
Other Study ID Numbers: CEPE18, FAPESP2008/09565-2
Study First Received: December 13, 2010
Last Updated: June 22, 2011
Health Authority: Brazil: Ethics Committee

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

ClinicalTrials.gov processed this record on July 29, 2014