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Completed

NCT Number: NCT04799821

The Role of Walnut Consumption on Sleep Quality

Walnuts have a unique nutritional profile, including the sleep-regulating hormone melatonin, tryptophan, and omega-3 fatty acids, the two latest nutrients involved in melatonin and serotonin synthesis. Although it has been claimed that walnuts may improve sleep, to the investigators' knowledge, no studies have been conducted to objectively determine the impact of walnut consumption on sleep and overall well-being. Therefore, this study aims to investigate the effect of daily walnut consumption on sleep parameters (such as quality and duration). Secondarily, it aims to investigate the impact of daily walnut consumption on body composition, eating behavior, and well-being.

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Key information

Conditions

Healthy Diet Dyssomnias Mental Disorders Nervous System Diseases Sleep Sleep Disorders, Intrinsic Sleep Initiation and Maintenance Disorders Sleep Wake Disorders

Age range

20 year–40 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

Torribera Campus, University of Barcelona

Santa Coloma de Gramenet, Barcelona, 08921, Spain

About this study

The study to investigate the effect of daily walnut consumption on sleep quality will be conducted in an 18-week randomized crossover trial, in which participants will be initially assigned to intervention or control conditions for 8-weeks. After 2 weeks of washout, subjects will be crossed over to the alternate intervention and will continue for another 8 weeks. Note that throughout the whole study, each participant will attend 5 visits: 1 initial visit (baseline) and 2 visits in each one of the study conditions (intervention and control).

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • BMI 19-26 kg/m^2
  • Habitual moderate exercise level
  • No recent history of weight change exceeding 2.3kg (5lb) within the prior 3 months.

Exclusion criteria

  • Nuts allergy
  • Any acute or chronic diseases
  • Smokers
  • Any drugs or supplementations
  • Any alimentary restrictions or specific diets
  • Being a shift or night workers
  • Being unable to give written informed consent.

Treatment and study plan

Control

Other

Participants will be asked to refrain from walnut intake and to follow an isocaloric meal plan that complies with the recommendations of a healthy Mediterranean-style eating pattern.

Walnut intake

Other

Participants will be asked to consume walnuts along with an isocaloric meal plan that complies with the recommendations of a healthy Mediterranean-style eating pattern.

Primary outcomes

  1. Changes in sleep onset latency from baseline to weeks 4, 8, 14, and 18

    Time frame: Weeks 4, 8, 14 and 18

    Measured in hours of sleep with an actigraph (ActTrust, CONDOR, Brazil)

  2. Changes in sleep efficiency from baseline to weeks 4, 8, 14, and 18

    Time frame: Weeks 4, 8, 14 and 18

    Calculated in percentage as the ratio of total sleep time (TST) to time in bed (TIB).

    Sleep efficiency (percent) = (TST/TIB)*100

  3. Changes in wake after sleep onset (WASO) from baseline to weeks 4, 8, 14, and 18

    Time frame: Week 4, 8, 14, and 18

    Measured in minutes of WASO with an actigraph (ActTrust, CONDOR, Brazil)

  4. Changes in sleep duration from baseline to weeks 4, 8, 14, and 18

    Time frame: Weeks 4, 8, 14, and 18

    Measured in hours of sleep time with an actigraph (ActTrust, CONDOR, Brazil)

  5. Changes in urinary 6-sulphaoxymelatonin from baseline to week 4, 8, 14 and 18

    Time frame: Week 4, 8, 14 and 18

    Quantified using urine Melatonin-Sulfate ELISA kit

Secondary outcomes

  1. Changes in body mass index (BMI) from baseline to weeks 4, 8, 14, and 18

    Time frame: Weeks 4, 8, 14 and 18

    Calculated as weight (kg) divided by height (in squared meters), BMI= kg/m^2

  2. Changes in body fat from baseline to weeks 4, 8, 14, and 18

    Time frame: Weeks 4, 8, 14 and 18

    Measured as the percentage of body fat with a body composition analyzer (Inbody 120, Korea)

  3. Changes in weight circumference from baseline to weeks 4, 8, 14, and 18

    Time frame: Weeks 4, 8, 14 and 18

    Measured midway between the lower rib margin and the iliac crest with the subject standing and wearing only underwear, at the end of gentle expiration with an anthropometric tape (CESCORF, Brazil)

  4. Changes in eating behavior from baseline to weeks 8 and 18

    Time frame: Weeks 8 and 18

    To evaluate changes in eating behavior, the Spanish version of the Food Cravings Questionnaire will be used (Cepeda-Benito et al, 2000).

    This questionnaire evaluates 10 dimensions of eating behavior:

    • Having Intentions and Plans to Consume Food
    • Anticipation of Positive Reinforcement that may Result from Eating
    • Anticipation of Relief from Negative States and Feelings as a Result of Eating
    • Lack of Control over Eating
    • Thoughts or Preoccupation with Food
    • Having Intentions and Plans to Consume Food
    • Craving as a Physiological State
    • Emotions that may be Experienced Before or During Food Cravings or Eating
    • Cues that may Trigger Food Cravings
    • Guilt from Cravings and/or for Giving in to Them

    For each subscale, scores range from 0 to 5, with higher scores indicating a stronger sensation of craving.

  5. Changes in well-being from baseline to weeks 8 and 18

    Time frame: Weeks 8 and 18

    Well-being will be measured with the Spanish version of the WHO-5 Well-being Index (Lucas-Carrasco et. al. 2012).

    Scores range from 0 to 100, with higher scores indicating higher well-being.

Sponsors and collaborators

Lead sponsor

University of Barcelona

Other

Collaborators

  • California Walnut Commission

Registry information

Official study title

Eat Walnuts and Sleep Better: Exploring the Potential Role of Walnuts as Sleep-promoting Food and Their Impact on Body Composition

Important dates

Study start
2021
Primary completion
2022
Study completion
2023
First posted
Mar 16, 2021
Registry last updated
Nov 29, 2023

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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