Effects of a Ketogenic Diet on Psychological Outcomes

September 6, 2019 updated by: Antonio Paoli, University of Padova

Effects of Ketonemia and Glycemia Variations During Ketogenic and Mediterranean Weight Loss Diets on Appetite Levels, Executive Functions and Mood

The aim of the study is to investigate how glycemia and ketonemia variations during three different diet protocols: a ketogenic diet without any restriction on calories intake (KD), a calorie-restricted ketogenic-mediterranean diet (KEMEPHY) and a calorie-restricted mediterranean diet (MD) affect appetite, executive functions and mood in overweight young women.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Completed

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Detailed Description

Fifty overweight young women with a body mass index (BMI) greater than 25 will be randomly assigned to a ten days of ketogenic diet (KD), calorie-restricted ketogenic-mediterranean diet (KEMEPHY) or Mediterranean diet (MD). All subjects will begin the prescribed diet at the beginning of their follicular phase. Body composition, fasting blood glucose and β-hydroxybutyrate (BHB), visual analogue scale (VAS) to test appetite as well as psychological tests (one mood test and two cognitive tasks) will be obtained 5 days before the beginning and on the last day of the diet-period.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Actual)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
50

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • Italy
      • Padova, Italy, 35131
        • Nutrition and Exercise Lab, DSB, University of Padova

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

20 years to 35 years (Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

Female

Description

Inclusion Criteria:

  • female sex age between 20 and 35 years,
  • 25<BMI>39.9 kg/m2

Exclusion Criteria:

  • smokers,
  • subjects under diet-treatment,
  • subjects treated for diseases such as diabetes,
  • cardiovascular diseases,
  • depression,
  • subjects doing sport more than 2 hours per week.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Basic Science
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Double

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Experimental: ketogenic-mediterranean diet with phytoextracts
The KEMEPHY diet (Paoli et al., 2011) is a mediterranean calorie-controlled ketogenic protocol (about 900 Kcal/day) with the use of some phytoextracts. During this protocol subjects are allowed to eat with no limits green leafy vegetables, cruciferous, zucchini, cucumbers and eggplants. The quantity of meat, eggs and fish was limited to once a day (120g of meat or 200g of fish or 1 egg). Moreover, subjects daily consumed four food supplements and liquid herbal extracts. Food supplements are high proteins (19g/portion) and very low carbohydrate (3.5g/portion) formulas simulating the aspect and taste of common carbohydrate rich foods added with dry phytoextracts (Lodi et al., 2016).
Other: KEMEPHY
The group received a plan for a ketogenic mediterranean with herbal extracts diet
Active Comparator: Ketogenic Diet
The KD is a protocol in which all foods containing carbohydrate are excluded, whereas meat, eggs, fish, ham, green leafy vegetables, cruciferous, zucchini, cucumbers and eggplants can be eat without any limit. This protocol allows the use of oil, lemon juice (2 tbs/day), spices and aromatic herbs with a limitation of the use of saturated fats like butter, margarine and lard. Coffee, tea and herbal tea could be sweetened with sweeteners
Other: KD
The group received a plan for a low carbohydrate ketogenic diet
Active Comparator: Mediterranean Diet
The MD is a balanced calorie-controlled diet. The calorie intake was 1200 Kcal/day of which 15% were proteins, 60% carbohydrates and 25% fat. In this protocol was highlighted the use of the typical ingredients of the mediterranean tradition, such as extravirgin olive oil, vegetables, fruits, fish, lean meat and whole grain cereals.
Other: Mediterranean diet
The group received a plan for a isocaloric Mediterranean Diet

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Motivation to eat and appetite
Time Frame: after 8 weeks
Motivation to eat and appetite were investigated by Visual Analog Scale (Hill & Blundell, 1982) , a test formed by 6 scales. Each scale was 10 cm long and was labelled with vertical lines and numbers (from 0 to10) every cm. Participants had to choose which part of the scale better described how they felt. The scale investigated appetite, fullness, desire to eat, how much would participant eat, urgency of eating and worries about food through 6 questions. Moreover, also the unfullness index (10 - fullness) was taken into account (R. J. Stubbs et al., 2000).
after 8 weeks
cognitive task1
Time Frame: after 8 weeks
The working memory test was an adapted version of the visuo-spatial N-back (Cui, Bray, Bryant, Glover, & Reiss, 2011; Haberecht et al., 2001). It consisted in remembering the position of the letter "o" that, in each trial, could appear in different positions, since a 9-part grid divides the screen. Number of correct or incorrect answers will be counted
after 8 weeks
Cognitive task2
Time Frame: after 8 weeks
The executive function test was an adapted version of the inhibitory control task (Amodio et al., 2010; Cona, Arcara, Amodio, Schiff, & Bisiacchi, 2013) . The stimulus were letters that appear in the centre of the screen. The task was formed by two main parts. In the first one the participant had to respond when the letter x or y appeared on the screen; in the second part the participant had to answer only when x preceded y and then vice versa. Number of correct or incorrect answers will be counted
after 8 weeks

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
body water content
Time Frame: after 8 weeks
Body composition will be assessed by body electrical impedance analysis (BIA) that measures Total body water and intra and extracellular water in liters
after 8 weeks
lean body mass
Time Frame: after 8 weeks
Body composition will be assessed by body electrical impedance analysis (BIA) that measures lean body mass in kg
after 8 weeks
fat body mass
Time Frame: after 8 weeks
Body composition will be assessed by body electrical impedance analysis (BIA) that measures fat body mass in kg
after 8 weeks
Mood
Time Frame: after 8 weeks
The mood test was the Italian Version of the Depression Anxiety Stress Scales-21. It was a self report measure formed by 21 items that reliably measure depression (lack of incentive, dysphoria and low self-esteem) as well as anxiety (somatic and subjective symptoms), stress (irritability, impatience, tension and arousal) and general distress (related to anxiety and depression) (Bottesi et al., 2015). The responses are given on a 4-point Likert scale, ranging from zero if "I strongly disagree" to 3 if "I totally agree".
after 8 weeks
blood glucose
Time Frame: after 8 weeks
to assess diets' effects on glycaemia, capillary blood will be analyzed. We measure glucose in mg/100ml
after 8 weeks
blood ketones
Time Frame: after 8 weeks
to assess diets' effects on ketonemia, capillary blood will be analyzed. We measure ketone in mol/L
after 8 weeks

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
University of Padova

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
April 1, 2015

Primary Completion (Actual)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
April 30, 2016

Study Completion (Actual)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
June 15, 2016

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
August 29, 2019

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
September 6, 2019

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
September 11, 2019

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
September 11, 2019

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
September 6, 2019

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
September 1, 2019

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • KDPSY2

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

Undecided

IPD Plan Description

Raw data of measured variables

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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