Development of a Nutrigenetic Test for Personalized Prescription of Body Weight Loss Diets (Obekit)

Body Weight Changes Clinical Trial

— Obekit  

Official title:

Development of a Nutrigenetic Test for Personalized Prescription of Body Weight Loss Diets (Obekit)

Clinical Trial Details — Status: Active, not recruiting

Administrative data

• NCT number: NCT02737267
• Other study ID #: 132/2015
• Status: Active, not recruiting
• Phase: N/A
• First received: March 10, 2016
• Last updated: March 28, 2017
• Start date: November 2015
• Est. completion date: December 2017

Study information

• Verified date: November 2015
• Source: Clinica Universidad de Navarra, Universidad de Navarra
• Contact: n/a
• Is FDA regulated: No
• Study type: Interventional

Clinical Trial Summary

This study evaluates the relationship between several genetic variants and the response to a hypocaloric diet, in order to design a genetic test which permits prescribe the more personalized diet for each individual according to her genotype. Half of the participants will assigned to a moderate high protein diet, while the other half will assigned to a high carbohydrate diet.

Description:

Obesity has reached epidemic proportions becoming a major global public health challenge since it is associated with an increased risk of type 2 diabetes, cardiovascular disease, stroke, arthritis and some forms of cancer. Therefore, a large number of strategies have been investigated in order to induce a negative energy balance and consequently body weight loss mainly inducing a low calorie diet and sometimes accompanied by an increase in physical activity. However, individual responses to body weight loss interventions vary widely and several studies have aimed to identify psychological, behavioral and personal predictors of this variability.

In this context, the hypothesis of the present study is that part of the interindividual variability in relation to the success of certain weight loss treatments is based on gene-diet interactions. Depending on the composition of the diet and the genotype of each individual, it is more or less easy to reduce and maintenance body weight.

After the recruitment and selection of the study participants, the study will consists of a 4-month hypocaloric diet ("body weight loss period") followed by a second 6-month period ("body weight maintenance period") in which the subjects of the study will continue with the diet, but without any energy restriction. The participants will assigned to one of the two hypocaloric diets (-30% of the studied requirements for each individual) with different macronutrient composition:

• Moderately high protein diet: 40% of the energy derived from carbohydrates, 30% of the energy derived from protein and 30% of the energy derived from fat.

• Low fat diet: 60% of the energy derived from carbohydrates, 30% of the energy derived from protein and 30% of the energy derived from fat.

A group of normal weight individuals (n 12) will be recruited in order to compare the different parameters obtained in the obese subjects with those of normal population. They will be not subjected to any intervention.

Recruitment information / eligibility

• Status: Active, not recruiting
• Enrollment: 260
• Est. completion date: December 2017
• Est. primary completion date: December 2017
• Accepts healthy volunteers: Accepts Healthy Volunteers
• Gender: All
• Age group: 18 Years to 70 Years

Eligibility

Inclusion Criteria:

• Body Mass Index (BMI) between 25 and 40 kg/m2

• Physical examination and vital signs normal, or is considered abnormal, but clinically insignificant by researcher.

• In the case of individuals with chronic stable dose drug treatment and during the last 3 previous months at baseline, the investigator will assess their possible inclusion.

Exclusion Criteria:

• BMI less than 25 or higher than 40 kg/m2

• Pregnant women

• Breastfeeding period. If artificial feeding until 6 months after birth.

• Type 1 diabetes

• Severe kidney diseases

• Severe digestive system diseases

• Electrolyte disorders (disorders of sodium, potassium, calcium, chlorine, phosphorus, magnesium)

• Acute cardiovascular diseases

• Cancer

• Anemia

• Eating disorders

• Recent prescription drug treatment (without stable doses scheduled)

• Drug therapy that can influence weight loss as corticosteroids.

• Some type of cognitive impairment and / psychic

• Subjects in which poor collaboration or, in the investigator's opinion, have difficulty following the procedures of the study is foreseen

• Lack of commitment (at the discretion of the investigator) with the intervention, suspected non-compliance, or real difficulties to follow the development of the study.

Related Conditions & MeSH terms

• Body Weight
• Body Weight Changes
• Weight Loss

Intervention

Behavioral:
• Moderately high protein diet
After the recruitment randomization of the study participants, the study will consists of a 4-month nutritional intervention ("body weight loss period") followed by a second 6-month period ("body weight maintenance period") in which the subjects of the study will continue with the assigned diet, but without any energy restriction.
• Low fat diet
After the recruitment randomization of the study participants, the study will consists of a 4-month nutritional intervention ("body weight loss period") followed by a second 6-month period ("body weight maintenance period") in which the subjects of the study will continue with the assigned diet, but without any energy restriction.the energy derived from fat

Locations

Country	Name	City	State
Spain	Centre for Nutrition Research, University of Navarra	Pamplona	Navarra

Sponsors (1)

Lead Sponsor	Collaborator
Clinica Universidad de Navarra, Universidad de Navarra

Country where clinical trial is conducted

Spain, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Change in body weight at Week 16		Baseline and 16 Weeks
Primary	Change in body weight at Week 40		16 Weeks and 40 Weeks
Secondary	Height		Baseline
Secondary	Change in waist and hip circumferences at 16 Weeks	Waist and hip circumferences will be measured with a tape measure at baseline and at the end of the body weight loss period (16 weeks)	Baseline and 16 Weeks
Secondary	Change in waist and hip circumferences at 40 Weeks	Waist and hip circumferences will be measured with a tape measure at the end of the body weight loss period (16 weeks) and at the end of the body weight maintenance period (40 Weeks)	16 Weeks and 40 Weeks
Secondary	Change in body fat mass at 16 Weeks	Fat mass will be measured by bioelectric bioimpedance and Dual X-ray absorptiometry at baseline and at the end of the body weight loss period (16 Weeks)	Baseline and 16 Weeks
Secondary	Change in body fat mass at 40 Weeks	Fat mass will be measured by bioelectric bioimpedance and Dual X-ray absorptiometry at the end of the body weight loss period (16 weeks) and at the end of the body weight maintenance period (40 Weeks)	16 Weeks and 40 Weeks
Secondary	Single nucleotide polymorphisms (SNPs)	Single nucleotide polymorphisms will be measured from Genomic DNA from oral epithelial cells (collected in ORAcollect DNA, DNAGenotek) and from peripheral blood mononuclear cells (PBMC) by using massive sequencing in a Ion Torrent sequencer	Baseline
Secondary	Changes in DNA methylation levels at 16 Weeks	DNA methylation levels will be measured in PBMC by Microarray (Illumina. 450k methylation array) and validation specific sites by Sequenom (MassArray) and Methylationsensitive High-Resolution Melting (MS-HRM) (Real Time PCR) at baseline and at the end of the body weight loss period (16 Weeks)	Baseline and 16 Weeks
Secondary	Changes in DNA methylation levels at 40 Weeks	DNA methylation levels will be measured in PBMC by Microarray (Illumina 450k methylation array) and validation specific sites by Sequenom (MassArray) and MS-HRM (Real Time PCR) at the end of the body weight loss period (16 weeks) and at the end of the maintenance body weight period (40 Weeks)	16 Weeks and 40 Weeks
Secondary	Changes in metabolic profiling at 16 Weeks	Metabolic profiling will be measured in urine by High Performance Liquid Chromatography-Mass Spectrometry (HPLC-MS) at baseline and at the end of the body weight loss period (16 Weeks)	Baseline and 16 Weeks
Secondary	Changes in metabolomic profile at 40 Weeks	Metabolomic profile will be measured in urine by HPLC-MS at the end of the body weight loss period (16 Weeks) and at the end of the body weight maintenance period (40 Weeks)	16 Weeks and 40 Weeks
Secondary	Changes in lipidomic profile at 16 Weeks	Lipidomic profile will be measured in plasma by HPLC-MS at baseline and at the end of the body weight loss period (16 Weeks)	Baseline and 16 Weeks
Secondary	Changes in lipidomic profile at 40 Weeks	Lipidomic profile will be measured in plasma by HPLC-MS at the end of the body weight loss period (16 weeks) and at the end of the body weight maintenance period (40 Weeks)	16 Weeks and 40 Weeks
Secondary	Changes in proteomic profile at 16 Weeks	Proteomic profile will be measured in plasma by Two-Dimensional Fluorescence Difference Gel Electrophoresis (2D-DIGE) and Liquid Chromatography Electrospray Ionization with Tandem Mass Spectrometry (LC-ESI-MS/MS) at baseline and at the end of the body weight loss period (16 Weeks)	Baseline and 16 Weeks
Secondary	Changes in proteomic profile at 40 Weeks	Proteomic profile will be measured in plasma by 2D-DIGE and LC-ESI-MS/MS at the end of the body weight loss period (16 Weeks) and at the end of the body weight maintenance period (40 Weeks)	16 Weeks and 40 Weeks
Secondary	Changes in gut microbiota composition at 16 Weeks	Gut microbiota composition will be measured by Pyrosequencing 16SR RNA at baseline and at the end of the body weight loss period (16 Weeks)	Baseline and 16 Weeks
Secondary	Changes in gut microbiota composition at 40 Weeks	Gut microbiota composition will be measured by Pyrosequencing 16SR RNA at the end of the body weight loss period (16 Weeks) and at the end of the body weight maintenance period (40 Weeks)	16 Weeks and 40 Weeks
Secondary	Changes in messenger ribonucleic acid (mRNA) expression at 16 Weeks	mRNA expression will be measured by GeneChip Human Transcriptome Array 2.0 (Affimetrix) at baseline and at the end of the body weight loss period (16 Weeks)	Baseline and 16 Weeks
Secondary	Changes in mRNA expression at 40 Weeks	mRNA expression will be measured by GeneChip Human Transcriptome Array 2.0 (Affimetrix) at the end of the body weight loss period (16 Weeks) and at the end of the body weight maintenance period (40 Weeks)	16 Weeks and 40 Weeks
Secondary	Changes in microARNs in exosomes at 16 weeks	microARNs levels in exosomes will be measured by NGS Illumina Myseq at baseline and at the end of the body weight loss period (16 Weeks)	Baseline and 16 Weeks
Secondary	Changes in microARNs in exosomes at 40 weeks	microARNs levels in exosomes will be measured by next-generation sequencing (NGS) Illumina Myseq at the end of the body weight loss period (16 Weeks) and at the end of the body weight maintenance period (40 Weeks)	16 Weeks and 40 Weeks
Secondary	Changes in DNA oxidation at 16 weeks	DNA oxidation will be measured by 8-hydroxy-deoxyguanosine at baseline and at the end of the body weight loss period (16 Weeks)	Baseline and 16 Weeks
Secondary	Changes in DNA oxidation at 40 weeks	DNA oxidation will be measured by 8-hydroxy-deoxyguanosine at the end of the body weight loss period (16 Weeks) and at the end of the body weight maintenance period (40 Weeks)	16 Weeks and 40 Weeks
Secondary	Changes in serum glucose levels at 16 Weeks	Serum glucose levels will be measured in a fasting state at baseline and at the end of the body weight loss period (16 Weeks)	Baseline and 16 weeks
Secondary	Changes in serum glucose levels at 40 Weeks	Serum glucose levels will be measured in a fasting state at the end of the body weight loss period (16 Weeks) and at the end of the body weight maintenance period (40 Weeks)	16 Weeks and 40 Weeks
Secondary	Changes in serum insulin concentration at 16 Weeks	Serum insulin concentration will be measured in a fasting state at baseline and at the end of the body weight loss period (16 Weeks)	Baseline and 16 Weeks
Secondary	Changes in serum insulin concentration at 40 Weeks	Serum insulin concentration will be measured in a fasting state at the end of the body weight loss period (16 Weeks) and at the end of the body weight maintenance period (40 Weeks)	16 Weeks and 40 Weeks
Secondary	Changes in serum lipid metabolism markers at 16 Weeks	Serum free fatty acids, triglycerides, total cholesterol, LDL cholesterol and HDL cholesterol concentrations will be measured in a fasting state at baseline and at the end of the body weight loss period (16 Weeks)	Baseline and 16 Weeks
Secondary	Changes in serum lipid metabolism markers at 40 Weeks	Serum free fatty acids, triglycerides, total cholesterol, LDL cholesterol and HDL cholesterol concentrations will be measured in a fasting state at the end of the body weight loss period (16 Weeks) and at the end of the body weight maintenance period (40 Weeks)	16 Weeks and 40 Weeks
Secondary	Changes in serum total protein concentration at 16 Weeks	Serum total protein concentration will be measured in a fasting state at baseline and at the end of the body weight loss period (16 Weeks)	Baseline and 16 Weeks
Secondary	Changes in serum total protein concentration at 40 Weeks	Serum total protein concentration will be measured in a fasting state at the end of the body weight loss period (16 Weeks) and at the end of the body weight maintenance period (40 Weeks)	16 Weeks and 40 Weeks
Secondary	Changes in serum uric acid levels at 16 Weeks	Serum uric acid levels will be measured in a fasting state at baseline and at the end of the body weight loss period (16 Weeks)	Baseline and 16 Weeks
Secondary	Changes in serum uric acid levels at 40 Weeks	Serum uric acid levels will be measured in a fasting state at the end of the body weight loss period (16 Weeks) and at the end of the body weight maintenance period (40 Weeks)	16 Weeks and 40 Weeks
Secondary	Changes in serum transaminases concentrations at 16 Weeks	Serum transaminases (AST & ALT) concentrations will be measured in a fasting state at baseline and at the end of the body weight loss period (16 Weeks)	Baseline and 16 Weeks
Secondary	Changes in serum transaminases concentrations at 40 Weeks	Serum transaminases (AST & ALT) concentrations will be measured in a fasting state at the end of the body weight loss period (16 Weeks) and at the end of the body weight maintenance period (40 Weeks)	16 Weeks and 40 Weeks
Secondary	Changes in serum homocystein concentration at 16 Weeks	Serum homocystein concentration will be measured in a fasting state at baseline and at the end of the body weight loss period (16 Weeks)	Baseline and 16 Weeks
Secondary	Changes in serum homocystein concentration at 40 Weeks	Serum homocystein concentration will be measured in a fasting state at the end of the body weight loss period (16 Weeks) and at the end of the body weight maintenance period (40 Weeks)	16 Weeks and 40 Weeks
Secondary	Changes in vascular endothelial growth factor (VEGF) at 16 Weeks	VEGF levels will be measured in a fasting state at baseline and at the end of the body weight loss period (16 Weeks)	Baseline and 16 Weeks
Secondary	Changes in vascular endothelial growth factor (VEGF) at 40 Weeks	VEGF levels will be measured in a fasting state at the end of the body weight loss period (16 Weeks) and at the end of the body weight maintenance period (40 Weeks)	16 Weeks and 40 Weeks
Secondary	Changes in asymmetric dimethylarginine (ADMA) at 16 Weeks	ADMA levels will be measured in a fasting state at baseline and at the end of the body weight loss period (16 Weeks)	Baseline and 16 Weeks
Secondary	Changes in asymmetric dimethylarginine (ADMA) at 40 Weeks	ADMA levels will be measured in a fasting state at the end of the body weight loss period (16 Weeks) and at the end of the body weight maintenance period (40 Weeks)	16 Weeks and 40 Weeks
Secondary	Changes in PAI-1 concentration at 16 Weeks	PAI-1 concentration will be measured in a fasting state at baseline and at the end of the body weight loss period (16 Weeks)	Baseline and 16 Weeks
Secondary	Changes in plasminogen activator inhibitor-1 (PAI-1) concentration at 40 Weeks	PAI-1 concentration will be measured in a fasting state at the end of the body weight loss period (16 Weeks) and at the end of the body weight maintenance period (40 Weeks)	16 Weeks and 40 Weeks
Secondary	Changes in nitric oxide levels at 16 Weeks	Nitric oxide levels will be measured in a fasting state at baseline and at the end of the body weight loss period (16 Weeks)	Baseline and 16 Weeks
Secondary	Changes in nitric oxide levels at 40 Weeks	Nitric oxide levels will be measured in a fasting state at the end of the body weight loss period (16 Weeks) and at the end of the body weight maintenance period (40 Weeks)	16 Weeks and 40 Weeks
Secondary	Changes in blood pressure at 16 Weeks	Changes in diastolic and systolic blood pressure will be measured at baseline and at the end of the body weight loss period (16 Weeks)	Baseline and 16 Weeks
Secondary	Changes in blood pressure at 40 Weeks	Changes in diastolic and systolic blood pressure will be measured at the end of the body weight loss period (16 Weeks) and at the end of the body weight maintenance period (40 Weeks)	16 Weeks and 40 Weeks
Secondary	Changes in plasma C-Reactive Protein levels at 16 Weeks	C-Reactive Protein levels will be measured in a fasting state at baseline and at the end of the body weight loss period (16 Weeks)	Baseline and 16 Weeks
Secondary	Changes in plasma C-Reactive Protein levels at 40 Weeks	C-Reactive Protein levels will be measured in a fasting state at the end of the body weight loss period (16 Weeks) and at the end of the body weight maintenance period (40 Weeks)	16 Weeks and 40 Weeks
Secondary	Changes in plasma interleukin-6 (IL-6) and interleukin-10 (IL-10) levels at 16 Weeks	IL-6 and IL-10 levels will be measured in a fasting state at baseline and at the end of the body weight loss period (16 Weeks)	Baseline and 16 Weeks
Secondary	Changes in plasma IL-6 and IL-10 levels at 40 Weeks	IL-6 and IL-10 levels will be measured in a fasting state at the end of the body weight loss period (16 Weeks) and at the end of the body weight maintenance period (40 Weeks)	16 Weeks and 40 Weeks
Secondary	Changes in plasma tumor necrosis factor-alpha (TNF-alpha) levels at 16 Weeks	TNF-alpha levels will be measured in a fasting state at baseline and at the end of the body weight loss period (16 Weeks)	Baseline and 16 Weeks
Secondary	Changes in plasma TNF-alpha levels at 40 Weeks	TNF-alpha levels will be measured in a fasting state at the end of the body weight loss period (16 Weeks) and at the end of the body weight maintenance period (40 Weeks)	16 Weeks and 40 Weeks
Secondary	Changes in adiponectin levels at 16 Weeks	Adiponectin levels will be measured in a fasting state at baseline and at the end of the body weight loss period (16 Weeks)	Baseline and 16 Weeks
Secondary	Changes in adiponectin levels at 40 Weeks	Adiponectin levels will be measured in a fasting state at the end of the body weight loss period (16 Weeks) and at the end of the body weight maintenance period (40 Weeks)	16 Weeks and 40 Weeks
Secondary	Changes in chemerin levels at 16 Weeks	Chemerin levels will be measured in a fasting state at baseline and at the end of the body weight loss period (16 Weeks)	Baseline and 16 Weeks
Secondary	Changes in chemerin levels at 40 Weeks	Chemerin levels will be measured in a fasting state at the end of the body weight loss period (16 Weeks) and at the end of the body weight maintenance period (40 Weeks)	16 Weeks and 40 Weeks
Secondary	Changes in leptin levels at 16 Weeks	Leptin levels will be measured in a fasting state at baseline and at the end of the body weight loss period (16 Weeks)	Baseline and 16 Weeks
Secondary	Changes in leptin levels at 40 Weeks	Leptin levels will be measured in a fasting state at the end of the body weight loss period (16 Weeks) and at the end of the body weight maintenance period (40 Weeks)	16 Weeks and 40 Weeks
Secondary	Changes in apelin levels at 16 Weeks	Apelin levels will be measured in a fasting state at baseline and at the end of the body weight loss period (16 Weeks)	Baseline and 16 Weeks
Secondary	Changes in apelin levels at 40 Weeks	Apelin levels will be measured in a fasting state at the end of the body weight loss period (16 Weeks) and at the end of the body weight maintenance period (40 Weeks)	16 Weeks and 40 Weeks
Secondary	Changes in haptoglobin levels at 16 Weeks	Haptoglobin levels will be measured in a fasting state at baseline and at the end of the body weight loss period (16 Weeks)	Baseline and 16 Weeks
Secondary	Changes in haptoglobin levels at 40 Weeks	Haptoglobin levels will be measured in a fasting state at the end of the body weight loss period (16 Weeks) and at the end of the body weight maintenance period (40 Weeks)	16 Weeks and 40 Weeks
Secondary	Changes in amyloid A levels at 16 Weeks	Amyloid A levels will be measured in a fasting state at baseline and at the end of the body weight loss period (16 Weeks)	Baseline and 16 Weeks
Secondary	Changes in amyloid A levels at 40 Weeks	Amyloid A levels will be measured in a fasting state at the end of the body weight loss period (16 Weeks) and at the end of the body weight maintenance period (40 Weeks)	16 Weeks and 40 Weeks
Secondary	Changes in leukocytes levels at 16 Weeks	Leukocytes levels will be measured in a fasting state at baseline and at the end of the body weight loss period (16 Weeks)	Baseline and 16 Weeks
Secondary	Changes in leukocytes levels at 40 Weeks	Leukocytes levels will be measured in a fasting state at the end of the body weight loss period (16 Weeks) and at the end of the body weight maintenance period (40 Weeks)	16 Weeks and 40 Weeks
Secondary	Changes in plasma LDL-ox levels at 16 Weeks	Levels of LDL-ox in plasma will be measured in a fasting state at baseline and at the end of the body weight loss period (16 Weeks)	Baseline and 16 Weeks
Secondary	Changes in plasma LDL-ox levels at 40 Weeks	Levels of LDL-ox in plasma will be measured in a fasting state at the end of the body weight loss period (16 Weeks) and at the end of the body weight maintenance period (40 Weeks)	16 Weeks and 40 Weeks
Secondary	Changes in glutathione peroxidase activity at 16 Weeks	Glutathione peroxidase activity will be measured in a fasting state at baseline and at the end of the body weight loss period (16 Weeks)	Baseline and 16 Weeks
Secondary	Changes in glutathione peroxidase activity at 40 Weeks	Glutathione peroxidase activity will be measured in a fasting state at the end of the body weight loss period (16 Weeks) and at the end of the body weight maintenance period (40 Weeks)	16 Weeks and 40 Weeks
Secondary	Changes in reduced and oxidized glutathione levels at 16 Weeks	Reduced and oxidized glutathione levels will be measured in a fasting state at baseline and at the end of the body weight loss period (16 Weeks)	Baseline and 16 Weeks
Secondary	Changes in reduced and oxidized glutathione levels at 40 Weeks	Reduced and oxidized glutathione levels will be measured in a fasting state at the end of the body weight loss period (16 Weeks) and at the end of the body weight maintenance period (40 Weeks)	16 Weeks and 40 Weeks
Secondary	Changes in superoxide dismutase levels at 16 Weeks	Superoxide dismutase levels will be measured in a fasting state at baseline and at the end of the body weight loss period (16 Weeks)	Baseline ant 16 Weeks
Secondary	Changes in superoxide dismutase levels at 40 Weeks	Superoxide dismutase levels will be measured in a fasting state at the end of the body weight loss period (16 Weeks) and at the end of the body weight maintenance period (40 Weeks)	16 Weeks and 40 Weeks
Secondary	Changes in serum isoprostanes levels at 16 Weeks	Serum isoprostanes levels will be measured in a fasting state at baseline and at the end of the body weight loss period (16 Weeks)	Baseline and 16 Weeks
Secondary	Changes in serum isoprostanes levels at 40 Weeks	Serum isoprostanes levels will be measured in a fasting state at the end of the body weight loss period (16 Weeks) and at the end of the body weight maintenance period (40 Weeks)	16 Weeks and 40 Weeks
Secondary	Changes in plasma malonyldialdehyde (MDA) concentration at 16 Weeks	MDA concentration will be measured in a fasting state at baseline and at the end of the body weight loss period (16 Weeks)	Baseline and 16 Weeks
Secondary	Changes in plasma malonyldialdehyde (MDA) concentration at 40 Weeks	MDA concentration will be measured in a fasting state at the end of the body weight loss period (16 Weeks) and at the end of the body weight maintenance period (40 Weeks)	16 Weeks and 40 Weeks
Secondary	Changes in monoamines levels at 16 Weeks	Plasma monoamines (dopamine, dopac, homovalic acid, serotonin, noradrenalin) levels will be measured in a fasting state at baseline and at the end of the body weight loss period (16 Weeks)	Baseline and 16 Weeks
Secondary	Changes in monoamines levels at 40 Weeks	Plasma monoamines (dopamine, dopac, homovalic acid, serotonin, noradrenalin) levels will be measured in a fasting state at the end of the body weight loss period (16 Weeks) and at the end of the body weight maintenance period (40 Weeks)	16 Weeks and 40 Weeks
Secondary	Changes in physical activity at 16 Weeks	Physical activity level will be measured by a validated physical activity questionnaire and by a pedometer at baseline and at the end of the body weight loss period (16 Weeks)	Baseline and 16 Weeks
Secondary	Changes in physical activity at 40 Weeks	Physical activity level will be measured by a validated physical activity questionnaire and by a pedometer at the end of the body weight loss period (16 Weeks) and at the end of the body weight maintenance period (40 Weeks)	16 Weeks and 40 Weeks
Secondary	Changes in depression degree at 16 Weeks	Depression degree will be measured by the Beck Depression Inventory at baseline and at the end of the body weight loss period (16 Weeks)	Baseline and 16 Weeks
Secondary	Changes in depression degree at 40 Weeks	Depression degree will be measured by the Beck Depression Inventory at the end of the body weight loss period (16 Weeks) and at the end of the body weight maintenance period (40 Weeks)	16 Weeks and 40 Weeks
Secondary	Changes in anxiety degree at 16 Weeks	Anxiety degree will be measured by the State-Trait Anxiety Inventory (STAI) at baseline and at the end of the body weight loss period (16 Weeks)	Baseline and 16 Weeks
Secondary	Changes in anxiety degree at 40 Weeks	Anxiety degree will be measured by the State-Trait Anxiety Inventory (STAI) at the end of the body weight loss period (16 Weeks) and at the end of the body weight maintenance period (40 Weeks)	16 Weeks and 40 Weeks
Secondary	Changes in the chronotype at 16 Weeks	Chronotype will be defined by two questionnaires at baseline and at the end of the intervention period (16 Weeks)	Baseline and 16 Weeks
Secondary	Changes in the chronotype at 40 Weeks	Chronotype will be defined by two questionnaires at the end of the body weight loss period (16 Weeks) and at the end of the body weight maintenance period (40 Weeks)	16 Weeks and 40 Weeks
Secondary	Changes in food intake at 16 Weeks	Food intake will be evaluated by a 72 hours dietary record at baseline and at the end of the body weight loss period (16 Weeks)	Baseline and 16 weeks
Secondary	Changes in food intake at 40 Weeks	Food intake will be evaluated by a 72 hours dietary record and by a validated Food Frequency Questionnaire at baseline and at the end of the body weight maintenance period (40 Weeks)	Baseline and 40 weeks
Secondary	Changes in satiety at 16 Weeks	Satiety will be evaluated by the Visual Analogue Scale (VAS) at baseline and at the end of the body weight loss period (16 Weeks)	Baseline and 16 Weeks
Secondary	Changes in satiety at 40 Weeks	Satiety will be evaluated by the Visual Analogue Scale (VAS) at the end of the body weight loss period (16 Weeks) and at the end of the body weight maintenance period (40 Weeks)	16 Weeks and 40 Weeks