Chronic Effect of Fasting

Study Overview
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Brief Summary
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The aim of the study is to determine if time-restricted feeding (TRF) is an effective dietary strategy to weight loss after 8 weeks intervention. TRF will be compared with an intervention without restriction in time for feeding. Both strategies will be with caloric restriction.

Detailed Description
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The participants of the study will be divided in two groups: (1) a group with caloric restriction and without restriction in time for feeding and (2) a group with caloric restriction and restriction in time for feeding. This second group will be subdivided according to the participant's preference: (2.1) first meal at 8 a.m. and last meal at 4 p.m. or (2.2) first meal at 12 p.m. and last meal at 8 p.m. The caloric restriction for all participants will be 513 to 770 kcal from estimated energy requirement.

Official Title
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Comparison of Weight Loss Induced by Daily Time-Restricted Feeding Versus Daily Caloric Restriction in Women With Overweight and Obesity

Conditions
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Overweight and Obesity

Intervention / Treatment
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* Behavioral: Caloric restriction only
* Behavioral: Caloric restriction plus TRF morning
* Behavioral: Caloric restriction plus TRF night


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Females; Aged between 18 and 59 years old; Body mass index equal or greater 25 kg/m²; Agree to sign the informed consent. Exclusion Criteria: Any chronic health conditions (e.g. chronic renal failure, autoimmune, heart, and liver disease); Thyroid diseases or medications for its treatment; Medications known to affect total energy expenditure; Use of steroids, immunosuppressants or non-steroidal anti-inflammatory drugs, weight-loss medications, oral hypoglycemic agents or insulin and any medications that influence metabolic and/or inflammatory parameters; Previous surgery for weight loss; Pregnancy or breast-feeding; Smoking; Alcohol use (>2 doses/day).

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 59 Years

Sexes Eligible for Study
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Female

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Caloric restriction only<br>Participants in this group will receive a eating plan with caloric restriction as dietary weight loss strategy. | Behavioral: Caloric restriction only<br>* Participants in this group will receive a eating plan with caloric restriction (513 to 770 kcal from estimated energy requirements), without restriction in time for feeding, for 8 weeks.<br>|
| Experimental: Caloric restriction plus TRF morning<br>Participants in this group will receive a eating plan with caloric and time restriction as dietary weight loss strategy. | Behavioral: Caloric restriction plus TRF morning<br>* Participants in this group will receive a eating plan with caloric restriction (513 to 770 kcal from estimated energy requirements) and 8 hours for eating (from 12 p.m. to 8 p.m.) and 16 hours of fasting, for 8 weeks.<br>|
| Experimental: Caloric restriction plus TRF night<br>Participants in this group will receive a eating plan with caloric and time restriction as dietary weight loss strategy. | Behavioral: Caloric restriction plus TRF night<br>* Participants in this group will receive a eating plan with caloric restriction (513 to 770 kcal from estimated energy requirements) and 8 hours for eating (from 8 a.m. to 4 p.m.) and 16 hours of fasting, for 8 weeks.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in body weight | Body weight will be assessed by mechanical scale | Baseline and weeks 2, 4 and 8 | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in body composition | Body composition will be assessed by electrical bioimpedance | Baseline and weeks 2, 4 and 8 | 
| Change in resting energy expenditure | Resting energy expenditure will be assessed by indirect calorimetry | Baseline and weeks 2, 4 and 8 | 
| Change in self-reported energy intake | Dietary energy intake will be assessed with 3-days food records | Baseline and weeks 2, 4 and 8 | 
| Change in self-reported diet composition | Dietary macronutrient intake will be assessed with 3-days food records | Baseline and weeks 2, 4 and 8 | 
| Change in self-reported intervention adherence | Adherence will be assessed by daily record of feeding hours | Baseline and weeks 2, 4 and 8 | 
| Change in metabolic profile | Fasting lipids, glucose and free fatty acids | Baseline and weeks 2, 4 and 8 | 
| Change in self-reported stress | Self-reported stress will be assessed by a questionnaire (Perceived Stress Scale). The total of the scale is a sum of scores of 14 questions. Total score can range from zero to 56. The higher the score, the higher the level of stress. | Baseline and weeks 2, 4 and 8 | 
| Change in self-reported anxiety | Self-reported anxiety will be assessed by a questionnaire (Beck Anxiety Inventory). The questionnaire consists of 21 items and the severity of each of them scored from 0 to 3. The degree of anxiety will be classified according to the final score obtained: 0-7 absent or minimum; 8-15 light; 16-25 moderate; 26-63 severe. | Baseline and weeks 2, 4 and 8 | 
| Change in self-reported depression | Self-reported depression will be assessed by a questionnaire (Beck Depression Inventory). The questionnaire consists of 21 items and the severity of each one scored from 0 to 3. The volunteers will be classified according to the score obtained: BDI ≤ 15: without depression; 16 ≤ BDI ≤ 20: dysphoria; BDI> 20: depression. | Baseline and weeks 2, 4 and 8 | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Obesity, Overweight, Weight loss, Fasting