Intermittent Fasting, Obesity, Overweight and Obesity, Time Restricted Feeding
Conditions
Brief summary
Time-restricted eating (TRE) is a dietary approach that aims to increase fasting time and decrease the eating window. Promising TRE effects on weight loss and some cardiometabolic risk factors have been reported. However, there is a lack of randomized clinical trials that directly investigate the effect of TRE at different times of the day (early vs. delayed) in individuals with overweight and obesity. The present study investigates the effects of 8 weeks of TRE performed at different moments of the day on body composition and cardiometabolic parameters in adults with overweight and obesity.
Interventions
BEHAVIORALDietary Approach
Dietary approaches with energy restriction performed at different times of the day.
Sponsors
Federal University of Rio Grande do Sul
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
SINGLE (Outcomes Assessor)
Eligibility
Sex/Gender
ALL
Age
20 Years to 40 Years
Healthy volunteers
Yes
Inclusion criteria
* Male and female; * Body mass index (BMI) between 25 and 34.9 kg/m²; * Age between 20 and 40 years; * Not engaged in any structured exercise program; * Weight stable for \ 3 months prior to the beginning of the study; * Able to give written informed consent.
Exclusion criteria
* Current smoker; * Cardiometabolic diseases (dyslipidemia, diabetes, hypertension, etc); * Current treatment with medication or supplements which significantly affect the main studied variables; * Night-shift workers; * Night eating syndrome; * Irregular sleep patterns; * For women: pregnancy, planned pregnancy (within the study period), lactating or menopause; * Habitual fasting window \>16 hours; * Concomitant participation in other studies.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Insulin resistance (indices) | Change from baseline. Measured at baseline and after 8 weeks. | Including but not limited to Homeostatic Model Assessment for Insulin Resistance (HOMA-IR). |
| Fasting insulin levels (µIU/mL) | Change from baseline. Measured at baseline and after 8 weeks. | Measured by enzyme-Linked Immunosorbent Assay |
| Fasting glucose levels (mg/dL) | Change from baseline. Measured at baseline and after 8 weeks. | Measured by colorimetric method |
| Insulin Sensitivity (indices) | Change from baseline. Measured at baseline and after 8 weeks. | Including but not limited to the Matsuda index |
| Glucose tolerance | Change from baseline. Measured at baseline and after 8 weeks. | Measured by oral glucose tolerance test (OGTT; 0,30,60,90, and 120 min) |
| Fasting lipid profile levels (mg/dL) | Change from baseline. Measured at baseline and after 8 weeks. | Measured by colorimetric method |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Body Mass Index (kg/m^2) | Change from baseline. Measured at baseline and after 8 weeks. | Calculated from weight in kilograms divided by height in meters squared. |
| Fasting ketones (β-hydroxybutyrate) levels (mmol/L) | Change from baseline. Measured at baseline and after 8 weeks. | — |
| Resting metabolic rate (Kcal/day) | Change from baseline. Measured at baseline and after 8 weeks. | Measured by indirect calorimetry under resting and fasting conditions. |
| Substrate Oxidation (respiratory exchange ratio) | Change from baseline. Measured at baseline and after 8 weeks. | Measured by indirect calorimetry under resting and fasting conditions. |
| β cell function (indices) | Change from baseline. Measured at baseline and after 8 weeks. | Including but not limited to HOMA-BETA |
| Quality of sleep | Change from baseline. Measured at baseline and after 8 weeks. | Measured by Pittsburgh Sleep Quality Index Questionnaire. Higher scores indicate worse sleep quality. |
| Risk of binge eating | Change from baseline. Measured at baseline and after 8 weeks. | Measured by binge eating scale. Higher scores indicate greater risk of binge eating. |
| Subjective appetite parameters (hunger, fullness, prospective food consumption, and desire to eat). | Change from baseline. Measured at baseline and after 8 weeks. | Measured by visual analog scale.The scale range is 0-100 mm and each end represent the extremes. |
| Peak oxygen consumption (mL/min and mL/kg/min) | Change from baseline. Measured at baseline and after 8 weeks. | Measured by an open-circuit spirometry system |
| Fat Mass (kg) | Change from baseline. Measured at baseline and after 8 weeks. | Measured by Dual-energy X-ray Absorptiometry under fasting condition. |
| Fat Percentage (%) | Change from baseline. Measured at baseline and after 8 weeks. | Measured by Dual-energy X-ray Absorptiometry under fasting condition. |
| Fat Free Mass (kg) | Change from baseline. Measured at baseline and after 8 weeks. | Measured by Dual-energy X-ray Absorptiometry under fasting condition. |
| Body Weight (kg) | Change from baseline. Measured at baseline and after 8 weeks. | Measured by Dual-energy X-ray Absorptiometry under fasting condition. |
| Bone Mineral Content (kg) | Change from baseline. Measured at baseline and after 8 weeks. | Measured by Dual-energy X-ray Absorptiometry under fasting condition. |
Countries
Brazil
Outcome results
None listed