Obesity
Conditions
Brief summary
Time-restricted feeding (TRF) is a novel type of intermittent fasting that involves eating within a daily period of 10 hours or less, followed by fasting for at least 14 hours daily. Several studies in rodents report that TRF reduces body weight, improves blood sugar control, and reduces the risk of cardiovascular disease-even when food intake is matched to the control group or no weight loss occurs. Preliminary evidence suggests that TRF may also increase weight loss, fat loss, and reduce the risk of diabetes and cardiovascular disease in humans. This study will test whether TRF enhances fat loss and increases weight loss in adults with obesity, relative to conventional dieting alone. In addition, this study will determine whether TRF reduces risk factors for type 2 diabetes and cardiovascular disease and will measure the feasibility and acceptability of TRF. In conjunction with the parent study described above, four ancillary studies will be conducted: 1. Effect of weight loss on nitrogen metabolism and bacteria in the mouth. The primary endpoints for this ancillary study are plasma and salivary nitrate and nitrite, and the secondary endpoints are salivary nitrate reductase activity and salivary bacterial abundance. 2. Effect of weight loss on several biomarkers related to kidney stones. The primary endpoint for this ancillary study is urinary oxalate, and the secondary endpoints are urinary citrate, chloride, sodium, potassium, calcium, phosphorus, uric acid, and creatinine. 3. Effect of meal timing on blood pressure regulation and kidney function. The primary endpoints of this ancillary study include urinary aldosterone excretion, sodium, potassium, and endothelin, whereas the secondary endpoints include nitric oxide and albumin. Additional exploratory endpoints include renal injury markers (KIM-1, nephrin, and urine albumin-to-creatinine ratio), measures of reactive oxidative stress (e.g., hydrogen peroxide and TBARs), and urinary exosomes. Urine will be analyzed in 12-hour bins to determine how meal timing affects differentially affects these endpoints during the daytime and nighttime. The effects of weight loss on these endpoints may also be considered. 4. Validation of a meal timing questionnaire to assess the distribution of food intake throughout the day.
Interventions
BEHAVIORALEarly Time-Restricted Feeding
Eat all meals between 7 am - 3 pm for an average of ≥6 days per week.
BEHAVIORALControl Schedule
Eat all meals over a 12-hour or longer period for an average of ≥6 days per week.
BEHAVIORALStructured Weight Loss Program
A structured weight loss program with physical activity recommendations and dietary counseling.
Sponsors
University of Alabama at Birmingham
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
NONE
Masking description
Statistical analyses will be performed blinded.
Eligibility
Sex/Gender
ALL
Age
25 Years to 75 Years
Healthy volunteers
Yes
Inclusion criteria
* Are a new patient at the UAB Weight Loss Medicine Clinic * Aged 25-75 years old * BMI between 30-60 kg/m2 (inclusive) * Weigh less than 450 lbs * Wake up regularly between 4-9 am on most days.
Exclusion criteria
* Diagnosed with diabetes, have an HbA1c of ≥6.5%, or are on diabetes medication * On weight loss medication * Addition of or withdrawal from a chronic medication within the past 10 weeks * Clinically significant laboratory abnormality (e.g., abnormal hemoglobin levels) * Significant gastrointestinal disease, major gastrointestinal surgery, or gallstones * Significant cardiovascular, renal, cardiac, liver, lung, adrenal, or nervous system disease that might compromise the participant's safety or data validity * Evidence of cancer (other than non-melanoma skin cancer) within the last 5 years * Unstable psychiatric, sleep, or circadian conditions (common conditions such as sleep apnea and depression are acceptable as long as they are stabilized and not rapidly worsening) * Lost or gained more than 5 lbs of weight in the past month * Currently perform overnight shift work more than once per week on average * Regularly eat within a less than 10-hour period each day * Regularly eat dinner before 6 pm * Traveled more than two time zones away in the two months prior to enrolling in the trial * Will travel more than one time zone away during the study * Pregnant or breastfeeding
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Fat loss and lean mass retention | 14 weeks | Percent of weight lost as fat, as measured by dual-energy X-ray absorptiometry (DXA). Lean mass retention will be quantified as 100% minus percent of weight lost as fat (i.e., is measured in the same units). |
| Weight loss | 14 weeks | Change in body weight (kg), as measured by scale weight |
| Absolute changes in body composition | 14 weeks | Changes in total fat mass, lean mass, bone mass, and regional values (kg), as measured by DXA. (This will be secondary to the assessment of fat loss and lean mass retention as specified above.) |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Lipids | 14 weeks | Total cholesterol (mg/dl), LDL cholesterol (mg/dl), HDL cholesterol (mg/dl), and triglycerides (mg/dl) |
| Blood pressure | 14 weeks | Systolic and diastolic blood pressure (mm Hg) |
| Fasting glucose | 14 weeks | Fasting glucose (mg/dl) |
| Waist circumference | 14 weeks | Waist circumference (cm) |
| Heart rate | 14 weeks | Heart rate in beats per minute |
| Fasting insulin | 14 weeks | Fasting insulin (IU/L) |
| HbA1c | 14 weeks | HbA1c (%) |
Other
| Measure | Time frame | Description |
|---|---|---|
| Adherence | 14 weeks | Self-reported adherence rate in days per week |
| Reasons for non-adherence | 14 weeks | Reasons for non-adherence, as measured by the daily adherence survey |
| Retention | 14 weeks | Attrition rate (%) |
| Depression | 14 weeks | Depression as measured by the Patient Health Questionnaire-9. (Each question is scored on a 0-3 scale, where 0 means Not at all and 3 means Nearly every day. Answers to each question are tallied to create a single composite score of depression from 0-27, with higher values meaning more depressive symptoms.) |
| Mood states | 14 weeks | Mood states as measured by the Profile of Mood States (a 5-point scale with 1 meaning Not at all and 5 meaning Extremely). This study is particularly interested in the scores for anxiety and related moods. |
| Chronotype | 14 weeks | Chronotype/mid-point of sleep (in clock time), as measured by the Munich Chronotype Questionnaire |
| Stimulant usage | 14 weeks | Stimulant usage, as measured by the Munich Chronotype Questionnaire (in servings per time) |
| Sleep duration | 14 weeks | Sleep duration, as measured by the Pittsburgh Sleep Quality Index |
| Sleep quality | 14 weeks | Sleep quality, as assessed by the Pittsburgh Sleep Quality Index (PQSI) (This study will use the Global PQSI score, which ranges from 0-21, where higher values correspond to worse sleep quality.) |
| Eating Behaviors | 14 weeks | Restrained, emotional, and external eating, as measured by the Dutch Eating Behavior Questionnaire. (Individual questions are scored on a 5-point scale ranging from Never to Very often, and composite scores for restrained, emotional, and external eating are tabulated, with higher numbers reflecting more of each trait.) |
| Loneliness | 14 weeks | Loneliness, as measured by the UCLA Loneliness Scale (a 3-point scale with 1 meaning hardly ever and 3 meaning often) |
| Intervention satisfaction | 14 weeks | Intervention satisfaction and barriers and facilitators of adherence, as measured by qualitative exit interview |
| Social life and daily habits | 14 weeks | Social life and daily habits, as measured by the frequency of occurrence of social activities (5- and 8-point rating scales) |
| Physical activity | 14 weeks | Physical activity status, as measured by the Baecke Physical Activity questionnaire |
| Plasma and salivary nitrate and nitrite | 14 weeks | Plasma and salivary nitrate and nitrite (nM) |
| Salivary nitrate reductase activity | 14 weeks | Salivary nitrate reductase activity (nmol / min / colony forming unit) in tongue swab samples |
| Salivary bacterial abundance | 14 weeks | Salivary bacterial abundance (colony forming units) in tongue swab samples |
| 24-hour urinary oxalate, citrate, sodium, calcium, chloride, potassium, and creatinine | 14 weeks | 24-hour urinary oxalate, citrate, sodium, calcium, chloride, potassium, and creatinine, as measured in mg/day |
| 24-hour urinary phosphorus and uric acid | 14 weeks | 24-hour urinary phosphorus and uric acid, as measured in g/day |
| 24-hour urinary aldosterone excretion | 14 weeks | 24-hour urinary aldosterone excretion (µg/12 hr) |
| 12-hour albumin-to-creatinine ratio | 14 weeks | 12-hour albumin-to-creatinine ratio |
| 12-hour urinary endothelin | 14 weeks | 12-hour urinary endothelin (ng/12 hr) |
| 12-hour urinary nitric oxide | 14 weeks | 12-hour urinary nitric oxide (mmol/12 hr) |
| 12-hour urinary albumin | 14 weeks | 12-hour urinary albumin (mg/12 hr) |
| 12-hour urinary KIM-1 | 14 weeks | 12-hour urinary KIM-1 (pg/g creatinine or pg/12 hr) |
| 12-hour urinary nephrin | 14 weeks | 12-hour urinary nephrin (ng/g creatinine or ng/12 hr) |
| 12-hour urinary reactive oxidative stress | 14 weeks | 12-hour urinary hydrogen peroxide and TBARs (µmol/g creatinine or µmol/12 hr) |
| Urinary exosomes | 14 weeks | Urinary exosomes (particles/ml) |
| 12-hour urinary sodium and potassium | 14 weeks | 12-hour urinary sodium and potassium (mmol/12 hr) |
| Appetite | 14 weeks | Hunger and fullness as measured by Likert (1-5 scale) and visual analog scales (a 0-100 scale, with 0 meaning Not at all and 100 meaning Extremely) |
| Food intake | 14 weeks | Energy intake and food intake in kcal/day, as measured using Remote Food Photography Method (RFPM) |
| Macronutrient intake | 14 weeks | % of calories as fat, carbohydrate, and protein, as measured using RFPM |
| Meal frequency | 14 weeks | Number of meals and snacks per day, as measured using RFPM |
| Meal times | 14 weeks | Clock times of meals and snacks, as measured using RFPM |
| Times of eating | 14 weeks | Start and stop times and mid-points of daily eating in clock time, as assessed by the daily adherence survey |
| Duration of daily eating | 14 weeks | Average duration of the daily eating period (hours), as measured by the daily adherence survey |
| Distribution of food intake across the daytime | 14 weeks | Distribution of calories eaten across the day in % per time period, as measured by a novel questionnaire that is being validated |
| Breakfast and nighttime eating habits | 14 weeks | Presence and degree of breakfast and nighttime eating, as measured by a novel questionnaire that is being validated |
Countries
United States
Outcome results
None listed