Effect of Time-Restricted Feeding on Fat Loss and Cardiometabolic Risk Factors in Overweight Adults

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.

Study Overview

• Status: Completed
• Conditions: Obesity
• Intervention / Treatment: Behavioral: Early Time-Restricted Feeding; Behavioral: Structured Weight Loss Program; Behavioral: Control Schedule

• Study Type: Interventional
• Enrollment (Actual): 90
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United States
  • Alabama
    • Birmingham, Alabama, United States, 35205
      • UAB Weight Loss Medicine Clinic

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 25 years to 75 years (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

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

Study Plan

How is the study designed?

Design Details

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

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Early Time-Restricted Feeding	Behavioral: Early Time-Restricted Feeding; Eat all meals between 7 am - 3 pm for an average of ≥6 days per week.; Other Names: Early TRF; eTRF; Behavioral: Structured Weight Loss Program; A structured weight loss program with physical activity recommendations and dietary counseling.
Active Comparator: Control Schedule	Behavioral: Structured Weight Loss Program; A structured weight loss program with physical activity recommendations and dietary counseling.; Behavioral: Control Schedule; Eat all meals over a 12-hour or longer period for an average of ≥6 days per week.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Fat loss and lean mass retention	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).	14 weeks
Weight loss	Change in body weight (kg), as measured by scale weight	14 weeks
Absolute changes in body composition	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.)	14 weeks

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Fasting glucose	Fasting glucose (mg/dl)	14 weeks
Fasting insulin	Fasting insulin (IU/L)	14 weeks
HbA1c	HbA1c (%)	14 weeks
Lipids	Total cholesterol (mg/dl), LDL cholesterol (mg/dl), HDL cholesterol (mg/dl), and triglycerides (mg/dl)	14 weeks
Blood pressure	Systolic and diastolic blood pressure (mm Hg)	14 weeks
Heart rate	Heart rate in beats per minute	14 weeks
Waist circumference	Waist circumference (cm)	14 weeks

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Appetite	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")	14 weeks
Food intake	Energy intake and food intake in kcal/day, as measured using Remote Food Photography Method (RFPM)	14 weeks
Macronutrient intake	% of calories as fat, carbohydrate, and protein, as measured using RFPM	14 weeks
Meal frequency	Number of meals and snacks per day, as measured using RFPM	14 weeks
Meal times	Clock times of meals and snacks, as measured using RFPM	14 weeks
Times of eating	Start and stop times and mid-points of daily eating in clock time, as assessed by the daily adherence survey	14 weeks
Duration of daily eating	Average duration of the daily eating period (hours), as measured by the daily adherence survey	14 weeks
Distribution of food intake across the daytime	Distribution of calories eaten across the day in % per time period, as measured by a novel questionnaire that is being validated	14 weeks
Breakfast and nighttime eating habits	Presence and degree of breakfast and nighttime eating, as measured by a novel questionnaire that is being validated	14 weeks
Adherence	Self-reported adherence rate in days per week	14 weeks
Reasons for non-adherence	Reasons for non-adherence, as measured by the daily adherence survey	14 weeks
Retention	Attrition rate (%)	14 weeks
Depression	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.)	14 weeks
Mood states	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.	14 weeks
Chronotype	Chronotype/mid-point of sleep (in clock time), as measured by the Munich Chronotype Questionnaire	14 weeks
Stimulant usage	Stimulant usage, as measured by the Munich Chronotype Questionnaire (in "servings" per time)	14 weeks
Sleep duration	Sleep duration, as measured by the Pittsburgh Sleep Quality Index	14 weeks
Sleep quality	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.)	14 weeks
Eating Behaviors	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.)	14 weeks
Loneliness	Loneliness, as measured by the UCLA Loneliness Scale (a 3-point scale with 1 meaning "hardly ever" and 3 meaning "often")	14 weeks
Intervention satisfaction	Intervention satisfaction and barriers and facilitators of adherence, as measured by qualitative exit interview	14 weeks
Social life and daily habits	Social life and daily habits, as measured by the frequency of occurrence of social activities (5- and 8-point rating scales)	14 weeks
Physical activity	Physical activity status, as measured by the Baecke Physical Activity questionnaire	14 weeks
Plasma and salivary nitrate and nitrite	Plasma and salivary nitrate and nitrite (nM)	14 weeks
Salivary nitrate reductase activity	Salivary nitrate reductase activity (nmol / min / colony forming unit) in tongue swab samples	14 weeks
Salivary bacterial abundance	Salivary bacterial abundance (colony forming units) in tongue swab samples	14 weeks
24-hour urinary oxalate, citrate, sodium, calcium, chloride, potassium, and creatinine	24-hour urinary oxalate, citrate, sodium, calcium, chloride, potassium, and creatinine, as measured in mg/day	14 weeks
24-hour urinary phosphorus and uric acid	24-hour urinary phosphorus and uric acid, as measured in g/day	14 weeks
24-hour urinary aldosterone excretion	24-hour urinary aldosterone excretion (µg/12 hr)	14 weeks
12-hour urinary sodium and potassium	12-hour urinary sodium and potassium (mmol/12 hr)	14 weeks
12-hour urinary endothelin	12-hour urinary endothelin (ng/12 hr)	14 weeks
12-hour urinary nitric oxide	12-hour urinary nitric oxide (mmol/12 hr)	14 weeks
12-hour urinary albumin	12-hour urinary albumin (mg/12 hr)	14 weeks
12-hour urinary KIM-1	12-hour urinary KIM-1 (pg/g creatinine or pg/12 hr)	14 weeks
12-hour urinary nephrin	12-hour urinary nephrin (ng/g creatinine or ng/12 hr)	14 weeks
12-hour albumin-to-creatinine ratio	12-hour albumin-to-creatinine ratio	14 weeks
12-hour urinary reactive oxidative stress	12-hour urinary hydrogen peroxide and TBARs (µmol/g creatinine or µmol/12 hr)	14 weeks
Urinary exosomes	Urinary exosomes (particles/ml)	14 weeks

Collaborators and Investigators

• Sponsor: University of Alabama at Birmingham
• Investigators: Principal Investigator: Courtney M Peterson, Ph.D., University of Alabama at Birmingham

Publications and helpful links

General Publications

• Allaf M, Elghazaly H, Mohamed OG, Fareen MFK, Zaman S, Salmasi AM, Tsilidis K, Dehghan A. Intermittent fasting for the prevention of cardiovascular disease. Cochrane Database Syst Rev. 2021 Jan 29;1(1):CD013496. doi: 10.1002/14651858.CD013496.pub2.
• Jamshed H, Steger FL, Bryan DR, Richman JS, Warriner AH, Hanick CJ, Martin CK, Salvy SJ, Peterson CM. Effectiveness of Early Time-Restricted Eating for Weight Loss, Fat Loss, and Cardiometabolic Health in Adults With Obesity: A Randomized Clinical Trial. JAMA Intern Med. 2022 Sep 1;182(9):953-962. doi: 10.1001/jamainternmed.2022.3050.

Study record dates

Study Major Dates

• Study Start (Actual): July 12, 2018
• Primary Completion (Actual): April 30, 2020
• Study Completion (Actual): April 30, 2020

Study Registration Dates

• First Submitted: February 14, 2018
• First Submitted That Met QC Criteria: March 2, 2018
• First Posted (Actual): March 9, 2018

Study Record Updates

• Last Update Posted (Actual): July 8, 2020
• Last Update Submitted That Met QC Criteria: July 6, 2020
• Last Verified: July 1, 2020

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Body Weight; Overweight
• Other Study ID Numbers: IRB-300001207

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No