TRE: Microbiome, Metabolic Health and Bone (TREMBO)

Time Restricted Eating on the Microbiome Affecting Metabolic Health and Bone in Older Women

In the Time-Restricted Eating: Microbiome and Bone (TREMBO) study, the primary goal is to determine the effect of time-restricted eating with caloric restriction compared to caloric restriction alone on bone health, as well as body weight and the gut microbiota in older women who are overweight or obese.

Study Overview

• Status: Completed
• Conditions: Weight Loss; Bone Loss; Time Restricted Feeding
• Intervention / Treatment: Behavioral: Time Restricted Eating (TRE); Behavioral: Calorie Restriction

Detailed Description

Time-restricted eating (TRE) has gained increased attention due to the possibility to induce weight loss and improve cardiometabolic health as a result of the purported alignment of circadian rhythm. However, since TRE is often reported to cause a spontaneous reduction of calories, it is not well understood if these health benefits are due to weight loss, circadian rhythm alignment, or a combination of the two. Furthermore, while weight loss can improve cardiometabolic health, it can also induce bone loss, which is problematic in older women who are at a higher risk of fracture. Interestingly, both bone turnover and the gut microbiota are responsive to diurnal variations, such as meal timing, and alterations in the gut microbiota have been associated with differences in bone health. In rodent models, caloric restriction can alter the gut microbiota composition with further alterations shown due to time-restricted eating. This suggests that time-restricted eating could affect bone health, which may be partially mediated by changes in the gut microbiota. Also, lifestyle patterns affects both the microbiota and bone. This randomized controlled trial will use behavior modification to examine TRE plus caloric restriction (CR) to achieve an evening energy deficit compared to CR alone on bone health, as well as body weight and the gut microbiota in older women who have overweight or obese.

• Study Type: Interventional
• Enrollment (Actual): 49
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United States
  • New Jersey
    • New Brunswick, New Jersey, United States, 08901
      • Rutgers University - NJ Inst Food Nutrition & Health

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 50 years to 79 years (Adult, Older Adult)
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• Postmenopausal women (>2 years since last menses)
• Body mass index (25-45 kg/m2)
• Agree to be randomly assigned to consume food for ≤ 9 hours/day or ≥12 hours/day
• Must attend on-site visits (about 10) in New Brunswick, NJ, USA (transportation/reimbursement for travel not included)

Exclusion Criteria:

• Participants with >5% weight loss in the past 6 months or extreme dietary/physical activity habits
• An inability to follow the experimental intervention or to perform the required specimen collections
• Antibiotic use in the past 2 months
• Current diagnosis, or history of cancer in past 3 years
• History of surgical procedure for weight loss in the past 3 years
• Current diagnosis or history of bone diseases, type I or II diabetes, gastrointestinal disease, hyperparathyroidism, untreated thyroid disease, significant immune, hepatic, cardiac, or renal disease
• Uncontrolled hypertension or hyperlipidemia in abnormal ranges
• Regular use of medications that affect bone metabolism, including bisphosphonates or hormone replacement.
• A colonoscopy within the past 2 months
• Alcohol or illicit drug abuse
• Current smoker or having quit smoking in the past 3 months
• Shift work
• Participation in another clinical research trial which may interfere with the results of this study.

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: Time restricted eating and calorie restriction; Subjects will be asked to adhere to a calorie-restricted diet and will be counseled by a dietitian for diet and lifestyle behavior education. In addition, they will be asked to only consume calories during a 9-hour window (15:9).	Behavioral: Time Restricted Eating (TRE); 9-hour eating window; Behavioral: Calorie Restriction; daily calorie restriction
Active Comparator: Calorie restriction alone; Subjects will be asked to adhere to a calorie-restricted diet and will be counseled by a dietitian for diet and lifestyle behavior education. They will be advised to continue to consume foods throughout the day and into the evening.	Behavioral: Calorie Restriction; daily calorie restriction

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Bone mineral density (BMD - hip)	dual energy x-ray absorptiometry	change from baseline to an average 6 months

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Weight loss	Body weight in kg	change from baseline to an average 6 months
Glucose - response to oral glucose tolerance test	fasting and response to glucose solution	change from baseline to an average 6 months
Insulin - response to oral glucose tolerance test	fasting and response to glucose solution	change from baseline to an average 6 months
Areal BMD (radius, lumbar spine)	dual energy x-ray absorptiometry	change from baseline to an average 6 months
Gut Microbiota	stool	change from baseline to an average 6 months
Soft tissues	dual energy x-ray absorptiometry (lean, fat mass, visceral adipose tissue)	change from baseline to an average 6 months
Trabecular bone	peripheral quantitative computed tomography (volumetric BMD, bone volume / total volume, and separation)	Change from baseline to an average 6 months
Cortical (Ct) bone	peripheral quantitative computed tomography (Ct volumetric BMD, Ct thickness and porosity, and total BMD)	change from baseline to an average 6 months

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
25-hydroxyvitamin D (25OHD)	serum	change from baseline to an average 6 months
estradiol	serum	change from baseline to an average 6 months
Fasting osteocalcin	serum bone formation and energy marker	change from baseline to an average 6 months
Fasting procollagen type 1 N-terminal propeptide (PINP)	serum bone formation marker	change from baseline to an average 6 months
Fasting C-telopeptide of type I collagen (CTX)	serum bone resorption marker	change from baseline to an average 6 months
melatonin	serum	change from baseline to an average 6 months
cortisol	serum	change from baseline to an average 6 months
Quality of sleep	Pittsburgh sleep quality index (0-21; higher score is worse)	change from baseline to an average 6 months
Diet quality score	nutrient analysis software (Healthy Eating Index 0-100; higher score is better)	change from baseline to an average 6 months
Eating self-efficacy	Weight lifestyle efficacy questionnaire short-form (0-80; higher score is better)	change from baseline to an average 6 months
Circumferences	tape measure (waist, hip and thigh)	change from baseline to an average 6 months
Short physical performance battery (SPPB)	Total score of SPPB (0-12; higher score is better)	change from baseline to an average 6 months
6 minute walk test	total distance	change from baseline to an average 6 months
Timed up and go	total time	change from baseline to an average 6 months
Hand Grip	dynanometer (isometric grip force)	change from baseline to an average 6 months
Total body bone	dual energy x-ray absorptiometry (BMD and BMC)	Change from baseline to an average 6 months
Blood pressure (BP)	sphygmomanometer (systolic and diastolic BP)	change from baseline to an average 6 months
Parathyroid hormone (PTH)	serum	change from baseline to an average 6 months
Cognitive function	Cambridge Neuropsychological Test Automated Battery (SOC, PAL, RTI, MTT)	change from baseline to an average 6 months
Biomarkers of brain health	Serum amyloid-beta (42,40) and tau markers (217, 181), BDNF, NfL	change from baseline to 6 months

Collaborators and Investigators

• Sponsor: Rutgers, The State University of New Jersey

Study record dates

Study Major Dates

• Study Start (Actual): October 15, 2022
• Primary Completion (Actual): August 15, 2024
• Study Completion (Actual): September 15, 2025

Study Registration Dates

• First Submitted: September 14, 2022
• First Submitted That Met QC Criteria: September 14, 2022
• First Posted (Actual): September 21, 2022

Study Record Updates

• Last Update Posted (Actual): April 13, 2026
• Last Update Submitted That Met QC Criteria: April 6, 2026
• Last Verified: April 1, 2026

More Information

Terms related to this study

• Keywords: Microbiome; bone mineral density; time restricted feeding; obesity and overweight; metabolic health; energy restriction
• Additional Relevant MeSH Terms: Bone Diseases; Musculoskeletal Diseases; Nutrition Disorders; Metabolic Diseases; Overnutrition; Body Weight; Body Weight Changes; Pathological Conditions, Signs and Symptoms; Behavior; Nutritional and Metabolic Diseases; Signs and Symptoms; Feeding Behavior; Fasting; Overweight; Obesity; Weight Loss; Bone Diseases, Metabolic; Intermittent Fasting; Therapeutics; Diet, Food, and Nutrition; Physiological Phenomena; Nutritional Physiological Phenomena; Diet Therapy; Nutrition Therapy; Diet; Energy Intake; Caloric Restriction
• Other Study ID Numbers: Pro2021002434

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

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