University of Surrey
Guildford, GU2 7XH, United Kingdom
Location status: Recruiting
Location contact
Dr Collins
CONTACT
Dr Collins
PRINCIPAL_INVESTIGATOR
Yana Petkova
CONTACT
Recruiting
NCT Number: NCT07314658
Time-restricted Eating (TRE) and Protein in Older Adults
The aim this study is to investigate the effects of time-restricted eating (TRE) on body composition, muscle function and markers of metabolic health of adults over 60 years old. This study will compare different variations of TRE - with and without an additional protein.
This study involves attending two study days at the University of Surrey for baseline and end-of-intervention measurement of body composition using a gold-standard dual energy x-ray absorptiometry (DEXA) scan; muscle function using hand grip strength and 30-second sit-to-stand tests; weight. A blood sample will be taken at each study visit to measure markers of lipid and glucose control, and insulin sensitivity.
Participants will be randomly allocated to one of four study groups:
* control group: maintain habitual dietary patterns * TRE group: fast for 16 hours overnight, eat between 12-8pm * TRE + Protein (AM): fast for 16 hours overnight, eat between 12-8pm; take a 30g plant-based protein supplement in the morning * TRE + Protein (PM): fast for 16 hours overnight, eat between 12-8pm; take a 30g plant-based protein supplement in the afternoon Participants will be asked to follow the intervention according to their allocated group for 8 weeks.
Recruiting
Interested in participating?
Request InfoKey information
Conditions
Age range
60 year and older
Sex eligibility
All sexes
Study type
Interventional
Phase
Not applicable
Primary location
Who can participate
Healthy volunteers accepted: Yes
Only the study team can determine whether someone qualifies for participation.
Inclusion criteria
- Gender: male and female
- Age range: 60 years or older
- Fasting for 12 or less hours on a daily basis
- BMI range: 23-30 kg/m2
- Weight stability: no more than 3kg weight gain or loss in the past 3 months
- Regular eating pattern, i.e. 3 meals a day
- Able to prepare the protein supplement
Exclusion criteria
- Any of the following present (in line with exclusion criteria used in previous TRE research in older adults):
- known renal impairment
- heart attack or stroke in the past three months
- continuous use of supplemental oxygen to manage a chronic pulmonary condition or heart failure
- rheumatoid arthritis
- Parkinson's disease
- active treatment for cancer in the past year
- insulin dependent diabetes mellitus
- taking medications that preclude fasting for 16 h
- actively trying or planning to lose weight
- history of an eating disorder
- outside of stated age or BMI range
- fasting for longer than 12 hours on a daily basis
- unable to prepare the protein supplement
- extreme morning/evening chronotype
- sleep disorders
- regular meal skipping
- history of difficulty having a blood sample taken
- Recent exposure to high-dose radiation
- Vigorous exercise on more than 3 occasions a week
Treatment and study plan
TRE
Other- Participants will be asked to follow a 16:8 TRE protocol, consuming all their daily within 8 hours, between 12 and 8pm, and fast for 16 hours overnight.
- Outside of the eating window, participants will be allowed to consume energy-free drinks only, i.e. water, black tea/coffee, 0-calorie soft drinks.
ProtAM TRE
Other- Participants will be asked to follow a 16:8 TRE protocol, consuming all their daily within 8 hours, between 12 and 8pm, and fast for 16 hours overnight.
- Outside of the eating window, participants will be allowed to consume energy-free drinks only, i.e. water, black tea/coffee, 0-calorie soft drinks.
- In addition, they will be asked to consume a protein drink containing 30g protein in the morning, 2 hours before the 8-hour eating window opens at 12pm (i.e. at 10am).
Other names: TRE + morning protein 'snack'
ProtPM TRE
Other- Participants will be asked to follow a 16:8 TRE protocol, consuming all their daily within 8 hours, between 12 and 8pm, and fast for 16 hours overnight.
- Outside of the eating window, participants will be allowed to consume energy-free drinks only, i.e. water, black tea/coffee, 0-calorie soft drinks.
- In addition, they will be asked to consume a protein drink containing 30g protein in the afternoon, either 2 hours after their first meal or 2 hours before their last meal of the day.
Other names: TRE + afternoon protein 'snack'
Primary outcomes
-
Change from baseline in body composition at 2 months using whole-body dual-energy x-ray absorptiometry (DEXA)
Time frame: For 8 weeks of the assigned study intervention
Measured using whole-body dual-energy x-ray absorptiometry (DEXA) In addition to the above, body composition will also be assessed using Tanita Bioelectrical impedance analysis (BIA). Fat free and fat mass will be reported in kg.
-
Change from baseline in muscle function at 2 months
Time frame: At the start and end of 8 weeks of the assigned study intervention
Measured using grip strength
-
Change from baseline in muscle function at 2 months
Time frame: At the start and end of 8 weeks of the assigned study intervention
Measured using 30-second sit-to-stand test.
Secondary outcomes
-
Change in fasting glucose control indicators
Time frame: At the start and end of 8 weeks of the assigned study intervention
HbA1c
-
Change from baseline in insulin sensitivity at 2 months
Time frame: At the start and end of 8 weeks of the assigned study intervention
HOMA-IR
-
Change from baseline in lipid metabolism at 2 months
Time frame: At the start and end of 8 weeks of the assigned study intervention
fasting total, LDL- and HDL cholesterol and triglyerides
-
Change from baseline in diet composition at 2 months
Time frame: At the start, mid-point (week 4) and end of 8 weeks of the assigned study intervention
Macro- and micronutrient analysis using the nutrition analysis platform Nutritics of 3-day food diaries administered at the start, mid-point and end of the assigned study intervention.
-
Feasibility of the assigned TRE intervention
Time frame: at the end of the 8 week intervention
semi-structured interviews
Study contacts
Contact information is provided by the study sponsor or research team.
Sponsors and collaborators
Lead sponsor
University of Surrey
Other
Registry information
Official study title
The Effects of Time-restricted Eating (TRE) With and Without Additional Protein on Body Composition, Muscle Function and Markers of Metabolic Health in Older Adults
Important dates
- Study start
- 2025
- Primary completion
- 2027
- Study completion
- 2027
- First posted
- Jan 2, 2026
- Registry last updated
- Jan 2, 2026
OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.
View the official ClinicalTrials.gov record (opens in a new tab)This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.