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Overweight and Obese AdultsNCT07781410

Role of Leucine on Muscle Preservation During Weight Loss in Older Men

A study testing Protein and Leucine in people with Overweight and Obese Adults and BMI>=23 kg/m2, run by Nanyang Technological University at 1 site in Singapore.

Completed

Finished. The study has ended and is not enrolling. Results may be posted on the official record.

Official record
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Trial summary

Overweight and obesity are part of a global health epidemic. However, older adults trying to lose weight face a dual challenge: first, muscle mass and strength naturally decline at an accelerating rate with age; second, effective weight loss diets like alternate-day fasting (ADF) are typically accompanied by… Read more about this study

Who is it for?
Ages 60 years and older, men only
Conditions the study is for
Overweight and Obese Adults, BMI>=23 kg/m2
What is being tested?
Protein and Leucine
Could I receive a placebo?
Yes, some participants may receive a placebo
How many people
80 participants
Where
1 siteSingapore
Study dates
14 Nov 2022to 20 Jun 2023
Phase
Interventional
Are there results?
None posted in the registry

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

  • Ages 60 years and older
  • Men only
  • No healthy volunteers
  • Adult, Older adult

Who may be able to join

  • Of Asian descent
  • Do not smoke or use tobacco products (including shisha)
  • Have a body mass index (BMI = body mass in kilograms divided by the square of height in metres) ≥ 23 kg/m2

Who cannot join

  • Unable to adhere to the requirements regarding physical activity and diet as stated in the research methodologies. All supplements; including but not limited to vitamins, minerals, amino acids and proteins; which are not provided by this research, and traditional Chinese medicine are not allowed.
  • Vegetarians or vegans due to potential differences in responses and that the supplements provided may contain dairy products.
  • Allergic or intolerant to milk. The supplement that you will be required to consume may contain milk proteins, and lactose (milk sugar).
  • Failed an exercise stress test.
  • Have any health condition(s) that would be made worse by fasting.
  • History of familial leucine-sensitive hypoglycaemia, i.e., highly symptomatic hypoglycaemia triggered by protein meals or the amino acid, leucine.
Show all 14Show fewer
  • Have diabetes, pre-diabetes, or abnormally high fasting blood glucose (> 6.0 mmol/L).
  • Have uncontrolled hypertension (≥ 150/90 mmHg for ≥ 80 years old, ≥ 140/90 mmHg for < 80 years old).
  • Have liver or kidney conditions.
  • Have existing musculoskeletal conditions that could be exacerbated by the physical assessments in this study.
  • More than twice per week of regular and structured resistance training (lifting weights).
  • Competed in resistance exercise-related competitions in the past 6 months.
  • Taking long-term prescribed medications (including traditional Chinese medicine and other alternative medicine), drugs, steroids, or hormones that can affect any of the measurements in this study.
  • Have electrical implant (such as pacemaker, implantable cardioverter defibrillator or neurostimulator), metal or plastic implant/rod/plate, or joint replacement in the body as these objects can affect the accuracy of the body composition measurement.

Trial locations and contacts

1 site in 1 country.

Singapore1 site
  • Nanyang Technological University

    Singapore

Other trials in Singapore

About this study

Overweight and obesity are part of a global health epidemic. However, older adults trying to lose weight face a dual challenge: first, muscle mass and strength naturally decline at an accelerating rate with age; second, effective weight loss diets like alternate-day fasting (ADF) are typically accompanied by significant muscle loss. Together, these factors can increase the risk of developing sarcopenia, a muscle disease characterized by critical losses in muscle mass and strength, especially when overweight or obese older adults try to lose weight through dieting alone. While high protein diets have often been advocated as a muscle preserving strategy when losing weight, recently, high leucine intake has been promoted for its critical role in stimulating muscle protein synthesis (MPS) with lower overall protein consumption, potentially reducing calorie intake while maintaining muscle during weight loss. Nonetheless, the effects of body mass-scaled protein and leucine intakes on muscular outcomes during weight loss remain uncertain. This study examines the effects of body mass-scaled protein and leucine supplementation on body composition during four weeks of ADF in older men.

Read the detailed description

Participation in this study requires a total of 4 weeks of alternate day fasting (ADF) and 3 laboratory visits (sessions) spread over 5-6 weeks. All sessions are done in a fasted and rested state. Participants will complete 4 weeks of ADF alternating between ad libitum feeding days and fasting days consisting of a small midday meal of up to 600 kcal. Supplements will be provided to participants (3 servings on feeding days and 1 serving on fasting day).

Prior to each session, participants are required to:

  • Abstain from any physical activity except activities of daily living for at least 48 hours.
  • Abstain from alcohol and caffeine for at least 24 hours.
  • Fast (i.e., do not eat or drink except plain water) overnight for 10 hours. In consideration of the fasting, these sessions will take place in the morning. To control for diurnal variation, the sessions will be timed such that the same measurements will be taken at approximately the same time of the day (+/- 1 hour difference).
  • Obtain a full night of sleep the night before.

Session 1

  • Read and sign consent form
  • Pre-screening:
  • Subject screening questionnaire
  • Global Physical Activity Questionnaire
  • Body mass
  • Height
  • Resting blood pressure and heart rate
  • Fasting blood glucose (via finger prick)

Session 2 The 4-week alternate-day fasting programme will start within 14 days from session 1

  • Collection of 4 weeks of supplements
  • Body mass
  • Height
  • Resting blood pressure and heart rate
  • Fasting blood glucose (via finger prick)
  • Waist and hip circumference measurements
  • Body composition using bioelectrical impedance analysis and dual-energy X-ray absorptiometry
  • Handgrip strength test
  • Gait speed test
  • Short physical performance battery
  • Complete questionnaires on food craving, mood, appetite, hunger, satiety, diet satisfaction, and cognitive function
  • Blood sample from forearm (35 ml)

Session 3 28 days (4 weeks) after the start of alternate-day fasting

  • Same as session 2 except collection of supplements (not applicable)
Being tested
Placebo, Protein, Leucine
Keywords
Overweight, Obese, Intermittent Fasting, Alternate Day Fasting, Protein, Leucine, Skeletal muscle, muscle, blood health, mood, appetite, food craving
Medical subject headings
Overweight, Obesity, Intermittent Fasting

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • PlaceboDietary supplement

    Control (placebo supplements) 0.0 g/kg protein and 0.0 g/kg leucine supplementation per meal

  • ProteinDietary supplement

    Protein supplements: 0.4 g/kg protein and 0.04 g/kg leucine supplementation per meal

  • LeucineDietary supplement

    Leucine supplementation: 0.0 g/kg protein and 0.08 g/kg leucine supplementation per meal

Study groups in NCT07781410
Study groupRoleWhat they receive
ControlPlacebo comparator0.0 g/kg protein and 0.0 g/kg leucine supplementation per meal
Receives: Dietary Supplement: Placebo
ProteinExperimental0.4 g/kg protein and 0.04 g/kg leucine supplementation per meal
Receives: Dietary Supplement: Protein
LeucineExperimental0.0 g/kg protein and 0.08 g/kg leucine supplementation per meal
Receives: Dietary Supplement: Leucine

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Body Mass

    Measured: Start and end of 4-week intervention

  2. Lean Mass

    Measured: Start and end of 4-week intervention

  3. Appendicular Lean Mass

    Sum of lean mass in upper and lower limbs

    Measured: Start and end of 4-week intervention

  4. Body mass index

    body mass in kilograms divided by square of height in metres

    Measured: Start and end of 4-week intervention

  5. Lean mass index

    lean mass in kilograms divided by square of height in metres

    Measured: Start and end of 4-week intervention

  6. Appendicular lean mass index

    Appendicular lean mass in kilograms divided by square of height in metres

    Measured: Start and end of 4-week intervention

  7. Fat mass

    Measured: Start and end of 4-week intervention

  8. Percentage body fat

    Measured: Start and end of 4-week intervention

  9. Fat mass index

    Fat mass in kilograms divided by square of height in metres

    Measured: Start and end of 4-week intervention

  10. Trunk fat

    Fat mass around the trunk

    Measured: Start and end of 4-week intervention

  11. Appendicular fat mass

    Sum of fat mass in the upper and lower limbs

    Measured: Start and end of 4-week intervention

  12. Appendicular fat mass index

    Appendicular fat mass in kilograms divided by square of height in metres

    Measured: Start and end of 4-week intervention

  13. Resting systolic blood pressure

    Measured: Start and end of 4-week intervention

  14. Resting diastolic blood pressure

    Measured: Start and end of 4-week intervention

  15. Fasting blood glucose

    Measured: Start and end of 4-week intervention

  16. HbA1c

    Measured: Start and end of 4-week intervention

  17. Insulin

    Measured: Start and end of 4-week intervention

  18. HOMA-IR

    Measured: Start and end of 4-week intervention

  19. Total cholesterol

    Measured: Start and end of 4-week intervention

  20. HDL cholesterol

    Measured: Start and end of 4-week intervention

  21. LDL cholesterol

    Measured: Start and end of 4-week intervention

  22. Total cholesterol to HDL cholesterol ration

    Measured: Start and end of 4-week intervention

  23. Triglycerides

    Measured: Start and end of 4-week intervention

Secondary outcomes (30)
  1. Android fat

    fat around stomach

    Measured: Start and end of 4-week intervention

  2. Gynoid fat

    fat around hips and mid section

    Measured: Start and end of 4-week intervention

  3. Bone mineral content

    Measured: Start and end of 4-week intervention

  4. bone mineral density

    Measured: Start and end of 4-week intervention

  5. Waist Circumference

    Measured: Start and end of 4-week intervention

  6. Hip circumference

    Measured: Start and end of 4-week intervention

  7. Waist-to-hip ratio

    Measured: Start and end of 4-week intervention

  8. Fat free mass

    Fat free mass measured using BIA

    Measured: Start and end of 4-week intervention

  9. Skeletal muscle mass

    Skeletal muscle mass measured using BIA

    Measured: Start and end of 4-week intervention

  10. Appendicular fat-free mass

    Sum of fat free mass in upper and lower limbs measured using BIA

    Measured: Start and end of 4-week intervention

  11. Visceral fat area

    Visceral fat area measured using BIA

    Measured: Start and end of 4-week intervention

  12. Fat-free mass index

    Fat-free mass in kilograms divided by square of height in metres

    Measured: Start and end of 4-week intervention

  13. Skeletal muscle mass index

    Skeletal muscle mass in kilograms divided by square of height in metres

    Measured: Start and end of 4-week intervention

  14. Appendicular fat-free mass index

    Appendicular fat-free mass in kilograms divided by square of height in metres

    Measured: Start and end of 4-week intervention

  15. Insulin growth factor-1

    Measured: Start and end of 4-week intervention

  16. Mood

    Brunel Mood Scale (BRUMS). BRUMS is the modified and shorter version of the Profile of Mood Stats (POMS). The 24-item BRUMS was used to assess mood responses. It has six subscales (tension, depression, anger, vigour, fatigue, and confusion) of four mood descriptors each, with respondents rating how they feel "right now" on a 5-point Likert-type scale (0 = not at all, 1 = a little, 2 = moderately, 3 = quite a bit; 4 = extremely). During its development, the BRUMS showed robust psychometric properties across samples of adult students, adult athletes, young athletes, and schoolchildren, and has since demonstrated psychometric integrity for use with many other population groups (doi.org/10.3390/su13116116).For each subscale, the raw score are summed and converted to a T-score based on the norms published in the paper (doi.org/10.3390/su13116116). Higher T-score for each subscale reflects higher profile of that subscale (i.e. tension, depression, anger, vigour, fatigue, or confusion).

    Measured: Start and end of 4-week intervention

  17. Food craving - habitual

    The Food Craving Questionnaire-Trait Reduced (FCQ-T-r) measures the habitual (unspecified time frame) trait craving for food in general. It predicts food cravings in daily life. It represents a stable trait but is also sensitive to changes in eating behaviour. The questionnaire consists of 15 questions, participants are required to rate the frequency of each statement with a 6-likert scale (never or not applicable = 1, to always = 6). By summing up the scores of the scales, higher scores represent higher level of food cravings.

    Measured: Start and end of 4-week intervention

  18. Food craving - specific foods

    Food Craving Inventory (FCI) measures food craving for specific foods and the versions validated for use in United States and United Kingdom were used. Questionnaire items pertaining to specific local foods were also added for a combined total of 61 food items (i.e. questionnaire items). For each item, participants were asked how often they have experienced a craving for that particular food on a 5-point Likert scale (never = 1, to always/almost every day = 5). The higher the score, the higher the food craving.

    Measured: Start and end of 4-week intervention

  19. Eating Behaviour

    Three-Factor Eating Questionnaire-R18 - cognitive restraint component (TFEQ-r18 Cog). It has 6 items and each scored 1 to 4 for a total of 24 points. The higher the total score, the more disordered the eating behaviour.

    Measured: Start and end of 4-week intervention

  20. Hunger over past 4 weeks

    Hunger over past 4 weeks. Visual analogue scale 0 to 100. The higher the number the greater the amount of hunger.

    Measured: Start and end of 4-week intervention

  21. Baseline appetite

    Baseline appetite using visual analogue scale 0 to 100. The higher the score, the higher the baseline appetite

    Measured: Start and end of 4-week intervention upon arrival in the laboratory

  22. Satiety over past 4 weeks

    Satiety over past 4 weeks. Visual analogue scale 0 to 100. The higher the number, the greater amount of satiety.

    Measured: Start and end of 4-week intervention

  23. Diet satisfaction over past 4 weeks

    Diet satisfaction over past 4 weeks. Visual analogue scale 0 to 100. The higher the number the greater the satisfaction.

    Measured: Start and end of 4-week intervention

  24. Implicit satiety goal

    mplicit satiety goal (unconscious, habitual, or subjective levels of fullness that individuals aim to achieve when eating) using visual analogue scale 0 to 100. The higher the number, the greater implicit satiety goal.

    Measured: Start and end of 4-week intervention

  25. Ideal portion size

    Ideal portion size (IPS). Participants were presented with a diverse range of 25 foods typically consumed in Singapore. The computerised portion selection tasks presented a series of 50 images of each food that increased in portion size in 20 kcal increments (20-1000 kcal). Participants could increase or decrease the portion size by 20 kcal using the left and right arrow-keys on the keyboard and were encouraged to view the full range of portions before selecting their ideal portion. Foods were presented in a randomised order and an average portion size for each participant was calculated by averaging the selected portion sizes of all 25 foods (α = 0.95). This created an overall index of IPS.

    Measured: Start and end of 4-week intervention

  26. Expected satiety

    Expected satiety (ES) measured using computerised task. The ES task followed the same format as the IPS task, in other words, 50 images were presented depicting 20 kcal increment changes in portion size. This task sought to measure participants' expectations about how satiating a diverse range of foods were. Larger portions selected indicated that participants require larger quantities of the food to delay the onset of hunger, in other words they have lower expected satiety. The same 25 foods presented in the IPS were also presented in the ES in a randomised order and were averaged to create an overall index of ES (α = 0.95).

    Measured: Start and end of 4-week intervention

  27. Food-related characteristics

    A single image of each food item was presented to participants alongside questions of food-related characteristics. Participants were asked to rate how filling they expected each food to be (not filling at all (0) to very filling (100)), how much they like each food in general (not at all (0) to very much (100)) and how often they eat each food (never (0) to more than once a week (5)). Each food was presented in a randomised order and average scores across all 25 foods for participants perceptions of how filling, frequently consumed and preference for foods were calculated.

    Measured: Start and end of 4-week intervention

  28. Handgrip strength

    Measurement of handgrip strength using a handheld dynamometer

    Measured: Start and end of 4-week intervention

  29. Short physical performance battery

    Standardised physical performance test

    Measured: Start and end of 4-week intervention

  30. 6m gait speed

    Gait speed over 6m

    Measured: Start and end of 4-week intervention

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted24 Aug 2026
  2. Study start14 Nov 2022
  3. Primary completion20 Jun 2023
  4. Study completion20 Jun 2023

Resources

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design
Study type
Interventional
Phase
Phase N/A
Primary purpose
Treatment
Allocation
Randomised
Intervention model
Parallel groups
Model description
Three-arm, double-blind, randomized controlled trial
Masking
Quadruple blind
Who is masked
Participant, Care provider, Investigator, Outcomes assessor
Enrolment
80 participants (actual)
IDs, dates and publications
ClinicalTrials.gov ID
NCT07781410
Sponsor's protocol ID
IRB-2022-090
Status last verified
Aug 2026
First submitted
17 Aug 2026
Last updated
24 Aug 2026
Results posted
No
Data monitoring committee
Yes
FDA-regulated drug
No
FDA-regulated device
No
Individual data sharing
Yes: Individual participant data (IPD) will be made available to qualified researchers upon request. To access the data, researchers must submit a formal request, which will be reviewed and approved by the data sharing committee. Data access will be granted for research purposes only and will require adherence to data use agreements and ethics guidelines.

Questions about this trial

What is this clinical trial studying?

A study testing Protein and Leucine in people with Overweight and Obese Adults and BMI>=23 kg/m2, run by Nanyang Technological University at 1 site in Singapore.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 3 inclusion and 14 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: finished, as of the sponsor's last update on 24 Aug 2026. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 1 site in Singapore. Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. Some participants in this study may receive a placebo. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

Are results available for this study?

The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.

How can a doctor refer a patient or contact the research team?

The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Body Mass (time frame: Start and end of 4-week intervention). The study lists 23 primary outcomes in all. It is what the study was designed to measure, not a finding.

Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 24 Aug 2026.

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