Energy BalanceCarpe DIEMNCT07122778
Impact of Diet-induced Change in Energy Balance on Metabolism in Endurance Athletes
A study testing Habitual diet with surplus snacks in people with Energy Balance and Energy Deficit, run by University of Bath at 1 site in United Kingdom.
Trial summary
Recent research has suggested that increasing levels of physical activity are associated with a reduction in the independent components that contribute to total energy expenditure (such as resting metabolic rate and non-exercise movement) - this occurs to conserve energy required for physical activity where energy… Read more about this study
- Who is it for?
- Ages 18 to 49 yearsHealthy volunteers can take part
- Conditions the study is for
- Energy Balance, Energy Deficit, Low Energy Availability
- What is being tested?
- Habitual diet with surplus snacks
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 20 participants
- Where
- 1 siteUnited Kingdom
- Study dates
- Aug 2025to May 2027
- Phase
- Interventional
- Are there results?
- Not yet: the study is under way
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 18 to 49 years
- All sexes
- Healthy volunteers accepted
- Adult
Who may be able to join
- Self-identified endurance-trained sport participants
- Training volume: >7 hours per week endurance training
- Training frequency: at least 5 days per week
Who cannot join
- Diagnosis of Relative Energy Deficiency in Sport (REDs)
- Active eating disorder (EDE-Q)
- Active flare of a chronic disease (e.g. inflammatory bowel disease)
- Type 1 or 2 diabetes mellitus
- Untreated or undergoing active treatment of anaemia (any cause)
- Current injury which precludes undertaking high volume endurance training
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- Individuals following a habitual low-carbohydrate, high-fat diet
- Any medical diagnosis which precludes intense exercise (e.g. untreated cardiac arrhythmia)
- Allergy or intolerance to study foods
- Blood donation within preceding 8 weeks of study start date
- Use of medications that affect substrate utilisation (e.g. statins, corticosteroids, thyroxine, HRT)
- For females: current pregnancy, breastfeeding within past 6 months or post-menopausal
- Unable to undertake a treadmill running test
- Participation in any research study in the past 8 weeks
- Participation in a research study within the past year involving more than one DEXA scan
- Unable to provide informed consent due to impaired cognitive capacity or decision-making ability
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
United Kingdom1 site
University of Bath
Bath, BA2 7AY
Joshua J Bakker-Dyos, +447740191473, jbd28@bath.ac.uk
About this study
Official title: Impact of Diet-induced Change in Energy Balance on Metabolism in Endurance Athletes: the Carpe DIEM Study
Recent research has suggested that increasing levels of physical activity are associated with a reduction in the independent components that contribute to total energy expenditure (such as resting metabolic rate and non-exercise movement) - this occurs to conserve energy required for physical activity where energy provision becomes scarce. There are potential deleterious health and performance consequences of a reduced energy supply to fundamental metabolic processes, putting individuals regularly undertaking high levels of physical activity, such as endurance athletes, at risk. However, this association is largely based on observational data in only moderately active populations, and it is currently unclear what role energy balance status and biological sex has on this relationship.
This research intends to address these unknowns by assessing the impact of diet-induced manipulation of energy balance (conditions of energy deficit and energy surplus) in individuals undertaking habitually high levels of physical activity on independent components of total energy expenditure (resting metabolism, exercise and non-exercise movement).
Male and female athletes conducting regular moderate-to-high training volumes will undertake a randomised crossover study with a 7-day state of energy deficit and a 7-day state of energy surplus. Participants will continue to live and train as normal, but their diet will be controlled by specific food provision over the intervention periods in order to facilitate both conditions. Independent components of energy expenditure, markers of health, metabolism and performance will be measured to allow for comparison of conditions.
Read the detailed description
People with very active lifestyles such as athletes, dancers, and military personnel, need to eat a lot of food to make up for the large amount of energy they burn. If they don't match their food intake to their energy needs, they may enter a state of 'energy deficit'. This means their bodies are burning more calories than they're taking in, which can lower performance, increase the risk of injuries and illnesses, and potentially harm overall health.
Traditional scientific understanding assumes that more doing physically activity leads to burning more calories (the 'additive' model). However, newer studies suggest that the body might have built-in safeguards to limit how many total calories it burns, no matter how much a person exercises. This idea (the 'constrained' model) proposes that when people exercise more, their bodies might compensate by slowing down other metabolic processes to keep overall energy use within a certain range. Although this mechanism could help the body conserve energy, it may also mean that essential functions (like immune system support and reproductive function) can become impaired.
Most research on energy deficit so far has focused on people with normal or moderate levels of physical activity. Because extremely active people experience far higher daily energy demands, the 'constrained' mechanisms could manifest differently or to a greater degree and the negative health and performance consequences might be more severe. There is also limited knowledge about how quickly these changes in energy use begin and how they affect important processes at the cellular level, such as muscle mitochondrial function or immune cell health.
This study aims to fill these gaps by measuring total energy use (and its separate parts) in highly active individuals under two conditions: when participants eat enough to cover their energy demands and when participants are purposely in an energy deficit (intentionally eating less than they need). One of our main goals is to measure changes in resting metabolic rate (RMR), which is the energy the body uses at rest to keep vital functions going. Investigators will also examine cellular changes by looking at indicators like immune cell function to see how these might help us detect early signs of harmful energy shortages.
By understanding whether, and to what extent, the body's energy use is 'constrained', investigators can develop better guidelines to help very active individuals avoid unhealthy energy deficits. Ultimately, this research could improve both performance and long-term health for athletes, military personnel, dancers, and anyone else who regularly exercises at high levels.
- Conditions
- Energy Balance, Energy Deficit, Low Energy Availability, Relative Energy Deficiency in Sport
- Being tested
- Controlled energy-deficit diet, Habitual diet with surplus snacks
- Keywords
- energy deficit, energy balance, energy availability, physical activity
- Medical subject headings
- Relative Energy Deficiency in Sport, Motor Activity
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Controlled energy-deficit dietDietary supplement
Also called Energy deficit
Participants receive a prepared diet providing approximately 50% of their estimated daily energy expenditure to induce a sustained energy deficit
Habitual diet with surplus snacksDietary supplement
Also called Energy surplus
Participants continue their normal diet with the addition of high-calorie snack items to achieve an approximate daily energy surplus
| Study group | Role | What they receive |
|---|---|---|
| Energy deficit | Experimental | Diet-induced 50% energy deficit (based on estimated average total daily energy expenditure) by allocation of pre-made meals and snacks over 7-days Receives: Dietary Supplement: Controlled energy-deficit diet |
| Energy surplus | Experimental | Diet-induced energy surplus (approximately 500-1000kcal/day) achieved by allocation of additional snacks to be consumed on top of habitual free-living diet, to avoid inadvertent energy deficit Receives: Dietary Supplement: Habitual diet with surplus snacks |
What is being measured
The primary outcome is the main question the study is designed to answer.
Resting metabolic rate (RMR) in kcal/day
The effect of a 7-day period of energy expenditure-matched diet-induced energy deficit versus energy surplus on RMR. Measured via indirect calorimetry using the Douglas bag method. Expired gas will be collected in a seated, fasted state under thermoneutral conditions, and oxygen consumption and carbon dioxide production will be used to calculate energy expenditure.
Measured: Measured at lab visits 1-5 (baseline and pre- and post-interventions) from 0 to 12 weeks.
Secondary outcomes (36)
Total energy expenditure (from doubly labelled water) in kcal/day
Measured: Measured during both 7-day interventions starting at approximately week 4 and week 9.
Total energy expenditure ( from sum of independent components of energy expenditure) in kcal/day
Measured: Measured during both 7-day interventions starting at approximately week 4 and week 9
Peripheral blood mononuclear cell (PBMC) mitochondrial respiration
Assessment of mitochondrial respiratory function in isolated PBMCs using high-resolution respirometry (Oroboros). Measures include basal (routine), leak, oxidative phosphorylation (OXPHOS), and electron transfer system (ETS) capacity states. Data will be used to assess changes in mitochondrial function in response to exercise and nutritional intervention. Units: pmol O₂·s-¹·10⁶ cells-¹ (picomoles of oxygen consumed per second per million PBMCs).
Measured: Measured pre- and post-exercise at visits 2/3 (pre- and post-intervention 1) and visits 4/5 (pre- and post-intervention 2), approximately weeks 4-12.
Sub-maximal exercise performance (during steady-state treadmill exercise)
Running economy (oxygen consumption at a fixed submaximal speed, expressed as ml O₂·kg-¹·min-¹)
Measured: Measured at lab visits 1-5 (baseline and pre- and post-interventions) from 0 to 12 weeks.
Free T3 in pmol/L
Measured: Measured at lab visits 2-5 (pre- and post-interventions) from 4 to 12 weeks.
Interstitial glucose concentration in mmol/l
Continuous glucose monitoring using Dexcom G7 reporting mean daily and daily variability in interstitial glucose concentration.
Measured: Measured during both 7-day interventions starting at approximately week 4 and week 9.
Bone mineral density (DEXA)
Bone mineral density will be assessed using dual-energy X-ray absorptiometry (DEXA). DEXA will provide areal BMD (g/cm²).
Measured: Measured at lab visits 1-5 (baseline and pre- and post-interventions) from 0 to 12 weeks.
Bone mineral density (pQCT)
Bone mineral density will be assessed using peripheral quantitative computed tomography (pQCT) at the tibia. Measures will include volumetric BMD (vBMD) in mg/cm³ in cortical and trabecular compartments.
Measured: Measured at lab visits 1-5 (baseline and pre- and post-interventions) from 0 to 12 weeks.
Subjective measures of fatigue
Daily subjective fatigue will be assessed using the Hooper Index (fatigue subscale, 5-item 1-5 Likert scale). Higher scores indicate greater perceived fatigue.
Units: Hooper Index: total score (5-25)
Measured: Measured at lab visits 1-5 (baseline and pre- and post-interventions) from 0 to 12 weeks.
Sleep duration in h/night
Accelerometer-dervied using arm-worn Actigraph LEAP device.
Measured: Measured during both 7-day interventions starting at approximately week 4 and week 9.
Non-exercise activity thermogenesis (NEAT) (estimated from ActiGraph LEAP device) in kcal/day
Measured: Measured during both 7-day interventions starting at approximately week 4 and week 9
Exercise energy expenditure (estimated from ActiGraph LEAP device) in kcal/day
Measured: Measured during both 7-day interventions starting at approximately week 4 and week 9
Sub-maximal exercise performance (during steady-state treadmill exercise)
Substrate utilisation (absolute in g·min-¹)
Measured: Measured at lab visits 1-5 (baseline and pre- and post-interventions) from 0 to 12 weeks
Sub-maximal exercise performance (during steady-state treadmill exercise)
Substrate utilisation (relative as % total energy expenditure)
Measured: Measured at lab visits 1-5 (baseline and pre- and post-interventions) from 0 to 12 weeks
Bone mineral density (pQCT)
Cross-sectional area in mm²
Measured: Measured at lab visits 1-5 (baseline and pre- and post-interventions) from 0 to 12 weeks
Bone mineral density (pQCT)
Strength-strain index in mm³
Measured: Measured at lab visits 1-5 (baseline and pre- and post-interventions) from 0 to 12 weeks
Subjective measures of fatigue
Daily subjective fatigue will be assessed using the Fatigue Assessment Scale (FAS), a 10-item validated questionnaire scored from 10 to 50. Higher scores indicate greater perceived fatigue.
Units: total score (10-50).
Measured: Measured at lab visits 1-5 (baseline and pre- and post-interventions) from 0 to 12 weeks.
Total testosterone in nmol/L
Measured: Measured at lab visits 2-5 (pre- and post-interventions) from 4 to 12 weeks
Free testosterone in pg/mL
Measured: Measured at lab visits 2-5 (pre- and post-interventions) from 4 to 12 weeks
cortisol in nmol/L
Measured: Measured at lab visits 2-5 (pre- and post-interventions) from 4 to 12 weeks
IGF-1 in ng/mL
Measured: Measured at lab visits 2-5 (pre- and post-interventions) from 4 to 12 weeks
leptin in ng/mL
Measured: Measured at lab visits 2-5 (pre- and post-interventions) from 4 to 12 weeks
Female-specific hormones: oestradiol in pmol/L
Measured: Measured at lab visits 2-5 (pre- and post-interventions) from 4 to 12 weeks
Female-specific hormones: FSH in IU/L
Measured: Measured at lab visits 2-5 (pre- and post-interventions) from 4 to 12 weeks
Female-specific hormones: LH in IU/L
Measured: Measured at lab visits 2-5 (pre- and post-interventions) from 4 to 12 weeks
Inflammatory markers: interleukin-6 (IL-6) in pg/mL
Measured: Measured at lab visits 2-5 (pre- and post-interventions) from 4 to 12 weeks
high-sensitivity C-reactive protein (hsCRP) in mg/L
Measured: Measured at lab visits 2-5 (pre- and post-interventions) from 4 to 12 weeks
ferritin in µg/L
Measured: Measured at lab visits 2-5 (pre- and post-interventions) from 4 to 12 weeks
serum iron in µmol/L
Measured: Measured at lab visits 2-5 (pre- and post-interventions) from 4 to 12 weeks
transferrin in g/L
Measured: Measured at lab visits 2-5 (pre- and post-interventions) from 4 to 12 weeks
total iron binding capacity (TIBC) in µmol/L
Measured: Measured at lab visits 2-5 (pre- and post-interventions) from 4 to 12 weeks
transferrin saturation as a percentage
Measured: Measured at lab visits 2-5 (pre- and post-interventions) from 4 to 12 weeks
soluble transferrin receptor in mg/L
Measured: Measured at lab visits 2-5 (pre- and post-interventions) from 4 to 12 weeks
hepcidin in ng/mL
Measured: Measured at lab visits 2-5 (pre- and post-interventions) from 4 to 12 weeks
Lipid markers: total cholesterol, LDL cholesterol, HDL cholesterol, and triglycerides in mmol/L; non-esterified fatty acids (NEFA) in mmol/L; and glycerol in µmol/L.
Measured: Measured at lab visits 2-5 (pre- and post-interventions) from 4 to 12 weeks
HbA1c will be reported in both % (DCCT-aligned) and mmol/mol (IFCC standard).
Measured: Measured at lab visits 2-5 (pre- and post-interventions) from 4 to 12 weeks
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted14 Aug 2025
- Study startAug 2025 (estimated)
- Primary completionAug 2026 (estimated)
- Study completionMay 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Energy BalanceStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
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
- Basic science
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- None (open label)
- Enrolment
- 20 participants (estimated)
Sponsor and investigators
- Lead sponsor
- University of Bath
- Sponsor type
- University, hospital or other
- Collaborators
- Royal Centre for Defence Medicine
- Responsible party
- Principal investigator, Josh Bakker-Dyos, University of Bath
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07122778
- Sponsor's protocol ID
- 6854-11590
- Other IDs
- 345572
- Acronym
- Carpe DIEM
- Status last verified
- Aug 2025
- First submitted
- 14 Apr 2025
- Last updated
- 14 Aug 2025
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Undecided
Study at a glance
From the registry record, last updated by the sponsor on 14 Aug 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Impact of Diet-induced Change in Energy Balance on Metabolism in Endurance Athletes: the Carpe DIEM Study
- ClinicalTrials.gov ID
- NCT07122778
- Acronym / sponsor ID
- Carpe DIEM / 6854-11590
- Conditions
- Energy Balance, Energy Deficit, Low Energy Availability, Relative Energy Deficiency in Sport
- Keywords
- energy deficit, energy balance, energy availability, physical activity
- Study type
- Interventional
- Recruitment status
- Not yet recruiting
- Enrolment
- 20 participants (estimated)
- Lead sponsor
- University of BathUniversity, hospital or other
- Collaborators
- Royal Centre for Defence Medicine
- Study start
- Aug 2025 (estimated)
- Primary completion
- Aug 2026 (estimated)
- Study completion
- May 2027 (estimated)
- First posted
- 14 Aug 2025 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Recent research has suggested that increasing levels of physical activity are associated with a reduction in the independent components that contribute to total energy expenditure (such as resting metabolic rate and non-exercise movement) - this occurs to conserve energy required for physical activity where energy provision becomes scarce. There are potential deleterious health and performance consequences of a reduced energy supply to fundamental metabolic processes, putting individuals regularly undertaking high levels of physical activity, such as endurance athletes, at risk. However, this association is largely based on observational data in only moderately active populations, and it is currently unclear what role energy balance status and biological sex has on this relationship.
This research intends to address these unknowns by assessing the impact of diet-induced manipulation of energy balance (conditions of energy deficit and energy surplus) in individuals undertaking habitually high levels of physical activity on independent components of total energy expenditure (resting metabolism, exercise and non-exercise movement).
Male and female athletes conducting regular moderate-to-high training volumes will undertake a randomised crossover study with a 7-day state of energy deficit and a 7-day state of energy surplus. Participants will continue to live and train as normal, but their diet will be controlled by specific food provision over the intervention periods in order to facilitate both conditions. Independent components of energy expenditure, markers of health, metabolism and performance will be measured to allow for comparison of conditions.
Detailed description
People with very active lifestyles such as athletes, dancers, and military personnel, need to eat a lot of food to make up for the large amount of energy they burn. If they don't match their food intake to their energy needs, they may enter a state of 'energy deficit'. This means their bodies are burning more calories than they're taking in, which can lower performance, increase the risk of injuries and illnesses, and potentially harm overall health.
Traditional scientific understanding assumes that more doing physically activity leads to burning more calories (the 'additive' model). However, newer studies suggest that the body might have built-in safeguards to limit how many total calories it burns, no matter how much a person exercises. This idea (the 'constrained' model) proposes that when people exercise more, their bodies might compensate by slowing down other metabolic processes to keep overall energy use within a certain range. Although this mechanism could help the body conserve energy, it may also mean that essential functions (like immune system support and reproductive function) can become impaired.
Most research on energy deficit so far has focused on people with normal or moderate levels of physical activity. Because extremely active people experience far higher daily energy demands, the 'constrained' mechanisms could manifest differently or to a greater degree and the negative health and performance consequences might be more severe. There is also limited knowledge about how quickly these changes in energy use begin and how they affect important processes at the cellular level, such as muscle mitochondrial function or immune cell health.
This study aims to fill these gaps by measuring total energy use (and its separate parts) in highly active individuals under two conditions: when participants eat enough to cover their energy demands and when participants are purposely in an energy deficit (intentionally eating less than they need). One of our main goals is to measure changes in resting metabolic rate (RMR), which is the energy the body uses at rest to keep vital functions going. Investigators will also examine cellular changes by looking at indicators like immune cell function to see how these might help us detect early signs of harmful energy shortages.
By understanding whether, and to what extent, the body's energy use is 'constrained', investigators can develop better guidelines to help very active individuals avoid unhealthy energy deficits. Ultimately, this research could improve both performance and long-term health for athletes, military personnel, dancers, and anyone else who regularly exercises at high levels.
Study design
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- None (open label)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Energy deficit | Experimental | Dietary Supplement: Controlled energy-deficit dietDiet-induced 50% energy deficit (based on estimated average total daily energy expenditure) by allocation of pre-made meals and snacks over 7-days |
| Energy surplus | Experimental | Dietary Supplement: Habitual diet with surplus snacksDiet-induced energy surplus (approximately 500-1000kcal/day) achieved by allocation of additional snacks to be consumed on top of habitual free-living diet, to avoid inadvertent energy deficit |
Who may qualify
- Ages
- 18 to 49 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult
Key inclusion criteria (3 listed)
- Self-identified endurance-trained sport participants
- Training volume: >7 hours per week endurance training
- Training frequency: at least 5 days per week
Key exclusion criteria (16 listed)
- Diagnosis of Relative Energy Deficiency in Sport (REDs)
- Active eating disorder (EDE-Q)
- Active flare of a chronic disease (e.g. inflammatory bowel disease)
- Type 1 or 2 diabetes mellitus
- Untreated or undergoing active treatment of anaemia (any cause)
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Controlled energy-deficit dietAlso: Energy deficitParticipants receive a prepared diet providing approximately 50% of their estimated daily energy expenditure to induce a sustained energy deficit | Dietary supplement | Energy deficit |
| Habitual diet with surplus snacksAlso: Energy surplusParticipants continue their normal diet with the addition of high-calorie snack items to achieve an approximate daily energy surplus | Dietary supplement | Energy surplus |
Primary outcome
Resting metabolic rate (RMR) in kcal/day
Time frame: Measured at lab visits 1-5 (baseline and pre- and post-interventions) from 0 to 12 weeks.
The effect of a 7-day period of energy expenditure-matched diet-induced energy deficit versus energy surplus on RMR. Measured via indirect calorimetry using the Douglas bag method. Expired gas will be collected in a seated, fasted state under thermoneutral conditions, and oxygen consumption and carbon dioxide production will be used to calculate energy expenditure.
36 secondary outcomes
Total energy expenditure (from doubly labelled water) in kcal/day
Time frame: Measured during both 7-day interventions starting at approximately week 4 and week 9.
Total energy expenditure ( from sum of independent components of energy expenditure) in kcal/day
Time frame: Measured during both 7-day interventions starting at approximately week 4 and week 9
Peripheral blood mononuclear cell (PBMC) mitochondrial respiration
Time frame: Measured pre- and post-exercise at visits 2/3 (pre- and post-intervention 1) and visits 4/5 (pre- and post-intervention 2), approximately weeks 4-12.
Sub-maximal exercise performance (during steady-state treadmill exercise)
Time frame: Measured at lab visits 1-5 (baseline and pre- and post-interventions) from 0 to 12 weeks.
Free T3 in pmol/L
Time frame: Measured at lab visits 2-5 (pre- and post-interventions) from 4 to 12 weeks.
Interstitial glucose concentration in mmol/l
Time frame: Measured during both 7-day interventions starting at approximately week 4 and week 9.
Bone mineral density (DEXA)
Time frame: Measured at lab visits 1-5 (baseline and pre- and post-interventions) from 0 to 12 weeks.
Bone mineral density (pQCT)
Time frame: Measured at lab visits 1-5 (baseline and pre- and post-interventions) from 0 to 12 weeks.
Subjective measures of fatigue
Time frame: Measured at lab visits 1-5 (baseline and pre- and post-interventions) from 0 to 12 weeks.
Sleep duration in h/night
Time frame: Measured during both 7-day interventions starting at approximately week 4 and week 9.
Non-exercise activity thermogenesis (NEAT) (estimated from ActiGraph LEAP device) in kcal/day
Time frame: Measured during both 7-day interventions starting at approximately week 4 and week 9
Exercise energy expenditure (estimated from ActiGraph LEAP device) in kcal/day
Time frame: Measured during both 7-day interventions starting at approximately week 4 and week 9
Sub-maximal exercise performance (during steady-state treadmill exercise)
Time frame: Measured at lab visits 1-5 (baseline and pre- and post-interventions) from 0 to 12 weeks
Sub-maximal exercise performance (during steady-state treadmill exercise)
Time frame: Measured at lab visits 1-5 (baseline and pre- and post-interventions) from 0 to 12 weeks
Bone mineral density (pQCT)
Time frame: Measured at lab visits 1-5 (baseline and pre- and post-interventions) from 0 to 12 weeks
Bone mineral density (pQCT)
Time frame: Measured at lab visits 1-5 (baseline and pre- and post-interventions) from 0 to 12 weeks
Subjective measures of fatigue
Time frame: Measured at lab visits 1-5 (baseline and pre- and post-interventions) from 0 to 12 weeks.
Total testosterone in nmol/L
Time frame: Measured at lab visits 2-5 (pre- and post-interventions) from 4 to 12 weeks
Free testosterone in pg/mL
Time frame: Measured at lab visits 2-5 (pre- and post-interventions) from 4 to 12 weeks
cortisol in nmol/L
Time frame: Measured at lab visits 2-5 (pre- and post-interventions) from 4 to 12 weeks
IGF-1 in ng/mL
Time frame: Measured at lab visits 2-5 (pre- and post-interventions) from 4 to 12 weeks
leptin in ng/mL
Time frame: Measured at lab visits 2-5 (pre- and post-interventions) from 4 to 12 weeks
Female-specific hormones: oestradiol in pmol/L
Time frame: Measured at lab visits 2-5 (pre- and post-interventions) from 4 to 12 weeks
Female-specific hormones: FSH in IU/L
Time frame: Measured at lab visits 2-5 (pre- and post-interventions) from 4 to 12 weeks
Female-specific hormones: LH in IU/L
Time frame: Measured at lab visits 2-5 (pre- and post-interventions) from 4 to 12 weeks
Inflammatory markers: interleukin-6 (IL-6) in pg/mL
Time frame: Measured at lab visits 2-5 (pre- and post-interventions) from 4 to 12 weeks
high-sensitivity C-reactive protein (hsCRP) in mg/L
Time frame: Measured at lab visits 2-5 (pre- and post-interventions) from 4 to 12 weeks
ferritin in µg/L
Time frame: Measured at lab visits 2-5 (pre- and post-interventions) from 4 to 12 weeks
serum iron in µmol/L
Time frame: Measured at lab visits 2-5 (pre- and post-interventions) from 4 to 12 weeks
transferrin in g/L
Time frame: Measured at lab visits 2-5 (pre- and post-interventions) from 4 to 12 weeks
total iron binding capacity (TIBC) in µmol/L
Time frame: Measured at lab visits 2-5 (pre- and post-interventions) from 4 to 12 weeks
transferrin saturation as a percentage
Time frame: Measured at lab visits 2-5 (pre- and post-interventions) from 4 to 12 weeks
soluble transferrin receptor in mg/L
Time frame: Measured at lab visits 2-5 (pre- and post-interventions) from 4 to 12 weeks
hepcidin in ng/mL
Time frame: Measured at lab visits 2-5 (pre- and post-interventions) from 4 to 12 weeks
Lipid markers: total cholesterol, LDL cholesterol, HDL cholesterol, and triglycerides in mmol/L; non-esterified fatty acids (NEFA) in mmol/L; and glycerol in µmol/L.
Time frame: Measured at lab visits 2-5 (pre- and post-interventions) from 4 to 12 weeks
HbA1c will be reported in both % (DCCT-aligned) and mmol/mol (IFCC standard).
Time frame: Measured at lab visits 2-5 (pre- and post-interventions) from 4 to 12 weeks
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 14 Aug 2025.
- Individual participant dataSharing planned: Undecided
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Habitual diet with surplus snacks in people with Energy Balance and Energy Deficit, run by University of Bath at 1 site in United Kingdom.
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 16 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: opening soon, as of the sponsor's last update on 14 Aug 2025. 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 United Kingdom. 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. 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?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Joshua J Bakker-Dyos, BSc(Hons) MBChB (+447740191473, jbd28@bath.ac.uk), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Resting metabolic rate (RMR) in kcal/day (time frame: Measured at lab visits 1-5 (baseline and pre- and post-interventions) from 0 to 12 weeks.). 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 14 Aug 2025.