UMIN-CTR Clinical Trial
| Unique ID issued by UMIN | UMIN000063342 |
|---|---|
| Receipt number | R000072500 |
| Scientific Title | Effects of Chocolate Odour Exposure on Subjective Appetite, Appetite-Related Hormones, and Resistance Exercise Performance in Fasted Resistance-Trained Men: A Randomized Crossover Study |
| Date of disclosure of the study information | 2026/10/19 |
| Last modified on | 2026/10/19 17:23:04 |
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Basic information
Public title
Effects of Chocolate Odour on Appetite and Resistance Exercise Performance in Healthy Men
Acronym
CO-APP
Scientific Title
Effects of Chocolate Odour Exposure on Subjective Appetite, Appetite-Related Hormones, and Resistance Exercise Performance in Fasted Resistance-Trained Men: A Randomized Crossover Study
Scientific Title:Acronym
CO-APP
Region
| Asia(except Japan) |
Condition
Condition
Appetite regulation and resistance exercise performance under overnight-fasted conditions in healthy resistance-trained adults.
Classification by specialty
| Adult |
Classification by malignancy
Others
Genomic information
NO
Objectives
Narrative objectives1
To investigate the acute effects of chocolate odour exposure on subjective appetite and resistance exercise performance in healthy resistance-trained men under overnight-fasted conditions, and to determine whether changes in appetite perception are accompanied by corresponding changes in circulating ghrelin and glucagon-like peptide-1 (GLP-1).
Basic objectives2
Efficacy
Basic objectives -Others
Trial characteristics_1
Exploratory
Trial characteristics_2
Explanatory
Developmental phase
Not applicable
Assessment
Primary outcomes
1. Subjective appetite: Hunger and fullness assessed using 100-mm visual analogue scales at baseline and at 0, 1, 8, and 15 min during the pre-exercise odour-exposure period.
2. Resistance exercise performance: Total number of valid repetitions completed across four sets of back squat and four sets of bench press, assessed during the exercise session following the pre-exercise odour intervention.
Key secondary outcomes
1. Plasma ghrelin and total glucagon-like peptide-1 (GLP-1) concentrations, measured from venous blood samples collected at baseline and immediately after the 15-min pre-exercise odour-exposure period using enzyme-linked immunosorbent assays (ELISA).
2. Odour pleasantness, assessed using a 100-mm visual analogue scale at 0, 1, 8, and 15 min during the pre-exercise odour-exposure period.
3. Exercise-phase subjective appetite: Hunger and fullness assessed using 100-mm visual analogue scales during the recovery periods following each of the four sets of back squat and bench press.
Base
Study type
Interventional
Study design
Basic design
Cross-over
Randomization
Randomized
Randomization unit
Individual
Blinding
Double blind -all involved are blinded
Control
Placebo
Stratification
NO
Dynamic allocation
NO
Institution consideration
Institution is not considered as adjustment factor.
Blocking
NO
Concealment
Numbered container method
Intervention
No. of arms
4
Purpose of intervention
Treatment
Type of intervention
| Medicine |
Interventions/Control_1
90DC (90% dark-chocolate odour): Participants were exposed to a dark-chocolate olfactory stimulus prepared using 36 g of 100% cocoa dark chocolate, 3.8 mL of distilled water, and 2.0 mL of propylene glycol (approximately 40 mL final volume). Odour exposure lasted 30 s at 0, 1, 8, and 15 min during the pre-exercise assessment period and was repeated for 30 s immediately before each of four back-squat sets and four bench-press sets. Each participant completed one trial under this condition.
Interventions/Control_2
60MC (60% milk-chocolate odour): Participants were exposed to a milk-chocolate olfactory stimulus prepared using 12 g of 100% cocoa dark chocolate, 22.8 mL of whole milk, 3.8 mL of distilled water, and 2.0 mL of propylene glycol (approximately 40 mL final volume). The exposure schedule was identical to that of 90DC, consisting of 30-s exposures at 0, 1, 8, and 15 min before exercise and immediately before each of four back-squat and four bench-press sets. Each participant completed one trial under this condition.
Interventions/Control_3
PLA (placebo odour): Participants were exposed to a cocoa-free, sweet-like placebo odour prepared using 0.20 mL of vanilla essence, 0.10 mL of caramel essence, 37.7 mL of distilled water, and 2.0 mL of propylene glycol (approximately 40 mL final volume). The exposure schedule was identical to the chocolate-odour conditions, with 30-s exposures at 0, 1, 8, and 15 min before exercise and immediately before each of four back-squat and four bench-press sets. Each participant completed one trial under this condition.
Interventions/Control_4
CON (vehicle control): Participants were exposed to a vehicle-only preparation containing 38.0 mL of distilled water and 2.0 mL of propylene glycol, without chocolate or added flavouring. The exposure schedule was identical to the other conditions, with 30-s exposures at 0, 1, 8, and 15 min before exercise and immediately before each of four back-squat and four bench-press sets. Each participant completed one trial under this condition.
Interventions/Control_5
Interventions/Control_6
Interventions/Control_7
Interventions/Control_8
Interventions/Control_9
Interventions/Control_10
Eligibility
Age-lower limit
| 18 | years-old | <= |
Age-upper limit
| 30 | years-old | >= |
Gender
Male
Key inclusion criteria
1. Healthy adult men.
2. Engaged in resistance training at least twice per week for a minimum of one year.
3. Non-smokers.
4. Habitual breakfast consumers.
5. No aversion to cocoa-related or sweet food odours.
6. Willing and able to provide written informed consent and comply with the experimental procedures.
Key exclusion criteria
1. Self-reported olfactory dysfunction.
2. Metabolic or cardiovascular disease.
3. History of substance abuse.
4. Musculoskeletal injury that could impair resistance exercise performance.
Target sample size
14
Research contact person
Name of lead principal investigator
| 1st name | Xiaohan |
| Middle name | |
| Last name | Fan |
Organization
Universiti Malaya
Division name
Faculty of Sports and Exercise Science
Zip code
50603
Address
Faculty of Sports and Exercise Science, Universiti Malaya, 50603 Kuala Lumpur, Malaysia
TEL
0122488566
fanxiaohan5@gmail.com
Public contact
Name of contact person
| 1st name | Xiaohan |
| Middle name | |
| Last name | Fan |
Organization
Faculty of Sports and Exercise Science, Universiti Malaya
Division name
Faculty of Sports and Exercise Science
Zip code
50603
Address
Faculty of Sports and Exercise Science, Universiti Malaya, 50603 Kuala Lumpur, Malaysia
TEL
0122488566
Homepage URL
fanxiaohan5@gmail.com
Sponsor or person
Institute
Universiti Malaya
Institute
Department
Personal name
Xiaohan Fan
Funding Source
Organization
None
Organization
Division
Category of Funding Organization
Self funding
Nationality of Funding Organization
Malaysia
Other related organizations
Co-sponsor
Name of secondary funder(s)
IRB Contact (For public release)
Organization
Universiti Malaya Research Ethics Committee (UMREC)
Address
Universiti Malaya,
Tel
60379677022
umrec@um.edu.my
Secondary IDs
Secondary IDs
NO
Study ID_1
Org. issuing International ID_1
Study ID_2
Org. issuing International ID_2
IND to MHLW
Institutions
Institutions
Faculty of Sports and Exercise Science, Universiti Malaya (Kuala Lumpur, Malaysia)
Other administrative information
Date of disclosure of the study information
| 2026 | Year | 10 | Month | 19 | Day |
Related information
URL releasing protocol
The study protocol is not publicly available.
Publication of results
Unpublished
Result
URL related to results and publications
No public URL is currently available; the manuscript has not yet been published.
Number of participants that the trial has enrolled
14
Results
Fourteen resistance-trained men completed the study. Compared with 60MC, PLA, and CON, 90DC reduced pre-exercise hunger and increased fullness (all adjusted p <= 0.004 and p < 0.001, respectively). Plasma ghrelin (p = 0.064) and total GLP-1 (p = 0.302) did not differ significantly between conditions. Total back-squat repetitions were greater under 90DC than PLA (p = 0.018), while bench-press repetitions were greater under 90DC than 60MC (p < 0.001) and PLA (p = 0.002).
Results date posted
| 2026 | Year | 10 | Month | 19 | Day |
Results Delayed
Results Delay Reason
Date of the first journal publication of results
Baseline Characteristics
Fourteen healthy resistance-trained men completed the study. Participants had a mean age of 23.2 +/- 1.2 years, body mass of 72.9 +/- 4.6 kg, height of 174.8 +/- 3.4 cm, body mass index of 23.8 +/- 0.7 kg/m^2, and resistance-training experience of 2.1 +/- 0.5 years. All participants completed the experimental trials under standardized overnight-fasted conditions.
Participant flow
Fourteen participants were enrolled in the randomized four-condition crossover study. Each participant completed the 90DC, 60MC, PLA, and CON conditions in a counterbalanced order, with a washout interval of at least four days between experimental trials. All 14 participants completed all four experimental conditions and were included in the final analysis. No participant withdrawals were reported.
Adverse events
No adverse events were recorded during the study, including olfactory exposure, venous blood sampling, and resistance exercise testing.
Outcome measures
Primary outcomes:
1. Subjective appetite: A significant condition-by-time interaction was observed for hunger (F(9,52) = 3.286, p = 0.003). Hunger was lower under 90DC than 60MC, PLA, and CON at 0, 1, 8, and 15 min (all adjusted p <= 0.004). Fullness showed a significant condition effect (F(3,51.03) = 42.766, p < 0.001), with greater fullness under 90DC than the comparison conditions.
2. Resistance exercise performance: Total back-squat repetitions differed between conditions (F(3,39) = 3.923, p = 0.015), with more repetitions under 90DC than PLA (75.21 +/- 11.10 vs 71.79 +/- 9.50, adjusted p = 0.018). Total bench-press repetitions also differed (F(3,39) = 9.126, p < 0.001), with greater repetitions under 90DC than 60MC (adjusted p < 0.001) and PLA (adjusted p = 0.002).
Secondary outcomes:
3. Plasma ghrelin: No significant between-condition difference after baseline adjustment (F(3,40.95) = 2.608, p = 0.064).
4. Plasma total GLP-1: No significant between-condition difference after baseline adjustment (F(3,51) = 1.247, p = 0.302).
5. Odour pleasantness and exercise-phase appetite: Condition-dependent differences were observed in odour pleasantness and in selected hunger and fullness measurements during resistance exercise.
Plan to share IPD
IPD sharing Plan description
Progress
Recruitment status
Completed
Date of protocol fixation
| 2024 | Year | 02 | Month | 01 | Day |
Date of IRB
| 2024 | Year | 07 | Month | 12 | Day |
Anticipated trial start date
| 2024 | Year | 03 | Month | 01 | Day |
Last follow-up date
| 2025 | Year | 09 | Month | 10 | Day |
Date of closure to data entry
Date trial data considered complete
Date analysis concluded
Other
Other related information
Management information
Registered date
| 2026 | Year | 10 | Month | 19 | Day |
Last modified on
| 2026 | Year | 10 | Month | 19 | Day |
Link to view the page
Value
https://center6.umin.ac.jp/cgi-open-bin/ctr_e/ctr_view.cgi?recptno=R000072500
