Influence of wake-up time and intervention with rice balls and coffee beverages on the circadian rhythm of core body temperature.

Influence of wake-up time and intervention with rice balls and coffee beverages on the circadian rhythm of core body temperature. - Influence of wake-up time and intervention with rice balls and coffee beverages on the circadian rhythm of core body temperature.

Status

Active, not recruiting

Phases

Unknown

Study type

Interventional

Source

JPRN

Registry ID

JPRN-UMIN000054216

Enrollment

Registered

2024-04-24

Start date

2024-04-24

Completion date

Unknown

Last updated

2026-06-29

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Healthy individuals

Interventions

No breakfast Rice ball Coffee beverage Rice ball, Coffee beverage

Eligibility

Sex/Gender

All

Inclusion criteria

Inclusion criteria: 1. University students aged 18 and above. 2. Individuals without a breakfast consumption habit (those who usually engage in lifestyles such as consuming 'snacks, fruits, dairy products, flavored beverages only' in the morning, supplementing nutrients with tablets, nutrition drinks only,' or 'not eating anything' for five or more days a week). 3. Individuals available to participate during the specified examination period designated by us and able to visit the research laboratory on specified dates. 4. Individuals able to download and use a mobile app on their own mobile device.

Exclusion criteria

Exclusion criteria: 1. Individuals with extremely irregular eating and sleeping habits. 2. Individuals with health conditions (those with medications affecting metabolism, mental disorders, severe cardiovascular diseases, cancer, pregnant individuals, individuals with a history of gastrointestinal surgery). 3. Individuals engaged in shift work or night shift jobs 4. Individuals who regularly use sleeping pills or sleep supplements 5. Individuals who typically consume caffeine-containing beverages equivalent to 400mg or more of caffeine per day (approximately 3 cups for coffee in a mug (200ml each), approximately 10 cups for green tea, hojicha, or oolong tea, or more than 6 cups for black tea) 6. Individuals with food allergies to the target food ingredients or those who experience significant physical changes in response to caffeine intake." 7. Students attending lectures given by the Department of Public Health, Hiroshima University.

Design outcomes

Primary

Measure	Time frame
changes in the circadian rhythm of core body temperature	—

Secondary

Measure	Time frame
Changes in sleep, activity level, electrocardiogram, glucose concentration in interstitial fluid, cortisol concentration in saliva, performance, daily dietary intake, daily activities, daily mood, and OSA sleep survey.	—

Countries

Japan

Contacts

Public ContactYu Tahara

Hiroshima University Department of Public Health and Health Policy

yutahara@hiroshima-u.ac.jp07026426103

Outcome results

None listed

Source: JPRN (via WHO ICTRP) · Data processed: Jul 3, 2026