How dark, milk, and white chocolate affect cardiovascular responses during long periods of sitting

Effects of Dark, Milk, and White Chocolate Consumption Prior to Prolonged Sitting on Cardiovascular Health in Healthy Adults: A Randomized Crossover Trial

This trial will see if eating dark, milk, or white chocolate before a 3-hour sitting period changes blood pressure, heart rate, blood vessel stiffness, blood sugar, appetite, pain, or leg swelling in healthy adults aged 18–40 with blood pressure under 130/80.

Quick facts

• Phase: NA
• Study type: Interventional
• Enrollment: 22 (estimated)
• Ages: 18 Years to 40 Years
• Sex: All
• Sponsor: King Saud University (other)
• Locations: 1 site (Riyadh, Riyadh Region)
• Trial ID: NCT07556627 on ClinicalTrials.gov

What this trial studies

This is a randomized, crossover trial in which each participant attends three visits and consumes dark, milk, or white chocolate in a randomized order with a 7-day washout between visits. Baseline measures are taken, participants eat the assigned chocolate, and repeated measurements are collected during a standardized 3-hour seated period. Outcomes include blood pressure, heart rate, pulse wave velocity, capillary blood glucose, appetite and pain visual analogue scales, and calf circumference. The within-subject design compares acute physiological responses to the three chocolate types in otherwise healthy young adults.

Who should consider this trial

Good fit: Healthy adults aged 18–40 with blood pressure below 130/80 mmHg who are not menopausal, have no nut or dairy allergies, no chronic diseases affecting circulation, and are not taking medications that alter cardiovascular or metabolic measures.

Not a fit: People with cardiovascular disease, diabetes, other chronic conditions, menopausal women, those with nut or dairy allergies, or those on interfering medications are unlikely to benefit or qualify for this protocol.

Why it matters

Potential benefit: If successful, the findings could point to a simple dietary choice that reduces some of the short-term cardiovascular or metabolic effects of prolonged sitting.

How similar studies have performed: Previous studies have shown that cocoa-rich dark chocolate can acutely improve vascular function, but direct comparisons of dark versus milk versus white chocolate before prolonged sitting are limited.

Eligibility criteria

Inclusion Criteria:

* Adult males and females aged between 18 and 40 years.
* Participants with blood pressure within the normal or elevated range (less than 130/80 mmHg), according to the American Heart Association guidelines.

Exclusion Criteria:

* Females with menopause will be excluded due to the physiological effects of menopause and to ensure hormonal stability.
* Participants with nut allergies, due to the possibility that the chocolate used may contain traces of nuts resulting from manufacturing processes.
* Participants with dairy allergies, due to the use of milk chocolate and white chocolate, and the possibility that dark chocolate may contain traces of milk resulting from manufacturing processes .
* Participants with chronic diseases that may affect the study variables, such as cardiovascular diseases, respiratory diseases, diabetes, or any medical condition that affects circulation.
* Participants using medications that may affect the targeted physiological measurements in the study, such as antihypertensive medications, antidiabetic medications, or drugs affecting the autonomic nervous system.
* Participants with a body mass index (BMI) ≥ 30 kg/m², due to the association between obesity and vascular dysfunction, characterized by increased blood pressure and arterial stiffness, which may lead to variability in vascular responses.
* Participants who are physically active (≥150 minutes per week of moderate-to-vigorous physical activity), to avoid the impact of high levels of training on vascular responses.
* Smokers, due to the chronic effects of smoking on endothelial function and arterial stiffness.
* Participants with back injuries that limit their ability to sit continuously for three hours.
* Female participants who are pregnant, breastfeeding, due to the associated hormonal changes that may influence the physiological indicators measured in the study.

Where this trial is running

Riyadh, Riyadh Region

• Exercise Physiology Laboratory, King Saud University — Riyadh, Riyadh Region, Saudi Arabia (RECRUITING)

Study contacts

• Study coordinator: Razan S Alahmadi, MSc Candidate

Conditions: Cardiovascular Health During Prolonged Sitting, Dark Chocolate, Milk Chocolate, White Chocolate, Prolonged Sitting, Blood Pressure, Pulse Wave Velocity, Heart Rate Variability