Effect of Chocolate Consumption Prior to Prolonged Sitting on Cardiovascular Health in Young Women

Prolonged sitting is associated with acute adverse changes in vascular and metabolic health. Cocoa-rich chocolate contains bioactive compounds that may influence vascular responses; however, the effects of different chocolate types consumed before prolonged sitting are not fully understood.

This study is a randomized controlled crossover trial in healthy young women. Each participant completes three experimental visits and receives all three chocolate conditions (dark chocolate, milk chocolate, and white chocolate) in a randomized sequence determined before enrollment. A 7-day washout period is maintained between visits to minimize carryover effects.

At each visit, baseline measurements are obtained before chocolate consumption. Participants then consume the assigned chocolate condition, followed by post-consumption assessments and a standardized 3-hour sitting period. Repeated measurements are collected throughout the sitting period.

Outcome measures include blood pressure, heart rate, pulse wave velocity, capillary blood glucose, appetite visual analogue scale(VAS), pain visual analogue scale(VAS), and calf circumference. The study aims to compare acute physiological responses among the three chocolate conditions before prolonged sitting.

• dark chocolate (Dietary supplement): Participants consume dark chocolate 1 hour before prolonged sitting.
• Milk Chocolate (Dietary supplement): Participants consume milk chocolate 1 hour before prolonged sitting.
• White Chocolate (Dietary supplement): Participants consume white chocolate 1 hour before prolonged sitting.

Primary outcomes

• Blood Pressure (Systolic, Diastolic, Mean Arterial Pressure) [Baseline, 1 hour post-chocolate, and hourly during 3 hours of prolonged sitting]: Blood pressure will be measured using an automated sphygmomanometer under each chocolate condition (dark, milk, white).
• Pulse Wave Velocity [Baseline, 1 hour post-chocolate, and hourly during 3 hours of prolonged sitting]: Arterial stiffness will be assessed using estimated pulse wave velocity under each chocolate condition.
• Heart Rate Variability [Baseline, 1 hour post-chocolate, and hourly during 3 hours of prolonged sitting]: Autonomic cardiac function will be assessed using heart rate variability derived from RR interval recordings under each chocolate condition.
• Heart Rate [Baseline, 1 hour post-chocolate, and hourly during 3 hours of prolonged sitting.]: Heart rate will be measured under each chocolate condition during the study visits.

Secondary outcomes

• Capillary Blood Glucose [Baseline, 1 hour post-chocolate, and hourly during 3 hours of prolonged sitting]: Capillary blood glucose will be measured using finger-prick blood samples under each chocolate condition.
• Appetite Visual Analog Scale [Baseline, 1 hour post-chocolate, and hourly during 3 hours of prolonged sitting]: Subjective appetite sensations, including hunger, satiety, fullness, and prospective food consumption, will be assessed using 100-mm Visual Analogue Scales (VAS), ranging from 0 to 100 mm. Higher scores indicate a greater intensity of the appetite sensation being assessed.
• Pain Visual Analog Scale [Baseline, 1 hour post-chocolate, and hourly during 3 hours of prolonged sitting]: Pain will be assessed using a 100-mm Visual Analogue Scale (VAS), ranging from 0 mm ("no pain") to 100 mm ("worst pain imaginable"). Higher scores indicate greater pain intensity (a worse outcome).
• Calf Circumference [Baseline and hourly during 3 hours of prolonged sitting]: Calf circumference will be measured to assess lower limb swelling during prolonged sitting.

Sex: Female, ages: 18 Years to 40 Years, accepts healthy volunteers

Inclusion Criteria:

* Healthy young aged 18 - 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.

• Abdullah B Alansare, PhD, Study director, King Saud University