Comparative Evaluation of Low-Carbohydrate and Balanced Diets on Anthropometric and Cardiovascular Risk Markers in Healthy Volunteers: A Single-Blind Randomized Controlled Trial
Phase: NA
Conditions: Healthy Adult Participants
Sponsor: Trisakti University

 
 
Cover Page for 
ClinicalTrials.gov 
 
 
Title: Comparative Evaluation of Low-
Carbohydrate and Balanced Diets on 
Anthropometric and Cardiovascular Risk Markers 
in Healthy Volunteers: A Randomized Controlled 
Trial 
 
Document Date: 1-May-2025 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

 
Comparative Evaluation of Low-Carbohydrate and Balanced Diets on Anthropometric and 
Cardiovascular Risk Markers in Healthy Volunteers: A Randomized Controlled Trial 
 
 
INTRODUCTION 
Cardiovascular disease (CVD) is one of the diseases whose prevalence is currently increasing, with 
the age of sufferers getting younger. In addition, CVD is the leading cause of death in the world, with an 
estimated 20.5 million people dying, which is 32% of all deaths in the world. 1 Based on Basic Health 
Research (Riskesdas 2018), the prevalence of heart disease in Indonesia is 1.5%, with a prevalence in DKI 
Jakarta of 1.9%. 2 Cardiovascular disease is associated with lipid profile disorders, 3 nutritional status 
obesity,4 and hypertension.5 
Carbohydrates are the primary energy-producing macronutrient, but carbohydrate consumption is 
currently suspected to be a contributing factor in various diseases. A meta-analysis found that individuals 
with high carbohydrate intake had a 1.15-fold higher risk of CVD compared to individuals with low 
carbohydrate intake (Hazard Ratio (RH) = 1.15; 95% confidence interval (CI) = 1.07–1.23).6 Carbohydrate 
intake stimulates insulin secretion, which promotes fat storage and inhibits adipose tissue lipolysis and 
fatty acid oxidation. Carbohydrate restriction can correct abnormal fatty acid composition. A cross-
sectional study conducted by Kalumpiu et al. 5 showed a significant association between blood pressure, 
total cholesterol, and triglycerides with cardiovascular risk scores. Another study showed that normal 
HDL-C concentrations were 0.18 times less likely to be associated with poor Health-Related Quality of 
Life (HRQoL) (Adjusted Odds Ratio (aOR) = 0.18; 95%CI = 0.03–0.91; p = 0.038).3 
Chronic inflammation is a major factor in the development of atherosclerosis. High concentrations 
of inflammatory markers such as C-reactive protein (CRP) and high-sensitivity C-reactive protein 
(hsCRP) are strong predictors of CVD risk and are associated with insulin resistance and metabolic 
syndrome. C-reactive protein (CRP/hsCRP) is a key indicator of systemic inflammation and a predictor 
of cardiovascular events, and is closely associated with visceral adiposity, which is induced by adipocyte-
mediated cytokines.7,8 Furthermore, there is strong evidence that apolipoprotein (apo) B is a more accurate 
indicator of CVD risk than total cholesterol and LDL. 9 
The interaction between carbohydrate intake and inflammatory markers and their relationship to 
predictors of atherosclerotic CVD remains understudied, particularly in Indonesia. Lifestyle changes, 
including dietary changes, are the primary approach to managing cardiometabolic risk factors.10 The main 
cardiometabolic risk factors are diabetes, hypertension, dyslipidemia, and excess abdominal fat, all of 
which are affected by dietary changes. 11 
Several studies have demonstrated the contribution of carbohydrate intake to inflammation. 12-14 
Studies have shown that low-carbohydrate diets are associated with a greater risk reduction compared with 
low-fat diets. 15 A systematic review and meta-analysis of cohort studies published in 2024 showed that 
high carbohydrate intake is associated with an increased risk of CVD death. 16 Another study, a systematic 

review and meta-analysis of prospective studies published in 2024, showed that individuals with high 
carbohydrate intakes had a 1.15-fold increased risk of CVD compared with individuals with low 
carbohydrate intakes (RH = 1.15; 95% CI = 1.07–1.23). 17 
 
While Western 18 and Mediterranean 19 diets have been well studied, other dietary patterns, 
particularly in Eastern populations, such as Indonesia, require further investigation to understand their 
impact on cardiovascular parameters. To date, published dietary intervention studies examining the impact 
on atherosclerotic cardiovascular disease parameters in the adult population in Indonesia are still limited, 
primarily focusing on dietary knowledge. This study will fill this gap by providing robust empirical 
evidence to support the development of more effective dietary policies and guidelines. 
 
The novelty of this study is that, to the researchers' knowledge, it is the first intervention study in 
Indonesia to directly compare the effects of two types of diet composition (low-carbohydrate versus 
different balanced diets) on anthropometric parameters, hsCRP, and ApoB serum concentration, markers 
of cardiovascular inflammation in healthy adult volunteers, with a control group. Most previous studies 
in Indonesia analyzing the relationship between diet and cardiovascular disease risk used a cross-sectional 
design, which only provides a single point in time. This study employed an intervention design with a 
control, enabling direct observation of changes in cardiovascular parameters in response to dietary 
interventions. This is expected to result in dietary composition recommendations tailored to the 
characteristics and needs of Indonesian adults. 
 
 
Research objectives: 
Primary outcome:  
Change from baseline in Body Mass Index (BMI) at 4 weeks 
 
Secondary outcome: 
1. Change from baseline in Mean Seated Systolic Blood Pressure at 4 weeks 
2. Change from baseline in Mean Seated Diastolic Blood Pressure at 4 weeks 
3. Change from baseline in Serum Apolipoprotein B (ApoB) concentration at 4 weeks 
4. Change from baseline in serum High-Sensitivity C-Reactive Protein (hsCRP) concentration at 4 
weeks 
 
METODE 
Design: 
This study is a randomized, controlled, open-label clinical trial. 
Settings & Time: 
Faculty of Medicine, Trisakti University, Jakarta, Indonesia.  
The study was conducted for 1 year, May 2025–May 2026. 

Study Population 
This study recruited from residents living near or employees working at Trisakti University. The study 
subjects will be randomly assigned to three intervention groups: one group following a low-carbohydrate 
diet (45 participants), one group following a balanced diet (45 participants), and one group following a 
control group (45 participants). The study will be conducted in a 1:1:1 ratio by personnel blinded to the 
intervention. 
Before participation, all individuals provided written informed consent, and the study was conducted in 
accordance with the Declaration of Helsinki. The study protocol was approved by the Research Ethics 
Committee, Faculty of Medicine Universitas Trisakti, under ethics approval No. 002/KER/FK/1/2025. 
 
Subject recruitment criteria: 
Inclusion criteria for this study are age 18–59, willingness to participate for the duration of the study (one 
month), ability to follow the prescribed meal plan and examination schedule, and informed consent to 
participate in the study, which included diet tracking, biometric testing, and adherence to the intervention 
program. 
Exclusion criteria included a history of type 1 or type 2 diabetes, autoimmune disease, thyroid disease that 
can affect carbohydrate metabolism, major surgery in the past six months, as this can affect carbohydrate 
metabolism and the body's response to dietary changes, eating disorders, allergies or intolerances to 
ingredients used in the study meal plan, participation in other clinical trials that could affect the results of 
this study, impaired kidney function with serum creatinine ≥1.5 mg/dL, and abnormal liver function with 
alanine aminotransferase and aspartate aminotransferase concentrations exceeding threefold. 
 
Subject Size Estimation: 
The sample size was calculated using a one-way ANOVA test with a statistical significance concentration 
of α = 0.05 and a power of 80%, using the effect size approach (Cohen's f = 0.44). Therefore, the planned 
sample size was 41 subjects in each group, plus 45 dropouts per group. 
Participant Selection Process and Criteria 
 
The selection process includes: 
1. Recruitment: Participants will be recruited from Trisakti University employees, and recruitment will be 
disseminated through various channels, including social media, health forums, and interfaculty 
collaboration to ensure participant diversity. 
2. Selection: Potential participants in the control or case groups will undergo a screening process to ensure 
they meet inclusion criteria, which may include age range (e.g., 18–59 years), stable health status, and 
ability to comply with the study requirements. Exclusion criteria include individuals who do not meet the 
study participant criteria. 

3. Research Consent: All participants must provide informed consent, stating their understanding of the 
study's purpose, procedures, risks, and benefits. 
 
Research Procedures 
1. Biometric testing is essential for establishing baseline research parameters and monitoring changes 
throughout the study. The procedures include: 
a. Baseline Assessment: At the beginning of the study, participants will undergo comprehensive biometric 
testing in the laboratory, and other assessments will include anthropometric measurements (weight, height, 
waist circumference), blood pressure, lipid profile, and inflammatory biomarkers (hsCRP, ApoB). 
b. Follow-up Testing: After the intervention, participants will undergo follow-up testing to track changes 
in research parameters, allowing for assessment of the effects of the dietary intervention. 
2. Diet Monitoring and Intervention Strategies 
Diet Recording: Participants will record their food choices and meal times and respond to surveys related 
to their eating habits. This data will provide insight into dietary patterns and their relationship to the study 
parameters. 
3. Ethical Considerations 
This study will be conducted in accordance with the ethical principles of the Declaration of Helsinki. All 
participants will provide written informed consent before data collection. 
 
Dietary Intervention: 
Participants will be randomly divided into three study groups, with two groups (a balanced diet group and 
a low-carbohydrate diet group) receiving three meals and two snacks for 20 days (on weekdays for four 
weeks). The balanced diet group will receive a dietary intervention consisting of 45-65% of total calories 
from carbohydrates, 20-25% from fat, and 10% from protein. The low-carbohydrate diet group will 
receive a dietary intervention focused on a diet with <45% of total energy from carbohydrates. Total 
calories will be calculated using the Brocca equation (height - 100 cm) for normal weight. The third group, 
as a control (without dietary intervention), will maintain their usual diet.  
Study dropout criteria: consuming 80% or less of the intake (subjects in the balanced diet and low-
carbohydrate diet groups), and if subjects (all groups) submitted food records for 80% or less of the 
required submissions. 
Measurements 
Questionnaires will be used to measure characteristics (age, gender, education concentration, employee 
status), habit history (smoking, alcohol consumption, physical activity), and dietary assessment. 
Age was categorized into <40 years and  ≥ 40 years, sex into male and female, concentration of education 
into high school, bachelor's degree, master's degree/doctoral degree, jobs into employees, 
professionals/health workers, and not working, smoking into yes and no, physical activity in to yes and 

physical activity into <150 minutes/weeks and ≥ 150 minutes/weeks.  
Dietary intake measured by a 3 x 24 hr record (2 weekdays and one weekend). During the study period, 
all participants will submit food records three times a week (two days on weekdays and one day on 
weekends). At the end of each week, the food record from the participant will be assessed by the 
nutritionist for compliance, and the participant's intake will be analyzed.  
 
Anthropometric measurements included (weight, height, and BMI), and blood pressure (systolic and 
diastolic). Body weight measurements were taken in the morning between  8:00  and  10:00  am.  Subjects 
were instructed not to eat breakfast before body weight measurements.  
Height in meters will be measured using Seca 213 scales (Hamburg, Germany) at an accuracy of 0.1 cm. 
Weight in kg was determined using Seca 876 scales(Hamburg, Germany) at 0.1 kg accuracy. Subjects 
were asked to remove their footwear, hat, hair accessories, or any high hairdos, take off belts, and empty 
their pockets to remove cell phones, wallets, or coins. In measuring height, the subject was asked to stand 
with the feet together, heels against the wall, knees straight, and eyes on the same concentration with the 
ears. The measuring arm was slid gently down onto the head, and the subject was asked to breathe in, with 
the results being recorded at an accuracy of 0.1 cm. In determining the body weight, the portable scale 
was placed on a firm and flat surface. The scale was then switched on until the digits 0.0 appeared, then 
the subject was asked to step onto the scale, face forward, arms at the sides, while standing still, then the 
weight was recorded at an accuracy of 0.1 cm. Body mass index was calculated by dividing the weight in 
kg by the square of the height in meters, and was classified into non-obese (BMI <25 kg/m2) and obese (≥ 
25 kg/m2) in accordance with the WHO Asia-Pacific BMI categories.  
 
The blood pressure in mmHg was measured using an Omron HEM7120 (Vietnam) between 8:00 and 
10:00 am. Subjects were instructed not to exercise, not to consume coffee for at least 4 hours prior to the 
blood pressure test, to get sufficient sleep (7–8 hours), and not to use antihypertensive medication. Blood 
pressure was measured while sitting, and the average of 2 measurements was calculated. Blood pressure 
checks were performed by doctors who were not members of the research team to ensure the objectivity 
of the findings.   
 
Laboratory measurement 
Approximately 5 mL of venous blood was collected from each participant after an overnight fast using 
serum separator tubes. Following centrifugation, serum samples were either analyzed immediately or 
stored at 2–8 °C until analysis. A portion of the collected blood was used for screening the eligibility of 
study participants. The assay required 6 µL of serum per test to determine apolipoprotein B (Apo B) and 
high-sensitivity C-reactive protein (hsCRP) serum concentrations. 
 
 

Apo B measurement 
Serum apolipoprotein B (ApoB) was measured using an automated immunoturbidimetric assay (Tina-
quant® Apolipoprotein B ver.2, Roche Diagnostics, Mannheim, Germany) on a cobas® c analyzer. The 
method is based on the formation of antigen–antibody complexes between ApoB in the sample and 
specific anti-human ApoB antibodies, which are quantified. 
Calibration was performed using Roche Calibrator f.a.s. Lipids, with traceability to the IFCC/WHO 
reference material SP3-07 for apolipoprotein B. Internal quality control materials at normal and 
pathological concentrations were analyzed routinely. The analytical measuring range was 0.2–4.0 g/L, and 
assay precision met acceptable clinical laboratory performance criteria. turbidimetrically. 
Apo B serum concentration will be presented in mg/dL 
 
hsCRP measurement 
High-sensitivity C-reactive protein (hsCRP) concentrations were measured using a particle-enhanced 
immunoturbidimetric assay (Cardiac C-Reactive Protein [Latex] High Sensitive, Roche Diagnostics, 
Mannheim, Germany) on a cobas® c analyzer. The method is based on the agglutination of latex particles 
coated with monoclonal anti-CRP antibodies in the presence of CRP, which is quantified turbidimetrically. 
Calibration was performed using Roche Calibrator f.a.s. Proteins, with traceability to the IFCC/BCR 
reference material (CRM 470). Internal quality control materials were analyzed routinely. The analytical 
measuring range was 0.15–20.0 mg/L, and assay precision fulfilled acceptable clinical laboratory 
performance criteria for hsCRP serum concentration measurement. 
hsCRP serum concentration will be presented in mg/dL 
 
Statistical Analysis 
Normality testing was performed on numerical scale data using the Kolmogorov–Smirnov test. Normally 
distributed data are presented as mean ± SD, while non-normally distributed data are presented as median 
(25–75%). Categorical data are presented as proportions. 
Differences between the three groups' data categories will be assessed using the chi-square test. If the chi-
square test did not meet the requirements, as in the case of the smoking status variable, a chi-square test 
with Bonferroni correction was used to assess the difference between the low-carb or balanced diet group 
and the control group, with a significance concentration of p<0.025. The delta % variable was used to 
assess the change in variable values at the end of treatment compared to the start of treatment. The formula 
used was delta% = [(A-B)/A] x 100, where A = initial-treatment value and B = post-treatment value. A 
repeated measures ANOVA test was used to assess differences between baseline and after 4 weeks, and 
differences between the three groups before and after the intervention. The significance concentration 
considered was p<0.05. The analysis was performed using SPSS v31. 
 
Funding: Universitas Trisakti No. 1064/PUF/FK/2024-2025 

 
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Federation. 2023 [cited 2025 31 March]. Available from: https://world-heart-federation.org/wp-
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12. Cipryan L, Maffetone PB, Plews DJ, Laursen PB. Effects of a four-week very low-carbohydrate high-
fat diet on biomarkers of inflammation: non-randomised parallel-group study. Nutrition and health. 
2020;26(1):35-42.  
13. Karimi E, Yarizadeh H, Setayesh L, Sajjadi SF, Ghodoosi N, Khorraminezhad L, et al. High 
carbohydrate intakes may predict more inflammatory status than high fat intakes in pre-menopause women 
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Cardiovascular Disease Risk and Mortality: A Systematic Review and Dose-Response Meta-Analysis of 
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Cover Page for 
ClinicalTrials.gov 
Document: Informed Consent Form 
 
 
Title: Comparative Evaluation of Low-
Carbohydrate and Balanced Diets on 
Anthropometric and Cardiovascular Risk Markers 
in Healthy Volunteers: A Randomized Controlled 
Trial 
 
Document Date: 1-May-2025 
 
 
 
 
 
 
 

 
 
 

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CONSENT FORM 
Title of the study: Comparative Evaluation of Low-
Carbohydrate and Balanced Diets on Anthropometric and 
Cardiovascular Risk Markers in Healthy Volunteers: A 
Randomized Controlled Trial 
Name:  
   
Age:  
 
Contact number:  
  
• 
I confirm that I have read and understood the information about the project as 
provided in the Participant Information Sheet dated [Insert Date]. 
• 
I confirm that I have had the opportunity to ask questions and the 
researcher has answered any questions about the study to my 
satisfaction. 
• 
I understand that my participation is voluntary and that I am free to 
withdraw from the project at any time, without having to give a reason and 
without any consequences. 
• 
I understand that I can withdraw my data from the study at any time. 
• 
I understand that any information recorded in the investigation will remain 
confidential and no information that identifies me will be made publicly 
available. 
• 
I consent use of this data in research, publications, sharing and archiving as 
explained in the Participant Information Sheet. 
• 
I agree / do not agree (delete as appropriate) to take part in the above study. 
 
Name of Participant Date :  
Doctor: Yenny 
Date / Signature 
…………………………….. 
…………………………… 
Interview Signature Date: 
 

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