The present randomized controlled trial aims to evaluate the relationship between gene expression profiling and the response to a precision diet compared to a personalized Mediterranean-style diet (control diet) in metabolically healthy individuals with overweight and obesity. Compared to the control diet, the precision diet is expected to increase adherence to dietary recommendations (resulting in weight loss and maintenance). In addition, the investigators postulate that the precision diet will lead to greater lifestyle changes, improving long-term well-being and health in people with overweight and obesity.
The study aims to evaluate the effectiveness of a precision diet based on gene expression versus a personalized Mediterranean-style diet. For this purpose, a 12-week parallel randomized controlled trial will be conducted. Once eligible participants are recruited, each volunteer will attend two clinical visits (at baseline-week 0 \[T0\], and week 12 \[T1\]), a study initiation visit (at week 1), and three online follow-up visits (at weeks 3, 6 and 9). First, the participants will come to the baseline visit \[T0\] in which, the investigators will collect data related to health status, body composition, lifestyle, and well-being. In addition, a registered nurse will collect a blood sample for gene expression profiling, along with other biochemical parameters, such as glycemic and lipid markers. In the following days, the biochemical results from the baseline visit will be evaluated to confirm that the volunteers are metabolically healthy. For this reason, it will not be until seven days after the baseline visit that the eligibility of the participants will be confirmed. After this confirmation, participants will be scheduled for the study initiation visit. At this visit, the volunteers will be randomly assigned to one of the two study arms, intervention (precision diet) or control diet. Those assigned to the intervention arm will follow the precision diet (a hypocaloric Mediterranean-style diet based on gene expression), while those assigned to the control arm will follow the control diet (a personalized hypocaloric Mediterranean-style diet without considering gene expression). Then, 12 weeks after the start of the intervention, the end of the intervention \[T1\] will be scheduled, in which the investigators will evaluate the same variables as in the baseline visit \[T0\]. In addition, during the 12 weeks of the study, both groups will attend three online follow-up visits (every 3 weeks) to ensure adherence to the intervention, as well as continuous care and to adapt dietary recommendations when needed.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
TREATMENT
Masking
SINGLE
Enrollment
29
After the recruitment and randomization, the participants will follow the assigned diet and recommendations for 3-months.
After the recruitment and randomization, the participants will follow the assigned diet and recommendations for 3-months.
Fundació Institut de Recerca de l'Hospital de la Santa Creu i Sant Pau
Barcelona, Barcelona, Spain
Changes in body mass index (BMI) from baseline to weeks 12.
Calculated as weight (kg) divided by height (in squared meters), BMI= kg/m\^2.
Time frame: Week 0 and 12.
Changes in body fat from baseline to weeks 12.
Measured as the percentage of body fat with a body composition analyzer (Inbody 120, Korea).
Time frame: Week 0 and 12.
Changes in gene expression profiling from baseline to weeks 12.
The RNA from fasting blood samples will be sequenced using Illumina technology and then the Limma software package will be used to analyze gene expression data from the RNA sequence.
Time frame: Week 0 and 12.
Changes in fasting blood lipids from baseline to weeks 12.
Fasting measurement of triglycerides, total cholesterol, LDL-cholesterol and HDL-cholesterol (mmol/L) will be measured in venous blood with the standard methodology of the clinical analysis laboratory of the Hospital de Sant Pau.
Time frame: Week 0 and 12.
Changes in glycemic markers from baseline to weeks 12.
Fasting measurement of glucose, insulin, and glycated hemoglobin (mmol/L) will be measured in venous blood with the standard methodology of the clinical analysis laboratory of the Hospital de Sant Pau.
Time frame: Week 0 and 12.
Changes in C-Reactive Protein (CRP) levels from baseline to weeks 12.
Fasting measurement of CRP will be measured in venous blood with the standard methodology of the clinical analysis laboratory of the Hospital de Sant Pau.
Time frame: Week 0 and 12.
Changes in waist and hip circumference from baseline to weeks 12.
Measured to the nearest 0.1 cm using a flexible steel anthropometric tape (CESCORF, Brazil) calibrated in centimeters.
Time frame: Week 0 and 12.
Changes in muscle mass from baseline to weeks 12.
Measured as the kilograms of muscle mass with a body composition analyzer (Inbody 120, Korea).
Time frame: Week 0 and 12.
Changes in physical activity from baseline to weeks 12.
Measured in Metabolic Equivalents of Task (MET) per minute and week, using the short version of the International Physical Activity Questionnaire (IPAQ). The IPAQ consists of 7 questions that assess the frequency, duration, and intensity of physical activity (moderate and vigorous) performed in the last seven days, as well as walking and sitting time on a workday. The minimum value is 0 MET-minutes/week, indicating no physical activity. Higher scores represent a higher amount of physical activity, while lower scores indicate lower levels of physical activity.
Time frame: Week 0 and 12.
Changes in energy and nutrient intake from baseline to week 12.
Energy and nutrient intake will be assessed with a 151-item semi-quantitative food frequency questionnaire (FFQ) and a 3-day dietary record (DR), in which participants will record their food intake for three days. The frequency of consumption for each food item is reported on a nine-level incremental scale (never or almost never, 1-3 times per month, once per week, 2-4 times per week, 5-6 times per week, once per day, 2-3 times per day, 4-6 times per day and more than six times per day). To calculate energy and nutrient intake from both methods (FFQ and DR), the Spanish food composition tables will be used.
Time frame: Week 0 and 12.
Changes in diet quality from baseline to week 12.
Diet quality will be evaluated through the 17-item Mediterranean Diet Adherence Screener (MEDAS). The score ranges from 0 to 17, where higher scores indicate greater adherence to the Mediterranean Diet.
Time frame: Week 0 and 12.
Changes in eating behavior from baseline to weeks 12.
Eating behaviors will be measured with the Spanish version of the Three Factor Eating Questionnaire (TFEQ-R21). It consists of three subscales: Cognitive Restraint (CR), Uncontrolled Eating (UE), and Emotional Eating (EE). Scores range from 0 to 21 for CR and UE, and from 0 to 15 for EE. Higher scores on each subscale indicate higher levels of the corresponding eating behavior.
Time frame: Week 0 and 12.
Changes in well-being from baseline to weeks 12.
Well-being will be measured with the Spanish version of the World Health Organization (WHO-5) Well-being Index. Scores range from 0 to 25, where higher scores indicate higher well-being.
Time frame: Week 0 and 12.
Changes in stress levels from baseline to week 12.
Stress will be evaluated through the Perceived Stress Scale (PSS-10), validated for Spanish population. Scores range from 0 to 40, where higher scores indicate a higher level of perceived stress.
Time frame: Week 0 and12.
Changes in depression and anxiety degree from baseline to week 12.
Anxiety and depression state will be measured by the Hospital Anxiety and Depression Scale (HADS), validated for Spanish population. It consists of two subscales: HADS-A, designed to detect anxious states, and HADS-D, designed to detect depressive states. Scores range from o to 21, where higher scores indicate greater levels of anxiety or depression.
Time frame: Week 0 and 12.
Changes in satiety from baseline to weeks 9.
Satiety will be evaluated using the Visual Analogue Scale (VAS) after each meal. Scores range from 0 to 100 mm, where higher scores indicate greater levels of satiety.
Time frame: Week 1 and 9.
This platform is for informational purposes only and does not constitute medical advice. Always consult a qualified healthcare professional.