This study aims to evaluate the impact of public health interventions on changes in healthy lifestyle habits over time and their subsequent effects on health outcomes. The investigators hypothesize that exposing at-risk populations to structured physical activity programs, education on healthy nutrition, promotion of the Mediterranean diet, and workshops focused on strengthening psychological resilience will lead to improvements in anthropometric, oxidative, metabolic, and psychological parameters. Anthropometric and laboratory measures will be collected at multiple time points throughout the study. The longitudinal follow-up will span 12 months. It is anticipated that sustained adherence to healthy lifestyle behaviors will result in positive lifestyle changes and enhanced health-related quality of life.
Contemporary lifestyle patterns are characterized by a fast pace of life, exposure to stressful stimuli, and unhealthy habits. Physically inactive adults who are exposed to stress, smoke, and have poor dietary habits are at increased risk of developing metabolic syndrome, oxidative stress, overweight, hormonal imbalance, insulin resistance, impaired mental health, and lower health-related quality of life. Studies confirm that lifestyle is one of the most influential modifiable factors in disease development. This study aims to evaluate whether a structured lifestyle intervention, including supervised physical exercise, adherence to a healthy diet, and stress-resilience training, can improve metabolic health, reduce oxidative stress, and enhance mental health and quality of life in adults with overweight, compared to a control group receiving standard lifestyle advice. Participants will be randomly assigned to one of two groups: supervised lifestyle group with exercise , Mediterranean diet education , stress-resilience and support; and control group receiving standard lifestyle recommendations. Participants in the experimental groups will engage in regular physical activity, follow a Mediterranean diet, participate in psychological resilience-building workshops and support groups, and attend weekly individual and group sessions, followed by a 12-month follow-up period. The study will assess anthropometric measures (body weight, waist and hip circumference), metabolic parameters (blood glucose, HbA1c, cholesterol, HOMA-IR), oxidative stress markers (AGEs), hormonal responses (cortisol, thyroid hormones), mental health, perceived stress, and quality of life. Participants will wear smart bracelets to monitor daily activity, steps, heart rate, and sleep. Measurements will be taken at baseline, immediately after the 12-week intervention (3 month), and during follow-up at 6, and 12 months. The investigators hypothesize that the structured lifestyle intervention combining physical activity, Mediterranean diet education, and stress-resilience training will lead to significant improvements in metabolic, oxidative, and psychological health outcomes compared to standard lifestyle advice. The scientific findings gained from this study may significantly contribute to understanding the effectiveness of lifestyle interventions in preventing chronic diseases associated with unhealthy lifestyles. The findings from this study are expected to provide insights into effective lifestyle interventions for at-risk populations, ultimately benefiting both individuals and communities. These interventions can improve the effectiveness of programs aimed at preventing the development of metabolic and chronic diseases, thereby enhancing overall health and quality of life. In addition, the results are anticipated to contribute to evidence-based public health policies and inform strategies for the prevention and management of chronic non-communicable diseases.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
TREATMENT
Masking
SINGLE
Enrollment
120
The intervention combines supervised physical activity (2 times a week for 12 weeks) with the use of a smart bracelet to continuously monitor heart rate, steps and hours of sleep. The intervention aims to reduce sedentary behavior and improve metabolic, oxidative and psychological health in adults with overweight or obesity.
Participants will take part in a 12 week nutritional intervention, followed by a 12 month follow-up period. The program includes 14 weekly group education sessions and one 30-minute individual consultation. Group sessions cover healthy eating principles, Mediterranean diet, intuitive eating, meal planning, hunger and satiety awareness, emotional triggers, mindful eating, real-life nutrition situations, motivation, and strategies for maintaining healthy habits. The individual consultation addresses personal challenges and tailors dietary guidance to the participant's lifestyle and health status. Dietary intake is monitored using structured 24-hour recalls at multiple time points throughout the intervention and follow-up periods.Participants will wear smart bracelets to monitor physical activity, heart rate, and sleep to track their daily routine and progress.
Participants will take part in a 12-week program focused on strengthening psychological resilience and stress management. The program includes workshops and group support sessions to encourage experience sharing and motivation, with additional online and telephone support. Participants will wear smart bracelets to monitor physical activity, heart rate, and sleep to track their daily routine and progress.
University of Zadar
Zadar, Croatia
Mediterranean diet adherence
Assessed using validated dietary questionnaires to evaluate participants' adherence to Mediterranean diet principles and monitor changes over time. The Mediterranean Dietary Serving Score (MDSS) evaluates 14 food groups, including cereals, fruits, vegetables, olive oil, nuts, dairy, meat, fish, eggs, legumes, potatoes, wine/beer, and sweets. Consumption is rated on a 7-point Likert scale. Scores above 14 indicate regular adherence to a Mediterranean diet.
Time frame: Baseline, 3 months after intervention, 6 months after intervention, and 12 months after intervention
Physical Activity
Assessed using the Godin Leisure-Time Exercise Questionnaire to evaluate participants' frequency and intensity of physical activity during free time, and to monitor changes in exercise behavior over time. Godin Leisure-Time Exercise Questionnaire (GLTEQ), calculates a total score by multiplying the weekly frequency of strenuous, moderate, and light activities by 9, 5, and 3, respectively. Higher scores indicate greater levels of physical activity and allow monitoring of changes in exercise behavior over time.
Time frame: Baseline, 3 months after intervention, 6 months after intervention, and 12 months after intervention
Sleep Hygiene
Assessed using validated sleep hygiene questionnaires to evaluate participants' sleep habits, routines, and behaviors that promote restorative sleep. The Sleep Hygiene Index (SHI) consists of 13 items for self-assessment of sleep-related behaviors. Participants rate how often they engage in specific behaviors on a 5-point scale: 0 = never, 1 = rarely, 2 = sometimes, 3 = often, 4 = always. Scores are summed to provide a global sleep hygiene score, with higher scores indicating poorer (maladaptive) sleep hygiene and a greater presence of behaviors that disrupt sleep quality
Time frame: Baseline, 3 months after intervention, 6 months after intervention, and 12 months after intervention
Perceived Stress
Self-reported questionnaire to assess perceived stress levels. The Perceived Stress Scale-10 (PSS-10) assesses the perception of stressful situations over the past month through 10 items rated on a 0-4 scale. Total scores range from 0 to 40, with higher scores indicating higher perceived stress levels.
Time frame: Baseline, 3 months after intervention, 6 months after intervention, and 12 months after intervention
Healthy Days (Physical and Mental Health)
Assessed using the CDC Healthy Days questionnaire to evaluate the number of days in the past 30 days when participants perceived their physical or mental health as not good. The Health Related Quality of Life 14 item measure (CDC HRQOL 14) is a generic self report questionnaire developed by the U.S. Centers for Disease Control and Prevention to assess overall health related quality of life. It comprises 14 items that capture perceived physical and mental health status over the past 30 days, including self rated general health, the number of days with poor physical health, poor mental health, days when health limited usual activities, and additional questions on activity limitations and symptoms such as pain, depression, anxiety, rest, and energy. The measure provides a summary of health related quality of life and has been widely used in public health surveillance, research, and population health studies. Higher scores generally reflect poorer health related quality of life.
Time frame: Baseline, 3 months after intervention, 6 months after intervention, and 12 months after intervention
Body Mass Index (BMI)
Calculated from measured weight and height to assess changes in body composition. Body weight will be measured using a Tanita scale. Body Mass Index (BMI) will be calculated by dividing body weight in kilograms by the square of body height in meters (kg/m²). Reference values will be applied: 18.5-24.9 kg/m² as normal weight, 25-29.9 kg/m² as overweight, and ≥30 kg/m² as obesity.
Time frame: Baseline, 3 months after intervention, 6 months after intervention, and 12 months after intervention
HbA1c
Measured from capillary blood using a point-of-care device to assess long-term changes in blood glucose control following lifestyle interventions. HbA1c will be measured from capillary blood samples and expressed as a percentage (%) or in mmol/mol. Reference values will be applied, with 4-5.6 % (20-38 mmol/mol) considered normal, 5.7-6.4 % (39-46 mmol/mol) indicating prediabetes, and ≥6.5 % (≥48 mmol/mol) indicating diabetes.
Time frame: Baseline, 3 months after intervention, 6 months after intervention, and 12 months after intervention
Waist Circumference
Waist circumference will be measured at the midpoint between the lower margin of the last palpable rib and the top of the iliac crest using a flexible measuring tape. Reference values will be applied: \<94 cm for men and \<80 cm for women as normal, 94-102 cm for men and 80-88 cm for women as increased risk, and \>102 cm for men and \>88 cm for women as high risk of metabolic complications.
Time frame: Baseline, 3 months after intervention, 6 months after intervention, and 12 months after intervention
Advanced Glycation End Products (AGEs)
Advanced Glycation End Products (AGEs) will be measured non-invasively in the skin using an AGE Reader device as a marker of oxidative stress. Skin autofluorescence will be assessed on the forearm of the participant's dominant arm, placed on the armrest of the AGE Reader device (DiagnOptics, Groningen, Netherlands). After entering the participant's age, the device displays the AGEs result in arbitrary units (AU). Reference values for advanced glycation end products (AGEs) will be age-dependent. For ages 20-30 years, the reference value is 1.53 ± 0.30 AU; for 30-40 years, 1.73 ± 0.42 AU; for 40-50 years, 1.81 ± 0.36 AU; for 50-60 years, 2.09 ± 0.36 AU; for 60-70 years, 2.46 ± 0.57 AU; for 70-80 years, 2.73 ± 0.55 AU; and for participants aged ≥80 years, 2.71 ± 0.44 AU.
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Time frame: Baseline, 3 months after intervention, 6 months after intervention, and 12 months after intervention
Lipid Profile (Total Cholesterol, LDL, HDL, Triglycerides)
Measured from fasting blood samples to assess cardiovascular risk. Reference values will be applied, with total cholesterol \<5.0 mmol/L, LDL \<3.0 mmol/L, HDL ≥1.0 mmol/L for men and ≥1.2 mmol/L for women, and triglycerides \<1.7 mmol/L considered within the normal range.
Time frame: Baseline, 3 months after intervention, 6 months after intervention, and 12 months after intervention
HOMA-IR (Homeostatic Model Assessment of Insulin Resistance)
Calculated from fasting glucose and insulin to evaluate insulin resistance. Reference values will be applied, with HOMA-IR \<2.5 considered normal, 2.5-3.9 indicating moderate insulin resistance, and ≥4.0 indicating significant insulin resistance.
Time frame: Baseline, 3 months after intervention, 6 months after intervention, and 12 months after intervention
Salivary Cortisol
Collected at four time points during the day to evaluate stress response and HPA axis function. Salivary cortisol will be measured at four time points during one day: immediately upon awakening, 30 minutes after awakening, at 16:00, and at 22:00. Salivary cortisol will be measured in nmol/L. Reference values are ≤19 nmol/L for morning cortisol and ≤8 nmol/L for evening cortisol.
Time frame: Baseline, 3 months after intervention
Psychological Resilience
Self-reported questionnaire to assess participants' coping capacity. The Brief Resilience Scale (BRS) is a short questionnaire with 6 questions, used for the assessment of an individual's ability to recover from stress, where a higher score denotes higher stress resilience (average score \<3.0 equals low, and score \>4.3 denotes high resilience)
Time frame: Baseline, 3 months after intervention, 6 months after intervention, and 12 months after intervention
Mental Health - The Generalized Anxiety Disorder Scale (GAD-7)
Assessed using validated self-report questionnaires to evaluate symptoms of depression and anxiety and monitor changes over time. The Generalized Anxiety Disorder Scale (GAD-7) was developed to assess nervous, anxious, and irritable feelings as well as problems with relaxing during the last 2 weeks. A score of 0-4 represents none to minimal level of anxiety, 5-9 is mild level, score of 10-14 indicates moderate level, while a score of 15-21 indicates a severe anxiety level.
Time frame: Baseline, 3 months after intervention, 6 months after intervention, and 12 months after intervention
Mental Health -The Patient Health Questionnaire (PHQ-9)
The Patient Health Questionnaire (PHQ-9) was used for the assessment of the presence and severity of depression over the last 2 weeks. Scores of 0-4 represent none to minimal depression, 5-9 represent mild, 10-14 is moderate level of depression, while a score of 15-19 denotes moderate severe, and 20-27 indicates severe depression.
Time frame: Baseline, 3 months after intervention, 6 months after intervention, and 12 months after intervention