The primary objective of the Personalized Responses \& Integrated Systems for Metabolism (PRISM-I) pilot study is to assess the feasibility of conducting a definitive randomized controlled trial evaluating precision lifestyle interventions for improving insulin resistance in adults with metabolic syndrome.
Specific objectives are to: 1. Evaluate the feasibility and acceptability of the PRISM intervention and study procedures, including participant recruitment, retention, adherence, intervention delivery, and digital platform usability. 2. Explore the preliminary effects of the four lifestyle interventions (time-restricted eating, increased physical activity, low-glycaemic load diet, and sleep hygiene) on insulin resistance, measured using the Homeostatic Model Assessment of Insulin Resistance (HOMA-IR). 3. Examine the preliminary effects of the interventions on biochemical, anthropometric, behavioural, cognitive, and psychological outcomes. 4. Explore the potential behavioural and physiological pathways through which the lifestyle interventions may influence insulin resistance to inform the design of the definitive PRISM trial.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
TREATMENT
Masking
SINGLE
Enrollment
200
Following a 2-week baseline assessment, participants will begin a time-restricted eating (TRE) intervention by consuming all meals within a self-selected 8-hour eating window and fasting for the remaining 16 hours each day. They will measure blood ketone levels daily before breaking their fast using a glucometer. At Week 6, participants will be randomly assigned an additional lifestyle intervention (physical activity, low glycemic load diet, or sleep hygiene).
Following a 2-week baseline assessment, participants will begin a physical activity intervention. They will be instructed to complete home-based resistance training three times per week and aerobic interval training twice per week using a guided exercise programme. Exercise sessions will be performed independently without direct supervision. Participants will also be encouraged to aim for at least 8,000 steps daily, take a 15-minute walk after lunch and dinner where feasible, and break up prolonged sitting every 30-60 minutes with light movement or standing. At Week 6, participants will be randomly assigned an additional lifestyle intervention (time-restricted eating, low-glycemic load diet, or sleep hygiene).
National University of Singapore
Singapore, Singapore
Homeostatic Model Assessment of Insulin Resistance (HOMA-IR)
Insulin resistance will be assessed using the Homeostatic Model Assessment of Insulin Resistance (HOMA-IR), calculated as: HOMA-IR = (fasting plasma insulin × fasting plasma glucose) / 22.5 Higher HOMA-IR values indicate greater insulin resistance, whereas lower values indicate improved insulin sensitivity (reduced insulin resistance).
Time frame: At baseline, Week 10
Glycated haemoglobin (HbA1c) (%)
Glycated haemoglobin (HbA1c) reflects average blood glucose levels over the preceding two to three months and is measured using standard laboratory blood analysis. Higher values indicate poorer long-term glycaemic control.
Time frame: At baseline, Week 10
Fasting plasma glucose (mmol/L)
Fasting blood glucose is a biochemical measure of blood glucose concentration after an overnight fast, measured using standard laboratory blood analysis. Higher values indicate poorer glycaemic control.
Time frame: At baseline, Week 10
Fasting Insulin (µIU/mL)
Fasting plasma insulin is a biochemical marker measured using standard laboratory blood analysis following an overnight fast. Higher values indicate greater insulin resistance and impaired glucose metabolism.
Time frame: At baseline, Week 10
Total cholesterol (mmol/L)
Total cholesterol is a lipid biomarker measured using standard laboratory blood analysis to assess overall blood cholesterol levels. Higher values indicate poorer lipid profiles and increased cardiometabolic risk.
Time frame: At baseline, Week 10
High-density lipoprotein cholesterol (HDL-C) (mmol/L)
This platform is for informational purposes only and does not constitute medical advice. Always consult a qualified healthcare professional.
Following a 2-week baseline assessment, participants will begin a low-glycaemic load (GL) diet intervention. They will be instructed to replace high-GL foods with lower-GL alternatives, reduce their intake of refined carbohydrates, sugary foods and beverages, and ultra-processed foods, and follow healthy meal composition and meal sequencing principles. At Week 6, participants will be randomly assigned an additional lifestyle intervention (time-restricted eating, physical activity, or sleep hygiene).
Following a 2-week baseline assessment, participants will begin a sleep hygiene intervention. They will be instructed to adopt healthy sleep habits, including maintaining a regular sleep schedule with adequate sleep duration, practicing good bedtime routines, and optimizing the sleep environment to improve sleep quality. At Week 6, participants will be randomly assigned an additional lifestyle intervention (time-restricted eating, physical activity, or a low-glycemic load diet).
High-density lipoprotein cholesterol (HDL-C) is a lipid biomarker measured using standard laboratory blood analysis to assess protective cholesterol levels. Lower values indicate poorer lipid profiles and increased cardiometabolic risk.
Time frame: At baseline, Week 10
Low-density lipoprotein cholesterol (LDL-C) (mmol/L)
Low-density lipoprotein cholesterol (LDL-C) is a lipid biomarker measured using standard laboratory blood analysis to assess atherogenic cholesterol levels. Higher values indicate poorer lipid profiles and increased cardiovascular risk.
Time frame: At baseline, Week 10
Cholesterol/HDL ratio
The total cholesterol to HDL cholesterol ratio is calculated from standard laboratory blood analysis and is used to assess cardiovascular risk. Higher values indicate a poorer lipid profile and increased cardiometabolic risk.
Time frame: At baseline, Week 10
Triglycerides (mmol/L)
Triglycerides are a lipid biomarker measured using standard laboratory blood analysis to assess circulating triglyceride levels. Higher values indicate poorer lipid profiles and increased cardiometabolic risk.
Time frame: At baseline, Week 10
Lipoprotein a (nmol/L)
Lipoprotein(a) is an advanced lipid biomarker measured using standard laboratory blood analysis to assess inherited cardiovascular risk. Higher values are associated with increased risk of atherosclerotic cardiovascular disease
Time frame: At baseline, Week 10
Apolipoprotein A1 (g/L)
Apolipoprotein A1 (ApoA1) is a lipid biomarker measured using standard laboratory blood analysis to assess the major protein component of HDL cholesterol. Higher values generally indicate a more favourable lipid profile.
Time frame: At baseline, Week 10
Apolipoprotein B (g/L)
Apolipoprotein B (ApoB) is a lipid biomarker measured using standard laboratory blood analysis to assess the number of atherogenic lipoprotein particles. Higher values indicate increased cardiovascular risk.
Time frame: At baseline, Week 10
Apolipoprotein B/ A1 ratio
The Apolipoprotein B/A1 ratio is calculated from standard laboratory blood analysis and reflects the balance between atherogenic and protective lipoproteins. Higher values indicate increased cardiovascular risk
Time frame: At baseline, Week 10
High-sensitivity C-reactive protein (hs-CRP) (mg/L)
High-sensitivity C-reactive protein (hs-CRP) is an inflammatory biomarker measured using standard laboratory blood analysis to assess low-grade systemic inflammation. Higher values indicate greater systemic inflammation and increased cardiometabolic risk.
Time frame: At baseline, Week 10
Total protein (g/L)
Total protein is measured using standard laboratory blood analysis to assess the combined concentration of albumin and globulins in blood.
Time frame: At baseline, Week 10
Albumin (g/L)
Albumin is a plasma protein measured using standard laboratory blood analysis to assess nutritional status and liver function. Lower values may indicate impaired liver function, malnutrition, or inflammation.
Time frame: At baseline, Week 10
Globulin (g/L)
Globulin is measured using standard laboratory blood analysis to assess immune and inflammatory proteins in the blood.
Time frame: At baseline, Week 10
A/G ratio
The albumin-to-globulin (A/G) ratio is calculated from serum albumin and globulin concentrations and is used to assess liver function, nutritional status, and inflammatory conditions.
Time frame: At baseline, Week 10
Bilirubin (µmol/L)
Bilirubin is measured using standard laboratory blood analysis to assess liver function and bilirubin metabolism.
Time frame: At baseline, Week 10
Alkaline phosphatase (ALP) (U/L)
Alkaline phosphatase (ALP) is a liver enzyme measured using standard laboratory blood analysis to assess liver and biliary tract function.
Time frame: At baseline, Week 10
Alanine aminotransferase (ALT/SGPT) (U/L)
Alanine aminotransferase (ALT/SGPT) is a liver enzyme measured using standard laboratory blood analysis to assess liver cell injury.
Time frame: At baseline, Week 10
Aspartate aminotransferase (AST/SGOT) (U/L)
Aspartate aminotransferase (AST/SGOT) is a liver enzyme measured using standard laboratory blood analysis to assess liver and muscle cell injury. Higher values may indicate liver damage or other tissue injury.
Time frame: At baseline, Week 10
Blood pressure (mmHg)
Both systolic and diastolic blood pressure will be assessed.
Time frame: At baseline, Week 10
Montreal Cognitive Assessment (MoCA)
The Montreal Cognitive Assessment is a validated screening instrument designed to detect mild cognitive impairment. It assesses multiple cognitive domains, including attention and concentration, executive function, memory, language, visuospatial skills, abstraction, calculation, and orientation. Total scores range from 0 to 30, with higher scores indicating better cognitive function.
Time frame: At baseline, Week 10
Hand grip strength (kg)
Hand grip strength will be measured using a Jamar dynamometer as an indicator of muscle strength. Higher values indicate greater muscle strength.
Time frame: At baseline, Week 10
Weight (kg)
Time frame: At baseline, Weeks 5,10
Waist circumference (cm)
Time frame: At baseline, Weeks 5,10
Body mass index (BMI) (kg/m²)
Body mass index (BMI) will be calculated as weight (kg)/height² (m²). Lower values indicate lower overall adiposity.
Time frame: At baseline, Weeks 5,10
Percentage Body Fat (%)
Percentage body fat will be estimated using bioelectrical impedance analysis (InBody 120). Lower values indicate lower adiposity.
Time frame: At baseline, Weeks 5,10
Body Fat Mass (kg)
Measured using InBody 120.
Time frame: At baseline, Weeks 5,10
Visceral Fat Level
Visceral fat level will be estimated using bioelectrical impedance analysis (InBody 120). Lower values indicate reduced visceral adiposity.
Time frame: At baseline, Week 10
ABSI (body shape index)
A Body Shape Index (ABSI) is calculated from waist circumference, height, and body weight to assess central adiposity independently of BMI. Higher values indicate greater abdominal obesity and cardiometabolic risk.
Time frame: At baseline, Weeks 5,10
BRI (body roundness index)
Body Roundness Index (BRI) is calculated from height and waist circumference to estimate body fat distribution and central adiposity. Higher values indicate greater abdominal adiposity and cardiometabolic risk.
Time frame: At baseline, Weeks 5,10
Three Factor Eating Questionnaire (TFEQ)
The Three-Factor Eating Questionnaire-Revised 18 is a validated self-administered instrument used to assess eating-related behaviours. It measures three domains: cognitive restraint, uncontrolled eating, and emotional eating. Scores are calculated separately for each domain and transformed to a 0-100 scale, with higher scores indicating greater levels of the respective eating behaviour.
Time frame: At baseline, Week 10
International Physical Activity Questionnaire Short-Form (IPAQ-SF)
The International Physical Activity Questionnaire - Short Form is a validated self-administered questionnaire used to assess self-reported physical activity levels over the previous 7 days. It captures the frequency and duration of walking, moderate-intensity activity, vigorous-intensity activity, and time spent sitting. Responses are used to calculate total physical activity expressed as MET-minutes/week. There is no fixed minimum or maximum score; higher MET-minutes/week indicate higher levels of physical activity.
Time frame: At baseline, Week 10
Generalized Anxiety Disorder 7-item (GAD-7)
The Generalized Anxiety Disorder 7-item questionnaire is a validated self-administered screening instrument used to assess the frequency of anxiety symptoms over the previous 2 weeks. Total scores range from 0 to 21, with higher scores indicating greater anxiety symptom severity.
Time frame: At baseline, Week 10
Patient Health Questionnaire-9 (PHQ-9)
The Patient Health Questionnaire-9 is a validated self-administered screening instrument used to assess the frequency of depressive symptoms over the previous 2 weeks. Total scores range from 0 to 27, with higher scores indicating greater depressive symptom severity.
Time frame: At baseline, Week 10
Perceived Stress Scale (PSS-10)
The Perceived Stress Scale-10 is a validated self-administered questionnaire used to assess the degree to which individuals perceive situations in their lives as stressful over the previous month. Total scores range from 0 to 40, with higher scores indicating greater perceived stress.
Time frame: At baseline, Week 10
Big Five Inventory - 44 item (BFI-44)
The Big Five Inventory-44 is a validated self-administered questionnaire used to assess personality across five domains: openness, conscientiousness, extraversion, agreeableness, and neuroticism. Scores are calculated separately for each domain; there is no overall total score. Domain scores are typically calculated as the mean of the items within each domain and range from 1 to 5, with higher scores indicating greater expression of the respective personality trait. As this is a descriptive measure of personality, higher scores do not represent universally better or worse outcomes.
Time frame: At baseline, Week 10
Sleep Hygiene Index (SHI)
The Sleep Hygiene Index is a validated 13-item self-administered questionnaire that assesses behaviours associated with sleep hygiene. Total scores range from 13 to 65, with higher scores indicating poorer sleep hygiene practices.
Time frame: At baseline, Week 10
Gut microbiome
Time frame: At baseline, Week 10
Resting heart rate (beats/min)
Resting heart rate measured using the Oura Ring. Resting heart rate represents the average heart rate during periods of rest. Lower values generally indicate better cardiovascular fitness.
Time frame: Baseline through Week 10
Heart rate variability (ms)
Heart rate variability measured using the Oura Ring. HRV reflects variation in the time interval between successive heartbeats and is an indicator of autonomic nervous system function. Higher values generally indicate better autonomic regulation and recovery.
Time frame: Baseline through Week 10
Heart rate recovery (beats/min)
Heart rate recovery measured using the Oura Ring. Heart rate recovery represents the reduction in heart rate following physical activity and reflects cardiovascular recovery capacity. Higher values indicate faster recovery and better cardiovascular fitness.
Time frame: Baseline through Week 10
Sleep duration (hours)
Sleep duration measured using the Oura Ring. Sleep duration represents the total amount of sleep obtained per night. Higher values generally indicate longer sleep duration.
Time frame: Baseline through Week 10
Sleep quality score (0-100)
Sleep quality score measured using the Oura Ring. Scores range from 0 to 100, with higher scores indicating better sleep quality.
Time frame: Baseline through Week 10
Daily step count (steps/day)
Daily step count measured using the Oura Ring. Step count represents the total number of steps accumulated per day. Higher values indicate greater daily physical activity.
Time frame: Baseline through Week 10
Activity intensity minutes (minutes/day)
Activity intensity minutes measured using the Oura Ring. This metric represents the daily duration of moderate-to-vigorous physical activity. Higher values indicate greater participation in physical activity.
Time frame: Baseline through Week 10
Energy expenditure (kcal/day)
Energy expenditure measured using the Oura Ring. This metric represents the estimated daily energy expenditure from physical activity. Higher values indicate greater energy expenditure.
Time frame: Baseline through Week 10
Mean glucose (mmol/L)
Mean glucose concentration measured using continuous glucose monitoring. Mean glucose represents the average glucose concentration over the monitoring period. Lower values generally indicate better glycaemic control.
Time frame: Baseline through Week 10
Coefficient of variation (%)
Coefficient of variation of glucose measured using continuous glucose monitoring. CV reflects glucose variability relative to mean glucose concentration. Lower values indicate more stable glucose levels and better glycaemic control.
Time frame: Baseline through Week 10
Time Below Range (TBR, %)
Percentage of time spent below the target glucose range (\<3.9 mmol/L), measured using continuous glucose monitoring. Lower values indicate less time spent in hypoglycaemia and better glycaemic control.
Time frame: Baseline through Week 10
Time In Range (TIR, %)
Percentage of time spent within the target glucose range (3.9-10.0 mmol/L), measured using continuous glucose monitoring. Higher values indicate better glycaemic control.
Time frame: Baseline through Week 10
Time Above Range (TAR, %)
Percentage of time spent above the target glucose range (\>10.0 mmol/L), measured using continuous glucose monitoring. Lower values indicate less hyperglycaemia and better glycaemic control.
Time frame: Baseline through Week 10
Postprandial glucose excursion (PPGE) (mmol/L)
Postprandial glucose excursion measured using continuous glucose monitoring. PPGE is calculated as the difference between peak glucose concentration and pre-meal glucose concentration within 2 hours after the start of a meal. Higher values indicate greater postprandial glucose excursions.
Time frame: Baseline through Week 10
Incremental Area Under the Curve (iAUC, mmol/L·min)
Incremental area under the glucose curve measured using continuous glucose monitoring. iAUC represents the area under the glucose curve above the pre-meal baseline during the 2-hour period following a meal. Higher values indicate greater overall postprandial glucose exposure.
Time frame: Baseline through Week 10