Monitoring Intermittent Fasting for Human Optimization Using Wearable Technology: An N-of-1 Study

Intermittent Fasting Monitoring for Human Optimization Utilizing Wearable Technology: an N-of-1 Prospective Study

There is a growing interest in personalized health strategies, including diet, exercise, and fasting regimens, to enhance metabolic fitness. Recent research indicates that intermittent fasting (IF) is useful not only for weight management, but also for energy production and improvement of metabolic well-being.

IF can potentially reduce systemic inflammation and help to prevent chronic diseases. IF research can also help athletes sustain performance during fasting periods. This prospective study aims to investigate the effects of a human optimization program on an individual's metabolic health and overall well-being.

This research examines the correlations between continuous glucose monitoring, ketone measurement, exercise routines, heat/cold interventions, diet, supplements and intermittent fasting patterns. The study involves a single participant -the principal investigator- who will adhere to a personalized regimen involving wearable monitoring of metabolic changes, training and intermittent fasting. This research seeks to understand the potential relationships between these factors, contributing to the emerging knowledge on individualized health optimization.

Study Overview

• Status: Completed
• Conditions: Healthy; Intermittent Fasting; Digital Health
• Intervention / Treatment: Behavioral: Glucose-Ketone Index (GKI) monitoring; Behavioral: Continuous Glucose Monitoring (CGM); Other: Digital dynamometer; Device: Wearables; Diagnostic test: Blood tests; Diagnostic test: Stool tests; Diagnostic test: Saliva tests; Behavioral: Fitness intervention; Behavioral: Cold & heat intervention; Device: Airofit; Behavioral: 18h fasting; Behavioral: 48h fasting; Behavioral: Three meal phase; Behavioral: Mediterranean-inspired diet; Dietary supplement: Supplements; Behavioral: Generative AI; Other: Interviews

• Study Type: Interventional
• Enrollment (Actual): 1
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Singapore
  • Singapore, Singapore, 117456
    • The Institute for Digital Medicine (WisDM)

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• The principal investigator is the sole participant in this N-of-1 trial: a healthy individual with no chronic diseases or conditions affecting metabolic health.

Exclusion Criteria:

• The principal investigator is the sole participant in this N-of-1 trial.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Basic Science
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm

Intervention / Treatment

Experimental: Personalized Health Intervention Arm; This arm involves the the single participant following a personalized regimen that includes intermittent fasting, exercise routines, heat/cold interventions, diet modifications, and supplementation. The participant will engage in continuous monitoring of metabolic changes using wearable technology, continuous glucose monitoring, and ketone measurements, along with blood, saliva, and stool lab tests. The goal is to assess the effects of these interventions on metabolic health and overall well-being, identifying potential trends and correlations throughout the study period.

Behavioral: Glucose-Ketone Index (GKI) monitoring; Ketone and blood glucose monitoring with Abbott Optium Neo up to 10 times per day to observe GKI dynamics for gamification of adherence.; Behavioral: Continuous Glucose Monitoring (CGM); Monitoring with an Abbott Freestyle Libre to observe glucose dynamics for gamification of adherence.; Other: Digital dynamometer; Grip strength measurements, right and left hand, up to 20 readings per day per hand.; Device: Wearables; All Apple Watch 9 and Whoop data daily [heart rate variability (HRV), resting heart rate, cardio recovery, sleep duration, composition (stages of sleep) and analogous scores, potential maximum rate of oxygen consumption attainable during physical exertion (VO2 max), basal metabolic rate and potential respiratory rate].; Diagnostic test: Blood tests; Pre- and Post-fast (48h) testing of lipid panel, ApoB, ApoA1, CRP, interleukin panel, omega 3:6 ratio, and autophagy analysis. Potential CBC, renal and liver panels to be taken where appropriate.; Diagnostic test: Stool tests; 15 g of stool will be collected from the subject pre- and post-fast for microbiome assessment and pre- and post- the first week (the "three meal phase"). After the first week, the maximum number of tests is four per month (maximum of two fasts, with a pre- and post-fast test for each fast).; Diagnostic test: Saliva tests; Saliva samples will be collected from the subject pre- and post-fast for microbiome assessment. Maximum number of tests is four per month (maximum of two fasts, with a pre- and post-fast test for each fast).; Behavioral: Fitness intervention; 90 minutes of strength and/or cardiovascular training for a minimum of 5 days per week.; Behavioral: Cold & heat intervention; Cold plunge: at least 3 days per week, 2 sessions of maximum 5 minutes each (minimum 2 minutes between sessions) at a minimum of 6 degrees Celsius. Potential inclusion of GKI measurements before and after plunge. Heat Therapy: maximum of 2 sessions of 20 minutes each of dry sauna blanket (minimum 5 minutes break between sessions) following the cold plunge intervention.; Device: Airofit; Airofit is a smart breathing training device designed to improve respiratory strength and efficiency. It is used for enhancing sport performance, well-being, and overall health. The device works by providing adjustable resistance to breathing muscles. 5-10 minutes of daily use.; Behavioral: 18h fasting; Minimum of 18 hours fasting per day, with feeding window to occur between 5pm-8pm or 12pm-3pm. The fasting procedures will occur only after the Three Meal Phase.; Behavioral: 48h fasting; 48h fasting maximum twice monthly, at least one week apart. Multivitamin and electrolytes with water, and black coffee or tea (0-calorie drinks) will be consumed.The fasting procedures will occur the Three Meal Phase.; Behavioral: Three meal phase; During the first week of the study, the participant will follow a regime of three meals per day.; Behavioral: Mediterranean-inspired diet; Regimen of Mediterranean-inspired nutrition comprised of Olive Oil, Olives, Leafy Green Vegetables, Lean Protein (Beef, Chicken, Lamb, Pork, Duck, Salmon, Tuna), Chia Seeds, Pecans, Macadamia, Pumpkin Seeds, Walnuts, Greek Yogurt, Salt, Pepper, Paprika, Cumin, Garlic powder, onion powder; Fruit: Blueberry, Grapefruit; Carbohydrates: Rolled Oats; Hydration: Water, Black Coffee, Black Tea, Coke Zero and 100 Zero sparingly, Ultima electrolytes. Photographs of meals will be taken to create a visual record of the diet followed. Photographs of the devices will be taken to create a visual record of the blood glucose and ketone concentration results.; Dietary supplement: Supplements; Multivitamin (Centrum), Vitamin D (Up to 2000 IU per day), Creatine (Up to 2000mg), Fisetin (1 pill), Omega-3 (1 tablet), Turmeric, Pre-Probiotic, Blueberry Extract, Holy Basil Extract.; Behavioral: Generative AI; Feeding ketone data, glucose data (from finger prick and/or CGM), any/all Apple Watch Data, and dietary images into a generative AI platform to convert data into images using any selected prompts, with the intent of the images serving as immediate, visual readouts as a function of activity and/or inactivity.; Other: Interviews; Three interviews, of 30-60 minutes each one, at baseline, end of three meal phase and end of study, to gain insights into the participant's experience. Exploration of daily routines including diet, exercise and the use of technology and aspects of a healthy lifestyle.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Metabolic biomarker analysis: total cholesterol levels	Blood testing of total cholesterol: milligrams per deciliter (mg/dL)	Pre and post 48 hour fasts (2 fasts per month for 12 months)
Metabolic biomarker analysis: low density lipoprotein (LDL) cholesterol levels	Blood testing of LDL cholesterol: milligrams per deciliter (mg/dL)	Pre and post 48 hour fasts (2 fasts per month for 12 months)
Metabolic biomarker analysis: high density lipoprotein (HDL) cholesterol levels	Blood testing of HDL cholesterol: milligrams per deciliter (mg/dL)	Pre and post 48 hour fasts (2 fasts per month for 12 months)
Metabolic biomarker analysis: triglycerides levels	Blood testing of triglycerides: milligrams per deciliter (mg/dL)	Pre and post 48 hour fasts (2 fasts per month for 12 months)
Metabolic biomarker analysis: apolipoprotein B (ApoB) levels	Blood testing of apolipoprotein B (ApoB): milligrams per deciliter (mg/dL)	Pre and post 48 hour fasts (2 fasts per month for 12 months)
Metabolic biomarker analysis: apolipoprotein A1 (ApoA1) levels	Blood testing of apolipoprotein A1 (ApoA1): milligrams per deciliter (mg/dL)	Pre and post 48 hour fasts (2 fasts per month for 12 months)
Metabolic biomarker analysis: C reactive protein (CRP) levels	Blood testing of C reactive protein (CRP): milligrams per liter (mg/L)	Pre and post 48 hour fasts (2 fasts per month for 12 months)
Metabolic biomarker analysis: interleukin 1β (IL- 1β) levels	Blood testing of IL- 1β: picograms per milliliter (pg/mL)	Pre and post 48 hour fasts (2 fasts per month for 12 months)
Metabolic biomarker analysis: interleukin 6 (IL- 6) levels	Blood testing of IL-6: picograms per milliliter (pg/mL)	Pre and post 48 hour fasts (2 fasts per month for 12 months)
Metabolic biomarker analysis: interleukin 8 (IL- 8) levels	Blood testing of IL-8: picograms per milliliter (pg/mL)	Pre and post 48 hour fasts (2 fasts per month for 12 months)
Metabolic biomarker analysis: interleukin 10 (IL- 10) levels	Blood testing of IL-10: picograms per milliliter (pg/mL)	Pre and post 48 hour fasts (2 fasts per month for 12 months)
Metabolic biomarker analysis: interleukin 12 (IL- 12) levels	Blood testing of IL-12: picograms per milliliter (pg/mL)	Pre and post 48 hour fasts (2 fasts per month for 12 months)
Metabolic biomarker analysis: interleukin 17 (IL- 17) levels	Blood testing of IL-17: picograms per milliliter (pg/mL)	Pre and post 48 hour fasts (2 fasts per month for 12 months)
Metabolic biomarker analysis: omega 3:6 ratio	Blood testing of omega 3:6 ratio (no specific units)	Pre and post 48 hour fasts (2 fasts per month for 12 months)
Metabolic biomarker analysis: Microtubule-associated protein 1A/1B-light chain 3 (LC3) levels	Blood testing of autophagy biomarker LC3: Nanograms per milliliter (ng/mL)	Pre and post 48 hour fasts (2 fasts per month for 12 months)
Metabolic biomarker analysis: Sequestosome 1 (p62/SQSTM1) levels	Blood testing of autophagy biomarker p62/SQSTM1: Nanograms per milliliter (ng/mL)	Pre and post 48 hour fasts (2 fasts per month for 12 months)
Metabolic biomarker analysis: Beclin-1 levels	Blood testing of autophagy biomarker Beclin-1: Nanograms per milliliter (ng/mL)	Pre and post 48 hour fasts (2 fasts per month for 12 months)
Metabolic biomarker analysis: Red Blood Cells (RBCs)	Red Blood Cells (RBCs): Million cells per microliter (million/µL)	Pre and post 48 hour fasts (2 fasts per month for 12 months)
Metabolic biomarker analysis: White Blood Cells (WBCs)	White Blood Cells (WBCs): Thousand cells per microliter (thousand/µL)	Pre and post 48 hour fasts (2 fasts per month for 12 months)
Metabolic biomarker analysis: Hemoglobin (Hb)	Hemoglobin (Hb): Grams per deciliter (g/dL)	Pre and post 48 hour fasts (2 fasts per month for 12 months)
Metabolic biomarker analysis: Hematocrit (Hct)	Hematocrit (Hct): Percentage (%)	Pre and post 48 hour fasts (2 fasts per month for 12 months)
Metabolic biomarker analysis: Platelets (PLT)	Platelets (PLT): Thousand cells per microliter (thousand/µL)	Pre and post 48 hour fasts (2 fasts per month for 12 months)
Metabolic biomarker analysis: Blood Urea Nitrogen (BUN)	Blood Urea Nitrogen (BUN): Milligrams per deciliter (mg/dL)	Pre and post 48 hour fasts (2 fasts per month for 12 months)
Metabolic biomarker analysis: Creatinine	Creatinine: Milligrams per deciliter (mg/dL) Estimated Glomerular Filtration Rate (eGFR): Milliliters per minute per 1.73 square meters (mL/min/1.73m²) Sodium: Milliequivalents per liter (mEq/L) Potassium: Milliequivalents per liter (mEq/L) Chloride: Milliequivalents per liter (mEq/L)	Pre and post 48 hour fasts (2 fasts per month for 12 months)
Metabolic biomarker analysis: Estimated Glomerular Filtration Rate (eGFR)	Estimated Glomerular Filtration Rate (eGFR): Milliliters per minute per 1.73 square meters (mL/min/1.73m²)	Pre and post 48 hour fasts (2 fasts per month for 12 months)
Metabolic biomarker analysis: Sodium	Sodium: Milliequivalents per liter (mEq/L)	Pre and post 48 hour fasts (2 fasts per month for 12 months)
Metabolic biomarker analysis: Potassium	Potassium: Milliequivalents per liter (mEq/L)	Pre and post 48 hour fasts (2 fasts per month for 12 months)
Metabolic biomarker analysis: Chloride	Chloride: Milliequivalents per liter (mEq/L)	Pre and post 48 hour fasts (2 fasts per month for 12 months)
Metabolic biomarker analysis: Alanine Aminotransferase (ALT)	Alanine Aminotransferase (ALT): Units per liter (U/L)	Pre and post 48 hour fasts (2 fasts per month for 12 months)
Metabolic biomarker analysis: Aspartate Aminotransferase (AST)	Aspartate Aminotransferase (AST): Units per liter (U/L) Alkaline Phosphatase (ALP): Units per liter (U/L) Total Bilirubin: Milligrams per deciliter (mg/dL) Albumin: Grams per deciliter (g/dL)	Pre and post 48 hour fasts (2 fasts per month for 12 months)
Metabolic biomarker analysis: Alkaline Phosphatase (ALP)	Alkaline Phosphatase (ALP): Units per liter (U/L)	Pre and post 48 hour fasts (2 fasts per month for 12 months)
Metabolic biomarker analysis: Total Bilirubin	Total Bilirubin: Milligrams per deciliter (mg/dL)	Pre and post 48 hour fasts (2 fasts per month for 12 months)
Metabolic biomarker analysis: Albumin	Albumin: Grams per deciliter (g/dL)	Pre and post 48 hour fasts (2 fasts per month for 12 months)
Microbial diversity	Stool/saliva analysis of microbial diversity: Shannon diversity index (no specific units)	Pre and post 48 hour fasts (2 fasts per month for 12 months)
Taxonomic abundance	Stool/saliva analysis of taxonomic abundance: reads per million (RPM)	Pre and post 48 hour fasts (2 fasts per month for 12 months)
Concentrations of metabolites	Stool/saliva analysis of concentrations of metabolites: Micromoles per liter (µmol/L)	Pre and post 48 hour fasts (2 fasts per month for 12 months)
Glycemic and ketone monitoring for adherence assessment	Glucose-Ketone Index (GKI): A calculated value derived from dividing the blood glucose level (in mmol/L) by the ketone level (in mmol/L).	10 times per day for up to 12 months
Wearable health metrics analysis for physiological monitoring	Apple Watch 9 and Whoop data [heart rate variability (HRV), resting heart rate, cardio recovery, sleep duration, composition (stages of sleep) and analogous scores, potential maximum rate of oxygen consumption attainable during physical exertion (VO2 max), basal metabolic rate and potential respiratory rate].	Daily for up to 12 months
Artificial intelligence (AI)-enhanced visual data representation for activity monitoring	Feeding ketone data, glucose data, any/all wearable data, and dietary images into a generative AI platform to convert data into images using any selected prompts, with the intent of the images serving as immediate, visual readouts as a function of activity and/or inactivity.	Once a month for up to 12 months

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Qualitative assessment of participant experience	This outcome involves conducting interviews with the participant to gather qualitative data on the experiences, challenges, and adherence related to the dietary and exercise interventions throughout the study. The interviews aim to provide insights into the participant's perceptions of the interventions, their effects on metabolic health and overall well-being, and any adjustments needed for optimal adherence and outcomes.	Day one, day 8, at study completion (12 months)

Collaborators and Investigators

• Sponsor: Institute for Digital Medicine (WisDM)
• Investigators: Principal Investigator: Dean Ho, PhD, The Institute for Digital Medicine (WisDM)

Publications and helpful links

General Publications

• Tinsley GM, La Bounty PM. Effects of intermittent fasting on body composition and clinical health markers in humans. Nutr Rev. 2015 Oct;73(10):661-74. doi: 10.1093/nutrit/nuv041. Epub 2015 Sep 15.
• Patterson RE, Sears DD. Metabolic Effects of Intermittent Fasting. Annu Rev Nutr. 2017 Aug 21;37:371-393. doi: 10.1146/annurev-nutr-071816-064634. Epub 2017 Jul 17.
• Mandal S, Simmons N, Awan S, Chamari K, Ahmed I. Intermittent fasting: eating by the clock for health and exercise performance. BMJ Open Sport Exerc Med. 2022 Jan 7;8(1):e001206. doi: 10.1136/bmjsem-2021-001206. eCollection 2022.
• Levy E, Chu T. Intermittent Fasting and Its Effects on Athletic Performance: A Review. Curr Sports Med Rep. 2019 Jul;18(7):266-269. doi: 10.1249/JSR.0000000000000614.
• Wang P, Tadeo X, Chew HSJ, Sapanel Y, Ong YH, Leung NYT, Chow EK, Ho D. N-of-1 health optimization: Digital monitoring of biomarker dynamics to gamify adherence to metabolic switching. PNAS Nexus. 2024 May 30;3(6):pgae214. doi: 10.1093/pnasnexus/pgae214. eCollection 2024 Jun.

Study record dates

Study Major Dates

• Study Start (Actual): October 7, 2024
• Primary Completion (Actual): June 7, 2025
• Study Completion (Actual): July 2, 2025

Study Registration Dates

• First Submitted: September 30, 2024
• First Submitted That Met QC Criteria: October 3, 2024
• First Posted (Actual): October 8, 2024

Study Record Updates

• Last Update Posted (Actual): July 4, 2025
• Last Update Submitted That Met QC Criteria: July 3, 2025
• Last Verified: July 1, 2025

More Information

Terms related to this study

• Keywords: N-of-1; Digital Health; Continuous Glucose Monitoring (CGM); Wearable Technology; Sensors; Intermittent Fasting (IF); Ketone Measurement; Exercise Routines; Heat/Cold Interventions; Diet and Supplements; Human Optimization; Single Participant; Personalized Health
• Other Study ID Numbers: HO_prospective

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No