Westlake Precision Nutrition Study 2 (WePrecision2)
Condition: Healthy; Overweight and Obesity
MeSH terms: Overweight
Study type: Interventional

Summary: 
      This is a dietary intervention study, which aims to explore different diet challenges for
      glucose metabolism, including carbohydrates and fasting dietary pattern. Considering the
      glucose responses to the same food are largely heterogeneous among people, this study
      integrates the concepts of precision nutrition and N-of-1 design. The study also aims to
      discover the different impact of the time-restricted diet (TRD) and the energy-restricted
      diet (ERD) on host metabolic health and our hair growth.
    

Detailed description: 
      The project is mainly based on classic field trial study design to compare impacts of
      different fasting patterns on host metabolic health. Under the condition of controlled diet
      background, individual N-of-1 study design is also organically integrated to compare
      personalized responses for standard meal tests. Participants will be required to wear
      continuous glucose monitoring (CGM) for 14 days. The diet intervention will be carried out
      after wearing CGM on Day 1. Then, all participants will be divided into three groups:
      energy-restricted diet (ERD), 18:6 time-restricted diet (TRD), and normal diet (ND). During
      Day 3 to Day 12, ERD restricts daily total energy intake within 1200-1500 kcal without meal
      timing limits, while TRD restricts the daily feeding window from 10:00 to 16:00, without
      total energy intake restriction. ND will maintain volunteers' original eating habits and
      rhythms as the control group. Individual N-of-1 trial design will be employed to all
      participants during Day 3 to Day 12 to compare the difference of postprandial glucose
      response to white bread or plain oats. These two standard breakfasts will appear in
      pseudo-random order. The TRD group needs to adjust the breakfast time to after 10:00 in the
      intervention periods.
    

Intervention name(s): refined carbohydrate breakfast; whole grain breakfast; energy-restricted diet; time-restricted diet
Intervention type(s): Other; Other; Other; Other
Intervention description(s): After wearing CGM on Day 1, participants will be provided with breakfast A once daily on Day 3, Day 4, Day 7, Day 8, Day 10, Day 12. Breakfast A contains white bread (50g) and milk powder (25g). Since lunch and dinner would serve as wash-out meals, participants will be free to choose food but provide a record of their diets.; After wearing CGM on Day 1, participants will be provided with Breakfast B once daily on Day 5, Day 6, Day 9, Day 11. Breakfast B contains plain oats (35g) and milk powder (25g). Since lunch and dinner would serve as wash-out meals, participants will be free to choose food but provide a record of their diets.; After completing the baseline data and biological sample collection, the ERD group volunteers underwent a 10-day dietary intervention from day 3 to day 12. During this period, a standard breakfast was provided to all volunteers daily by the research staff through the school cafeteria. The ERD group volunteers still had their lunch and dinner provided by the research staff through the school cafeteria to ensure their daily energy intake was controlled between 1200-1500 kcal.; After completing the baseline data and biological sample collection, the volunteers in the TRD group will undergo a 10-day dietary intervention from day 3 to day 12. The TRD group needs to adjust their breakfast eating time to after 10:00 am daily, and they are free to choose their own lunch and dinner according to their dietary habits but must finish their meals before 4:00 pm. During this time window, no other energy-providing foods should be consumed.
Other intervention name(s): Breakfast A; Breakfast B; ERD; TRD
Allocation: Randomized
Intervention model: Crossover Assignment
Masking: Single (Participant)
Primary purpose: Prevention
Keywords: Personalized Nutrition; N-of-1; fasting; glucose metabolism; hair growth