Westlake Precision Nutrition Study 2 (WePrecision2) (WePrecision2)

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.

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.

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.

Serum inflammatory factors (including IL-1β, IL-6, and IL-12) will be tested by enzyme-linked immunosorbent assay (ELISA) in pg/mL.

Triglyceride, cholesterol, high density lipoprotein cholesterol, low density lipoprotein cholesterol, apolipoprotein A1 and apolipoprotein B.

Inclusion Criteria: Participants have completed WePrecision trial in 2021 Participants reside in Hangzhou Participants have no traveling plans within 3 months Exclusion Criteria: Participants with metabolic diseases including diabetes, hypertension and cardiovascular diseases (CVD) Participants with craniocerebral trauma, cancer, liver disease, kidney disease, or other critical illness, or history of operation or medication Participants with bulimia nervosa, post-traumatic stress disorder (PTSD), chronic anxiety and depression or other critical neuronal disorder or history of relevant medication Being or to be pregnant or lactating. Participants with history of alcohol or drug addiction, or smoke above 15 cigarettes per day Concurrently participating other clinical trials.