Chrono-ALIGN: A Chronotype-Based Chrono-Nutrition Intervention in Post-Bariatric Patients

Summary

This randomized controlled trial will evaluate the impact of chrono-nutrition, a dietary approach that aligns meal timing with the body's circadian rhythms, on weight change, metabolic outcomes, appetite, and gut microbiota in post-bariatric surgery patients. A total of 246 adults who underwent sleeve gastrectomy at least six months earlier will be enrolled at King Saud Medical City. Participants will be randomized to receive either standard post-bariatric nutritional care or personalized chrono-nutrition based on individual chronotype. Outcomes include weight change, metabolic biomarkers, dietary behaviors, sleep patterns, and gut microbiota composition. The study aims to determine whether integrating chrono-nutrition into post-bariatric follow-up can enhance metabolic health and improve long-term health.

Conditions

• Obesity (Disorder)
• Morbid Obesity
• Bariatric Sleeve Gastrectomy
• Meal Time
• Chronotype
• Circadian Rhythm

Interventions

BEHAVIORAL

Standard Post-Bariatric Care (Control)

Participants receive routine post-bariatric nutritional care with no prescribed meal-timing window. Dietitians provide standard guidance on protein adequacy (\~60-80 g/day unless otherwise indicated), hydration, and routine micronutrient supplementation per clinic practice. Follow-ups occur at 3, 6, and 12 months; outcomes include body weight, metabolic markers, appetite-related hormones, questionnaires, wearables, and stool samples. This arm controls for the effects of usual care and non-timing dietary counseling.

BEHAVIORAL

Early Time-Restricted Eating (eTRE)

Participants consume all caloric intake within a fixed daytime 10-hour window (08:00-18:00) on ≥6 days/week. Water/unsweetened tea/black coffee are allowed outside the window. Diet composition follows bariatric guidelines (protein \~60-80 g/day, hydration, routine micronutrients). Dietitians provide structured meal-timing plans and problem-solving support; timing logs and wearables document adherence. Assessments at 3, 6, and 12 months mirror the control arm.

BEHAVIORAL

Chronotype-Based Chrono-Nutrition (CB-CN)

Meal timing is personalized to chronotype (morning/intermediate/evening) determined with the Munich Chronotype Questionnaire (MCTQ). Plans target an earlier first meal and completion of the last meal ≥3-4 h before habitual bedtime, with an eating window of \~10 h/day on ≥6 days/week, adjusted to chronotype using stepwise phase-advance strategies where needed. Diet composition follows bariatric guidelines (protein, hydration, micronutrients). Timing logs and wearables track adherence; visits at 3, 6, and 12 months.

Sponsors & Collaborators

• King Saud Medical City

  collaborator OTHER_GOV

• King Saud University

  lead OTHER

Principal Investigators

• Amani A Al-Farraj, Master · King Saud University

Study Design

Allocation

RANDOMIZED

Purpose

TREATMENT

Masking

SINGLE

Model

PARALLEL

Eligibility

Min Age

18 Years

Max Age

50 Years

Sex

ALL

Healthy Volunteers

Yes

Timeline & Regulatory

Start

2026-01-01

Primary Completion

2027-12-01

Completion

2028-12-01

Countries

• Saudi Arabia

Study Locations