Cognitive Behavioral Therapy for Insomnia as an Adjunct to Time-restricted Eating on Weight Loss in Adults With Overweight or Obesity and Chronic Insomnia

N/ANot Yet RecruitingNCT07770516

Chinese University of Hong Kong50 enrolled

Overview

Obesity (being overweight due to excess body fat) is a common health condition that increases the risk of developing problems such as diabetes, high blood pressure, and heart disease. Time-restricted eating (TRE), which involves eating all meals within a set period each day, has become a popular and simple approach for weight management. However, not everyone achieves the same results from TRE. Research suggests that poor sleep and chronic insomnia can increase hunger, affect food choices, and lead to higher calorie intake, which may make weight loss more difficult. This study aims to examine whether improving sleep can enhance the effectiveness of flexible time-restricted eating (FTRE) for weight loss. Participants will receive either FTRE alone or FTRE combined with Cognitive Behavioural Therapy for Insomnia (CBTI), a well-established treatment for chronic insomnia. By comparing these two approaches, this study will help determine whether addressing sleep problems can improve weight management outcomes in individuals with overweight or obesity and chronic insomnia. The findings may contribute to the development of more effective and comprehensive lifestyle programmes for improving both sleep and weight-related health.

This study aims to investigate whether CBTI can enhance the effectiveness of TRE for weight control in adults with chronic insomnia and overweight or obesity. This assessor-blinded, two-arm, parallel-group randomized controlled pilot trial plans to recruit 50 Chinese adults aged 18 years or older with chronic insomnia and overweight or obesity (BMI ≥23 kg/m²) in Hong Kong. Participants will be randomized (1:1) to a flexible time-restricted eating group (FTRE, n=25) or a flexible time-restricted eating plus CBTI group (CBTI+FTRE, n=25). Both groups will follow a 16:8 time-restricted eating schedule for 12 weeks, while participants in the CBTI+FTRE group will additionally receive a 12-week group-based CBTI program consisting of biweekly 90-minute sessions. Assessments will be conducted at baseline, post-intervention (week 12), and follow-up (week 24). The primary outcome is body weight. Secondary outcomes include body mass index, waist and neck circumferences, body composition, insomnia severity, sleep quality, objective and subjective sleep parameters, physical activity, blood pressure, appetite, food intake, eating window, and exercise habits. We hypothesize that the addition of CBTI to TRE will result in greater weight loss and improved sleep outcomes compared with TRE alone

Study Type

INTERVENTIONAL

Interventions

Flexible Time-restricted eating group (FTRE)BEHAVIORAL

Participants assigned to the FTRE group will be instructed to follow a 16:8 time-restricted eating schedule, consuming food ad libitum within an 8-hour eating window and fasting for the remaining 16 hours of the day. No restrictions will be placed on the type or quantity of foods consumed during the eating window, and participants will not be required to track their energy intake. During fasting periods, participants will be encouraged to maintain adequate hydration by drinking water and may also consume non-caloric beverages, such as plain tea or black coffee. Participants will be allowed to select their preferred 8-hour eating window, provided it begins between 8:00 AM and 12:00 PM and ends between 4:00 PM and 8:00 PM.

Flexible Time-restricted eating plus cognitive behavioural therapy for insomnia group (CBTI+FTRE)BEHAVIORAL

In addition to following the TRE instruction in the TRE group, participants in the CBTI+TRE group will also participate in a 12-week group-based CBTI intervention with biweekly 90-minute sessions. The intervention comprises all CBTI elements, including sleep hygiene, sleep restriction, stimulus control, cognitive restructuring, and stress and relaxation techniques. Intervention will be delivered by trained research personnel.

Eligibility

Sex: ALLMin age: 18 Years

Medical Language ↔ Plain English

Inclusion Criteria: 1. Ethnic Chinese; 2. Age 18 years or older; 3. Fulfill the criteria of chronic insomnia defined by Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition, Text Revision (DSM-5-TR) , which are: i. manifestation of predominant, subpar sleep quantity or quality; ii. exhibition of any sleep difficulties ranging from sleep initiation, sleep maintenance to early awakening with the inability to restore sleep. iii. concomitant presentation of significant distress or impairment, including fatigue or low energy, cognitive impairment, mood disturbance, behavioral problems, impaired occupational or academic functioning, impaired interpersonal or social functioning and negative impact on caregiver or family functioning; iv. sleep difficulty occurs at least three nights per week; v. sleep difficulty has been persistent for at least three months; and vi. sleep difficulty is not affected regardless of adequate opportunity given for sleep. 4. With Overweight or obesity: BMI ≥ 23 kg/m2 5. Weight stable for the past 3 months 6. Habitual eating window ≥ 10 hours Exclusion Criteria: 1. Known cardiovascular disease; 2. Type 1 or 2 diabetes mellitus; 3. Current use of GLP-1 receptor agonists or other prescription weight-loss medications within the past 3 months; 4. Currently on a special or prescribed diet for other reasons; 5. Currently receiving any psychological treatment for insomnia; 6. Previously received CBTI; 7. Night shift workers; 8. Breastfeeding, pregnant or trying to become pregnant; 9. Smokers.

Outcomes

Primary Outcomes

Weight

Body weight will be measured using a bioelectrical impedance analyzer (BIA) to the nearest 0.1 kg following a minimum 4-hour fast. Participants will be instructed to void their bladder immediately before the assessment, remove their shoes and heavy clothing, and stand upright on the analyzer platform during the measurement.