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

Effects of Cognitive Behavioral Therapy for Insomnia (CBTI) as an Adjunct Intervention for Time-restricted Eating on Weight Loss in Adults With Overweight or Obesity and Chronic Insomnia

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.

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.