Highlight
- Cognitive behavioural therapy for insomnia (CBTi) significantly improves self-reported sleep duration and quality in overweight adults.
- CBTi reduces cravings for sweet and savoury foods, improving food craving control and shifting implicit food preferences.
- Objective accelerometer data showed no significant differences in sleep duration or efficiency, suggesting subjective improvements may precede measurable changes.
- No clear evidence found yet for changes in actual dietary intake post-intervention, possibly due to under-reporting and limited sample size.
Study Background and Disease Burden
Short sleep duration and poor sleep quality have been consistently linked to increased caloric intake and a heightened preference for sweet, energy-dense foods. These factors contribute to the development and persistence of overweight and obesity, which are global public health concerns associated with increased morbidity and mortality risks, including cardiovascular disease, diabetes, and metabolic syndrome. Insomnia is a common comorbidity in individuals with overweight and obesity and may exacerbate eating behaviours that promote weight gain. Thus, interventions that improve sleep could potentially influence dietary behaviours and assist weight management strategies. Cognitive behavioural therapy for insomnia (CBTi) is an evidence-based approach recommended for improving sleep without medication, but its effects on food preferences and craving control have not been fully established.
Study Design
This randomized controlled trial enrolled 27 adults with overweight or obesity (BMI ≥ 25 kg/m²), short sleep duration ( 5). Participants were randomized to receive 8 weeks of CBTi (n=14) or serve as controls (n=13). Outcome measures included self-reported sleep duration and quality, daytime sleepiness (Epworth Sleepiness Scale), accelerometer-measured sleep parameters, three-day dietary food diaries, food craving assessments (Control of Eating Questionnaire), and explicit and implicit food preferences (Leeds Food Preference Questionnaire). Assessments were conducted before and after the intervention period.
Key Findings
The CBTi group self-reported a significantly greater increase in sleep duration (+1.11 ± 0.21 hours) compared to controls (+0.29 ± 0.30 hours; p=0.01). Sleep quality improved markedly in the CBTi group (PSQI reduction of -5.86 ± 0.73) versus controls (-0.62 ± 0.92; p=0.00002). Daytime sleepiness decreased significantly (-2.64 ± 0.80) with CBTi compared to an increase in the control group (+1.54 ± 0.66; p=0.00004). However, objective accelerometer data revealed no significant differences between groups in sleep duration or efficiency.
Importantly, the CBTi group demonstrated enhanced control over food cravings (+21.9 ± 4.7 mm) compared to controls who experienced a slight decline (-3.0 ± 4.3 mm; p=0.002). Cravings for sweet (-16.4 ± 6.0 mm vs +3.3 ± 4.2 mm; p=0.01) and savoury foods (-15.0 ± 3.0 mm vs +0.8 ± 4.8 mm; p=0.003) decreased more among CBTi participants. Implicit wanting for low-fat savoury foods increased (+12.3 ± 3.2) while that for high-fat sweet foods decreased (-15.8 ± 7.4) in the CBTi group versus respective changes in controls (-2.1 ± 3.1 and +9.8 ± 4.4; p=0.006 and p=0.001 respectively).
Regarding dietary intake, substantial under-reporting was evident with 19 participants reporting energy intakes below 1.1 times their basal metabolic rate. Among those who provided valid dietary data, no statistically significant differences were found between groups in changes to total energy intake or macronutrient composition, although limited statistical power due to small sample size must be acknowledged.
Expert Commentary
This trial provides compelling evidence that psychological interventions targeting sleep can positively influence food-related behaviours and preferences in adults with overweight and obesity. The observed subjective improvements in sleep and reductions in food cravings suggest a potential pathway through which improved sleep quality may contribute to healthier eating patterns. However, the lack of objective changes in sleep measured by accelerometer and absence of clear dietary intake modifications warrant cautious interpretation. Measurement challenges including under-reporting and the complexity of accurately assessing habitual dietary intake highlight ongoing methodological limitations in this field.
The neurobiological mechanisms underpinning these findings may involve improved regulation of appetite-related hormones (e.g., leptin, ghrelin) and altered reward processing circuits linked to food motivation following sleep restoration. Future studies incorporating biomarker analyses, larger sample sizes, and longer follow-up periods will be critical to determine the clinical significance of these behavioural changes and their impact on weight management outcomes.
Conclusion
Cognitive behavioural therapy for insomnia in overweight and obese adults enhances self-perceived sleep quality and duration, improves control over food cravings, and modifies implicit preferences toward healthier food options. While objective sleep improvements and clear dietary intake changes were not observed, the findings highlight CBTi as a promising adjunctive intervention for addressing modifiable behavioural risk factors associated with obesity. Further research is necessary to elucidate translation into long-term dietary behaviour modifications and weight loss.
References
Merchant AM, Gray SR, Gray CM, Finlayson G, Manyara AM, Gabler Trisotti MF, Gill JMR. Effect of a cognitive behavioural therapy intervention to improve sleep on food preferences: A randomized controlled trial in adults with overweight and obesity. Appetite. 2025 Aug 1;212:108022. doi: 10.1016/j.appet.2025.108022. Epub 2025 Apr 25. PMID: 40288612.
