The first study to investigate cognitive behavioral therapy (CBT) for NES was conducted by Allison and colleagues8
in response to the observed cognitive component of night eating behavior. A central feature of this disorder is, “If I don’t eat, I won’t be able to fall asleep.” Vinai and colleagues have found that this thought distinguishes persons with NES from those with binge eating disorder.20
Allison et al.8
designed a cognitive behavioral treatment to target NES-specific symptoms by adapting features from CBT protocols for binge eating disorder21
and behavioral weight loss.22
The primary goal of CBT for NES is to correct the delay in circadian eating rhythms by shifting food intake to earlier in the day, while simultaneously interrupting the overlearned relationship between night time eating, faulty cognitions, and sleep onset.23
The strategies used to achieve these treatment goals include a combination of behavioral weight management components (monitoring food consumption, regulating meals and snacks, restricting daily caloric intake) and cognitive therapy components (identifying, evaluating, and restructuring maladaptive thoughts).
Allison et al.8
studied 25 participants with NES who were enrolled in a 10-session, uncontrolled CBT intervention that lasted 12 weeks; 14 participants completed the treatment. It is difficult to know with certainty why the attrition rate was so high, but clinical observations suggested factors that included: 1) feeling overwhelmed with keeping a food and sleep log each day; and 2) not losing more weight than desired in the early weeks. Future studies should stress the importance of daily logging and should set realistic weight management goals to help maximize treatment adherence.
Similar to observations from the sertraline treatment studies, significant reductions in all primary and secondary treatment outcomes were noted following completion of the 10-week CBT program, including reductions in the proportion of calories consumed after dinner, falling from 35% to 25%, and the number of nocturnal ingestions, falling from 8.7 per week to 2.6 ingestions per week (see ). Mixed modeling regression models were used to account for participant drop-out. Closer examination of night time eating showed a significant reduction in the proportion of calories consumed between sleep onset and morning awakening (15% to 5%), but not in the proportion of calories consumed between the evening meal and sleep onset (21.8% to 21.0%). Results from secondary outcome measures indicated significant decreases in daily caloric intake (2365 kcal/d to 1759 kcal/d), total number of awakenings (13.5/wk to 8.5/wk), body weight (−3.1kg), and NESS scores (29 to 16). Finally, BDI-II scores significantly decreased (9 to 6.5) and QLES-Q scores significantly increased (47.2 to 49.6), suggesting improved mood and quality of life, respectively. However, these latter improvements are small in magnitude when examining the clinical relevance of these changes. Study limitations, including the high attrition rate and the absence of a control group, require a tentative interpretation of the findings until these results are replicated under more controlled settings.
The implications from this research are promising and highlight the need for future randomized controlled trials. In particular, the CBT treatment seemed to be more effective in reducing eating during the night, than in reducing the proportion of eating before bedtime. This suggests that more time during sessions may be dedicated to addressing eating during the evening. It may be that more distress is associated with eating during the night, such that more effort is expended trying to eliminate that behavior. Future CBT studies for this population should improve intervention efforts in shifting this evening eating to earlier in the day.
Although food log data are imperfect, Allison et al.’s8
study suggested that patients can engage in behavioral weight loss while decreasing their nocturnal ingestions. The data revealed that participants had reduced their total daily intake by about 600 kcal/day, starting after week 3 when calorie counting was introduced. Given this information, the lack of change in the proportion of intake after the evening meal suggests that the circadian delay in energy intake remained present at the end of treatment, although not as pronounced when nocturnal ingestions were more frequent. It therefore appears that these individuals may benefit from maintaining their current level of energy intake but distributing it more evenly across breakfast, lunch, and daytime snacks. A recent study suggests that a positive and independent relationship exists between intake after 8:00 pm and BMI,24
although larger studies are needed to confirm this finding.
CBT case example ()
Carol presented for treatment of her NES, stating that her night eating began in her teen years. She offered that both of her parents had NES, and that her husband also now gets up to eat with her. When she married her husband and first lived independently at the age of 20, she did not think her NES was significant, because her parents did it too. Now in her 40s, the behavior had become particularly distressing because she was having trouble controlling her weight, which had risen to a BMI of 26 kg/m2 from 21 kg/m2 that she had maintained since the birth of her children about 20 years prior.
Carol woke most days before 7 am. She drank coffee, but did not eat until the afternoon, sometime between 12 – 2 pm; a couple days per week she did not eat anything until dinnertime. She prepared a home-cooked meal for dinner at 6 pm. Carol enjoyed coffee afterwards, but generally did not snack. Her bedtime has varied over the years, but at treatment intake she was going to bed at 9 or 10 pm without any initial insomnia. Then, every night at 2 am, she awoke and felt compelled to eat. She would occasionally use the bathroom first, but then headed to the kitchen where she would eat milk and cookies, pasta, peanut butter and jelly, and/or raisins. She reported that before she goes to bed, she knows she will wake up to eat. She makes it a priority to have food on hand, even when traveling. She stated that she would surely be up all night if she did not have something to eat. She described her experience as feeling the need for her stomach to be full before she can go back to sleep.
At treatment baseline, she was consuming 25.1% of her intake after dinner, and she reported 6 awakenings with 6 nocturnal ingestions in the previous week. Her average daily caloric intake from her food and sleep journal was 2078 kcals, and her baseline NESS score was a 29. She reported no significantly depressed mood, with a BDI score of 5.
Carol successfully started using stimulus control techniques by ridding her kitchen of the foods she most often ate during the night. Living with her husband and son prevented complete control of these foods, but her nocturnal ingestions decreased slowly and consistently across the weeks. She also worked to eat earlier in the day and to monitor her caloric intake while aiming for a goal of 1200–1500 kcals per day. She also engaged in cognitive restructuring regarding her beliefs about her need to eat during the night. We framed our approach with the idea that she needed to re-train her body not to expect food during the night.
At the end of the 10 sessions, Carol reported her first week without any nocturnal ingestions. Her proportion of calories consumed after dinner had decreased to 16.3%, based on her food journal, and her NESS score decreased to 13. Her BDI score stayed low throughout treatment, ranging between a score of 0–3. Carol moved out of the country after treatment. At an 8-month follow-up, her NESS score remained at a 14, and she was consuming 14% of her intake after dinner. However, she reported four awakenings and two nocturnal ingestions in that previous week, suggesting that she could have benefitted from a longer duration of treatment or occasional booster sessions.
Behavioral chain for Carol’s typical night eating episode.