"…people with NES tend to be more depressed than obese people without NES, and the mood of those with NES tends to worsen during the evening, something not seen in other obese people"(Logue, 2004, p. 185).
Among the many studies that provide insight into the background and origins of this syndrome, one of the most enlightening was Obesity by Stunkard, in Fairburn and Brownell (2002). This provides an in-depth analysis of night eating syndrome as well as a concise overview of the background of this condition. Stunkard also refers to a detailed overview of this condition.
Studies using the above criteria estimate that the prevalence of the night eating syndrome in the general population is approximately 1.5% and that prevalence increases with increasing weight, from about 10% of persons enrolling in obesity clinics to as high as 25% of patients undergoing surgical treatment for obesity…it occurs among about 5% of those presenting for the treatment of insomnia (although other sleep-related eating disturbances are also seen in which patients are either partially or totally unconscious). (Fairburn & Brownell, 2002, p. 183)
Of particular interest to the topic of this proposal are the behavioral characteristics of those who suffer from this syndrome. Stunkard refers to the different behavioral patterns in NES or night eating syndrome patients and those suffering from obesity.
The more striking difference between the two groups was in the temporal pattern of their food in- take….the cumulative caloric intake of the night eaters lagged behind that of the control subjects so that, by 6:00 P.M., they had consumed only 37% of their daily intake compared to 74% by the controls. The food intake of the controls slowed during the evening, while that of the night eaters continued at a rapid pace until after midnight. During the period from 8:00 P.M. To 6:00 A.M., the night eaters consumed 56% of their caloric intake, compared to 15% for the control subjects. (Fairburn & Brownell, 2002, p. 184)
As the above quotation suggests, another concern that is often noted in the literature on this subject is the complex and often controversial intersection between this condition and other eating disorders and obesity. Fairburn & Brownell ( 2002) note that researchers and experts are in agreement that, "NES shares characteristic of not only eating disorders but also sleep and mood disorders" (Fairburn & Brownell, 2002, p. 183). This is an important point as it views night eating syndrome in a holistic light which attempts to link it to other conditions and especially to stress and anxiety that the individual may experience. "Sufferers tend to exhibit symptoms such as feelings of anxiety and guilt, insomnia or interrupted sleep" (Fairburn & Brownell, 2002, p. 183).
Fairburn & Brownell ( 2002) also refer to the importance of a renewal of interest in the link between eating disorders and obesity. The authors of this study state that the view that obesity was believed to be due to an eating disorder is simplistic and does not take other factors such as disturbed eating patterns into consideration.
This simplistic view is no longer held and, as a result, for some time little attention was paid to the possibility that disturbed eating might contribute to obesity. This situation is changing, and two eating disorders have now been linked to obesity. The first is binge eating disorder & #8230;and the second is the night eating syndrome. (Fairburn & Brownell, 2002, p. 183)
This study therefore stresses the link between night eating disorder and obesity and this in turn has direct consequence for the cycle of stress and depression that the individual may experience.
The issue of prevalence and the demographics of this syndrome have also been a focus of research. A study by Lundgren (2006) conducted between University of Pennsylvania and the University of Minnesota, estimates that "… the prevalence of NES among patients seeking psychiatric services in university-based outpatient treatment clinics… NES was surprisingly high, with 12.3% of the sample meeting criteria based on a comprehensive telephone interview "(Lundgren, 2006, p.156). Importantly, this study also found a high correlation between obesity and night easting syndrome (Lundgren, 2006, p.156).
Another study by de Zwaan et al. ( 2003) suggest that while NES appears to be more common among obese individuals, "… within the obese, the lack of consistency in criteria used to diagnose NES, differences in patient populations and differences in methodology to assess NES, have contributed to a wide range of prevalence estimates" (de Zwaan et al., 2003, p.12). What is of special significance in the findings from the study by Lundgren is that; " These findings not only confirmed our hypothesis that night eating is associated with greater psychiatric comorbidity, but once again showed that night eating is associated with obesity" (Lundgren, 2006). This study therefore points to two aspects that have an impact on the life experience and the quality of life of individuals that suffer from this syndrome; namely, obesity and psychological disorders such as depression.
There are also various studies on strategies to overcome the disorder; for example, relaxation and visualization exercises are stressed as an important part of dealing with the syndrome -- which again sheds light on the issue of life experience (Overcoming Night Eating Syndrome: A Step-by-step Guide to Breaking the Cycle). Insight into some of the most recent research findings and developments is dealt with by Lundgren (2006).
Life Experience and Impact of the Condition
The above study by Lundgren (2006 emphasizes the comorbid aspects of this condition. Besides the issue of obesity, Lundgren refers to the association of night easting syndrome with" depressed mood and life stress" (Lundgren, 2006). "NES was more likely to occur among patients with a lifetime history of substance use disorders but not more likely to occur among patients diagnosed with mood disorders, anxiety disorders, psychotic disorders, or personality disorders" (Lundgren, 2006). This is an association that is encountered in various degrees and forms in the literature and which plays a significant role in ascertaining life experience and the impact of the syndrome.
The central factor of stress and tension in the lives of individuals who suffer from this condition is explored in an article by Theyer (2003) entitled Calm Energy: How People Regulate Mood with Food and Exercise. This study refers to research on behavior patterns of the individual who indulges in night-eating. The study explores the link between obesity, night-eating and anxiety or depression. As Thayer states in the study; "One researcher described personal interviews with obese night eaters who said they felt distressed and hopeless by their inability to stop eating at night, although they could maintain their diet during the day" (Thayer, 2003, p. 119).
This quotation emphasizes the feeling of helplessness and hopelessness that many individuals experience in their daily lives. This is added to by the inability to control excessive night eating. This also points to a cyclical situation where night easting leads to obesity, which in turn leads to further anxiety and depression. The study suggests that the underlying causative factors in this condition must be addressed to prevent a cycle of this nature from becoming self-perpetuating. As Stunkard has stated, "Not only is night eating syndrome an eating disorder, but one of mood & sleep as well…" (Night Eating). This has important implications that will be explored in this study in terms of the experience and situation of the individual.
The link between mood, feelings of anxiety and depression are emphasized by Stunkard. "Dr. Stunkard feels that night eating may be a way that people with an underlying mood disorder such as stress, anxiety or depression, may be trying to medicate themselves with food" (Night Eating).
The issue of mood in patients with this disorder is also discussed in Fairburn & Brownell ( 2002). "Changes in the mood of the night eaters were also distinctive" (Fairburn & Brownell, 2002, p. 184).
An important aspect referred to in the above study by Fairburn and Brownell, (2002) is the neuroendocrinology of the night eating syndrome. Research by Birketvedt et al. is referred to. This research found"… highly significant differences between night eaters and control subjects in plasma levels of melatonin, leptin, and cortisol… melatonin levels at night in the night eaters were significantly lower than those of controls" (Fairburn & Brownell, 2002, p. 185). The research also noted that, "The big difference between the night eaters and control subjects lay in their nighttime responses" (Fairburn & Brownell, 2002, p. 185).
Importantly, a study by Stunkard found that, "Thus, night eating syndrome appears to be a unique combination of eating disorder, sleep disorder, and mood disorder. A distinctive neuroendocrine pattern helps to link these three dimensions" (Fairburn & Brownell, 2002, p. 186). Furthermore, it has been found that lower levels of melatonin have been linked to depression and may be as factor in the mood structure of those who suffer from night eating disorder.
The issue of stress and tension in the lifestyles of those affected…