Renia and bipolar disorder who are also obese.21,108 Higher BDI scores are consistently found in NES subjects in comparison with control groups, with some evidence that degree of obesity may impact on the score.25,56,104 Many obese individuals describe overeating in the evening as a result of low mood as a main contributor to their obesity. It is possible that other factors related to obesity such as low self-esteem and shame are contributing to the degree of depression and influencing NE behaviour. Assessing the effect of obesity-related comorbidity on NES is difficult as evidence of the level and impact of OSA and type 2 diabetes in obese NES groups is limited.17,22,33 Although Olbrich109 suggests the construct of OSA is not closely related to NES, more evidence is required to support this as obesity-related comorbidity is often excluded from NES studies, not reported or assessment is based on incomplete NES criteria.9,22 Future directions Despite progress being made in the characterisation of NES, unanswered questions remain. It is viewed as both a circadian rhythm and ED. It is either relatively common or rare, depending on which criteria are adopted. Evidence from European and American studies suggests that it may feature strongly in some high-risk groups, such as obese and psychiatric populations. Whether this affects treatment outcomes is unclear with evidence from one weight loss programme suggesting NES participants fared no worse than others without NES.110 Further investigation is recommended on its relationship with traumatic life events, psychiatric comorbidity, the age of onset, course over time and effect on circadian rhythm. Bright light Tyrphostin AG 490 side effects therapy is also proposed as a possible treatment.2 Recent interest in the clock gene as a potential influence on obesity suggests that future studies examining circadian and endocrine desynchronicity should control for obesity.111 Current tools for investigating NES may be inadequate in severe obesity. Despite widespread use, the current NESHI lacks validation and no longer reflects updated criteria. A revised version is due for publication in the near future. Items are required to measure distress and impairment in functioning objectively and items relating to the characterisation of poor sleep and key diagnostic areas such as defining `supper’ and `degree of awareness’ need greater precision. More precise methods to identify calorie intake are also required, although in obese populations it may be less important to estimate exact volumes of food eaten and more important to identify abnormal cognitions and behaviour. Night-eaters exhibit too many features of other ED for this relationship to be ignored and previous guidance to L-660711 sodium salt site separate NES from other ED was probably counter-productive and a hindrance to its characterisation. Given that all factors identified through principal components analysis in the NEQ are also common in obesity, tools based on other characteristics may help discriminate NES further in obese populations.35 It is possible that different tools are required for an underweight teenager and a morbidly obese adult. Conclusion Understanding the significance of factors such as sleep duration, sleep quality, depression and other comorbidity in the development and existence of NES in obese populations is in its infancy.Nutrition and DiabetesNight eating syndrome J Cleator et al8 Current NES criteria propose that a diagnosis of NES is not appropriate if it is secondary to othe.Renia and bipolar disorder who are also obese.21,108 Higher BDI scores are consistently found in NES subjects in comparison with control groups, with some evidence that degree of obesity may impact on the score.25,56,104 Many obese individuals describe overeating in the evening as a result of low mood as a main contributor to their obesity. It is possible that other factors related to obesity such as low self-esteem and shame are contributing to the degree of depression and influencing NE behaviour. Assessing the effect of obesity-related comorbidity on NES is difficult as evidence of the level and impact of OSA and type 2 diabetes in obese NES groups is limited.17,22,33 Although Olbrich109 suggests the construct of OSA is not closely related to NES, more evidence is required to support this as obesity-related comorbidity is often excluded from NES studies, not reported or assessment is based on incomplete NES criteria.9,22 Future directions Despite progress being made in the characterisation of NES, unanswered questions remain. It is viewed as both a circadian rhythm and ED. It is either relatively common or rare, depending on which criteria are adopted. Evidence from European and American studies suggests that it may feature strongly in some high-risk groups, such as obese and psychiatric populations. Whether this affects treatment outcomes is unclear with evidence from one weight loss programme suggesting NES participants fared no worse than others without NES.110 Further investigation is recommended on its relationship with traumatic life events, psychiatric comorbidity, the age of onset, course over time and effect on circadian rhythm. Bright light therapy is also proposed as a possible treatment.2 Recent interest in the clock gene as a potential influence on obesity suggests that future studies examining circadian and endocrine desynchronicity should control for obesity.111 Current tools for investigating NES may be inadequate in severe obesity. Despite widespread use, the current NESHI lacks validation and no longer reflects updated criteria. A revised version is due for publication in the near future. Items are required to measure distress and impairment in functioning objectively and items relating to the characterisation of poor sleep and key diagnostic areas such as defining `supper’ and `degree of awareness’ need greater precision. More precise methods to identify calorie intake are also required, although in obese populations it may be less important to estimate exact volumes of food eaten and more important to identify abnormal cognitions and behaviour. Night-eaters exhibit too many features of other ED for this relationship to be ignored and previous guidance to separate NES from other ED was probably counter-productive and a hindrance to its characterisation. Given that all factors identified through principal components analysis in the NEQ are also common in obesity, tools based on other characteristics may help discriminate NES further in obese populations.35 It is possible that different tools are required for an underweight teenager and a morbidly obese adult. Conclusion Understanding the significance of factors such as sleep duration, sleep quality, depression and other comorbidity in the development and existence of NES in obese populations is in its infancy.Nutrition and DiabetesNight eating syndrome J Cleator et al8 Current NES criteria propose that a diagnosis of NES is not appropriate if it is secondary to othe.
