Validation of screening questions and symptom coherence of night eating in the Swedish Twin Registry.

BACKGROUND: Screening criteria have been used to estimate the prevalence of night eating syndrome (NES), but no validation studies have been conducted. METHOD: We examined the validity of two screening questions for NES using a structured interview with adults enrolled in the Swedish Twin Study of Adults: Genes and Environment (STAGE) study. We also examined the coherence of the proposed diagnostic criteria for NES. A total of 416 participants (men=179; women=237) completed the interview and reported complete data for study inclusion. RESULTS: The following values were calculated for the screening items after confirmation by interview for men and women, respectively: positive predictive value=.66 and .67, negative predictive value=.52 and .45, sensitivity=.62 and .63, and specificity=.56 and .50. As increasingly stringent diagnostic criteria were applied to the sample, prevalence of NES dropped. Nocturnal ingestions were more likely to co-occur with other NES symptoms than evening hyperphagia, which occurred frequently, but often in isolation; women were more likely to report a co-occurrence of symptoms than men, who were not likely to report distress related to NES symptoms. CONCLUSION: In sum, almost two-thirds of participants were correctly identified as having NES (without considering distress or impairment) if they answered positively on the screening questions, and about half of the participants were correctly identified as not having NES when answering negatively on the screening questions. Although self-report questions are somewhat informative, a structured interview remains the gold standard for diagnosing NES.

An open-label efficacy trial of escitalopram for night eating syndrome.

OBJECTIVE: Night eating syndrome (NES) has become increasingly recognized as a disorder in need of effective treatments. Selective serotonin reuptake inhibitors have shown efficacy in previous trials, so we sought to expand our understanding of the efficacy of escitalopram in the current trial. METHOD: Thirty-one adults with NES participated in a 12-week open-label trial of escitalopram. Outcome measures included the Night Eating Symptom Scale (NESS), percent of daily intake after the evening meal (% intake) and number of nocturnal ingestions/week (NI), weight, total awakenings/week, mood, and quality of life. Mixed-effects models were used to assess change over time. RESULTS: Significant reductions were observed from week 0 to week 12 for the NESS (30.2 to 15.2), % intake (46% to 17%), NI (5.8 to 1.2), weight (90.2 to 88.6 kg), awakenings (8.1 to 2.7), and BDI-II (12.1 to 7.7). Outcomes did not differ significantly by gender, age, race, or psychiatric co-morbidity status. Eighteen of 31 completed 12 weeks of treatment. DISCUSSION: This open-label trial of escitalopram showed significant reductions in symptoms associated with NES. Randomized controlled trials are warranted to test these findings. TRIAL REGISTRATION: clinicaltrials.gov identifier: NCT01401595.

Lifetime medical and psychiatric comorbidity of night eating behavior in the Swedish Twin Study of Adults: Genes and Environment (STAGE).

The medical and psychosocial comorbidity of two core features of night eating syndrome (NES), evening hyperphagia (EH) and nocturnal awakening and ingestion of food (NI), was evaluated in adults enrolled in the Swedish Twin Study of Adults: Genes and Environment (STAGE) study. As part of the STAGE study, more than 20,000 participants completed assessments of their physical and mental health, which included two night eating screening questions designed to assess EH and NI. STAGE participants who completed a night eating validation interview to confirm the presence or absence of night eating and who had comorbidity data available (n=463) were compared on the lifetime prevalence of several psychiatric and medical conditions. In contrast to previous studies, night eating (EH and/or NI) was not significantly associated with lifetime history of any mental or physical health variable.

Prevalence and familial patterns of night eating in the Québec adipose and lifestyle investigation in youth (QUALITY) study.

The prevalence and familial patterns of night eating syndrome (NES) in families enrolled in the Québec Adipose and Lifestyle InvesTigation in Youth (QUALITY) study was examined. Families (n = 395; one child, mother, and father for whom at least one parent was obese or had abdominal obesity) completed the Night Eating Questionnaire (NEQ) as part of a longitudinal study on the development of metabolic disease in children at risk for obesity. Responses on the NEQ were used to establish a diagnosis of NES and to determine the correlation and heritability of NES symptoms in families. Using comprehensive research diagnostic criteria, full threshold NES was rare: 0% of children, 0.5% of mothers, and 0.3% of fathers met criteria. When controlling for age, sex, and BMI, NEQ scores of spouses were not significantly correlated, but mothers' NEQ scores were significantly correlated with the scores of both sons (r = 0.19, P < 0.001) and daughters (r = 0.15, P = 0.05). The heritability of NEQ scores was 0.24 when controlling for age, sex, and BMI. These findings replicate previous research suggesting a low prevalence of night eating behavior in children and the aggregation of NES in families.

Validity of the night eating questionnaire in children.

OBJECTIVE: To measure the construct validity of the Night Eating Questionnaire (NEQ) in children against a parent report of child night eating syndrome (NES) symptoms (NEQ report) and a 3-day dietary recall. METHOD: NEQ of 304 children from the QUALITY (QUébec Adipose and Lifestyle InvesTigation in Youth) cohort were compared to a parent report and 3-day dietary recall. RESULTS: Child NEQ scores were related to the parent NEQ report (ρ = 0.30 p < 0.0001) yet there were inconsistencies between responses concerning sleep troubles. Total child NEQ scores, but not parent NEQ report scores, were associated with dietary manifestations of NES such as increased evening (ρ = 0.20, p < .001) and reduced morning intake (ρ= -0.12, p < .05). DISCUSSION: The NEQ score is related to eating patterns of NES in children and is more informative than a parent report, specifically when used in conjunction with dietary recall.

Maternal obesity associated with inflammation in their children.

BACKGROUND: This study explored the association between maternal obesity during pregnancy and the inflammatory markers, tumor necrosis factor-α, interleukin-6 and high sensitivity C-reactive protein (hs-CRP), and the cytokine, adiponectin, in the offspring. METHODS: Weight, height, Tanner stage and biomarkers were measured in thirty-four 12-year-old children, from the Infant Growth Study, who were divided into high risk (HR) and low risk (LR) groups based on maternal pre-pregnancy body mass index (BMI). RESULTS: The two groups differed markedly in their hs-CRP levels, but no group difference was found for the other three biomarkers. The odds ratio (OR) of HR children having detectable hs-CRP levels was 16 times greater than that of LR children after adjusting for confounding variables, including BMI z-score, Tanner stages and gender (OR: 16; 95% CI: 2-123). CONCLUSIONS: These results suggest that maternal obesity during pregnancy is associated with later development of elevated hs-CRP in the offspring, even after controlling for weight.

Is socioeconomic status of the rearing environment causally related to obesity in the offspring?

We attempt to elucidate whether there might be a causal connection between the socioeconomic status (SES) of the rearing environment and obesity in the offspring using data from two large-scale adoption studies: (1) The Copenhagen Adoption Study of Obesity (CASO), and (2) The Survey of Holt Adoptees and Their Families (HOLT). In CASO, the SES of both biological and adoptive parents was known, but all children were adopted. In HOLT, only the SES of the rearing parents was known, but the children could be either biological or adopted. After controlling for relevant covariates (e.g., adoptee age at measurement, adoptee age at transfer, adoptee sex) the raw (unstandardized) regression coefficients for adoptive and biological paternal SES on adoptee body mass index (BMI: kg/m(2)) in CASO were -.22 and -.23, respectively, both statistically significant (p = 0.01). Controlling for parental BMI (both adoptive and biological) reduced the coefficient for biological paternal SES by 44% (p = .034) and the coefficient for adoptive paternal SES by 1%. For HOLT, the regression coefficients for rearing parent SES were -.42 and -.25 for biological and adoptive children, respectively. Controlling for the average BMI of the rearing father and mother (i.e., mid-parental BMI) reduced the SES coefficient by 47% in their biological offspring (p≤.0001), and by 12% in their adoptive offspring (p = .09). Thus, despite the differing structures of the two adoption studies, both suggest that shared genetic diathesis and direct environmental transmission contribute about equally to the association between rearing SES and offspring BMI.

Eating disorders and obesity.

In conclusion, 2 types of disordered eating behaviors affect some overweight and obese persons. BED and NES present an excellent opportunity to recognize, treat, and prevent these disorders that, at the least, maintain, and at worst, promote, overweight and obesity. Articles in this volume by Wilson and co-workers and Allison and colleagues discuss current treatment options for BED and NES, respectively. Clinicians are encouraged to evaluate the presence of BED and NES in all patients who seek treatment for their obesity. Although the prevalence of these 2 eating disorders is relatively low, both are associated with significant distress and dysfunction that can be ameliorated with effective treatment.

Adolescent eating in the absence of hunger and relation to discretionary calorie allowance.

Eating in the absence of hunger is a risk factor for overeating during childhood. The objective of this study was to examine eating in the absence of hunger in adolescents based on their familial predisposition to obesity and current weight status. Thirty-one subjects (16 male, 15 female), who were 13 years of age and born at low risk or high risk for obesity, consumed lunch to fullness. After lunch, subjects had access to different snacks for 15 minutes. Eating in the absence of hunger referred to energy intake from the snacks. Low-risk females consumed two and a half times more calories from snacks than high-risk females and twice as many calories as low-risk and high-risk males when expressed as an individualized percentage of daily allowance for discretionary calories. Normal-weight females consumed two and a half times more calories from snacks than obese females and normal-weight males. The association between eating in the absence of hunger and weight and obesity risk status depended on adolescents' sex and could reflect emerging developmental differences, such as dieting or social desirability.

Cognitive behavior therapy for night eating syndrome: a pilot study.

Because no studies of psychotherapy treatments for night eating syndrome (NES) have been published, we conducted a pilot study of a 10-session cognitive behavior therapy (CBT) for NES. Twenty-five patients (19 female, 6 male) were screened and comprehensively assessed before being enrolled. At each visit, patients completed the Night Eating Symptom Scale (NESS), were weighed, and number of awakenings and the number of nocturnal ingestions and daily caloric intake were calculated from weekly food and sleep records. Mixed model regression analyses [of the data] showed significant decreases in caloric intake after dinner (35.0% to 24.9%); number of nocturnal ingestions (8.7 to 2.6 per week); weight (82.5 to 79.4 kg); and NESS score (28.7 to 16.3; all p values <0.0001). Number of awakenings per week, depressed mood, and quality of life also improved significantly (p values <.02). This first clinical trial of CBT for NES shows significant improvements in the core aspects of NES and weight reduction, suggesting the need for a controlled treatment trial.

Shared and unique genetic and environmental influences on binge eating and night eating: a Swedish twin study.

We applied twin methodology to female and male twin pairs to further understand the nature of the relation between two behaviors associated with eating disorders-binge eating (BE) and night eating (NE) in an effort to determine the extent of overlap of genetic and environmental factors influencing liability to these behaviors. We calculated heritability estimates for males and females for each behavior and applied bivariate twin modeling to the female data to estimate the genetic and environmental correlation between these two traits. Data on BE and NE were derived from the Swedish Twin study of Adults: Genes and Environment (STAGE) of the Swedish Twin Registry (STR; N=11,604). Prevalence estimates revealed sex differences with females more likely to endorse BE and males more likely to endorse NE. In males, we were only able to estimate univariate heritabilities due to small sample sizes: The heritability for BE was 0.74 [95% CI=(0.36, 0.93)] and for NE was 0.44 [95% CI=(0.24, 0.61)]. The best fitting bivariate model for females included additive genetic and unique environmental factors as well as the genetic correlation between BE and NE. Heritability estimates were 0.70 [95% CI=(0.26, 0.77)] for BE and 0.35 [95% CI=(0.17, 0.52)] for NE. The genetic correlation, 0.66 [95% CI=(0.48, 0.96)] suggests considerable overlap in the genetic factors influencing liability to BE and NE. In females, there is considerable overlap in the genetic factors that contribute to these traits, but the incomplete overlap allows for the influence of independent genetic and environmental factors as well. BE and NE in females are therefore best conceptualized as related but not identical traits.

Identification of an obese eating style in 4-year-old children born at high and low risk for obesity.

This study tested whether children's eating behavior and parental feeding prompts during a laboratory test meal differ among children born at high risk (HR) or low risk (LR) for obesity and are associated with excess child weight gain. At 4 years of age, 32 HR children (mean maternal prepregnancy BMI = 30.4 kg/m(2)) and 29 LR children (maternal BMI = 19.6 kg/m(2)) consumed a test meal in which their eating behavior was assessed, including rate of caloric consumption, mouthfuls/min, and requests for food. Parental prompts for the child to eat also were measured at year 4, and child body composition was measured at ages 4 and 6 years. T-tests, and logistic and multiple regression analyses tested study aims. Results indicated that HR and LR children did not differ in eating rate or parental feeding prompts. Greater maternal BMI, child mouthfuls of food/min, and total caloric intake/min during the test meal predicted an increased risk of being overweight or obese at age 6, whereas greater active mealtime was associated with a reduced risk of being overweight or obese. Regression analyses indicated that only mouthfuls of food/min predicted changes in BMI from 4 to 6 years, and mouthfuls of food/min and gender predicted 2-year changes in sum of skinfolds and total body fat. Thus, a rapid eating style, characterized by increased mouthfuls of food/min, may be a behavioral marker for the development of childhood obesity.

Proposed diagnostic criteria for night eating syndrome.

OBJECTIVE: To propose criteria for diagnosis of the night eating syndrome (NES). METHOD: An international research meeting was held in April 2008, and consensus criteria for NES diagnosis were determined. RESULTS: The core criterion is an abnormally increased food intake in the evening and nighttime, manifested by (1) consumption of at least 25% of intake after the evening meal, and/or (2) nocturnal awakenings with ingestions at least twice per week. Awareness of the eating episodes is required, as is distress or impairment in functioning. Three of five modifiers must also be endorsed. These criteria must be met for a minimum duration of 3 months. DISCUSSION: These criteria help standardize the definition of NES. Additional aspects of the nosology of NES yet to be fully elaborated include its relationship to other eating and sleep disorders. Assessment and analytic tools are needed to assess these new criteria more accurately.

Energy density at a buffet-style lunch differs for adolescents born at high and low risk of obesity.

The energy density (ED; kcal/g) of foods, when manipulated in the laboratory, affects short-term energy intake. The aim of this study was to examine if, when given a choice, dietary ED (foods only) and energy intake (expressed as a percentage of subjects' estimated daily energy requirement; EER) at a self-selected, single meal differ for teens born with a different familial predisposition to obesity and as a function of their sex. Subjects (13 males, 17 females) were 12years of age and born at high risk (HR; n=15) or low risk (LR; n=15) for obesity based on maternal pre-pregnancy body mass index (BMI; kg/m(2)). The buffet meal, served for lunch and consumed ad libitum, consisted of a variety of foods and beverages with a range in ED. HR subjects consumed a more energy-dense meal (foods only) than LR subjects (1.84 vs. 1.42kcal/g; P=0.02) and males consumed a more energy-dense meal than females (1.83 vs. 1.43kcal/g; P=0.03). Total energy intake, when expressed as a percentage of subjects' daily EER, did not differ between HR and LR subjects (42% vs. 33%; P=0.16). Males, compared to females, consumed ~59% more energy from foods and beverages during the meal (46 vs. 29%; P=0.008). During a single multi-item lunch meal, teens with a familial predisposition to obesity and males, independent of their obesity risk status, self-selected a more energy-dense meal. Familial risk for obesity, through either genetic or environmental pathways, may facilitate a more energy-dense diet.

Development of criteria for a diagnosis: lessons from the night eating syndrome.

Criteria for inclusion of diagnoses of Axis I disorders in the forthcoming Diagnostic and Statistical Manual (DSM-V) of the American Psychiatric Association are being considered. The 5 criteria that were proposed by Blashfield et al as necessary for inclusion in DSM-IV are reviewed and are met by the night eating syndrome (NES). Seventy-seven publications in refereed journals in the last decade indicate growing recognition of NES. Two core diagnostic criteria have been established: evening hyperphagia (consumption of at least 25% of daily food intake after the evening meal) and/or the presence of nocturnal awakenings with ingestions. These criteria have been validated in studies that used self-reports, structured interviews, and symptom scales. Night eating syndrome can be distinguished from binge eating disorder and sleep-related eating disorder. Four additional features attest to the usefulness of the diagnosis of NES: (1) its prevalence, (2) its association with obesity, (3) its extensive comorbidity, and (4) its biological aspects. In conclusion, research on NES supports the validity of the diagnosis and its inclusion in DSM-V.

Prevalence of night eating in obese and nonobese twins.

The aim of this study was to assess the prevalence of night eating (NE) and associated symptoms in a population-based sample of Swedish twins. A total of 21,741 individuals aged 20-47 years completed a questionnaire in 2005/2006. NE was defined as >/=25% of daily food intake after the evening meal and/or awakening at least once per week with eating episodes. The prevalence of NE was 4.6% in men and 3.4% in women. Among obese men and women, the prevalence was 8.4 and 7.5%, respectively. Men and women with NE had 3.4 and 3.6 times higher risk of binge eating compared to individuals without NE. The risk of sleep-related problems was 1.6-3.4 times higher in men and 2.5-3.3 times higher in women with NE compared to those without NE. This epidemiological study has estimated the prevalence of NE in a twin population. It revealed that NE is 2.5 and 2.8 times more common in obese men and women compared to normal weight men and women. Furthermore that NE is associated with binge eating and sleep-related problems.

The treatment of night eating: the patient's perspective.

Night eating (NE) is recognizable and treatable. The purpose of this study was to assess patients' satisfaction with their doctors' treatment of NE and to compare it to that of treatment of a control condition, 'headache'. An Internet-based questionnaire assessed patients' (n = 103) perceptions of their doctors' knowledge and treatment of NE versus headache, levels of treatment satisfaction and demographic and descriptive aspects of their NE. Most patients (61%) were 'not at all satisfied' with their doctors' treatment of NE. Patients reported low recognition and high levels of dismissal of NE by their doctors. Of patients who had been treated for both NE and headache by the same doctor, 29% were 'not at all satisfied' with their treatment of headache compared to 76% 'not at all satisfied' with their treatment of NE (p = 0.02). In conclusion, most patients reported that their doctors did not identify or treat NE, which led to dissatisfaction with their care.

Changes in symptoms of depression with weight loss: results of a randomized trial.

Recent studies of rimonabant have re-awakened interest in the possible adverse psychiatric effects of weight loss, as well as of weight loss medications. This study examined changes in symptoms of depression in 194 obese participants (age = 43.7 +/- 10.2 years; BMI = 37.6 +/- 4.1 kg/m(2)) in a 1-year randomized trial of lifestyle modification and medication. Participants were assigned to (i) sibutramine alone; (ii) lifestyle modification alone; (iii) sibutramine plus lifestyle modification (i.e., combined therapy); or (iv) sibutramine plus brief therapy. Participants completed the Beck Depression Inventory-II (BDI-II) at baseline and weeks 6, 10, 18, 26, 40, and 52. At 1 year, participants in combined therapy lost the most weight and those in sibutramine alone the least (12.1 +/- 8.8% vs. 5.5 +/- 6.5%; P < 0.01). Mean BDI-II scores across all participants declined from 8.1 +/- 6.9 to 6.2 +/- 7.7 at 1 year (P < 0.001), with no significant differences among groups. Despite this favorable change, 13.9% of participants (across the four groups) reported potentially discernible increases (>or= 5 points on the BDI-II) in symptoms of depression at week 52. They lost significantly less weight than participants in the rest of the sample (5.4 +/- 7.8% vs. 9.0 +/- 7.8%, respectively; P < 0.03). The baseline prevalence of suicidal ideation was 3.6%. Seven new cases of suicidal ideation were observed during the year, with three in lifestyle modification alone. Further research is needed to identify characteristics of obese patients at risk of negative mood changes (and suicidal ideation) in response to behavioral and pharmacologic therapies.

Greater history of weight-related stigmatizing experience is associated with greater weight loss in obesity treatment.

Experiences of obesity stigmatization and fear of fat, body image and self-esteem, were examined in relation to weight loss and weight maintenance. Participants in obesity treatment (N = 185) with more stigmatizing experiences had poorer body image and greater fear of fat. Higher initial BMI, more stigmatizing experiences, lower body dissatisfaction and greater fear of fat predicted greater weight loss. Higher initial BMI and more stigmatizing experiences predicted greater weight maintenance after six months in treatment. These findings suggest that despite the negative psychological correlates of stigmatization, experience and fear of obesity's negative consequences may also be associated with improved treatment outcome.