Food intake and mood in anorexia nervosa and bulimia

Too hot to handle: Mood states moderate implicit approach vs. avoidance tendencies toward food cues in patients with obesity and active binge eating disorder

Patients with binge eating disorder (BED) display recurring episodes of eating large amounts of food in a short period of time, especially during negative mood states. However, the psychological processes linking negative mood to binge eating behavior have not been sufficiently explored. This study investigated the effects of experimentally inducing a negative (sad) mood state upon reaction times in a computerized Approach-Avoidance-Task (AAT) using images of foods and compared to a neutral control procedure in which negative mood was not induced. Differences in reaction times between "pulling" and "pushing away" food cues in the AAT were considered surrogates for fast, automatic (i.e., implicit) preferences ("bias") for either the approach or avoidance of foods. Obese patients with BED (n = 40), weight-matched (obese) individuals (n = 40), and norm-weight controls (n = 29) were asked to approach ("pull") or avoid ("push") images of high- and low-calorie foods following the induction of a negative mood state vs. the neutral control procedure. Sample size was within the common range of previous investigations of the kind. Similar to previous findings, obese patients with BED exhibited an avoidance bias (i.e., faster reaction times in "pushing" compared to "pulling") during the neutral control condition. However, a contrast analysis revealed that negative mood was associated with decreased avoidance bias in obese patients with BED, but not in obese and norm-weight controls. Mood status exerted no effect on BED patients' self-reported (i.e., explicit) ratings of the urge to consume foods. These findings may help to advance current understanding of how negative (sad) mood states may affect binge eating behaviors. Implications of these findings for developing novel treatment approaches are discussed.

Changes of body composition in bulimia nervosa: increased visceral fat and adrenal gland size

OBJECTIVE

To study the hypothesis that young women suffering from active bulimia nervosa (BN) have more visceral fat and increased adrenal gland volumes (AGV) than healthy controls (HC).

METHODS

Thirteen patients with BN of purging type and 11 healthy age and weight matched women (HC), aged between 19 and 36 years (mean 24 +/- 3 years), with a BMI of 19 to 29 (mean 24 +/- SD 3) were examined. BN was diagnosed by DSM-IV criteria and the severity of illness by the Eating Disorder Inventory (EDI-2). Whole body fat distribution and AGV were determined using a whole body magnetic resonance (MR) scan (T1w) and a 3D-sequence (T1w) at 1.5 Tesla. Salivary cortisol was determined at 9 AM and 4 PM.

RESULTS

BN patients had significantly more visceral adipose tissue (VAT) (HC, 1589.3 +/- 967.6 ml versus 927.2 +/- 428.4 ml, p < .05) and an increased relative AGV (0.068% of body volume versus 0.048% of body volume, p < .05) compared with HC, although waist circumference and BMI did not differ. Although the VAT part in the upper abdomen was increased, especially the VAT of lower abdomen along with the pelvis or any subcutaneous fat compartment was not increased.

CONCLUSIONS

The increase of the VAT volume and the increased AGV in BN women with purging point to chronic high stress levels associated with a hyperactivity of the hypothalamic-pituitary-adrenal axis in these patients. This is the first MR study showing morphological changes in stress associated endocrine organs of young BN patients.

Energy and macronutrient intake in bulimia nervosa

Energy deprivation and malnutrition are often thought to be key factors in the maintenance of bulimia nervosa (BN). Our review shows that it is unclear how much energy is actually available to BN patients' metabolism because the contribution of food consumed during binge eating is generally neglected. Also, there is little evidence for another key hypothesis that binge-eating episodes are triggered by carbohydrate craving. This study examined energy consumption and macronutrient composition of meals and binge-eating episodes in food diaries. Forty female BN patients, 40 female panic disorder (PD) patients, and 40 healthy women recorded their food intake while in their natural environment during two consecutive days. We did not find the expected evidence for chronic energy deprivation and malnutrition in BN patients. Also, there was no evidence that carbohydrate craving drives binge eating. The implications for models of BN and for treatments targeting eating behavior are discussed.

Does binge eating play a role in the self-regulation of moods?

Self-reported emotional experiences and eating behaviors were studied in college students in an attempt to determine what types of emotional experiences precede and follow binge eating and how specific types of compensatory behaviors modify these experiences. First-year male and female students (N=390) were surveyed for depression, anxiety, health status, life satisfaction, and eating attitudes (EAT-26). Those reporting recurrent binge eating episodes were asked to describe their emotional feelings before and after bingeing and before and after compensatory activities. EAT-26 scores corresponding to scores previously reported for eating disordered patients were found in 9.7% of students. Binge eating was nearly twice as frequent among females (16.4%) as males (8.6%). Among females, positive relationships were found between specific EAT-26 factors scores and both anxiety and depression scores. The emotional antecedents and consequences of binge eating and of compensatory activities were compared in three sub-groups of individuals who reported recurrent bingeing with loss of self-control during binges. The three sub-groups consisted of individuals who reported, 1) bingeing without engaging in compensatory activities, 2) bingeing and compensating by means other than vomiting (fasting, exercising, or use of laxatives or diuretics), and 3) bingeing and compensating by vomiting. Regardless of the type of activity, those individuals who engaged in compensatory activities reported greater negative affect preceding binge episodes than those who did not compensate. In addition, contrary to expectations, negative affect did not decrease, but instead increased significantly, following binge episodes and decreased immediately before and after compensatory activities.

Acute tryptophan depletion in bulimia: effects on large neutral amino acids

Acute tryptophan depletion, which may reduce brain serotonin synthesis in humans, was evaluated in bulimic and normal subjects assessing its effects on the plasma ratio of tryptophan to the sum of the other large, neutral amino acids (TRP/sigma LNAA). Thirteen bulimic and 9 control women ingested an amino acid mixture containing either 2.3 g (control mixture) or 0 g of tryptophan (active mixture), in combination with 100 g of the other amino acids. Six healthy male volunteers were also studied, using a similar mixture containing 4.6 g of tryptophan. Bulimic and control women both experienced sizable reductions in the plasma TRP/sigma LNAA ratio, compared to baseline values, for both the active mixture (10% of baseline) or the control mixture (45% of baseline). For bulimic women, the active mixture produced a significant increase in fatigue and a trend toward increased anxiety and indecisiveness. The control mixture did not maintain baseline TRP/sigma LNAA ratios so we identified a control amino acid mixture that does not cause a drop in the plasma TRP/sigma LNAA ratio when ingested (4.6 g tryptophan in combination with 100 g of other amino acids). An oral, tryptophan-deficient amino acid mixture produced acute, substantial reductions in the plasma TRP/sigma LNAA ratio in all subjects, suggesting that the treatment should reduce brain tryptophan uptake and serotonin synthesis. A control mixture containing tryptophan was also identified that maintains the plasma TRP/sigma LNAA ratio at pretreatment values.