Prefrontal cortex activation by binge-eating status in individuals with obesity while attempting to reappraise responses to food using functional near infrared spectroscopy.

PURPOSE: Difficulty reappraising drives to consume palatable foods may promote poorer inhibition and binge eating (BE) in adults with obesity, but neural underpinnings of food-related reappraisal are underexamined. METHODS: To examine neural correlates of food-related reappraisal, adults with obesity with and without BE wore a portable neuroimaging tool, functional near-infrared spectroscopy (fNIRS). fNIRS measured activity in the prefrontal cortex while participants watched videos of food and attempt to "resist" the food stimuli (i.e., "consider the negative consequences of eating the food"). RESULTS: Participants (N = 32, 62.5% female; BMI 38.6 [Formula: see text] 7.1; 43.5 [Formula: see text] 13.4 y) had a BMI > 30 kg/m2. Eighteen adults (67.0% female; BMI 38.2 [Formula: see text] 7.6) reported BE (≥ 12 BE-episodes in preceding 3 months). The control group comprised 14 adults who denied BE (64.0% female; BMI 39.2 [Formula: see text] 6.6). Among the entire sample, mixed models showed significant, small hyperactivation during crave and resist compared to watch (relax) condition bilaterally in the medial superior frontal gyrus, dorsolateral areas, and middle frontal gyrus (optodes 5, 7, 9, 10, 11, and 12) in the total sample. No statistically significant differences in neural activation were observed between the BE and control group. Moreover, there were no significant group by condition interactions on neural activation. CONCLUSION: Among adults with obesity, BE status was not linked to differential activation in inhibitory prefrontal cortex areas during a food-related reappraisal task. Future research is needed with larger samples, adults without obesity, and inhibition paradigms with both behavioral and cognitive components. LEVEL OF EVIDENCE: Level III: Evidence obtained from well-designed cohort or case-control analytic studies. TRIAL REGISTRATION: # NCT03113669, date April 13, 2017.

Reward mediates the association between engagement in noneating activities and state body dissatisfaction: An ecological momentary assessment study.

OBJECTIVE: Momentary worsening (i.e., greater than one's average levels) of state body dissatisfaction (BD) has been implicated as a proximal risk factor for eating disorder (ED) behaviors in binge-spectrum EDs. Yet, research exploring the prospective association between noneating activities in daily life (e.g., chores, self-care/coping) and momentary state BD remains limited. Understanding the momentary link between engagement in noneating activities and state BD, and pathways through which engagement in said activities influences momentary state BD is critical to informing treatments. The current ecological momentary assessment (EMA) study examined whether (1) engagement in noneating activities at Time 1 prospectively predicted momentary state BD at Time 2 and (2) reward drawn from noneating activities at Time 1 mediates the prospective association between engagement in noneating activities at Time 1 and momentary state BD at Time 2. METHOD: Sixty-six adults with transdiagnostic binge eating completed an EMA protocol over 7-14 days. Participants received six EMA signals per day (total EMA observations = 4038). Multilevel modeling was used to examine the research questions. RESULTS: Engagement in an indoor hobby, outdoor recreation, socializing, and self-care/coping strategies prospectively predicted momentary state BD improvements, while using TV/social media and cooking prospectively predicted momentary state BD worsening. Reward drawn from engagement in these noneating activities mediated the associations. DISCUSSION: If replicated, these findings suggest that increasing the frequency of certain noneating activities and enhancing their rewarding aspects to improve state BD and decrease ED behavior risk during treatment may be worthy of further exploration. PUBLIC SIGNIFICANCE: Momentary worsening of state body dissatisfaction (BD) is a risk factor for eating disorder behaviors in individuals with binge eating. This study found that engaging in certain noneating activities (e.g., socializing) prospectively predicted momentary improvements in state BD, while other noneating activities (e.g., cooking) predicted momentary worsening of state BD. Reward drawn from activities mediated these relations. To improve state BD, treatments should target the frequency of, and reward obtained from these noneating activities.

The effect of weight suppression on eating behavior: Does the intentionality of weight loss matter?

Weight suppression (WS) has been consistently related to eating pathology. The weight loss that produces weight suppression has always been assumed to be intentional, but no study has tested whether unintentional weight loss would also be associated with eating pathology. The current study examined whether the association between WS and eating pathology may be moderated by intentionality of weight loss in a community-based sample of 520 adults. Participants were categorized into low WS (<5% weight loss from highest past weight), intentional, high WS (>5% intentional weight loss), and unintentional, high WS (>5% unintentional weight loss) groups. The intentional WS group reported greater restraint than the unintentional WS and low WS groups, and the low WS group reported greater restraint and more frequent loss-of-control (LOC) eating than those with unintentional WS. Further, WS was positively related to loss-of-control eating frequency only in the intentional WS group, and negatively associated with LOC eating frequency in the low WS group. Additionally, BMI was positively associated with LOC and binge eating frequency and restraint only in the low WS group. Given the relatively high prevalence of substantial but unintended weight loss found in this study, researchers studying weight suppression should consider asking about intentionality of weight loss and analyzing their data with and without unintentional weight suppressors included in the sample.

The independent and interacting effects of weight suppression and admission body mass index on treatment weight change in patients with anorexia nervosa or bulimia nervosa.

OBJECTIVE: Weight suppression (WS) and body mass index (BMI) have predicted weight change in individuals with eating disorders, but the interaction between these variables is understudied. Furthermore, WS is usually measured as absolute WS-the numeric difference between current weight and highest past weight-overlooking the potentially important influence of how much a person weighed at their highest historical weight. METHOD: The current study investigated the independent and interacting effects of BMI and two measures of WS at admission on residential treatment weight change. WS measures included absolute WS and the relative WS index, the percentage of total body weight lost from highest past weight. Participants were women with anorexia nervosa (n = 357) or bulimia nervosa (n = 293) who provided complete data, 87% of the eligible treatment sample. RESULTS: In both diagnostic subsamples, BMI, absolute WS, and the relative WS index all significantly predicted weight change. The interaction between BMI and WS predicted weight change, but only when the relative WS index was used. DISCUSSION: Results highlight the potential importance of considering an individual's weight and weight history when predicting their treatment weight change and support the importance of utilizing both methods of calculating WS in future research.

The relationship of weight suppression to treatment outcomes during behavioral weight loss.

Many adults enter behavioral weight loss (BWL) programs at a weight below their highest lifetime weight. The discrepancy between highest lifetime weight and current weight is known as weight suppression (WS). Research has yet to characterize WS during BWL or investigate its relation to weight loss outcomes or treatment acceptability. Adults (N = 272) in a 12-month BWL program were assessed. WS was calculated by subtracting measured baseline weight from self-reported highest lifetime weight. Participants with higher WS lost significantly less weight than those with lower WS during treatment, although they still had clinically meaningful weight losses (e.g., participants with WS above the median: 7.8 kg; participants with WS below the median: 12.0 kg). WS was unrelated to weight losses at 24-month follow-up. Controlling for weight loss, treatment acceptability was unrelated to WS. BWL appears appropriate for those with high WS, but future research should aim to improve outcomes in this group.

Characterization and effect of metal ions on the formation of the Thermus thermophilus Sco mixed disulfide intermediate.

The Sco protein from Thermus thermophilus has previously been shown to perform a disulfide bond reduction in the CuA protein from T. thermophilus, which is a soluble protein engineered from subunit II of cytochrome ba 3 oxidase that lacks the transmembrane helix. The native cysteines on TtSco and TtCuA were mutated to serine residues to probe the reactivities of the individual cysteines. Conjugation of TNB to the remaining cysteine in TtCuA and subsequent release upon incubation with the complementary TtSco protein demonstrated the formation of the mixed disulfide intermediate. The cysteine of TtSco that attacks the disulfide bond in the target TtCuA protein was determined to be TtSco Cysteine 49. This cysteine is likely more reactive than Cysteine 53 due to a higher degree of solvent exposure. Removal of the metal binding histidine, His 139, does not change MDI formation. However, altering the arginine adjacent to the reactive cysteine in Sco (Arginine 48) does alter the formation of the MDI. Binding of Cu2+ or Cu+ to TtSco prior to reaction with TtCuA was found to preclude formation of the mixed disulfide intermediate. These results shed light on a mechanism of disulfide bond reduction by the TtSco protein and may point to a possible role of metal binding in regulating the activity. IMPORTANCE: The function of Sco is at the center of many studies. The disulfide bond reduction in CuA by Sco is investigated herein and the effect of metal ions on the ability to reduce and form a mixed disulfide intermediate are also probed.

Weight Suppression in Eating Disorders: a Research and Conceptual Update.

PURPOSE OF REVIEW: Weight suppression, the discrepancy between an individual's highest past weight at adult height and his or her current weight, is related to many characteristics of individuals with eating disorders. This paper reviews research findings from the past 5 years, draws several implications regarding the mechanism underlying these effects, and proposes new approaches to measuring weight suppression. RECENT FINDINGS: Studies were reviewed under the categories of anorexia nervosa, bulimia nervosa, and mixed or miscellaneous samples, with more studies falling into the last category than in the first two. Recent findings have continued to show that weight suppression is related to a wide variety of biological and behavioral features in both diagnosed and sub-clinical samples. Weight suppression promotes weight gain which is anathema to individuals with eating disorders, putting them in a biobehavioral bind that appears to prolong their disorder. Priorities for future research are to understand the mechanisms underlying the effects of weight suppression, evaluate new ways of defining weight suppression, and study its implications for modifying treatment.

Conceptualizing body dissatisfaction in eating disorders within a self-discrepancy framework: a review of evidence.

Body dissatisfaction, the negative subjective evaluation of one's body, is associated with many negative psychological and physical health consequences. One conceptualization of body dissatisfaction includes an experience of discrepancy between perceived actual and ideal body shapes. This paper reviews the literature on three facets of body dissatisfaction from the framework of self-discrepancy theory: perceptions of current weight, ideal body weight, and the relative importance of conforming to ideals. We review components of body dissatisfaction among healthy individuals and eating-disordered individuals. We also address the conceptualization's relationship among body dissatisfaction, weight history, and dieting to expand the impact of body dissatisfaction research and to provide more information on the nature and treatment of eating disorders.

Eating in the absence of hunger is related to loss-of-control eating, hedonic hunger, and short-term weight gain in normal-weight women.

Eating beyond physiological need contributes to obesity onset. Measuring this behavior could help identify those at risk for weight gain. This study measured eating in the absence of hunger (EAH) and its relationship with weight change and self-report measures related to appetite and eating behavior. EAH was assessed in 46 lean young women (69% pre-selected for weight gain proneness) after lunch and defined as the number of calories subsequently consumed from snacks. Participants also completed questionnaires, and their body weights were measured regularly over the next year. Participants consumed a mean 188 calories (±140) during the EAH test. Caloric intake during the EAH test was associated with hedonic hunger (p < .01, R2 = 0.18), loss of control eating (p < .001, R2 = 0.29), and weight gain over two months (p < .01, R2 = 0.19), controlling for baseline body mass index. All were large effect sizes. In contrast, EAH was unrelated to emotional eating, disinhibition, and longer-term weight change. Amount of the test meal eaten in a hungry state was unrelated to these variables. While EAH has mainly been examined in children, these results expand its utility to adults. EAH seems to reflect naturalistic eating behavior, as shown by its relationship with short-term weight gain, drive to overconsume foods, and loss of control over eating. EAH may be a useful test to identify young adults at risk for weight gain and/or disordered eating, and may be a target for intervention.

Energy intake highs and lows: how much does consistency matter in weight control?

Behavioural weight control programmes recommend adherence to daily energy intake goals, yet also allow for flexibility in intake across days. Evidence is lacking as to whether intake consistency is important for weight control. The current study explored the relation between day-to-day intake consistency and weight loss in the context of behavioural weight loss treatment and examined the relationship between variability in intake and several factors known to be associated with weight control success. Participants (N = 283) enrolled in a 12-month behavioural weight loss programme completed 24-h recalls of dietary intake and psychological measures. At the end of treatment, low intake variability and greater weight loss were associated, but variability was not predictive of weight loss independent of mean intake in continuous analyses. Interestingly, participants who met the programme goal of ≥10% weight loss had less intake variability compared to those who lost <10%, although groups did not differ significantly on mean intake. Results suggest that daily intake consistency may facilitate successful weight loss for some. Additionally, autonomous motivation for weight management and cognitive dietary restraint were inversely related to end-of-treatment intake variability. Additional research is needed to examine whether recommendations to limit intake variability during behavioural weight loss treatment improve long-term weight control.

The role of negative reinforcement eating expectancies in the relation between experiential avoidance and disinhibition.

OBJECTIVES: Eating-related disinhibition (i.e., a tendency to overeat in response to various stimuli) is associated with weight gain and poorer long-term weight loss success. Theoretically, experiential avoidance (i.e., the desire or attempts to avoid uncomfortable internal experiences), may predispose individuals to developing negative reinforcement eating expectancies (i.e., the belief that eating will help to mitigate distress), which in turn promote disinhibition. Such relationships are consistent with an acquired preparedness model, which posits that dispositions influence learning and subsequent behavior. Drawing from this framework, the current study represents the first investigation of relations between negative reinforcement eating expectancies, experiential avoidance (both general and food-specific) and disinhibited eating. In particular, the mediating role of negative reinforcement eating expectancies in the relation between experiential avoidance and disinhibited eating was examined. METHOD: Participants (N=107) were overweight and obese individuals presenting for behavioral weight loss treatment who completed measures of general and food-related experiential avoidance, negative reinforcement eating expectancies, and disinhibition. RESULTS: Experiential avoidance and negative reinforcement eating expectancies significantly related to disinhibition. Furthermore, the relation between experiential avoidance and disinhibition was mediated by negative reinforcement eating expectancies. DISCUSSION: The current study supports an acquired preparedness model for disinhibition, such that the relation between experiential avoidance and disinhibition is accounted for by expectations that eating will alleviate distress. Findings highlight the potential role of eating expectancies in models accounting for obesity risk, and identify negative reinforcement eating expectancies as a potential treatment target for reducing disinhibition.

The relationship of alcohol use to weight loss in the context of behavioral weight loss treatment.

Despite common wisdom that reducing alcohol intake will facilitate weight loss, little research has examined whether participants in behavioral weight loss treatments actually decrease their alcohol intake, or whether reduced alcohol intake relates to weight loss outcomes in this context. This study examined the relationship of alcohol use to energy intake excluding alcohol and to weight in 283 overweight and obese adults participating in a 26-session behavioral weight loss treatment. The majority of participants consumed low to moderate levels of alcohol at baseline. Participants who consumed alcohol at baseline meaningfully reduced their alcohol intake by end-of-treatment. Alcohol use did not relate to weight at baseline or end-of-treatment when controlling for relevant demographic variables, and change in alcohol use was unrelated to weight change in the overall sample during treatment. However, end-of-treatment alcohol intake did relate to end-of-treatment energy intake excluding alcohol. In addition, behavioral impulsivity and change in alcohol intake interacted to predict weight loss, such that decreases in alcohol intake were associated with greater percent weight loss at end-of-treatment for participants with higher levels of impulsivity. Alcohol consumption may lead to overeating episodes, and highly impulsive individuals may be at risk for increased energy intake during or after episodes of drinking. Therefore, the recommendation to reduce alcohol intake in the context of behavioral weight loss treatment seems warranted, particularly for individuals with high levels of impulsivity.