Kristine L. Lokken

Neuropsychological performance of a clinical sample of extremely obese individuals

Obesity is a leading cause of preventable death in America and its prevalence is increasing at an alarming rate. While it is known that individuals with specific obesity-related medical conditions perform poorly on neuropsychological tasks, recent evidence suggests that cognitive dysfunction in obese individuals may occur independently of medical co-morbidities. This study examined neuropsychological performance in a clinical sample of extremely obese patients. Individuals seeking surgical treatment of obesity (N=68) were administered cognitive tests as part of a standard pre-surgical evaluation. Results indicated significant differences in performances of extremely obese individuals on tests of executive functioning (planning, problem solving, mental flexibility) in comparison to normative data. No significant differences emerged between obese patients with and without co-morbid medical conditions of hypertension, type II diabetes, and obstructive sleep apnea on the neuropsychological tasks specific to executive functioning. Taken together, these results provide further evidence of specific cognitive dysfunction in extremely obese individuals.

Evidence of executive dysfunction in extremely obese adolescents: a pilot study

BACKGROUND Obesity in children and adolescents is 1 of the most urgent and serious health threats confronting the United States. Extremely obese adolescents (body mass index >99th percentile for age and gender) are a unique subgroup of obese youth who are at considerable medical and psychosocial risk. Little is known about the cognitive function of extremely obese adolescents. The present study sought to examine the cognitive performance of a sample of extremely obese adolescents seeking primary treatment for weight loss. METHODS Adolescents were recruited during regularly scheduled medical appointments at a childrens center for weight management associated with a major childrens hospital in the Southeast United States. A computerized battery of cognitive tests was administered to obese adolescents (body mass index >99th percentile; n = 25). RESULTS Obese adolescents exhibited deficits in many cognitive domains, including impairment in attention and executive functions (e.g., mental flexibility, disinhibition) compared with the normative data. CONCLUSION Although preliminary, these data have provided evidence for specific cognitive deficits in extremely obese adolescents. These findings highlight a need to determine whether early weight loss interventions, such as bariatric surgery, for obese adolescents could potentially prevent or reverse cognitive deficits and/or reduce the risk of future adverse neurocognitive outcome.

The Iowa gambling task as a measure of decision making in women with bulimia nervosa.

Persistent chaotic feeding behavior (i.e., bingeing and purging), despite consequent adverse health and psychosocial consequences, is central to the definition and diagnosis of bulimia nervosa (BN). Repeatedly choosing immediate short-term gratification when long-term consequences are deleterious may reflect deficits in decision-making ability. However, to date, there has been no systematic examination of decision-making ability in individuals diagnosed with BN. In the present study, 20 undergraduate women with minimal bulimic symptoms (Control Group) and 20 with a diagnosis of BN (BN Group) were administered the Iowa Gambling Task (GT). Results indicated that the BN Group performed significantly worse on the GT in comparison to the Control Group and GT performance was negatively correlated with bulimic symptomatology. The presence of BN symptoms also predicted GT performance above and beyond demographic variables and depressive symptoms. These findings provide evidence for the presence of decision-making deficits in individuals with BN.

Body dissatisfaction, bulimic symptoms, and clothing practices among college women.

Clothing use may be a behavioral avoidance strategy for individuals with body dissatisfaction and eating pathology. The authors administered the Body Image Avoidance Questionnaire (J. C. Rosen, D. Srebnik, E. Saltzberg, & S. Wendt, 1991), the Bulimia Test-Revised (M. Thelen, J. Farmer, S. Wonderlich, & M. Smith, 1991), and the Body dissatisfaction subscale of the Eating Disorder Inventory (D. M. Garner, M. P. Olmstead, & J. Polivy, 1983) to undergraduate college women from two universities (N = 540). Results indicated that women who were more dissatisfied with their bodies (β = .396) and had greater disordered eating behaviors (β = .378) were more likely to engage in clothing-related appearance-management behaviors (p < .001), including wearing apparel to camouflage their bodies; avoiding revealing, brightly colored, or tightly fitting clothing; and avoiding shopping for clothing. These findings suggest that the presence of certain clothing-related appearance-management behaviors may be a warning sign that an individual is at risk for developing an eating disorder or may currently have an eating disorder.

Examining the Links Among Magazine Preference, Levels of Awareness and Internalization of Sociocultural Appearance Standards, and Presence of Eating-Disordered Symptoms in College Women

Research has shown that young women are negatively affected by media images representing thin female body types. Given the increasing prevalence of eating disorders among young women, it is important to look closer at this phenomenon and the role/responsibility of the media. This study examined the links among quantity of magazine exposure, preference for specific periodicals, awareness and internalization of sociocultural standards of beauty, and the presence of eating-disordered symptoms in a sample of college women. Small, but significant, correlations were found between magazine exposure and drive for thinness, and between preference for beauty and fashion magazines and internalization of sociocultural standards of appearance. Regression analyses found awareness and internalization of sociocultural standards of appearance to be significant predictors of body dissatisfaction, drive for thinness, and bulimic symptoms. The results of this study are discussed in terms of educational and social marketing strategies.

Effects of transcranial direct current stimulation (tDCS) on binge-eating disorder.

OBJECTIVE To investigate the effect of transcranial direct current stimulation (tDCS) on food craving, intake, binge eating desire, and binge eating frequency in individuals with binge eating disorder (BED). METHOD N = 30 adults with BED or subthreshold BED received a 20-min 2 milliampere (mA) session of tDCS targeting the dorsolateral prefrontal cortex (DLPFC; anode right/cathode left) and a sham session. Food image ratings assessed food craving, a laboratory eating test assessed food intake, and an electronic diary recorded binge variables. RESULTS tDCS versus sham decreased craving for sweets, savory proteins, and an all-foods category, with strongest reductions in men (p < 0.05). tDCS also decreased total and preferred food intake by 11 and 17.5%, regardless of sex (p < 0.05), and reduced desire to binge eat in men on the day of real tDCS administration (p < 0.05). The reductions in craving and food intake were predicted by eating less frequently for reward motives, and greater intent to restrict calories, respectively. DISCUSSION This proof of concept study is the first to find ameliorating effects of tDCS in BED. Stimulation of the right DLPFC suggests that enhanced cognitive control and/or decreased need for reward may be possible functional mechanisms. The results support investigation of repeated tDCS as a safe and noninvasive treatment adjunct for BED.

Prefrontal systems involvement in binge eating

OBJECTIVE: This study examined whether severity of binge eating is associated with dysfunction in behaviors mediated by the three main areas of the prefrontal cortex (PFC). METHODS: One hundred fifty-one adults (mean BMI=49.50) were classified into three groups based on the presence and severity of binge eating behaviors: Binge Eating Disorder (BED) group (N=22), Binge Eating Prone (BEP) group (N=47), and non-Eating Disorder (non-ED) group (N=82). Participants completed the Frontal Systems Behavior Scale (FrSBe), a widely used measure of neurobehavioral traits associated with the three primary regions of the PFC corresponding with the behavioral traits of apathy, disinhibition, and executive dysfunction. RESULTS: The BED and BEP groups scored significantly higher than the non-ED group on the three FrSBe subscales, as well as the FrSBe Total score. There were no significant correlations between the FrSBe and participant BMI. DISCUSSION: As expected, individuals who engaged in binge eating endorsed greater PFC dysfunction than those who did not binge eat. These results provide a complement to studies utilizing neuroimaging and neuropsychological methodologies and further support for the role of prefrontal systems in the regulation of eating behavior.

Demographic and lifestyle variables associated with obesity

Objective: Overweight and obesity rates are associated with chronic diseases and higher rates of disability and continue to rise in the United States and worldwide. The purpose of this study was to build on past research and further investigate demographic and lifestyle variables associated with increased body mass index (BMI: kg/m 2). Methods: Personal Information Worksheets were completed by 125 bariatric surgery candidates and 213 community dwelling individuals providing a sample size of 338. Hierarchical regression analysis was performed on three sets of independent variables (demographic characteristics, lifestyle variables and consumer response) and one dependent variable (BMI). Results: Lower levels of education and physical activity, higher levels of diet soda consumption and number of dieting attempts, and likelihood of starting a diet programme based on advertising testimonials were predictive of higher BMI. Conclusion: This research highlights the need for more education emphasizing the importance of increased healthy behaviours versus use of diet products and fad diets to improve success of weight loss efforts.

Bulimic Symptoms and Body Image Dissatisfaction in College Women: More Affected by Climate or Race?

The authors examined bulimic symptoms and body image dissatisfaction (BID) in a sample of college women. No differences were found in comparisons of bulimic symptoms or BID between Southern and Northern White women, and both groups reported similar levels of awareness and internalization of sociocultural aesthetic standards of appearance. Southeastern Black women reported (a) significantly lower levels of bulimic symptoms in comparison with White women from the North and (b) lower levels of BID in comparison with White women from both Southern and Northern regions. Further, Southeastern Black women were significantly less likely to be aware of and endorse mainstream standards of appearance in comparison with both groups of White women. Findings support the hypothesis that having a positive body image and less susceptibility to mainstream aesthetic standards of appearance may reduce the risk of eating disorder pathology in Black women.

Severity of bulimic symptoms is the best predictor of interference on an emotional Stroop paradigm

Objective: The goal of the current study was to further investigate whether an emotional Stroop effect exists among patients with bulimia nervosa. Method: Performances of 30 female controls, 30 females with subclinical eating disordered symptoms, and 30 females diagnosed with bulimia nervosa were compared on an emotional Stroop color naming task using stimuli separated into three areas of concern (eating, weight, and shape words). Results: Results indicated that overall the three groups differed significantly on the emotional Stroop task, with the interference latency for disorder salient words progressively increasing as the severity of bulimic symptoms increased. Severity of bulimic symptoms was the best predictor of interference on the emotional Stroop paradigm. Discussion: Results provide further evidence that interference on the emotional Stroop is uniquely related to the symptoms of bulimia nervosa and bear credence to the possibility of its use as an additional tool in the diagnosis of bulimia nervosa.