Showing papers by "Donald A. Williamson published in 2005"

Percent body fat measured by BIA and DEXA in obese, African-American adolescent girls.

Abstract: To compare the estimation of body fat between bioelectrical impedance analysis (BIA) and dual energy X-ray absorptiometry (DEXA) in overweight, African-American female adolescents. In total, 54 African-American adolescent female subjects were recruited for Study 1. Each adolescent's body mass index was greater than the 85th percentile and their average body fat was 45% according to DEXA. A total of 26 African-American adolescent female subjects were available for Study 2, and had an average body fat of 26% according to DEXA. Percent body fat was measured by DEXA and BIA. Seven different BIA equations were tested. Both sets of data were analyzed using Bland–Altman regression analyses, utilizing percent body fat measured by DEXA as the criterion. The Kushner equation provided estimates that were unaffected by body fat in both studies. Estimates were unbiased when applied to the exclusively overweight sample and biased when utilized with the separate sample of normal weight and obese girls. The remaining equations were biased, provided inconsistent estimates across body weight, or were biased and provided inconsistent estimates. Ethnicity-specific and ethnicity-combined equations performed similarly in the obese sample, but became more disparate when applied to a sample encompassing a wider body weight range. The limits of agreement between all BIA equations and the DEXA estimates ranged from 6 to 9%. The study suggests that the Kushner BIA equation is appropriate for use with African-American female adolescents across the weight spectrum, while the majority of BIA equations underestimated percent body fat as body fat increased.

Efficacy of an internet-based behavioral weight loss program for overweight adolescent African-American girls.

Abstract: Objective: This randomized controlled trial tested the efficacy of an internetbased lifestyle behavior modification program for weight management in African-American girls. Design: African-American girls were randomly assigned to an interactive behavioral internet program or an internet health education program, the control condition. The behavioral intervention included internet counseling and was highly interactive. The control intervention was a passive (non-interactive) educational program. Parents were also participants in the study. Participants in both treatment groups met in face-to-face sessions on four occasions over the first 12 weeks of a 6-month intervention. Subjects: The study enrolled 57 African-American adolescent girls (ages 11 to 15 years) who were overweight or obese and had at least one biological parent who was obese [body mass index (BMI) >30 kg/m2]. Of the 57 participants, 50 (88%) completed the 6-month trial. Measurements: Outcome data, including BMI, body weight, body composition, dietary intake, and weight loss behaviors were collected at baseline and 6-months later. A computer server tracked utilization of the websites. Participation in the program was measured by number of “hits” on the website. Results: Compared to the control condition, adolescents in the behavioral treatment lost more body fat (group difference =1.6% body fat) and parents lost significantly more body weight (group difference =2.1 kg). Utilization of the behavioral website by adolescents and parents was associated with positive outcome. Dietary fat intake was lowered for adolescents and parents in the behavioral treatment group. Conclusion: An internet-based behavioral intervention was superior to internet-based health education and yielded decreased body fat for adolescent girls and decreased body weight for parents.

Categorical versus dimensional models of eating disorders: An examination of the evidence

Abstract: Objective Eating disorders have been conceptualized as discrete syndromes or categories and as dimensions that differ in degree among individuals. Until recently, researchers have not directly addressed which of these models, categorical versus dimensional, is most valid. Methods The primary objective of this review was to examine the evidence related to the validity of dimensional versus categorical models of eating disorders. Results Findings from a series of taxometric studies have suggested that a conceptual representation of eating disorders may involve a latent taxon, related to binge eating (and possibly purging), and one or more dimensions. These studies found that binge eating was identified as a factor that does not occur on a continuum with anorexia nervosa, restricting subtype. Restricting subtype anorexia is continuous with normalcy, however. Discussion These findings should be viewed as preliminary evidence that may have implications for the etiology, assessment, prevention, and treatment of eating disorders. © 2004 by Wiley Periodicals, Inc.

Behavior and lifestyle: approaches to treatment of obesity.

Abstract: The increasing prevalence of overweight and obesity in adults and children demonstrates a steadily growing epidemic. This rising rate of obesity is associated with obesity related comorbidities including cardiovascular disease, hypertension, some cancers, joint disease, and particularly, type 2 diabetes. Modest weight loss (5% to 10% of total body weight) through lifestyle intervention approaches has been found to have a beneficial effect on comorbid conditions, particularly hypertension and type 2 diabetes. Effective behavioral treatment of obesity involves modification of eating and physical activity patterns to yield negative energy balance. Research studies have found that interventions that combine a low-calorie diet, increased physical activity, and behavior therapy are most effective for weight loss and maintenance. Furthermore, extended length of treatment contact, weight loss satisfaction, and social support may promote positive long-term outcomes in obese adults and children.

Assessment of Eating Disorders

Abstract: In this review, we have selected assessment methods that can be used for specific objectives, including screening measures, diagnostic interviews, multisymptom measures, measures that assess pathological eating, body image, body weight, comorbid pathology, and special problems. Table 8.2 provides a summary of the methods reviewed in this chapter and describes the symptom domains that are measured by each procedure. Recommendations are made for an assessment battery pertaining to eating disorders.

Association of body size estimation and age in African-American females

Abstract: This cross-sectional research study tested the hypothesis that body image estimates of African-American females differ as a function of age. To test this hypothesis, body image estimates of 379 African-American females, ranging in age from 16 to 96 years, were contrasted as a function of age group, while statistically controlling body mass index. Three body size estimates, current body size, ideal body size, and reasonable body size were measured using the Body Image Assessment for Obesity. The discrepancies between current and ideal body size estimates and between current and reasonable body size estimates were also analyzed to assess for differences in body size dissatisfaction. The study found that younger African-American women (16 to 35 years) differed from older African-American women (>35 years) on measures of body size dissatisfaction. Women in the age range of 26 to 35 years reported higher estimates of current body size in comparison to women older than 35 years. The youngest age group (16 to 25 years) reported thinner ideal body size goals in comparison to women who were slightly older (26 to 35 years) and women who were older than 75 years. The pattern of body image estimates across a large age range suggests that younger African-American women, in comparison to older African-American women, may have body images that may make them more susceptible to eating disorders.

Health and appearance concerns in young Caucasian and African-American women.

Abstract: Objective: The primary aim of this study was to examine the health- and appearance-related concerns of young African-American and Caucasian females. Research Methods: Participants were twenty Caucasian and twenty African-American college women, who were matched on age and BMI. All participants were administered the Multidimensional Body-Self Relations Questionnaire (MBSRQ), a demographics instrument, and a short inventory to assess concerns about health, appearance, and weight management, in a single testing session; height and weight data were self-reported. Results: African-American women and Caucasian women were not significantly different in their level of health consciousness or perception of health; however, African-American women were significantly more satisfied with their physical appearance in comparison to Caucasian women. Among African-American women, perception of health and level of health consciousness were highly related; this relationship was not found in Caucasian women. In addition, perception of health was related to satisfaction with appearance in both groups, although the relationship was stronger among African-Americans. Among Caucasian women, satisfaction with physical appearance was highly correlated with perception of weight status (from underweight to very overweight); this relationship was not found among African-American females. An inverse relationship between body mass index (BMI) and appearance evaluation was found only for Caucasian females. Discussion: These findings suggest that, on the whole, young African-American and Caucasian college females report similar evaluations of health and values placed on appearance and health, and differ primarily in terms of satisfaction with physical appearance.