Correlates of weight loss and muscle-gaining behavior in 10- to 14-year-old males and females.

BACKGROUND: This study examined the influence of appearance and social acceptance esteem, awareness and internalization of media stereotypes, body size acceptance, and teasing on the weight loss and muscle-gaining behaviors of 10- to 14-year-old boys and girls. METHODS: Male (n = 670) and female (n = 788) students were drawn from one of four public senior middle schools (grades 6-8) in Southern Ontario as part of a longitudinal outcome-based study. Students' baseline self-report questionnaires, measuring the above variables, were analyzed for the purposes of this study. RESULTS: A higher percentage of girls reported engaging in weight loss behaviors, whereas a higher percentage of boys admitted to muscle gaining and the use of specific weight control methods such as laxative use and vomiting. Regression analyses revealed that internalization of media messages and body size acceptance were equally predictive of boys' weight loss and muscle-gaining behaviors, while teasing was found to also predict their muscle-gaining behavior. Among the girls, appearance esteem, internalization of media stereotypes, and body size acceptance were predictive of weight loss behaviors. None of the study variables were predictive of girls' muscle-gaining behavior. CONCLUSIONS: weight loss and muscle-gaining behaviors appear to have their onset in children as young as 10 years. The findings support the need for prevention programs that focus on media literacy and ways to decrease weight-based teasing in the school setting.

An assessment of obesity among African-American women in an inner city primary care clinic.

Despite multiple patient assessments and interventions, obesity continues to cause significant morbidity and mortality nationwide. This study assesses the prevalence of obesity and weight control practices among middle-aged African-American women. In 1995, 307 women 30 years of age and older were consecutively selected in a non-random fashion from three clinic sites located within a public university hospital that served largely indigent, inner city African-American populations. Interviewers surveyed the respondents using the Centers for Disease Control and Prevention's Behavioral Risk Factor Surveillance System (BRFSS). The prevailing demographic profile of patients in the clinic was middle-aged, indigent, ill, and of low educational attainment. Over 35% of individuals were classified as being overweight (BMI 25 to 29.9 kg/m2) and 45% were classified as being obese (BMI > or = 30 kg/m2). Therefore, more than 80% of individuals in this study were either overweight or obese, with BMI exceeding 25 kg/m2. Of the overweight and obese African-American women in this study, only 40% were attempting current weight loss practices, and weight loss attempts varied directly with body mass index. Although 80% of women attempted weight loss by restricting caloric intake, only 50% were also using physical activity as part of their regime. African-American women in this population have a higher prevalence of obesity and encounter great difficulty losing weight. Counselors should emphasize the value and ease of adopting a moderate regimen of physical activity and not just reducing caloric intake when advising African-American women and their peer network.

Effect of weight loss on bone metabolism: comparison of vertical banded gastroplasty and medical intervention.

BACKGROUND: We studied the effects of weight loss on bone metabolism. METHODS: 16 consecutive surgically-treated (14 female, 2 male) morbidly obese patients and 65 obese (53 male, 12 female) medically-treated patients were enrolled in an observational study. Surgical treatment for morbidly obese patients was vertical banded gastroplasty (VBG). Studies were performed prior to and 12 months after the start of treatment. Bone mineral density (BMD), bone turnover markers, sex steroids, calcium excretion and parathyroid hormone measurements were done at each visit. RESULTS: weight loss was more prominent with surgical than with medical treatments. Bone loss was also pronounced in the surgical treatment group, and occurred at the hip level only (P<0.05). Compared to previously reported studies, where the effects of malabsorptive treatments for obesity on bone metabolism were studied, calcium excretion and parathyroid hormone levels did not change after VBG or medical therapy. For both groups, bone markers indicated an increased bone turnover, evidenced by increased urinary excretion of deoxypyridinoline and serum levels of osteocalcin (P<0.05). Sex steroid measurements revealed a decrease in estradiol levels in the surgical treatment group, but not in medical treatment group. This finding was thought to be secondary to less weight loss in the medical group. CONCLUSION: Our data indicate that weight loss causes bone loss. The bone loss is independent of the method of weight reduction. However, the mechanism of the bone loss is not clear. It may be explained partly by reduced estradiol levels in female patients. Because the mechanisms of bone disease after weight loss remain unclear, it is difficult to determine the most effective treatment. It is important to detect osteopenia early, before fractures occur. Measuring BMD appears to be the only reliable method for screening.

Ghrelin: a gut-brain hormone: effect of gastric bypass surgery.

BACKGROUND: Ghrelin is a newly recognized gastric hormone with orexigenic and adipogenic properties, produced primarily by the stomach. Ghrelin is reduced in obesity. weight loss is associated with an increase in fasting plasma ghrelin. We assessed the effect of massive weight loss on plasma ghrelin concentrations and its correlation with serum leptin levels and the presence of type 2 diabetes mellitus (DM) in severely obese patients. METHODS: A prospective study was conducted on 28 morbidly obese women (BMI 56.3 +/- 10.2 kg/m2) who underwent gastric bypass, divided into 2 groups: 14 non-diabetics (NGT) and 14 type 2 diabetics (DM2). Ghrelin and leptin were evaluated before silastic ring transected vertical gastric bypass, and again 12 months postoperatively. RESULTS: Fasting plasma ghrelin concentrations were 56% lower in NGT and 59% lower in DM2 compared with a lean control group (P < 0.001). There was no difference in ghrelin levels between NGT and DM2 groups before and after surgery (P > 0.05). Ghrelin was negatively correlated with leptin before gastric bypass surgery (r = 0.51, P < 0.01). The mean plasma ghrelin concentration decreased significantly after surgery in both groups (P < 0.001). CONCLUSION: Ghrelin was inversely related to leptin concentrations. Presence of diabetes did not affect the ghrelin pattern. Reduced production of ghrelin after gastric bypass could be partly responsible for the lack of hyperphagia and thus for the weight loss.