Gender Differences in the Response of Plasma Leptin Concentrations to Weight Loss in Obese Older Individuals

Plasma leptin concentration is directly related to the degree of obesity and is higher in women than in men of the same body mass index (BMI). We hypothesized that fasting plasma leptin concentrations and the response of leptin to weight loss would differ in older men and women of a similar fat mass. Plasma leptin concentrations (radioimmunoassay) and fat mass (DXA) were measured in 47 older, obese (BMI=30 ± 4 kg/m²) women and 23 older, obese (BMI=31 ± 3 kg/m²) men after a 2 to 4 week period of weight and dietary stabilization, and then in 22 of the women and 18 of the men after a 6-month weight loss intervention (250–350 kcal/d deficit). Leptin correlated with fat mass in men and women (r=0.75 and r=0.77, respectively; p values<0.0001), but women had 3-fold higher leptin levels for a given fat mass than men (p=0.01). In response to the 6-month hypocaloric diet, men and women lost a similar percentage of fat mass (?13% and ?16%, respectively), but the relative decline in circulating leptin was greater in women than men (-45% and ?21%, respectively; p<0.0001). In addition, when leptin was normalized for fat mass using the ratio method, the decrease in leptin per kilogram of fat mass was greater in women than men (-0.37 ± 0.34 vs. ?0.04 ± 0.06 ng/mL/kg; p<0.01). After weight loss, the change in leptin concentrations correlated positively with the change in fat mass in men (r=0.60; p<0.01), but not in women (r=0.31; p=0.17). Furthermore, the loss in fat mass correlated negatively with baseline leptin levels in women (r=-0.47; p<0.05), but not in men (r=0.03, p=NS). These results indicate that the decline in leptin concentration with weight loss correlates with the loss in fat mass in men; but, in women, other factors affect the decrease in leptin concentration. This suggests that the role of leptin in the regulation of obesity is gender-specific and may account for gender differences in response to hypocaloric treatment and maintenance of lost weight.     

Relationship of Co-Morbidities of Obesity to Weight Loss and Four-Year Weight Maintenance/Rebound

This study examined the effect of weight loss (separate from energy restriction) and weight maintenance/rebound over time on blood pressure, serum lipids, and body composition in 24 obese (mean 137% ideal body weight (IEW)) females with mild to moderate hypertension. Weight loss was induced under tightly controlled General Clinical Research Center conditions until each subject had lost at least 10 kg (mean 13 kg) and attained normal body weight (<120% IBW). After 4 years subjects returned for repeat evaluation. Weight changes were compared with 24 pair-matched normal weight controls who were also followed for 4 years. With weight loss, significant improvements were seen in standing mean arterial pressure (MAP), serum total cholesterol, low-density lipoprotein cholesterol, and triglycerides. Subjects regained 11 kg (87% of the weight lost) over the 4 year follow-up period while control subjects gained only 2 kg. Subjects who chose self-selected exercise gained less weight than nonexercisers (6 kg vs. 13 kg, P<0.05). With weight regain there were significant increases in standing and supine MAP, total cholesterol, and high-density lipoprotein (HDL) cholesterol. The amount of weight regained was significantly correlated with standing MAP (r=0.73), triglycerides (r=0.43), and HDL cholesterol (r=-0.47). The percentage fat of the weight regained was no greater than that of the weight previously lost. Weight loss, distinct from energy restriction, was associated with improvements in blood pressure and serum lipid levels. The ability to sustain these improvements in the co-morbidities of obesity was directly related to the persistence and magnitude of weight loss maintenance.     

Effects of Visceral Fat and Weight Loss on Lipoprotein(a) Concentration in Subjects with Obesity

ZAMBONI M, R FACCHINETTI, F ARMELLINI, E TURCATO, IA BERGAMO ANDREIS, O BOSELLO. Effects of visceral fat and weight loss on lipoprotein(a) concentration in subjects with obesity. We studied the relationships between regional body fat distribution and metabolic variables with lipoprotein(a) [Lp(a)] as well as the effects of weight loss on Lp(a) in 25 women and 9 men with obesity. Regional body fat distribution, as evaluated by the use of computed tomography; Lp(a); and fasting glucose, insulin, cholesterol, and triglycerides were analyzed before and after a very low-energy diet. No significant correlations were found between visceral, subcutaneous, and total fat and Lp(a) or between metabolic variables and Lp(a). All anthropometric variables significantly decreased after a very low-energy diet. Fasting glucose, insulin, triglycerides, and cholesterol significantly decreased after a very low-energy diet. No significant changes in Lp(a) concentration after a very low-energy diet were found. The correlation between the initial values of Lp(a) and changes of Lp(a) after a very low-energy diet was slightly significant (ρ=0.33, p<0.06). In conclusion, our study shows that Lp(a) is not influenced by obesity, visceral fat, metabolic variables, or weight loss induced by a very low-energy diet     

Fat Distribution and Insulin Sensitivity in Postmenopausal Women: Influence of Hormone Replacement

Objective: To examine cross‐sectionally the influence of hormone replacement therapy (HRT) on the relationship between body composition and insulin sensitivity (Si). Research Methods and Procedures: Subjects were 57 early postmenopausal white women, 33 receiving HRT and 24 controls. Body composition was estimated using DXA and computed tomography scans at the abdomen and mid‐thigh. Si was assessed by a frequently sampled intravenous glucose tolerance test with minimal model analysis. Results: Compared with nonusers, HRT users had lower visceral adipose tissue, fasting serum glucose, and fasting insulin. Total body fat and unadjusted Si did not differ between groups. Visceral adipose tissue mass (VATM) was the only body‐fat compartment significantly associated with Si (r² = 0.43, p < 0.0001) in a model including total‐body fat, upper‐trunk fat, subcutaneous abdominal fat mass, leg fat, and mid‐thigh low‐density lean tissue. Lean body mass was positively correlated with Si among HRT users and tended to be negatively correlated among nonusers. HRT status also affected the relationship between VATM and Si such that, relative to nonusers, HRT users had lower Si across lower VATM levels, but higher Si across higher VATM. Discussion: These results suggest that in postmenopausal women, VATM is uniquely related to Si. HRT affects the relationship between VATM and Si and between lean body mass and Si. These interactions should be considered in future studies.     

Serum Leptin Concentrations and Weight Gain in Postobese,Postmenopausal Women

Objective : This study was designed to determine if serum leptin concentrations (adjusted for fat mass) after weight loss on a low-calorie diet predict subsequent weight gain. Research Methods and Procedures : Body composition and serum leptin concentrations were determined on 14 moderately obese, postmenopausal, nondiabetic women with a familial predisposition to obesity. Assessments were obtained under tightly controlled metabolic ward conditions of macronutrient intake and weight maintenance both before (obese state) and after a mean weight loss of 12.0 kg to normal body weight (postobese state). Four years later, without intervention, body weight and body composition were reassessed. Results : Weight loss resulted in significant decreases in fat mass (29.7 ± 5.4 vs. 20.3 ± 4.7; kg), body mass index (27.7 ± 1.6 vs. 23.0 ± 1.5; kg/m2), percent body fat (40.7 ± 4.3 vs. 33.1 ± 5.0), and serum leptin concentrations (31.8 ± 16.0 vs. 11.5 ± 5.4; ng/mL). Serum leptin concentrations were positively correlated (p<<0.05) with fat mass in both the obese and postobese states (r = 0.67 and r = 0.56, respectively). However, residual serum leptin concentrations (adjusted for fat mass) in the obese and postobese states were not related to changes in body weight (p<= 0.61 and 0.52), fat mass (p = 0.72 and 0.42), body mass index (p = 0.59 and 0.33), or percent body fat (p = 0.84 and 0.46) over the follow-up period. Discussion : These finding do not support the hypothesis that relatively low concentrations of leptin predict weight regain after weight loss. However, because the number of subjects in this study was limited, further studies are warranted.     

Exercise‐Induced Reduction in Obesity and Insulin Resistance in Women: a Randomized Controlled Trial

Objectives : To determine the effects of equivalent diet‐ or exercise‐induced weight loss and exercise without weight loss on subcutaneous fat, visceral fat, and insulin sensitivity in obese women. Research Methods and Procedures : Fifty‐four premenopausal women with abdominal obesity [waist circumference 110.1 ± 5.8 cm (mean ± SD)] (BMI 31.3 ± 2.0 kg/m²) were randomly assigned to one of four groups: diet weight loss (n = 15), exercise weight loss (n = 17), exercise without weight loss (n = 12), and a weight‐stable control group (n = 10). All groups underwent a 14‐week intervention. Results : Body weight decreased by ～6.5% within both weight loss groups and was unchanged in the exercise without weight loss and control groups. In comparison with controls, cardiorespiratory fitness improved within the exercise groups only (p < 0.01). Reduction in total, abdominal, and abdominal subcutaneous fat within the exercise weight loss group was greater (p < 0.001) than within all other groups. The reduction in total and abdominal fat within the diet weight loss and exercise without weight loss groups was greater than within controls (p < 0.001) but not different from each other (p > 0.05). Visceral fat decreased within all treatment groups (p < 0.008), and these changes were not different from each other. In comparison with the control group, insulin sensitivity improved within the exercise weight loss group alone (p < 0.001). Discussion : Daily exercise without caloric restriction was associated with substantial reductions in total fat, abdominal fat, visceral fat, and insulin resistance in women. Exercise without weight loss was also associated with a substantial reduction in total and abdominal obesity.     

Treatment of Morbid Obesity in Inner‐City Women

Objective: To explore the use of the very‐low‐calorie formula diet (VLCD) in the indigent population of Newark, NJ, with the goal of achieving 10% weight loss within a relatively short period of 10 weeks. Research Methods and Procedures: We accepted 131 morbidly obese indigent women into our study program. The study was limited to women only and the average starting weight was 292.3 ± 5.9 lbs (± SE; 50.3 ± 0.9 body mass index [kg/m²]). We used three treatment paradigms: total cost‐free program for 10 weeks; cost‐free, but compliance requirements; and a weekly charge of $25. The results obtained were compared with two control populations: women enrolled during the same recruitment period in a comparable suburban VLCD program and a historical control population of suburban women treated from 1985 through 1995. Results: In group A (total cost‐free), 79% of patients completed the 10‐week program, but only 18% of patients achieved the goal of 10% weight loss. In group B when attendance and weight loss requirements were imposed, the dropout rate accelerated such that only 37% of patients completed the 10‐week course, and 16% of the women were successful with their weight loss. In group C, imposing $25/wk financial outlay also accelerated dropouts but had little effect on weight loss success, which was 10% of the starting group. By comparison, the suburban patients and the historical control group exhibited 67% and 76% attendance rates after 10 weeks, and 33% and 55% success rates, respectively, in achieving the weight loss goal. Discussion: We conclude that inner‐city patients exhibit great interest in weight loss when financial barriers are removed. Successful weight loss was achieved in 10% to 18% of patients using the VLCD approach, approximately one‐half of that obtained in affluent suburban women. Imposing financial or compliance restrictions to the inner‐city patients served only to enhance dropouts.     

Comparison of Obese NIDDM and Nondiabetic Women: Short- and Long-Term Weight Loss

Previous research suggests that overweight patients with diabetes lose less weight than non diabetics. We compared the response of obese women with NIDDM to non diabetic controls, matched for age and weight, to a behavior weight loss program. Forty-three overweight women (20 NIDDM, 23 non diabetic) participated in the study. NIDDM and non diabetic subjects were treated together and received the same 16-week behavioral weight loss program. Dependent measures included weight, 3-day food records, physical activity, fasting plasma glucose, and questionnaires assessing eating behavior and depressive symptomatology. Weight loss of NIDDM and non diabetic subjects at posttreatment was comparable (-7.4 ± 5.3 kg vs. ?6.4 ± 3.8 kg, respectively). Changes in caloric intake, eating behavior, exercise and depressive symptomatology were also similar between the two groups. However, during the 1-year follow-up period, NIDDM subjects regained 5.4 ± 6.1 kg compared to 1.0 ± 6.7 kg for nondiabetics (p=.058). These data indicate that NIDDM subjects can lose as much weight as their nondiabetic peers during active treatment Once treatment terminated, however, NIDDM subjects demonstrated poor weight loss maintenance. Thus the added motivation that comes from having diabetes and seeing improvements in glycemic control with weight loss were not sufficient to improve long term weight loss in diabetic subjects. A continuous care model of weight control may be particularly necessary for overweight patients with type II diabetes.     

Intentional Weight Loss in Young Adults: Sex‐Specific Genetic and Environmental Effects

Objective: To explore eating styles associated with intentional weight loss (IWL) and to determine whether the genetic liability in IWL is entirely shared with genetic liability affecting BMI. Research Methods and Procedures: As part of a longitudinal assessment of various health‐related behaviors in a large population‐based sample of twins, eating styles, BMI, and the number of times the study participants had intentionally lost ≥5 kg were assessed by questionnaire from 4667 male and female twins (22 to 27 years of age). Associations of eating styles and IWL were explored using polytomous logistic regression models adjusted for BMI. Sex‐specific bivariate structural equation modeling was used to explore genetic and environmental correlations of BMI and IWL. Results: Individuals who had engaged in IWL exhibited markedly more restricting, overeating, and alternating restricting/overeating than those in the no‐IWL group. Snacking and eating in the evening were characteristic of women with at least two IWL attempts. Eating in response to visual and emotional cues was very pronounced in women who had engaged in IWL but much less so in men. IWL was estimated to have a heritability of 38% [95% confidence interval (CI), 19% to 55%] in men and 66% (95% CI, 55% to 75%) in women. The genetic covariance of BMI and IWL was 0.38 (95% CI, 0.28 to 0.47) for men and 0.45 (95% CI, 0.41 to 0.52) for women. Discussion: Distinct sex differences exist in eating styles associated with IWL and in the heritability of IWL. Most genetic factors affecting BMI are different from those affecting IWL.     

Estradiol‐Induced Anorexia Is Independent of Leptin and Melanin‐Concentrating Hormone

Objective: Treatment of male rodents with estradiol (E₂) is associated with anorexia and weight loss by poorly understood mechanisms. We examined the role of the orexigenic hypothalamic peptide melanin‐concentrating hormone (MCH) and the appetite‐inhibiting, fat‐derived hormone leptin in mediating E₂‐induced anorexia. Research Methods and Procedures: We studied the effect of E₂ treatment (implantation of either E₂ pellet or matching placebo) in male C57Bl/6J mice, as well as in a lean mouse model (MCH knockout mice) and an obese model (leptin‐deficient ob/ob mice). We also studied the effect of E₂ treatment in the context of high‐fat diet. Results: We confirmed E₂ dose‐dependent anorexia in male wild type mice fed a normal chow diet. E₂ treatment was associated with a significant decrease in body fat, serum leptin levels, and arcuate hypothalamic proopiomelanocortin expression. E₂‐implanted mice also showed increased hypothalamic neuropeptide Y and MCH expression. As MCH has been implicated in E₂‐induced hypophagia, we performed E₂ pellet implantation in MCH knockout mice and observed hypophagia and weight loss, indicating that MCH is not an essential mediator of E₂‐induced anorexia. E₂‐implanted ob/ob mice also had hypophagia and weight loss, indicating that leptin is not essential for E₂‐induced anorexia. High‐fat diet significantly exacerbated the effect of E₂ treatment, leading to a 99.6% decrease in food intake at 48 hours and a 30% loss of body weight within 1 week. Discussion: The anorectic effects of E₂ were independent of MCH and leptin. Our results suggested that E₂ may have effects on nutrient preferences.     

History of Intentional and Unintentional Weight Loss in a Population-Based Sample of Women Aged 55 to 69 Years

FRENCH, SIMONE A, ROBERT W JEFFERY, AARON R FOLSOM, DAVID F WILLIAMSON AND TIM BYERS. History of intentional and unintentional weight loss in a population-based sample of women aged 55 to 69 years. Obes Res. 1995;3:163–170. Although both overweight and body weight fluctuation are related to chronic disease risk, little is known about the history of and reasons for body weight change in the general population. This paper reports the incidence of intentional and unintentional weight loss episodes during adulthood in a population-based sample of 26, 261 women aged 55 to 69 years. Intentional weight loss episodes of each of four amounts (5–9, 10–19, 20–49, 50+ lbs.) and unintentional weight loss episodes of 20 or more lbs. were recalled for each of three age periods (18–39, 40–54, 55+ years). At least one intentional weight loss episode of 5 or more lbs. was reported by 69% of women, 46% reported at least one intentional weight loss episode of 10 or more lbs, and 25% reported at least one intentional weight loss episode 20 or more lbs. At least one unintentional weight loss episode of 20 or more lbs. was reported by 29% of the women. Reasons for weight losses of 20 or more lbs. were also recalled. Women who had intentionally lost 20 or more lbs. were more likely to report weight losses due to low-calorie diets, exercise and weight loss groups, while women who had unintentionally lost 20 or more lbs. were more likely to report weight losses due to depression or stress. These findings question the common assumption that weight losses in adult women are primarily intentional and emphasize the need to distinguish the reasons for weight loss in studies examining the relationship between body weight changes and health outcomes.     

Birth Weight,Adulthood BMI,and Subsequent Weight Gain in Relation to Leptin Levels in Swedish Women

LISSNER, LAUREN, CECILIA KARLSSON, ANNA KARIN LINDROOS, LARS SJOSTROM, BJORN CARLSSON, LENA CARLSSON, AND CALLE BENGTSSON. Birth weight, adulthood BMI, and subsequent weight gain in relation to leptin levels in Swedish women. Obes Res. Objective Leptin seems to be involved in the regulation of energy balance, although little is known about the epidemiology of leptin with respect to prediction of weight gain and incidence of obesity-related diseases. The dual aim of this study is to document characteristics of leptin after long-term storage, and to describe its relation to body weight, from birth to old age, in an ongoing prospective study. Research Methods and Procedures A population-based sample of Swedish women was first examined at the ages of 38 to 60 and re-examined 24 years later. This study used 1358 frozen serum samples that had been stored 29 years for analysis of leptin concentrations and their relation to body weight history. Results Leptin values obtained from stored samples showed the same correlation with relative weight as that seen in a contemporary sample with similar demographic characteristics. Lower self-reported birth weight was associated with higher leptin levels in adulthood (p = 0.01), controlling for age and adult BMI. Prospective analyses revealed that high leptin in 38 to 46-year-olds predicted subsequent long-term weight gain (p = 0.003), although no significant associations were seen in women initially aged 50 or older. Discussion: It is feasible to use frozen serum for studying leptin in relation to obesity and related developments many years later. High leptin level was a risk factor for subsequent weight gain in 38- and 46-year-old women. Retrospective analyses involving birth weight suggest that leptin resistance in adulthood might have fetal origins.     

Hyperadiponectinemia in Newborns: Relationship with Leptin Levels and Birth Weight

Objective: Adiponectin is the only adipose‐specific hormone that, despite its exclusive production by adipose tissue, is reduced in obesity and is inversely correlated with leptin levels in adults. The aim of this study was to evaluate the adiponectin concentration in umbilical cord blood at different gestational ages and to investigate its possible associations with leptin levels and birth weight. Research Methods and Procedures: Umbilical cord blood was obtained from 132 newborns (male = 65, female = 67, gestational age: 35 to 42 weeks). The anthropometric variables of the newborns studied were birth weight, birth length, body weight/body length, and ponderal index. Adiponectin, insulin, and leptin levels were measured by radioimmunoassay methods. Results: Adiponectin levels in males were not different from those in females (24.10 ± 0.81 vs. 25.62 ± 0.84 μg/mL, p = 0.280). Adiponectin concentrations were positively correlated with birth weight (p < 0.05), birth length (p < 0.05), body weight/body length (p < 0.05), gestational age (p < 0.01), and leptin levels (p < 0.01). Discussion: These findings indicate that adiponectin is present in umbilical cord blood after 35 to 42 weeks of gestation, with higher levels than those usually found in adults, no gender differences, and a positive correlation with birth weight and leptin. These results suggest that not only could neonatal hyperadiponectinemia be associated with the increase of adiponectin production by fetal adipose tissue but also with a possible reduction in an unknown mechanism related to the suppression of adiponectin observed in adults.     

Use of Portion‐Controlled Entrees Enhances Weight Loss in Women

Objective: To determine the efficacy of a weight‐loss diet using packaged portion‐controlled entrees compared with a self‐selected diet based on the U.S. Department of Agriculture Food Guide Pyramid (FGP) (United States Department of Agriculture, Center for Nutrition Policy and Promotion, Washington, DC; 1996). Research Methods and Procedures: Sixty healthy women (BMI 26 to 40 kg/m²; 24 to 60 years old) were randomized into two intervention groups for an 8‐week parallel arm study. The portion‐controlled group consumed two frozen entrees daily, plus additional food servings from the FGP. The self‐selected diet group consumed a recommended number of servings from the FGP. Diets were designed to be the same in composition (55% carbohydrate, 25% protein, 20% fat) and energy level (1365 kcal). Each group met weekly to monitor compliance and take measures. Outcomes included weight, body composition by DXA, hip and waist circumference, blood pressure, fasting blood lipids, glucose, insulin, and C‐reactive protein. Significant differences were assessed using repeated measures ANOVA. Results: The portion‐controlled group (n = 26) experienced greater decreases in weight (5.6 ± 2.2 kg or 6.5% vs. 3.6 ± 2.5 kg or 4.2%), fat mass (3.6 ± 1.8 vs. 2.3 ± 1.4 kg), total cholesterol (24.4 ± 21.5 mg/dL or 12.4% vs. 13.0 ± 13.9 mg/dL or 6.7%), and fasting insulin (?1.8 ± 3.7 vs.+0.3 ± 3.8 μU/mL) than the self‐selected diet group (n = 27) (p < 0.05). Discussion: Consumption of portion‐controlled entrees resulted in greater losses of weight and fat, thereby reducing cardiovascular disease risk. Accurate portion control is an important factor in weight loss success, and use of packaged entrees is an effective method of achieving this.     

Relationships of Plasma Leptin Levels to Changes in Plasma Free Fatty Acids in Women Who Are Lean and Women Who Are Abdominally Obese

HENNES, MAGDA MI, ARNAVAZ DUA, DIANA L MAAS, GABRIELE E SONNENBERG, GLENN R KRAKOWER, AHMED H KISSEBAH. Relationships of plasma leptin levels to changes in plasma free fatty acids in women who are lean and women who are abdominally obese. Regulation of leptin production by the hormonal and metabolic milieu is poorly understood. Because abdominal obesity is commonly associated with elevated plasma free fatty acid (FFA) flux, we examined the effects of augmenting FFA on plasma leptin levels in women who were lean and of suppressing FFA in women with abdominal obesity. In study 1, nine subjects who were lean, after a 12-hour overnight fast, received either intravenous saline or Intralipid plus heparin to increase the plasma FFA concentration to approximately 1000 μmol/ L. After 3 hours of additional fasting, subjects underwent 3-hour hyperglycemic clamps. In study 2, seven subjects with abdominal obesity were evaluated by a similar protocol, but lipolysis and plasma FFA flux were instead maximally suppressed by acipimox. In the individuals who were lean, leptin levels were unchanged during clamping. Increasing plasma FFA reduced plasma leptin from 7.66 ± 0.66 to 7.05 ±0 0.66 (p=0.03), but 3 hours of hyperglycemia plus hyperinsulinemia had no additional effect on leptin levels (7.15 ± 0.71). Basal leptin levels, 4-fold higher in the subjects with obesity, were reduced from 34.6 ± 2.4 μg/L to 32.3 ± 1.1 μg/L (p=0.004) during the clamp period. When plasma FFA flux was suppressed, however, plasma leptin levels after clamped hyperglycemia/hyperinsulinemia were increased to 38.9 ± 1.2 μg/L (p=0.014 vs. time 0 and 0.001 vs. saline protocol). Changes in leptin concentrations are not correlated with changes in FFA. These results suggest that plasma FFA concentration does not regulate plasma leptin levels in basal, extended fasting, or hyperglycemic/hyperinsulinemic states.     

Effects of Sibutramine on Resting Metabolic Rate and Weight Loss in Overweight Women

Sibutramine, a monoamine re-uptake inhibitor, has recently been approved by the Food and Drug Administration as a weight loss agent. Sibutramine lowers body-weight in rodents by reducing energy intake and increasing energy expenditure. Sibutramine facilitates weight loss in human subjects, but it is not clear whether it acts on energy intake, energy expenditure, or both. The present study was a randomized clinical trial designed to assess the effects of sibutramine (at 10 or 30 mg/day) on body weight and resting metabolic rate (RMR). Forty-four overweight women were randomized to 1) placebo (n=15); 2) sibutramine at 10 mg/day (n=15) or, 3) sibutramine at 30 mg/day (n=14). All subjects were instructed to consume a 1200 kcal/day diet for 8 weeks while receiving drug or placebo. RMR was assessed by indirect calorimetry at baseline, at 3 hours after the first dose of drug (or placebo), and at the end of the 8-week weight-loss period. Sibutramine reduced body weight-relative to placebo, but there was no difference between weight loss on the two sibutramine doses. No significant differences in RMR between sibutramine and placebo were seen, either 3-hour post dose or after the 8-week weight-loss period. After the weight loss period, all groups were taken off medication and kept weight stable for another 4 weeks. RMR was measured again and was not different among groups. That there was no change in RMR when sibutramine was stopped further suggests that the drug does not directly affect RMR. In summary, while sibutramine was shown to be an effective weightloss agent over 8 weeks, we found no evidence that it increased RMR.     

Weight Loss Expectations in Patients with Binge‐Eating Disorder

Objective: To study weight loss expectations in patients with binge‐eating disorder and to examine whether expectations differed by sex and motivation for treatment. Research Methods and Procedures: One hundred and thirty patients (104 women and 26 men), aged 23 to 61 (mean age, 43.0 years), with BED completed a measure of desired weights that included their dream weight, happy weight, acceptable weight, and disappointed weight. In a structured interview, participants were asked their primary motivation for seeking treatment (appearance or health) and their lowest adult weight (LAW). Results: The BED participants reported weight loss expectations that far exceeded expert and governmental guidelines. In this sample, desired dream body mass index (BMI), happy BMI, and acceptable BMI averaged reductions in current weight of 36%, 29%, and 23%, respectively. Even the “disappointed” BMI was an average 14% reduction in current weight, and was 1.5 to 3 times greater than the expert recommendation (5% to 10%). Comparisons of desired weights were significantly different for women and men, whereas percent reductions from current weight were not. Although weight goal expectations were significantly lower for those motivated by appearance, compared with those motivated by health, percent reductions for current weight were not. Desired dream weight correlated with reported LAW, and the mean difference between these weights was not significant. Discussion: These findings suggest that patients with BED have weight loss expectations that far exceed expert and governmental guidelines and that these expectations do not differ by sex or motivation for seeking treatment. One possible explanation for these unrealistic desired weights may be the patients’ recollections of their LAWs.     

Effect of weight loss on free insulin-like growth factor-I in obese women with hyposomatotropism

Objective: It has been hypothesized that increased free insulin‐like growth factor (IGF)‐I levels generated from an increase in IGF‐binding protein (IGFBP) protease activity could be the inhibitory mechanism for the decreased growth hormone (GH) secretion observed in obese subjects. Research Methods and Procedures: In this study, we determined basal and 24‐hour levels of free IGF‐I and ‐II, total IGF‐I and ‐II, IGFBP‐1, as well as basal IGFBP‐2, ?3, and ?4, acid‐labile subunit (ALS), IGFBP‐1, ?2, and ?3 protease activity, and 24‐hour GH release in obese women before and after a diet‐induced weight loss. Sixteen obese women (age, 29.5 ± 1.4 years) participated in a weight loss program and 16 age‐matched non‐obese women served as controls. Results: Circulating free IGF‐I and 24‐hour GH release were significantly decreased in obese women at before weight loss compared with non‐obese women (1.29 ± 0.12 vs. 0.60 ± 0.09 μg/L; p < 0.001 and 862 ± 90 vs. 404 ± 77 mU/24 hours; p < 0.001, respectively). Free IGF‐I and 24‐hour GH release were not inversely correlated to each other. IGFBP‐1 and ?2 levels were decreased, whereas ALS, IGFBP‐3 and ?4, and IGFBP‐1, ?2, and ?3 protease activity were similar in obese and non‐obese women. Eight of the 16 obese women achieved an average weight loss of 30 ± 5 kg during 26 to 60 weeks of dieting. After the considerable weight loss, significant differences in free IGF‐I, GH release, and IGFBP‐1 and ?2 levels were no longer present between previously obese and non‐obese women. Discussion: We showed that circulating free IGF‐I is markedly decreased in severely obese women and does not per se mediate the concomitant hyposomatotropism. The decreased levels of free IGF‐I seem to be transient and restored to normal levels after weight loss.     

Obesity‐related Comorbidities in Obese African Americans in an Outpatient Weight Loss Program

Objective: To identify, among obese African‐American enrollees in an outpatient weight loss program, differences between those with and without obesity‐related comorbidities (ORCMs). Research Methods and Procedures: Data were from 237 obese African Americans (BMI, 30 to 50 kg/m²; 90% women) who enrolled in a 10‐week lifestyle weight loss program. Analyses compared subgroups defined by ORCM status (from medical history) on baseline characteristics, program attendance, and postprogram weight change. Results: Most participants (76%) had one or more ORCMs. Those with versus without ORCMs, respectively, were older (mean age, 45.6 vs. 37.1 years; p < 0.001), were less educated (59.2% vs. 76.6% with >12 years; p = 0.031), were more likely to perceive a physical limitation affecting activity (22.2% vs. 1.8%; p < 0.001), and had higher waist circumference (mean, 113.7 vs. 106.9 cm; p < 0.001) but not BMI (38.3 vs. 37.0 kg/m²; p = 0.095). Logistic regression analyses confirmed the independence of these associations. Having ORCMs was not associated with class attendance or return for data collection after the 10‐week program. Postprogram weight change (n = 134) was unrelated to ORCMs, but better weight loss was seen among those without perceived physical limitations (1.9 vs. 0.4 kg in those without versus with limitations; p = 0.069). Conclusion: Data from this clinical sample of obese African Americans suggest that waist circumference is relevant to ORCM status at BMI levels up to 50 kg/m². Clear indications for tailoring of treatment based on ORCM status were not identified, although the possible influence of ORCM‐related activity limitations warrants further study.