Applicability of maximal oxygen consumption criteria in obese, postmenopausal women.

This study examines the applicability of using three standard criteria (age-predicted maximal heart rate [HRmax], respiratory exchange ratio [RER>1.10], and plateau in oxygen uptake [Vo(2)] for the measurement of maximal oxygen consumption (Vo(2)max) in postmenopausal women. One hundred eight postmenopausal (60 +/- 6 years), overweight and obese (body mass index [BMI] = 33 +/- 4 kg/m(2)), sedentary (Vo(2)max = 19 +/- 3 ml/kg/min) women underwent one exercise test (Bruce protocol), and 71 of these women underwent a second test (modified Balke protocol). On test 1, 69 (64%) women achieved age-predicted HRmax, 61 (57%) reached an RER>1.10, and 16 (15%) achieved a plateau in Vo(2) (<2 ml/kg/min change). Women who reached age-predicted HRmax and reached an RER of at least 1.10 had a higher peak Vo(2) (p <0.01) than women who did not meet these criteria. There was no difference in the highest V02 obtained between women who did and did not achieve a plateau in Vo(2) during test 1 (p = 0.55). Resting HR, HRmax, and RER were similar between the two tests. On average, peak Vo(2) was higher on the second test (p <0.01). However, Vo(2)max was not different between exercise tests in women who achieved at least two of the three criteria on both tests (n = 24; test 1, 19.4 +/- 3.4; test 2: 19.8 +/- 3.7 ml/kg/min; p = NS). In addition, Vo(2)max was similar between the two exercise tests in 14 women who reached a plateau on the second test but did not reach a plateau on the first test (19.2 +/- 3.3 vs. 19.6 +/- 4.2 ml/kg/min; p = NS). We conclude that achievement of a plateau in Vo(2) is not a necessary criterion for a valid measurement of Vo(2)max in overweight and obese, sedentary, postmenopausal women.

Genetic variation in the peroxisome proliferator-activated receptor-gamma2 gene (Pro12Ala) affects metabolic responses to weight loss and subsequent weight regain.

This study determined the effects of the peroxisome proliferator-activated receptor (PPAR)-gamma2 Pro12Ala variant on body composition and metabolism and the magnitude of weight regain in 70 postmenopausal women (BMI 25-40 kg/m(2)) who completed 6 months of a hypocaloric diet. At baseline, BMI, percent body fat, intra-abdominal and subcutaneous abdominal fat areas, resting metabolic rate, substrate oxidation, and postprandial glucose and insulin responses were not different between genotypes (Pro/Pro = 56, Pro/Ala and Ala/Ala = 14). The intervention similarly decreased body weight by 8 +/- 1% in women homozygous for the Pro allele and by 7 +/- 1% in women with the Ala allele (P < 0.0001). Fat oxidation did not change in Pro/Pro women but decreased 19 +/- 9% in women with the Ala allele (P < 0.05). Changes in glucose area were not different between groups; however, women with the Ala allele decreased their insulin area more than women homozygous for the Pro allele (P < 0.05). Weight regain during follow-up was greater in women with the Ala allele than women homozygous for the Pro allele (5.4 +/- 0.9 vs. 2.8 +/- 0.4 kg, P < 0.01). PPAR-gamma2 genotype was the best predictor of weight regain (r = 0.50, P < 0.01), followed by the change in fat oxidation (partial r = 0.35, P < 0.05; cumulative r = 0.58). Thus, the Pro12Ala variant of the PPAR-gamma2 gene may influence susceptibility for obesity.

Racial disparities in metabolism, central obesity, and sex hormone-binding globulin in postmenopausal women.

Increased total and intraabdominal fat (IAF) obesity as well as other metabolic conditions associated with the insulin resistance syndrome (IRS) are related to low levels of sex hormone-binding globulin (SHBG) in young and older Caucasian (CAU) and young African-American (AA) women. We examined whether postmenopausal AA women, a population with a high incidence of obesity and IRS despite low IAF, would have higher levels of circulating SHBG compared with CAU women, and whether there would be negative relationships between indexes of obesity and risk factors associated with IRS and SHBG levels. We measured body composition, SHBG, free testosterone, leptin, glucose tolerance, insulin, and lipoprotein lipids in 55 CAU (mean +/- SD, 59 +/- 7 yr) and 35 AA (57 +/- 6 yr) sedentary women of comparable obesity (48% body fat, by dual energy x-ray absorptiometry). Compared with CAU women, AA women had larger waist (101 vs. 96 cm), larger fat mass (44.9 +/- 8.8 vs. 39.9 +/- 8.1 kg), larger sc fat area (552 +/- 109 vs. 452 +/- 109 cm(2)), and lower IAF/SC ratio (0.28 +/- 0.12 vs. 0.38 +/- 0.15; P < 0.01), but similar waist to hip ratio (0.83). Both groups had similar SHBG (117 vs. 124 nmol/L) and free testosterone (3.7 vs. 3.4 pmol/L) levels, but AA women had a 35% higher leptin, 34% higher fasting insulin, and 39% greater insulin response to a glucose load (P < 0.05) compared with CAU women. In CAU, but not AA, women SHBG correlated negatively with body mass index (r = -0.28; P < 0.05), waist (r = -0.36; P = 0.01), IAF (r = -0.34; P = 0.01), and insulin response to oral glucose (r = -0.37; P < 0.05) and positively with high density lipoprotein cholesterol (r = 0.30; P = 0.03). The relationship between insulin area and SHBG in CAU women disappeared after adjusting for IAF, whereas the relationship between high density lipoprotein cholesterol and SHBG persisted after adjusting for IAF, but not for fat mass. Leptin was positively related to fat mass (P < 0.05) in both groups, but it was related to insulin only in the Caucasian women (P< 0.01). There was a racial difference in the slopes (P< 0.05) of the relationships of leptin to fat mass (P < 0.05). Racial differences in leptin disappeared after adjustment for fasting insulin. These results suggest that the metabolic relationships between total and regional obesity, glucose, and lipid metabolism with SHBG in CAU women are different from those in postmenopausal obese AA women.

Obesity-related hospitalization costs to the U.S. Navy, 1993 to 1998.

The objective of this work was to estimate the cost to the U.S. Navy for obesity-related hospital admissions by examining (1) inpatient utilization associated with obesity; (2) the rank order, probability, and total facility costs of obesity-related diagnosis-related groups (DRGs); and (3) expected inpatient expenses. The frequency and probability of inpatient events in the Navy's active duty population were derived from the Department of Defense's Retrospective Case Mix Analysis System. Medicare-based facility costs per DRG were estimated. These measures were combined in a decision-analytic model. Expected facility costs per obesity-related admission for active duty Navy personnel increased by age group from $3,328 for 18 to 24 year olds to $5,746 for 45 to 64 year olds. The annual avoidable inpatient cost for the Navy was estimated to be $5,842,627 for the top 10 obesity-related DRGs. Improvements to the Navy Physical Readiness Program and other interventions that may reduce obesity, obesity-related health care use, and the public economic burden should be pursued.

Reductions in visceral fat during weight loss and walking are associated with improvements in VO(2 max).

The accumulation of visceral fat is independently associated with an increased risk for cardiovascular disease. The aim of this study was to determine whether the loss of visceral adipose tissue area (VAT; computed tomography) is related to improvements in maximal O(2) uptake (VO(2 max)) during a weight loss (250-350 kcal/day deficit) and walking (3 days/wk, 30-40 min) intervention. Forty obese [body fat 47 +/- 1 (SE) %], sedentary (VO(2 max) 19 +/- 1 ml. kg(-1). min(-1)) postmenopausal women (age 62 +/- 1 yr) participated in the study. The intervention resulted in significant declines in body weight (-8%), total fat mass (dual-energy X-ray absorptiometry; -17%), VAT (-17%), and subcutaneous adipose tissue area (-17%) with no change in lean body mass (all P < 0.001). Women with an average 10% increase in VO(2 max) reduced VAT by an average of 20%, whereas those who did not increase VO(2 max) decreased VAT by only 10%, despite comparable reductions in body fat, fat mass, and subcutaneous adipose tissue area. The decrease in VAT was independently related to the change in VO(2 max) (r(2) = 0.22; P < 0. 01) and fat mass (r(2) = 0.08; P = 0.05). These data indicate that greater improvements in VO(2 max) with weight loss and walking are associated with greater reductions in visceral adiposity in obese postmenopausal women.

Weight loss and exercise walking reduce pain and improve physical functioning in overweight postmenopausal women with knee osteoarthritis.

We conducted an uncontrolled pilot study to determine the effects of a weight loss and walking program on knee pain and physical function in overweight and obese (body mass index; BMI [kg/m] 25-29.9 and BMI > or = 30, respectively) postmenopausal women with knee osteoarthritis (OA). Forty-eight such women completed self-report (Western Ontario and McMaster University Osteoarthritis Index (WOMAC)) and performance-based measures of physical function ("up and go" test, 6-min walk) and enrolled in a 6-month intervention that included weekly nutrition classes and an exercise-walking program. The intervention produced an average weight loss of 5.6 +/- 4.0 kg in the 30 women who completed the program. There also were significant improvements in the 6-min walk and on VO(2max). Improvements in the timed up and go test and on the WOMAC pain and function scores, however, were restricted only to women who were classified as obese at baseline. These findings suggest that a 6-month weight loss and walking program improves measures of physical functioning and pain in overweight and obese postmenopausal women with knee OA. Among obese women, functional improvement correlated with weight loss, encouraging continued emphasis on weight loss for managing knee OA.

Self-efficacy targeted treatments for weight loss in postmenopausal women.

Matching behavioral treatment programs to different types of obese clients is a rarely studied strategy, thus guidelines for identifying who might benefit most from which program remain elusive. This study categorized the weight control self-efficacy beliefs of obese, postmenopausal women, and determined the effects of self-efficacy targeted versus non-targeted (control) treatment on weight loss outcomes (body habitus, physical conditioning, affect, and eating behaviors). Obese (BMI 33 +/- 5), postmenopausal (60 +/- 6 years old) women (n = 59) participated in a 6-month weight loss program. The 37 women categorized by Q methodology as Assured (self-confident, independent) were randomized to Assured (AT) or Non-Targeted (NT) treatment; the 22 Disbelievers (doubtful, wavering) were randomized to Disbeliever (DT) or NT treatment. At baseline, the Assureds had significantly smaller body girths and reported significantly greater self-esteem, fewer symptoms of binge eating, and less negative affect overeating than the Disbelievers. Improvement in these variables with weight loss erased significant differences between the groups and was a desired outcome. Treatment delivery type may have influenced attrition rate, since significantly more Assureds dropped from NT than AT and significantly more Disbelievers dropped from DT than NT. Thus, the self-efficacy type may serve as a means to identify different types of treatment needs (flexible vs. rigid) to sustain women's adherence and success in the program. The significant weight loss outcomes for women in all groups argues for the incorporation of strategies to enhance self-efficacy but not the need for specific treatments that directly target self-efficacy types.

Responses of adipose tissue lipoprotein lipase to weight loss affect lipid levels and weight regain in women.

This study determines whether changes in abdominal (ABD) and gluteal (GLT) adipose tissue lipoprotein lipase (LPL) activity in response to a 6-mo weight loss intervention, comprised of a hypocaloric diet and low-intensity walking, affect changes in body composition, fat distribution, lipid metabolism, and the magnitude of weight regain in 36 obese postmenopausal women. Average adipose tissue LPL activity did not change with an average 5.6-kg weight loss, but changes in LPL activity were inversely related to baseline LPL activity (ABD: r = -0.60, GLT: r = -0.48; P < 0.01). The loss of abdominal body fat and decreases in total and low-density lipoprotein cholesterol were greater in women whose adipose tissue LPL activity decreased with weight loss despite a similar loss of total body weight and fat mass. Moreover, weight regain after a 6-mo follow-up was less in women whose adipose tissue LPL activity decreased than in women whose LPL increased (ABD: 0.9 +/- 0.5 vs. 2.8 +/- 0.6 kg, P < 0.05; GLT: 0.2 +/- 0.5 vs. 2.8 +/- 0.5 kg, P < 0.01). These results suggest that a reduction in adipose tissue LPL activity with weight loss is associated with improvements in lipid metabolic risk factors with weight loss and with diminished weight regain in postmenopausal women.

Dietary restriction and walking reduce fat deposition in the midthigh in obese older women.

BACKGROUND: It is suggested that fat deposition within midthigh muscle, represented by low-density lean tissue, increases with deconditioning and obesity and is associated with risk factors for cardiovascular disease (CVD) in women. OBJECTIVE: We determined the effects of a 6-mo weight loss and walking (3 times/wk) program (WL+AEX) on midthigh low-density lean tissue and glucose and lipid metabolism in 24 sedentary, obese [body mass index (kg/m(2)): 32 +/- 1 (mean +/- SEM)] postmenopausal women aged 58 +/- 1 y. DESIGN: Total body fat and fat-free mass were measured by using dual-energy X-ray absorptiometry. Intraabdominal fat (IAF), subcutaneous abdominal fat (SAF), midthigh fat, midthigh muscle, and midthigh low-density lean tissue areas were measured by using computed tomography. Glucose and insulin responses were determined with a 3-h oral-glucose-tolerance test. RESULTS: Body weight decreased 8% (P: < 0.001) and maximal aerobic capacity increased 8% (P: < 0.001) with the weight loss and walking program. Total body fat decreased by 15% (P: < 0.001) whereas fat-free mass did not change. IAF and SAF decreased by 18% and 16%, respectively (P: < 0. 001). Midthigh fat and midthigh low-density lean tissue decreased by 16% and 18%, respectively (P: < 0.001), and midthigh muscle area increased by 7% (P: < 0.05). Fasting plasma insulin decreased by 12% and total glucose and insulin areas under the curve decreased by 6% and 24%, respectively (P: < 0.05). HDL-cholesterol concentrations increased 8% (P: < 0.05) and triacylglycerol concentrations decreased 19% (P: < 0.001). CONCLUSION: Increased physical fitness and weight loss reduce midthigh low-density lean tissue and improve glucose and lipid metabolic risk factors for CVD in obese postmenopausal women.

Lipoprotein lipase gene variation is associated with adipose tissue lipoprotein lipase activity, and lipoprotein lipid and glucose concentrations in overweight postmenopausal women.

Adipose tissue lipoprotein lipase (LPL) activity is under strong genetic control in both mice and humans. This study determines whether common DNA variation in the LPL gene (PvuII and HindIII polymorphisms) is associated with adipose tissue LPL activity and metabolic risk factors in a homogeneous population of 75 overweight postmenopausal women (body mass index >25 kg/m2; age: 51-69 years old). The allele frequencies for the presence of the cut-sites for LPL HindIII and PvuII were 0.71 and 0.49, respectively. There were no associations between the HindIII polymorphism and any of the measured variables. Age, body mass index, percent body fat, waist-hip ratio, visceral and subcutaneous fat area, and gluteal (GLT) and abdominal (ABD) adipocyte size did not differ by LPL PvuII genotype. However, adipose tissue LPL activity at both GLT and ABD sites was higher in women without the LPL PvuII cut-site (-/-) compared with women who were heterozygous (+/-) or homozygous (+/+) for the cut-site (P<0.05). Total and LDL cholesterol were lower in women without the LPL PvuII cut-site (-/-) compared with women who were heterozygous or homozygous for the cut-site (P<0.05), whereas triglyceride and HDL levels were similar between LPL PvuII genotypes. Fasting glucose, but not insulin, was lower in women without the LPL PvuII cut-site (-/-). These data suggest that the LPL PvuII polymorphism is a possible marker for a functional mutation that is found in the LPL gene and that alters LPL activity in older overweight women.

Leptin responses to weight loss in postmenopausal women: relationship to sex-hormone binding globulin and visceral obesity.

OBJECTIVE: Leptin concentrations increase with obesity and tend to decrease with weight loss. However, there is large variation in the response of serum leptin levels to decreases in body weight. This study examines which endocrine and body composition factors are related to changes in leptin concentrations following weight loss in obese, postmenopausal women. RESEARCH METHODS AND PROCEDURES: Body composition (DXA), visceral obesity (computed tomography), leptin, cortisol, insulin, and sex hormone-binding globulin (SHBG) concentrations were measured in 54 obese (body mass index [BMI] = 32.0+/-4.5 kg/m2; mean +/- SD), women (60+/-6 years) before and after a 6-month hypocaloric diet (250 to 350 kcal/day deficit). RESULTS: Body weight decreased by 5.8+/-3.4 kg (7.1%) and leptin levels decreased by 6.6+/-11.9 ng/mL (14.5%) after the 6-month treatment. Insulin levels decreased 10% (p< 0.05), but mean SHBG and cortisol levels did not change significantly. Relative changes in leptin with weight loss correlated positively with relative changes in body weight (r = 0.50, p<0.0001), fat mass (r = 0.38, p<0.01), subcutaneous fat area (r = 0.52, p<0.0001), and with baseline values of SHBG (r = 0.38, p<0.01) and baseline intra-abdominal fat area (r = -0.27, p<0.06). Stepwise multiple regression analysis showed that baseline SHBG levels (r2 = 0.24, p<0.01), relative changes in body weight (cumulative r2 = 0.40, p<0.05), and baseline intra-abdominal fat area (cumulative r2 = 0.48, p<0.05) were the only independent predictors of the relative change in leptin, accounting for 48% of the variance. DISCUSSION: These results suggest that obese, postmenopausal women with a lower initial SHBG and more visceral obesity have a greater decrease in leptin with weight loss, independent of the amount of weight lost.

The adoption of eating behaviors conducive to weight loss.

Given the plethora of eating behavior techniques that obese individuals might adopt for weight loss, it is not likely that they could, or would be willing to, adopt all of them. Therefore, the purpose of this study was to identify the specific eating behaviors conducive to weight loss adopted during the behavioral treatment of obesity, and to distinguish those that were deemed beneficial from the ones that were not. Fifty obese (BMI 32+/-4 kg/m(2), mean+/-SD), postmenopausal women (60+/-6 years old) participated in a 6-month behavior modification, dietary, low-intensity walking weight loss program. For analysis, they were divided into two groups: "no weight loss" (5 kg, n=32). At pre- and posttreatment women completed the Eating Behavior Inventory (EBI) that measures specific strategies conducive to weight loss. Women who lost weight increased their total eating behavior score by 20% (p<0.001) and improved the adoption of 14 eating behaviors, which was more than twice that of the non-weight losers. Topping the list of most strongly adopted behaviors were carefully watching and recording the type and quantity of food consumed. Maintaining a weight graph and weighing daily also were important to these women. Neither group of women adopted potentially helpful eating behaviors such as leaving food uneaten, refusing food offered by others, or shopping from a list. In studies of obesity treatment, attendance at class sessions is one marker of program adherence. More definitively, implementing the EBI in clinical and research obesity treatment programs will provide its leaders with insight into whether participants adopt, ignore, or fight the essential behaviors that will facilitate success toward their personal weight loss goals.

Racial differences in metabolic predictors of obesity among postmenopausal women.

OBJECTIVE: This study determined whether there are racial differences in resting metabolic rate (RMR), fat oxidation, and maximal oxygen consumption (VO2max) in obese [body mass index (BMI = 34+/-2 kg/m2)], postmenopausal (58+/-2 years) women. RESEARCH METHODS AND PROCEDURES: Twenty black and 20 white women were matched for fat mass and lean mass (LM), as determined by dual energy X-ray absorptiometry. RMR and fat oxidation were measured by indirect calorimetry in the early morning after a 12-hour fast using the ventilated hood technique. VO2max was measured on a treadmill during a progressive exercise test to voluntary exhaustion. RESULTS: RMR, adjusted for differences in LM, was 5% higher in white than black women (1566+/-27 and 1490+/-26 kcal/day, respectively; p<0.05); and fat oxidation rate was 17% higher in white than black women (87+/-4 and 72+/-3 g/day, respectively; p<0.01). VO2max (L/minute) was 150 mL per minute (8%) higher (p<0.05) in white than black women. VO2max correlated with LM in black (r=0.44, p=0.05) and white (r=0.53, p<0.05) women, but the intercept of the regression line was higher in white than black women (p<0.05), with no significant difference in slopes. In a multiple regression model including race, body weight, LM, and age, LM was the only independent predictor of RMR (r2 = 0.46, p<0.0001), whereas race was the only independent predictor of fat oxidation (r2 = 0.18, p<0.05). The best predictors of VO2max were LM (r2 = 0.22, p<0.05) and race (cumulative r2 = 0.30, p<0.05). DISCUSSION: These results show there are racial differences in metabolic predictors of obesity. Determination of whether these ethnic differences lead to, or are an effect of, obesity status or other lifestyle factors requires further study.

The impact of a shipboard weight control program.

OBJECTIVE: The specific aim was to determine whether a multifaceted approach to weight loss and physical readiness could be implemented onboard a deployed combatant ship of the U.S. Navy. RESEARCH METHODS AND PROCEDURES: Thirty-nine men (31+/-6 years old, mean+/-standard deviation) assigned to the USS ENTERPRISE (CVN 65) during a 6-month Mediterranean deployment who had failed their previous Physical Readiness Test due to excessive body weight (108+/-11 kg overweight) were randomly assigned to nutrition, cognitive-behavioral obesity treatment plus exercise or to the Navy's usual treatment (control), which is exercise alone. RESULTS: Outcomes for the treatment group were significantly better than the controls, with 8.6+/-5.0 vs. 5.0+/-4.1 kg weight loss, 8% vs. 5% reduction in original body weight, and body fat loss of 7% vs. 5%. Triglycerides declined significantly greater in the treatment group than the controls (145 mg/dL to 109 mg/dL vs. 146 mg/dL to 145 mg/dL, p<0.05), whereas depression and eating behaviors significantly improved among treated men. Problematic environmental factors were the limited variety of heart healthy foods in the galley, short meal breaks, and long mess hall lines that led to eating snacks from vending machines and frequent port calls. DISCUSSION: Although greater weight loss than would be expected of a Navy usual care group diluted the treatment effect, the treated men still fared significantly better. The physical readiness implication of this research has the potential to impact Navy health promotion programs and policy, the health and well-being of its personnel, and the Navy's ability to meet mission requirements.

Aerobic exercise maintains regional bone mineral density during weight loss in postmenopausal women.

This study examines the effects of weight loss by caloric restriction (WL) and aerobic exercise plus weight loss (AEx+WL) on total and regional bone mineral density (BMD) in older women. Healthy, postmenopausal women [age 63 +/- 1 (SE) yr] not on hormone-replacement therapy underwent 6 mo of WL (n = 15) consisting of dietary counseling one time per week with a caloric deficit (250-350 kcal/day) or AEx+WL (n = 15) consisting of treadmill exercise three times per week in addition to the weight loss. Maximal aerobic capacity increased only in the AEx+WL group (P < 0. 001). Body weight, percent fat, and fat mass decreased similarly in both groups (P < 0.005), with no changes in fat-free mass. Total body BMD (by dual-energy X-ray absorptiometry) decreased in both groups (P < 0.05). Femoral neck, Ward's triangle, and greater trochanter BMD decreased in the WL group (P

Regional differences in adrenoceptor binding and fat cell lipolysis in obese, postmenopausal women.

In women there is an increase in visceral obesity, subcutaneous abdominal adipocyte lipolysis, and risk of cardiovascular disease (CVD) associated with weight gain after menopause. The mechanisms underlying this increase in adrenoreceptor (AR)-agonist catecholamine-stimulated lipolysis and abdominal obesity in postmenopausal women were studied in intact adipocytes isolated from the abdominal and gluteal subcutaneous fat depots in 19 obese (48% +/- 1% body fat, mean +/- SE) women with a mean +/- SE age of 58 +/- 1 years. The fat cell size and adipose tissue lipoprotein lipase (ATLPL) activity were similar in both sites. The maximal lipolytic responsiveness and sensitivity to isoproterenol were higher (P < .05) in abdominal compared with gluteal adipocytes, but maximal lipolytic response to a post-AR agent was similar. Abdominal adipocytes had a higher beta-AR ([3H]-CGP-12177) and alpha2-AR ([3H]-yohimbine) affinity than gluteal cells (P < .05), lower alpha2-AR density (P < .05), but similar beta-AR density as gluteal cells. Both abdominal and gluteal cell size correlated with alpha2-AR density (P < .01), but not with beta-AR density. Thus, a higher beta-AR affinity and lower alpha2-AR relative to beta-AR density may explain the higher in vitro catecholamine-mediated lipolysis in abdominal compared with gluteal adipocytes in obese, postmenopausal women.

Effects of an American Heart Association diet and weight loss on lipoprotein lipids in obese, postmenopausal women.

The sequential effects of an American Heart Association (AHA) Step 1 diet and subsequent weight loss on lipoprotein lipids in obese [body mass index (in kg/m2) > 27], postmenopausal women (n = 48) were determined. Subjects followed a euenergetic AHA Step 1 diet for 2 mo, followed by a weight-loss diet (deficit of 1.0-1.5 MJ/d) for 6 mo. The AHA diet lowered concentrations of total (7%), low-density-lipoprotein (LDL) (6%), and high-density-lipoprotein (HDL) (14%) cholesterol (P < 0.01). Weight loss (-5.6 +/- 0.7 kg; P < 0.01) increased plasma triacylglycerol concentrations (9%; P < 0.01) and increased HDL-cholesterol concentrations (8%; P < 0.01) compared with changes after the AHA diet, but there were no changes in total or LDL cholesterol. The combined AHA diet and weight-loss interventions lowered triacylglycerol (10%) and total (6%), LDL (6%), and HDL (7%) cholesterol. These changes correlated indirectly with the baseline concentration for each lipid. When the women were divided on the basis of initial LDL-cholesterol concentration, the AHA diet and weight-loss interventions reduced (P < 0.01) triacylglycerol (19%), total cholesterol (13%), and LDL cholesterol (14%) in the women with hypercholesterolemia but not in normocholesterolemic or midly hypercholesterolemic women. Thus, an AHA Step 1 diet and subsequent weight loss improve lipoprotein lipid profiles of obese, postmenopausal women with hypercholesterolemia. However, because it lowers HDL cholesterol, a low-fat diet without substantial weight loss may not be beneficial for improving lipoprotein lipid risk factors for coronary artery disease in obese, postmenopausal women with normal lipid profiles.

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.

Weight control self-efficacy types and transitions affect weight-loss outcomes in obese women.

Matching obesity treatments to heterogeneous clients is a recent evolution in the development of more effective weight-control programs, yet most interventions emphasize the external features of treatments rather than the internal belief structures of individuals. The purpose of this study was to determine whether Q methodology would identify distinct types of weight-control self-efficacy beliefs in obese women that would be linked to outcomes of a weight-loss program. Fifty-four women (45 +/- 9 yrs, Mean +/- SD) 136 +/- 10% over ideal body weight participated in a 9-month nutritional/behavioral weight loss program. Two major self-efficacy categories emerged through factor analysis of Q sorts: assureds and disbelievers. The assureds (n = 28) had the strongest self-efficacy beliefs and at baseline reported significantly (p < .01) greater self-esteem and less depression than the disbelievers (n = 26). By posttreatment, the assureds had lost significantly more weight (10 +/- 6 vs. 7 +/- 7 kg). Regrouping the data for analysis by posttreatment self-efficacy types demonstrated transitions in the self-efficacy beliefs of the women during treatment. Those who were disbelievers at baseline but became assureds posttreatment (n = 7) lost twice as much weight as the women who started and finished as disbelievers (n = 19) (10 +/- 7 kg vs. 5 +/- 5 kg). The posttreatment assureds (n = 32) lost significantly more weight than the disbelievers (n = 22) (10 +/- 6 vs. 6 +/- 5 kg), and reported better self esteem, mood, and eating patterns. Thus, assessment of intrinsic belief systems, particularly weight-control self-efficacy, may provide new directions for designing interventions that target distinctly different needs of obese women to affect greater weight loss and more positive affective states.