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1.
Objective: The purpose of this study was to evaluate available variables of a long‐term weight maintenance study to investigate possible factors predisposing to weight regain after a period of weight loss. Research Methods and Procedures: The Maastricht Weight Maintenance Study is an ongoing longitudinal study of healthy men and women (29 men and 62 women; 18 to 65 years of age; BMI = 30.2 ± 3.1 kg/m2). A variety of parameters were measured before and after a very‐low‐energy diet and after a follow‐up of at least 2 years. Results: Mean weight loss was 7.9 ± 3.6 kg, and percent weight regain was 113.8 ± 98.1%. Percent BMI regain was negatively associated with an increase in dietary restraint (r = ?0.47, p < 0.05). Percent weight regain was negatively correlated with baseline resting metabolic rate (r = ?0.38, p = 0.01) and baseline fat mass (r = ?0.24, p = 0.05) and positively correlated with the magnitude of change in body weight (BW) expressed as maximum amplitude of BW (r = 0.21, p < 0.05). In addition, amplitude of BW was positively correlated with the frequency of dieting (r = 0.57, p < 0.01). Discussion: The best predictors for weight maintenance after weight loss were an increase in dietary restraint during weight loss, a high baseline resting metabolic rate, a relatively high baseline fat mass favoring a fat‐free mass–sparing effect during weight loss, a rather stable BW, and a low frequency of dieting. Therefore, BW maintenance after BW loss seems to be a multifactorial issue, including mechanisms that regulate an individuals’ energy expenditure, body composition, and eating behavior in such a way that energy homeostasis is maintained.  相似文献   

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Metformin often promotes weight loss in patients with obesity with non-insulin-dependent diabetes mellitus (NIDDM). The mechanism may be attributed to decreased food intake. This study has tested the effect of metformin on satiety and its efficacy in inducing weight loss. Twelve diet-treated NIDDM women with obesity were randomly given two dose levels (850 mg or 1700 mg) of metformin or placebo at 0800 for three consecutive days followed by a meal test on the third day on three occasions using a 3times3 Latin square design. The number of sandwich canapes eaten in three consecutive 10-minute periods beginning at 1400 hours was used to quantitate food intake, and the level of subjective hunger was rated just before the sandwich meal with a linear analogue hunger rating scale at 1400 after a 6-hour fast. The prior administration of metformin produced a reduction in calorie intake after each of the two doses of metformin treatment. The 1700-mg metformin dose had the most marked appetite suppressant action. Similarly, hunger ratings were significantly lowered after metformin, and the effect was most pronounced after the administration of 1700 mg of metformin. To assess the efficacy of metformin in reducing bodyweight, 48 diet-treated NIDDM women with obesity who had failed to lose weight by diet therapy were first placed on a 1200-kcal ADA (American Diabetes Association) diet before being randomized to receive either metformin (850 mg) or placebo twice daily in a double-blind fashion for 24 weeks. A 4-week single-blind placebo lead-in period preceded and a 6-week single-blind placebo period followed the 24-week double-blind treatment period. Subjects treated with metformin continued to lose weight throughout 24 weeks of treatment; their mean maximum weight loss was 8 kg greater than that of the placebo group, with corresponding lower HbA1C and fasting blood glucose levels at the end of the active treatment period. These results indicate that metformin decreases calorie intake in a dose-dependent manner and leads to a reduction in bodyweight in NIDDM patients with obesity.  相似文献   

3.
Objective: Studies suggest that high‐dairy and high‐fiber/low‐glycemic index diets may facilitate weight loss, but data are conflicting. The effects on weight loss and body fat of a high‐dairy diet and a diet high in dairy and fiber and low in glycemic index were compared with a standard diet. Research Methods and Procedures: Ninety obese subjects were recruited into a randomized trial of three diets designed to provide a calorie deficit of 500 calories/d over a 48‐week period. The study compared a moderate (not low)‐calcium diet with a high‐calcium diet. Results: Seventy‐two subjects completed the study. Significant weight and fat loss occurred with all three diets. A diet with 1400 mg of calcium did not result in greater weight (11.8 ± 6.1 kg) or fat (9.0 ± 6.0 kg) loss than a diet with 800 mg of calcium (10.0 ± 6.8 and 7.5 ± 6.6 kg, respectively). A diet with 1400 mg of calcium, increased fiber content, and fewer high‐glycemic index foods did not result in greater weight (10.6 ± 6.8 kg) or fat (8.5 ± 7.8 kg) loss than the standard diet with 800 mg of calcium. Lipid profile, high‐sensitivity C‐reactive protein, leptin, fasting glucose, and insulin improved significantly, but there were no significant differences between the experimental diets and the control diet. Discussion: We found no evidence that diets higher than 800 mg of calcium in dairy products or higher in fiber and lower in glycemic index enhance weight reduction beyond what is seen with calorie restriction alone.  相似文献   

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Objective: To characterize dyslipidemia before and after weight loss in the severely obese. Research Methods and Procedures: Five hundred fifteen subjects who had Lap‐Band surgery were followed with yearly conventional lipid profiles for up to 4 years. Preoperative data were collected from the most recent 381 subjects, and predictors of dyslipidemia were sought. One hundred seventy‐one subjects completed a 1‐year review, providing data to assess predictors of change in lipids. Results: Favorable changes in fasting triglycerides (TG), high‐density lipoprotein‐cholesterol (HDL‐C), and total cholesterol (TC):HDL‐C ratio occurred within 1 year. All improvements were maintained up to 4 years. Male gender, central obesity, elevated fasting glucose, and insulin resistance were associated with less favorable lipid levels. Fasting plasma glucose best predicted TG (r = 0.46, p < 0.001), whereas insulin sensitivity using the homeostatic model assessment (HOMA %S) correlated best with the HDL‐C (r =0.34, p < 0.001). Higher preoperative fasting glucose best predicted the decrease in TG; improved HOMA %S with weight loss correlated best with HDL‐C. The extent of weight loss had limited influence on lipid changes. However, low preoperative HOMA %S was associated with lower weight loss. Greater weight loss was associated with more favorable lipid measures after controlling for preoperative HOMA %S. Discussion: Dyslipidemia of obesity is related to weight distribution, insulin sensitivity, and impaired glucose tolerance. Improvement with weight loss is related to the decrease in fasting glucose, improvement in insulin sensitivity, and the extent of weight lost. Improvement in dyslipidemia is sustained with long‐term weight loss.  相似文献   

7.
Objective: This study examined the effects of topiramate (TPM), a novel neurotherapeutic agent reported to reduce body weight in humans, on the components of energy balance in female Zucker rats. Research Methods and Procedures: A 2 × 3 factorial experiment was performed in which two cohorts of Zucker rats differing in their phenotype (phenotype: lean, Fa/?; obese, fa/fa) were each divided into three groups defined by the dose of TPM administered (dose: TPM 0, vehicle; TPM 15, 15 mg/kg; TPM 60, 60 mg/kg). Results: The reduction in body weight gain induced by TPM in both lean and obese rats reflected a decrease in total body energy gain, which was more evident in obese than in lean rats. Whereas TPM administration did not influence the intake of digestible energy in lean rats, it induced a reduction in food intake in obese animals. In lean, but not in obese rats, apparent energy expenditure (as calculated by the difference between energy intake and energy gain) was higher in rats treated with TPM than in animals administered the vehicle. The low dose of TPM decreased fat gain (with emphasis on subcutaneous fat) without affecting protein gain, whereas the high dose of the drug induced a reduction in both fat and protein gains. The effects of TPM on muscle and fat depot weights were representative of the global effects of TPM on whole body fat and protein gains. The calculated energetic efficiency (energy gain/energy intake) was decreased in both lean and obese rats after TPM treatment. TPM dose independently reduced hyperinsulinemia of obese rats, but it did not alter insulinemia of lean animals. Discussion: The present results provide sound evidence for the ability of TPM to reduce fat and energy gains through reducing energetic efficiency in both lean and obese Zucker rats.  相似文献   

8.
Objective: To investigate the effect of S 23521, a new glucagon‐like peptide‐1‐(7‐36) amide analogue, on food intake and body weight gain in obese rats, as well as on gene expression of several proteins involved in energy homeostasis. Research Methods and Procedures: Lean and diet‐induced obese rats were treated with either S 23521 or vehicle. S 23521 was given either intraperitoneally (10 or 100 μg/kg) or subcutaneously (100 μg/kg) for 14 and 20 days, respectively. Because the low‐dose treatment did not affect food intake and body weight, the subcutaneous treatment at high dose was selected to test the effect on selected end‐points. Results: Treated obese rats significantly decreased their cumulative energy intake in relation to vehicle‐treated counterparts (3401 ± 65 vs. 3898 ± 72 kcal/kg per 20 days; p < 0.05). Moreover, their body weight gain was reduced by 110%, adiposity was reduced by 20%, and plasma triglyceride levels were reduced by 38%. The treatment also improved glucose tolerance and insulin sensitivity of obese rats. Regarding gene expression, no changes in uncoupling protein‐1, uncoupling protein‐3, leptin, resistin, and peroxisome proliferator‐activated receptor (PPAR)‐γ were observed. Discussion: S 23521 is an effective glucagon‐like peptide‐1‐(7‐36) amide analogue, which induced a decrease in energy intake, body weight, and adiposity in a rat model of diet‐induced obesity. In addition, the treatment also improved glucose tolerance and insulin sensitivity of obese rats. These results strongly support S 23521 as a putative molecule for the treatment of obesity.  相似文献   

9.
Objective: To examine prospectively the relationship between alcohol and 8‐year weight gain in women. Research Methods and Procedures: A prospective study of 49, 324 women 27 to 44 years old who did not have a history of cardiovascular disease, cancer, or diabetes, who were not pregnant during the study period, and who reported weights in 1991 and 1999. Results: In cross‐sectional analyses, there was a significant inverse relationship between alcohol and BMI even after adjustment for dietary factors and a wide range of confounders. In multivariate prospective analyses, a nonlinear relationship was seen between alcohol and weight gain (≥5 kg) in all women. Compared with nondrinkers, the adjusted relative odds [95% confidence interval (CI)] of weight gain according to grams per day were 0.94 (0.89, 0.99) for those consuming 0.1 to 4.9 g/d, 0.92 (0.85, 0.99) for 5 to 14.9 g/d, 0.86 (0.76, 0.78) for 15 to 29.9 g/d, and 1.07 (0.89, 1.28) for those consuming 30+ g/d (p < 0.0001 for quadratic trend). Women who continued to drink heavily and those who became heavy drinkers showed similar increased odds of weight gain. The increased odds of weight gain associated with heavy drinking (30+ g/d) were most marked in the younger women (<35 years) (odds ratio 1.64; 5% CI 1.03 to 2.61). In African‐American women, light drinking was associated with increased odds of weight gain compared with nondrinkers (odds ratio = 2.43; 95% CI 1.22 to 4.82) Discussion: Our data suggest that light to moderate drinking (up to 30 g/d) is not associated with weight gain in women except possibly in African‐American women. Heavier drinking may promote weight gain in women.  相似文献   

10.
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.  相似文献   

11.
Objective : Satiety plays an important role in weight control. The meaning of fasting hormone levels and satiety feelings, and how post-absorptive changes after meals high in carbohydrate regulate appetite remains to be demonstrated. Research Methods and Procedures : Prospective metabolic study with 25 non-diabetic obese women at the Energy Metabolism Research Unit of the Department of Nutrition Sciences, University of Alabama at Birmingham. We analyzed fasting and postprandial ratings of hunger-satiety and values of various metabolic parameters (serum glucose and insulin, plasma cholecystokinin, respiratory quotient) during controlled weight loss. The postprandial measures were assessed following a test meal providing 320 kcal and yielding a food quotient of 0.89. Results : In the fasting state, there was no correlation between hunger-satiety ratings and any of the measured metabolic parameters. Under postprandial conditions, satiety was positively related to glucose (p = 0.002) and insulin (p = 0.002) responses to the test meal. In multivariate analysis including glucose, insulin, cholecystokinin, hunger-satiety ratings and respiratory quotient, insulin was the only independent predictor of satiety in the postprandial state. Discussion : These data suggest an association between the endogenous insulin response and feelings of postprandial satiety. Insulin's satiation properties, which could well be mediated by other hormones, may represent a primary factor of food intake regulation after meals relatively high in carbohydrate.  相似文献   

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Long‐term behavioral self‐regulation is the hallmark of successful weight control. We tested mediators of weight loss and weight loss maintenance in middle‐aged women who participated in a randomized controlled 12‐month weight management intervention. Overweight and obese women (N = 225, BMI = 31.3 ± 4.1 kg/m2) were randomly assigned to a control or a 1‐year group intervention designed to promote autonomous self‐regulation of body weight. Key exercise, eating behavior, and body image variables were assessed before and after the program, and tested as mediators of weight loss (12 months, 86% retention) and weight loss maintenance (24 months, 81% retention). Multiple mediation was employed and an intention‐to‐treat analysis conducted. Treatment effects were observed for all putative mediators (Effect size: 0.32–0.79, P < 0.01 vs. controls). Weight change was ?7.3 ± 5.9% (12‐month) and ?5.5 ± 5.0% (24‐month) in the intervention group and ?1.7 ± 5.0% and ?2.2 ± 7.5% in controls. Change in most psychosocial variables was associated with 12‐month weight change, but only flexible cognitive restraint (P < 0.01), disinhibition (P < 0.05), exercise self‐efficacy (P < 0.001), exercise intrinsic motivation (P < 0.01), and body dissatisfaction (P < 0.05) predicted 24‐month weight change. Lower emotional eating, increased flexible cognitive restraint, and fewer exercise barriers mediated 12‐month weight loss (R2 = 0.31, P < 0.001; effect ratio: 0.37), but only flexible restraint and exercise self‐efficacy mediated 24‐month weight loss (R2 = 0.17, P < 0.001; effect ratio: 0.89). This is the first study to evaluate self‐regulation mediators of weight loss and 2‐year weight loss maintenance, in a large sample of overweight women. Results show that lowering emotional eating and adopting a flexible dietary restraint pattern are critical for sustained weight loss. For long‐term success, interventions must also be effective in promoting exercise intrinsic motivation and self‐efficacy.  相似文献   

15.
Objective: To test the hypothesis that major depression predicts an increase in long‐term body weight variability (BWV). Research Methods and Procedures: This was a prospective community‐based single‐age cohort study of young adults (N = 591) followed between the ages of 19 and 40. Following initial screening, information was derived from six subsequent semistructured diagnostic interviews conducted by mental health professionals. Major depression was diagnosed on the basis of DSM criteria. BWV was defined as the root mean square error of a regression line fitted to each individual's BMI values over time. Multiple regression analysis was used to test the association between major depression and BWV while controlling for potentially confounding variables including antidepressant treatment, eating disorder symptoms, and physical activity. We used random effects models to determine the temporal relationship between repeated measures of major depression and body weight change. Results: A highly significant positive association between major depression and BWV was found, whereas major depression was not associated with BMI level or BMI trend. Depression severity showed a dose‐response‐type relationship with the magnitude of BWV. After controlling for potentially confounding variables including antidepressant use, eating disorder symptoms, smoking, and physical activity, major depression remained a significant predictor of BWV (β= 0.13, p < 0.001). Longitudinal analysis revealed a unidirectional association between major depression and a later increase in body weight change rate irrespective of antidepressant medication. Discussion: Results from this study implicate depression as an important risk factor for increased BWV. Given increasing evidence for a link between major depression and both diabetes and cardiovascular disease, current results encourage further research on depression, BWV, and negative health outcomes.  相似文献   

16.
Objective: A reported lower resting metabolic rate (RMR) in African‐American women than in white women could explain the higher prevalence of obesity in the former group. Little information is available on RMR in African‐American men. Research Methods and Procedures: We assessed RMR by indirect calorimetry and body composition by DXA in 395 adults ages 28 to 40 years (100 African‐American men, 95 white men, 94 African‐American women, and 106 white women), recruited from participants in the Coronary Artery Risk Development in Young Adults (CARDIA), Birmingham, Alabama, and Oakland, California, field centers. Results: Using linear models, fat‐free mass, fat mass, visceral fat, and age were significantly related to RMR, but the usual level of physical activity was not. After adjustment for these variables, mean RMR was significantly higher in whites (1665.07 ± 10.78 kcal/d) than in African Americans (1585.05 ± 11.02 kcal/d) by 80 ± 16 kcal/d (p < 0.0001). The ethnic × gender interaction was not significant (p = 0.9512), indicating that the difference in RMR between African‐American and white subjects was similar for men and women. Discussion: RMR is ~5% higher in white than in African‐American participants in CARDIA. The difference was the same for men and women and for lean and obese individuals. The prevalence of obesity is not higher in African‐American men than in white men. Because of these reasons, we believe that RMR differences are unlikely to be a primary explanation for why African‐American women are more prone to obesity than white women.  相似文献   

17.
Objective: Our objective was to determine the effects of dairy consumption on adiposity and body composition in obese African Americans. Research Methods and Procedures: We performed two randomized trials in obese African‐American adults. In the first (weight maintenance), 34 subjects were maintained on a low calcium (500 mg/d)/low dairy (<1 serving/d) or high dairy (1200 mg Ca/d diet including 3 servings of dairy) diet with no change in energy or macronutrient intake for 24 weeks. In the second trial (weight loss), 29 subjects were similarly randomized to the low or high dairy diets and placed on a caloric restriction regimen (?500 kcal/d). Results: In the first trial, body weight remained stable for both groups throughout the maintenance study. The high dairy diet resulted in decreases in total body fat (2.16 kg, p < 0.01), trunk fat (1.03 kg, p < 0.01), insulin (18.7 pM, p < 0.04), and blood pressure (6.8 mm Hg systolic, p < 0.01; 4.25 mm Hg diastolic, p < 0.01) and an increase in lean mass (1.08 kg, p < 0.04), whereas there were no significant changes in the low dairy group. In the second trial, although both diets produced significant weight and fat loss, weight and fat loss on the high dairy diet were ~2‐fold higher (p < 0.01), and loss of lean body mass was markedly reduced (p < 0.001) compared with the low dairy diet. Discussion: Substitution of calcium‐rich foods in isocaloric diets reduced adiposity and improved metabolic profiles in obese African Americans without energy restriction or weight loss and augmented weight and fat loss secondary to energy restriction.  相似文献   

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Objective: With anthropometric models using skinfolds and circumferences, we studied changes in the percentage of subcutaneous fat in the total cross‐sectional area (SF%) at four body sites in obese women, before and after weight loss induced by 6 months of caloric restriction. Research Methods and Procedures: In 61 obese women [31 African Americans and 30 whites; ages, 24 to 68 years; body mass index (BMI), ≥28kg/m2], we measured SF% at the midpoint of the upper arm and thigh and the waistline and hipline, and we measured the percentage of total body fat by DXA before (Obs#1) and after (Obs#2) a 6‐month nonintervention control period and then after 6 months on a 1200 kcal/d diet (Obs#3). Results: The mean body weight and BMI increased (1.8 kg and 0.61 kg/m2; p = 0.0001), but there were no significant changes in any other body composition measurements from Obs#1 to Obs#2. The means of Obs#3 for weight and BMI decreased by 11%, and the percentage of total body fat decreased by 13% of Obs#2 mean values (p = 0.0001). The mean SF% at each site decreased 7.6% to 18.0% of the Obs#2 mean values (p < 0.001). The SF% decreases were greater at mid‐arm and mid‐thigh than in the cross‐sectional regions at the waistline and hipline (p = 0.05). There was no interaction between age or ethnicity (p > 0.2). Conclusions: In obese women, caloric restriction alone reduces anthropometrically measured subcutaneous fat proportionally more in peripheral than in central regions.  相似文献   

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Objective: On the basis of the clinical observations that bupropion facilitated weight loss, we investigated the efficacy and tolerability of this drug in overweight and obese adult women. Research Methods and Procedures: A total of 50 overweight and obese (body mass index: 28.0 to 52.6 kg/m2) women were included. The core component of the study was a randomized, double‐blind, placebo‐controlled comparison for 8 weeks. Bupropion or placebo was started at 100 mg/d with gradual dose increase to a maximum of 200 mg twice daily. All subjects were prescribed a 1600 kcal/d balanced diet and compliance was monitored with food diaries. Responders continued the same treatment in a double‐blind manner for an additional 16 weeks to a total of 24 weeks. There was additional single‐blind follow‐up treatment for a total of 2 years. Results: Subjects receiving bupropion achieved greater mean weight loss (last‐observation‐carried‐forward analysis) over the first 8 weeks of the study (p = 0.0001): 4.9% ± 3.4% (n = 25) for bupropion treatment compared with 1.3% ± 2.4% (n = 25) for placebo treatment. For those who completed the 8 weeks, the comparison was 6.2% ± 3.1% (n = 18) vs. 1.6% ± 2.9% (n = 13), respectively(p = 0.0002), with 12 of 18 of the bupropion subjects (67%) losing over 5% of baseline body weight compared with 2 of 13 in the placebo group (15%; p = 0.0094). In the continuation phase, 14 bupropion responders who completed 24 weeks achieved weight loss of 12.9% ± 5.6% with fat accounting for 73.5% ± 3.7% of the weight lost and no change in bone mineral density as assessed by DXA. Bupropion was generally well‐tolerated in this sample. Discussion: Bupropion was more effective than placebo in achieving weight loss at 8 weeks in overweight and obese adult women in this preliminary study. Initial responders to bupropion benefited further in the continuation phase.  相似文献   

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Objective: The longitudinal relationship between the consumption of energy‐dense snack (EDS) foods and relative weight change during adolescence is uncertain. Using data from the Massachusetts Institute of Technology Growth and Development Study, the current analysis was undertaken to examine the longitudinal relationship of EDS food intake with relative weight status and percentage body fat and to examine how EDS food consumption is related to television viewing. Research Methods and Procedures: One hundred ninety‐six nonobese premenarcheal girls 8 to 12 years old were enrolled between 1990 and 1993 and followed until 4 years after menarche. At each annual follow‐up visit, data were collected on percentage body fat (%BF), BMI z score, and dietary intake. Categories of EDS foods considered were baked goods, ice cream, chips, sugar‐sweetened soda, and candy. Results: At study entry, girls had a mean ± SD BMI z score of ?0.27 ± 0.89, consumed 2.3 ± 1.7 servings of EDS foods per day, and consumed 15.7 ± 8.1% of daily calories from EDS foods. Linear mixed effects modeling indicated no relationship between BMI z score or %BF and total EDS food consumption. Soda was the only EDS food that was significantly related to BMI z score over the 10‐year study period, but it was not related to %BF. In addition, a significant, positive relationship was observed between EDS food consumption and television viewing. Discussion: In this cohort of initially nonobese girls, overall EDS food consumption does not seem to influence weight status or fatness change over the adolescent period.  相似文献   

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