Loss of Total and Visceral Adipose Tissue Mass Predicts Decreases in Oxidative Stress After Weight‐loss Surgery

It is not known whether there are mechanisms linking adipose tissue mass and increased oxidative stress in obesity. This study investigated associations between decreasing general and abdominal fat depots and oxidative stress during weight loss. Subjects were severely obese women who were measured serially at baseline and at 1, 6 (n = 30), and 24 months (n = 18) after bariatric surgery. Total fat mass (FAT) and volumes of visceral (VAT) and subcutaneous abdominal adipose tissue (SAT) were related to plasma concentrations of derivatives of reactive oxidative metabolites (dROMS), a measure of lipid peroxides and oxidative stress. After intervention, BMI significantly decreased, from 47.7 ± 0.8 kg/m² to 43.3 ± 0.8 kg/m² (1 month), 35.2 ± 0.8 kg/m² (6 months), and 30.2 ± 1.2 kg/m² (24 months). Plasma dROMS also significantly deceased over time. At baseline, VAT (r = 0.46), FAT (r = 0.42), and BMI (r = 0.37) correlated with 6‐month decreases in dROMS. Similarly, at 1 month, VAT (r = 0.43) and FAT (r = 0.41) correlated with 6‐month decreases in dROMS. Multiple regression analysis showed that relationships between VAT and dROMS were significant after adjusting for FAT mass. Increased plasma dROMS at baseline were correlated with decreased concentrations of high‐density lipoprotein (HDL) at 1 and 6 months after surgery (r = ?0.38 and ?0.42). This study found longitudinal associations between general, and more specifically intra‐abdominal adiposity, and systemic lipid peroxides, suggesting that adipose tissue mass contributes to oxidative stress.     

Vegetarian and Weight‐Loss Diets among Young Adults

Objective: Young adults frequently experiment with vegetarian and weight‐loss diets. Comparisons of their experiences on these two different diets may help in the development of approaches to improve long‐term adherence to weight‐loss regimens. In the current study vegetarian and weight‐loss diets were compared on how long and how strictly they were followed, and reasons why they were initiated and discontinued. Research Methods and Procedures: From 428 college students surveyed, four groups were delineated: 1) 59 participants had been following a vegetarian diet but not a weight‐loss diet (Vegetarian), 2) 117 participants had tried a weight‐loss diet but not a vegetarian diet (Weight Loss), 3) 133 participants had followed both a vegetarian and a weight‐loss diet (Both), and 4) 119 participants had not tried either diet (Neither). Results: Differences were examined by comparing the Vegetarian and Weight‐Loss groups as well as by comparing the two diets within the Both group. Duration of the vegetarian diet was much greater than the weight‐loss diet; most participants in the Vegetarian group (62%) remained on their diet for more than 1 year, whereas the majority of the Weight‐Loss participants (61%) followed their diet for 1 to 3 months. Similar results were found when comparing the two diets within the Both group. How strictly the two diets were followed, however, did not differ. Analyses revealed that reasons for discontinuing a diet varied; participants were more likely to cite boredom as a reason for discontinuing a weight‐loss diet than a vegetarian diet (53% vs. 5% between groups and 30% vs. 10% within the Both group). Discussion: The longer duration of the vegetarian diet relative to the weight‐loss diet warrants further investigation. Results could possibly be applied to behavioral weight‐loss treatment to improve long‐term maintenance.     

Predictors of Attrition in a Large Clinic‐Based Weight‐Loss Program

Objective: Identifying client factors that predict dropout is critical for the development of effective weight‐loss programs. Although demographic predictors are studied, there are few consistent findings. The purpose of this study was to identify predictors of dropout in a large clinic‐based weight‐loss program using readily attainable demographic variables. Research Methods and Procedures: All 866 weight‐loss patients in a clinic‐based weight‐loss program enrolled during 1998 to 1999 were followed. Attrition and retention rates were measured at 8 and 16 weeks. Six variables (sex, race, marital status, age, BMI, and treatment protocol) were evaluated using bivariate and multivariable statistics for relative association with dropout. Results: The overall attrition rate for the 16‐week program was 31%. The retention rate was 69%. Significant risk for dropout, measured as bivariate relative risk (95% confidence interval), was found among patients who were: females, 1.32 (1.01 to 1.73); divorced, 1.54 (1.13 to 2.09); African Americans, 1.68 (1.26 to 2.23); age < 40, 1.66 (1.27 to 2.18); and ages 40 to 50, 1.33 (1.01 to 1.76). There were no significant differences in retention rates by BMI group or program protocol. After logistic regression analysis to control for all variables, young age < 50 years had the only significant association with dropout [odds ratio = 1.39 (1.02 to 1.90)]. Discussion: Multivariable modeling was helpful for prioritizing risk factors for program dropout. These findings have important implications for improving weight‐loss program effectiveness and reducing attrition. By knowing the groups at risk for dropout, we can improve or target program treatments to these populations.     

Combining Weight‐Loss Counseling with the Weight Watchers Plan for Obese Breast Cancer Survivors

Objective: The objective was to develop effective weight‐loss methods for women who have had breast cancer, because obesity may result in an adverse prognosis. Research Methods and Procedures: This randomized pilot study tested an individualized approach toward weight loss in obese women who have had a diagnosis of breast cancer. An individualized approach was applied either alone or combined with the commercial Weight Watchers program. Forty‐eight women (body mass index of 30 to 44 kg/m²) were enrolled. Results: Weight change after 12 months of intervention was as follows (mean ± SD): 0.85 ± 6.0 kg in the control group, ?2.6 ± 5.9 kg in the Weight Watchers group, ?8.0 ± 5.5 kg in the individualized group, and ?9.4 ± 8.6 kg in the comprehensive group that used both individualized counseling and Weight Watchers. Weight loss relative to control was statistically significant in the comprehensive group 3, 6, and 12 months after randomization, whereas weight loss in the individualized group was significant only at 12 months. Weight loss of 10% or more of initial body weight was observed in 6 of 10 women in the comprehensive group at 12 months. In the comprehensive and Weight Watchers–only groups, weight loss was significantly related to frequency of attendance at Weight Watchers meetings, and attendance was more frequent in the comprehensive group. Discussion: These data indicate that the most weight loss was achieved when the counseling approach combined both Weight Watchers and individualized contacts. This was effective even though most of the individualized contacts were by telephone.     

Body Fat Loss Automatically Reduces Lean Mass by Changing the Fat‐Free Component of Adipose Tissue

Fat‐free mass or lean tissue mass includes nonskeletal muscle components such as the fat‐free component of adipose tissue fat cells. This fat‐free component of adipose tissue may need to be taken into consideration when large changes in body fat occur following a weight loss intervention. It is not uncommon to see a loss of lean mass with interventions designed to promote the loss of large amounts of fat mass. However, after eliminating the influence of the fat‐free component of adipose tissue on dual‐energy x‐ray absorptiometry (DXA)‐derived lean mass, the original loss of lean mass is no longer observed or is markedly reduced. This suggests that the majority of the lean mass lost with dieting may be the fat‐free component of adipose tissue. To accurately estimate the change in lean tissue, eliminating the fat‐free adipose tissue from DXA‐derived lean mass is needed when large changes in body fat occur following an intervention.     

Dietary Calcium Intake Is Associated With Less Gain in Intra‐Abdominal Adipose Tissue Over 1 Year

Calcium intake is reported to enhance weight loss with a preferential loss in trunk fat. Discrepant findings exist as to the effects of calcium intake on longitudinal changes in total fat mass and central fat deposition. Therefore, the purpose of this study was to determine associations between dietary calcium intake and 1‐year change in body composition and fat distribution, specifically intra‐abdominal adipose tissue (IAAT). A total of 119 healthy, premenopausal women were evaluated at baseline and 1 year later. Average dietary calcium was determined via 4‐day food records. Total fat was determined by dual‐energy X‐ray absorptiometry (DXA) and subcutaneous abdominal adipose tissue (SAAT) and IAAT by computed tomography. Over the study period, participants' reported daily calcium and energy intakes were 610.0 ± 229.9 mg and 1,623.1 ± 348.5 kcal, respectively. The mean change in weight, total fat, IAAT, and SAAT was 4.9 ± 4.4 kg, 5.3 ± 4.0 kg, 7.7 ± 19.5 cm², and 49.3 ± 81.1 cm², respectively. Average calcium intake was significantly, inversely associated with 1‐year change in IAAT (standardized β: ?0.23, P < 0.05) after adjusting for confounding variables. For every 100 mg/day of calcium consumed, gain in IAAT was reduced by 2.7 cm². No significant associations were observed for average calcium intake with change in weight, total fat, or SAAT. In conclusion, dietary calcium intake was significantly associated with less gain in IAAT over 1 year in premenopausal women. Further investigation is needed to verify these findings and determine the calcium intake needed to exert beneficial effects on fat distribution.     

Impacts of Visceral Adipose Tissue and Subcutaneous Adipose Tissue on Metabolic Risk Factors in Middle‐aged Japanese

Regional fat distribution rather than overall fat volume has been considered to be important to understanding the link between obesity and metabolic disorders. We aimed to evaluate the independent associations of visceral adipose tissue (VAT) and subcutaneous adipose tissue (SAT) with metabolic risk factors in apparently healthy middle‐aged Japanese. Participants were 1,119 men and 854 women aged 38–60 years who were not taking medications for diabetes, hypertension, or dyslipidemia. VAT and SAT were measured by use of computed tomography (CT) scanning. VAT and SAT were significantly and positively correlated with each other in men (r = 0.531, P < 0.001) and women (r = 0.589, P < 0.001). In multiple regression analyses, either measure of abdominal adiposity (VAT or SAT) was positively associated with blood pressure, fasting plasma glucose, and log triglyceride (P < 0.001) and inversely with high‐density lipoprotein (HDL)‐cholesterol (P < 0.001). When VAT and SAT were simultaneously included in the model, the association of VAT with triglycerides was maintained (P < 0.001) but that of SAT was lost. The same was true for HDL‐cholesterol in women. For fasting plasma glucose, the association with VAT was strong (P < 0.001) and the borderline association with SAT was maintained (P = 0.060 in men and P = 0.020 in women). Both VAT and SAT were independently associated with blood pressure (P < 0.001). Further adjustment for anthropometric indices resulted in the independent association only with VAT for all risk factors. In conclusion, impacts of VAT and SAT differed among risk factors. VAT showed dominant impacts on triglyceride concentrations in both genders and on HDL‐cholesterol in women, while SAT also had an independent association with blood pressure.