Prevalence and correlates of large weight gains and losses.

OBJECTIVE: To examine the prevalence and correlates of large weight gains and losses over a 3 y period in a heterogeneous population of participants in a study of weight gain prevention. DESIGN AND MEASURES: Analyses based on a cohort of 823 participants in a weight gain prevention study whose weight was measured on at least two of four annual examinations. RESULTS: Weight gains and losses of >or=5% body weight over 1 y were observed in 9.3 and 15% of the population, respectively. Weight gains among those initially losing weight were significantly greater (3.9 kg) than among those experiencing stable weight (0.8 kg) or a large weight gain (1.5 kg) over the following 2 y. Cumulative weight changes over 3 y were -2.6, 1.0 and 7.6 kg among large loss, weight stable and large gain groups, respectively. Large weight loss was more common in smokers, large gains were more common in younger people and in those with a more extensive weight loss history, and stable weight was observed more often in individuals with less extensive histories of weight loss. CONCLUSION: The high prevalence of large short-term weight gains and losses in this heterogeneous population, their apparent resistance to short-term reversal, and the strength of their relationship to longer-term weight trends suggest that rapid weight change over relatively short time intervals is a phenomenon that deserves more research attention. Short periods of rapid weight gain may contribute importantly to rapidly rising obesity rates.

Weight Loss: a determinant of hip bone loss in older men and women.

The sex-specific effect of weight change on change in total hip bone mineral density was evaluated over 4 years (1992-1996) in 1,214 community-dwelling adults whose mean age at baseline was 71 years. Weight and bone mineral density (by dual-energy x-ray absorptiometry) were assessed at two study visits. The average bone loss was 0.5% per year in both sexes; 29% of men and 28% of women lost at least 1% of bone mineral density per year. More than one in five participants lost at least 1% of their body weight per year (21% of men and 23% of women). These weight losers were twice as likely as others to lose bone at the rate of at least 1% per year. In analyses controlling for age, baseline weight, and lifestyle, weight loss was the strongest independent predictor of bone loss (odds ratios were 1.53 for men and 1.56 for women). Persons with weight loss of at least 1% per year were more likely to report fair or poor health and functional limitation at the second visit and to die within 2 years of the second visit; however, most did not report declining health, and most survived for at least 2 additional years.

Psychiatric diagnosis and weight loss following gastric surgery for obesity.

BACKGROUND: The authors examined associations between lifetime Axis I and Axis II disorders and weight loss following gastric surgery for morbid obesity. METHODS: 44 morbidly obese subjects who had undergone vertical banded gastroplasty (VBG) were systematically interviewed with the Diagnostic Interview Schedule (DIS) and were administered the Personality Diagnostic Questionnaire (PDQ). Subjects were followed-up 6 months post-VBG to determine weight loss. RESULTS: The subjects had a mean +/- SD age of 37.7 +/- 10.6 years. Their baseline weight was 135.3 +/- 28.0 kg and their baseline body mass index (BMI) was 50.0 +/- 7.4. 34 (77%) were female. Results of linear regressions show a significant association between baseline BMI and weight loss at 6-month follow-up. After adjustment for baseline BMI, there was a non-significant trend toward increased weight loss in association with alcohol abuse/dependence. Similarly, among our analysis of 41 subjects who had received the PDQ, we found a non-significant trend toward increased weight loss in association with "any" PDQ diagnosis and with antisocial personality disorder/trait after adjusting for baseline BMI. CONCLUSION: The data suggest that Axis I and Axis II diagnoses were not predictive of weight loss following VBG during a 6-month follow-up.

Cardiovascular risk factors in patients with morbid obesity: weight loss influenceWe studied the presence of cardiovascular risk factors in patients with morbid obesity and analyzed the influence of weight loss achieved through diet on these factors. We also evaluated the influence of gender on the presence of cardiovascular risk factors and on its response to diet. PATIENTS AND METHODS: An anthropometric evaluation was performed in patients with morbid obesity (23 men and 36 women). The presence of cardiovascular risk factors was evaluated (fibrinogen, blood pressure, glucose metabolism determination by means of oral glucose tolerance test, complete lipid profile, sleep apnea syndrome), before and after following, on an alternative fashion, very-low calorie and low-calorie diets. The comparison was made with the t-test for paired samples. RESULTS: A very significant weight loss was achieved in our patients, particularly in men (decrease of 33.4 kg, 95% CI: 26.9 to 39.8). This was accompanied by a reduction in the presence of cardiovascular risk factors, particularly in men, in whom the body fat distribution improved significantly (decrease in waist: 24.8 cm, 95% CI 18.4 to 36.5), as well as the lipid profile including triglycerides, VLDLc, HDLc and B100 apoprotein. CONCLUSIONS: Patients with morbid obesity have a high prevalence of cardiovascular risk factors. A significant reduction of this prevalence can be achieved with diet during one year. This improvement is particularly significant in men.

Adiponectin, inflammation, and the expression of the metabolic syndrome in obese individuals: the impact of rapid weight loss through caloric restriction.

Severe obesity increases the prevalence of the metabolic syndrome, and moderate acute weight loss with a very low-calorie diet in obese subjects with the metabolic syndrome leads to significant metabolic benefits. Adiponectin has been implicated in both the pathogenesis of obesity-related insulin resistance and increased inflammation. We analyzed the relationship of the adipocyte-derived hormone adiponectin with indices of inflammation, adiposity, and insulin resistance in obese subjects with (MS+, n = 40) and without (MS-, n = 40) the metabolic syndrome and examined the acute effects of rapid weight loss. MS+ subjects had significantly lower adiponectin (7.6 +/- 0.6 vs. 10.4 +/- 0.6 microg/ml; P = 0.003) and significantly higher TNF-alpha (3.3 +/- 0.2 vs. 2.8 +/- 0.3 pg/ml; P = 0.004) levels compared with MS- subjects matched for age and body mass index. Plasma adiponectin and TNF-alpha levels were inversely related to the number of metabolic syndrome factors in a stepwise manner. After 4-6 wk of weight loss, there was marked improvement in glucose, insulin, leptin, and triglycerides, whereas adiponectin and TNF-alpha concentrations did not change. Thus, increases in plasma levels of adiponectin or reductions in TNF-alpha are not required for marked improvements in glucose/insulin and lipid metabolism with acute weight loss.

Plasma ghrelin levels after diet-induced weight loss or gastric bypass surgery.

BACKGROUND: weight loss causes changes in appetite and energy expenditure that promote weight regain. Ghrelin is a hormone that increases food intake in rodents and humans. If circulating ghrelin participates in the adaptive response to weight loss, its levels should rise with dieting. Because ghrelin is produced primarily by the stomach, weight loss after gastric bypass surgery may be accompanied by impaired ghrelin secretion. METHODS: We determined the 24-hour plasma ghrelin profiles, body composition, insulin levels, leptin levels, and insulin sensitivity in 13 obese subjects before and after a six-month dietary program for weight loss. The 24-hour ghrelin profiles were also determined in 5 subjects who had lost weight after gastric bypass and 10 normal-weight controls; 5 of the 13 obese subjects who participated in the dietary program were matched to the subjects in the gastric-bypass group and served as obese controls. RESULTS: Plasma ghrelin levels rose sharply shortly before and fell shortly after every meal. A diet-induced weight loss of 17 percent of initial body weight was associated with a 24 percent increase in the area under the curve for the 24-hour ghrelin profile (P=0.006). In contrast, despite a 36 percent weight loss after gastric bypass, the area under the curve for the ghrelin profile in the gastric-bypass group was 77 percent lower than in normal-weight controls (P<0.001) and 72 percent lower than in matched obese controls (P=0.01). The normal, meal-related fluctuations and diurnal rhythm of the ghrelin level were absent after gastric bypass. CONCLUSIONS: The increase in the plasma ghrelin level with diet-induced weight loss is consistent with the hypothesis that ghrelin has a role in the long-term regulation of body weight. Gastric bypass is associated with markedly suppressed ghrelin levels, possibly contributing to the weight-reducing effect of the procedure.

Predictors of complication and suboptimal weight loss after laparoscopic Roux-en-Y gastric bypass: a series of 188 patients.

HYPOTHESIS: An analysis of patients undergoing laparoscopic Roux-en-Y gastric bypass (RYGB) may identify factors predictive of complication and of suboptimal weight loss. DESIGN: Inception cohort. SETTING: Metropolitan university hospital. PATIENTS: One hundred eighty-eight consecutive patients with severe obesity who met National Institutes of Health consensus guidelines for bariatric surgery. INTERVENTIONS: Laparoscopic RYGB. MAIN OUTCOME MEASURES: Complications requiring therapeutic intervention and percentage of excess body weight lost at 1 year after surgery. RESULTS: Of the 188 patients who underwent laparoscopic RYGB, 50 (26.6%) developed complications that required an invasive therapeutic intervention, including 2 deaths. The average follow-up was 351 days (range, 89-1019 days). Multivariate analysis by stepwise logistic regression identified surgeon experience, sleep apnea (P =.003; odds ratio, 3.0; 95% confidence interval, 1.3-7.1), and hypertension (P =.07; odds ratio, 2.0; 95% confidence interval, 1.0-4.0) as predictors of complications. The most common complication requiring therapeutic intervention was stricture at the gastrojejunal anastomosis, occurring in 27 patients (14.4%). Of the 115 patients who underwent surgery more than 1 year previously, 1-year follow-up data were available for 93 (81%). The body mass index (weight in kilograms divided by the square of height in meters) decreased from 53 +/- 8 preoperatively to 35 +/- 6 at 1 year. The mean +/- SD percentage of excess body weight lost at 1 year was 61% +/- 14%. Diabetes mellitus was negatively correlated with percentage of excess body weight lost at 1 year (P =.06). CONCLUSIONS: Surgeon experience, sleep apnea, and hypertension are associated with complications after laparoscopic RYGB. Diabetes mellitus may be associated with poorer postoperative weight loss.

Evening ready-to-eat cereal consumption contributes to weight management.

OBJECTIVES: Post dinner snacking may constitute a significant proportion of total daily energy intake and contribute to overweight and obesity in some individuals (night snackers). This study tested the hypothesis that providing a structured snack in the form of a "ready-to-eat" breakfast cereal would help regulate excess energy intake and contribute to weight loss in night snackers. METHODS: Adults (18 to 65 years of age, BMI kg/m2 > or = 25), with self-reported night snacking behaviors, were randomized into a cereal group (CR) and a no-cereal group (NC). During a period of 4 weeks, the cereal group was instructed to consume a serving of ready-to-eat cereal with low-fat milk 90 minutes after their evening meal. Concurrently, the non-cereal group continued their regular diet ad libitum. RESULTS: At baseline, there were no significant differences between groups for age, body weight, body mass index, daily caloric intake, or evening caloric intake. There was a correlation between number of days of compliance with post-dinner cereal consumption and weight loss (r = -0.36, p = 0.057). After 4 weeks, the compliant subjects (cereal intake > or = 20 d) lost -1.85 +/- 3.56 lbs vs. -0.39 +/- 3.1 lb for the NC group (p = 0.06). Compared to baseline, the compliant CR group reduced their total daily caloric intake by -396.50 +/- 641.6 kcal (p < 0.02), whereas, the NC group experienced a reduction of -23.22 +/- 889.60 kcal/day during the same period (p = ns). Reduction in post-dinner calorie intake for the compliant CR group was significantly greater compared to the NC group (-141.74 +/- 385.58 kcal vs. 85.82 +/- 374.70 kcal; p = 0.042). CONCLUSION: Eating ready-to-eat cereal after the evening meal may attenuate caloric intake in night snackers and promote weight loss in compliant individuals.