Expanding the criteria for defining success when evaluating weight loss intervention programs.

In order to evaluate outcomes among former participants in a residential weight loss program, attendees were surveyed from 1 to 5 years post-intervention. A total of 187 respondents were studied for weight changes and behavioral practices. Diet practices were assessed by number of servings per day using the Food Guide Pyramid recommendations as a guideline for indicating fruit and vegetable intake. Exercise behaviors were measured in frequency, duration, and intensity, and a weighted score was computed to obtain units for describing physical activity. Maintaining a 10% weight loss from the program entry weight, consuming five or more servings per day of fruits and/or vegetables (5-a-day) and maintaining an "active" level of physical activity were included in criteria for describing intervention success. Those meeting two of the three criteria were categorized as "successful," which included 35.8% of the study population. Because each of these behaviors (5-a-day, active lifestyle, and modest weight loss maintenance) result in independent risk reduction, it is recommended that future weight loss intervention evaluations expand the criteria for describing successful impacts and outcomes to include not only weight maintenance, but also physical activity and diet compliance behaviors.

Impact of patient follow-up on weight loss after bariatric surgery.

BACKGROUND: Postoperative follow-up after bariatric surgery is important. Because of the need for adjustments, follow-up after gastric banding may have a greater impact on weight loss than after Roux-en-Y gastric bypass.We reviewed all patients at 1 year after these two operations. METHODS: During the first year after surgery, laparoscopic adjustable gastric banding (LAGB) patients were followed every 4 weeks and Roux-en-Y gastric bypass (RYGBP) patients were followed at 3 weeks postoperatively and then every 3 months.The number of follow-up visits for each patient was calculated, and 50% compliance for follow-up and weight loss was compared. RESULTS: Between October 2000 and September 2002, 216 LAGB and 139 RYGBP operations were performed. Of these patients, 186 LAGB patients and 115 RYGBP patients were available for 1-year follow-up. Age and BMI were similar for each group. Overall excess weight loss (EWL) after LAGB was 44.5%. 130 (70%) returned 6 or less times in the first year and achieved 42% EWL. 56 patients (30%) returned more than 6 times and had 50% EWL (P=0.005). Overall %EWL after RYGBP was 66.1%. 53 patients (46%) returned 3 or less times in the first year, achieving 66.1% EWL. 62 patients (54%) returned more than 3 times after surgery and achieved 67.6% EWL (P=NS). CONCLUSION: Patient follow-up plays a significant role in the amount of weight lost after LAGB, but not after RYGBP. Patient motivation and surgeon commitment for long-term follow-up is critical for successful weight loss after LAGB surgery.

Effect of a low-carbohydrate diet on appetite, blood glucose levels, and insulin resistance in obese patients with type 2 diabetes.

BACKGROUND: It is not known how a low-carbohydrate, high-protein, high-fat diet causes weight loss or how it affects blood glucose levels in patients with type 2 diabetes. OBJECTIVE: To determine effects of a strict low-carbohydrate diet on body weight, body water, energy intake and expenditure, glycemic control, insulin sensitivity, and lipid levels in obese patients with type 2 diabetes. DESIGN: Inpatient comparison of 2 diets. SETTING: General clinical research center of a university hospital. PATIENTS: 10 obese patients with type 2 diabetes. INTERVENTION: Usual diets for 7 days followed by a low-carbohydrate diet for 14 days. MEASUREMENTS: Body weight, water, and composition; energy intake and expenditure; diet satisfaction; hemoglobin A1c; insulin sensitivity; 24-hour urinary ketone excretion; and plasma profiles of glucose, insulin, leptin, and ghrelin. RESULTS: On the low-carbohydrate diet, mean energy intake decreased from 3111 kcal/d to 2164 kcal/d. The mean energy deficit of 1027 kcal/d (median, 737 kcal/d) completely accounted for the weight loss of 1.65 kg in 14 days (median, 1.34 kg in 14 days). Mean 24-hour plasma profiles of glucose levels normalized, mean hemoglobin A1c decreased from 7.3% to 6.8%, and insulin sensitivity improved by approximately 75%. Mean plasma triglyceride and cholesterol levels decreased (change, -35% and -10%, respectively). LIMITATIONS: The study was limited by the short duration, small number of participants, and lack of a strict control group. CONCLUSION: In a small group of obese patients with type 2 diabetes, a low-carbohydrate diet followed for 2 weeks resulted in spontaneous reduction in energy intake to a level appropriate to their height; weight loss that was completely accounted for by reduced caloric intake; much improved 24-hour blood glucose profiles, insulin sensitivity, and hemoglobin A1c; and decreased plasma triglyceride and cholesterol levels. The long-term effects of this diet, however, remain uncertain.

Elevated homocysteine levels with weight loss after Lap-Band surgery: higher folate and vitamin B12 levels required to maintain homocysteine level.

OBJECTIVE: To investigate homocysteine levels and their relationship with serum folate and vitamin B12 concentrations with weight loss after the Lap-Band form of gastric restrictive surgery, with the view to minimizing risk. METHODS: We measured levels of fasting plasma homocysteine (tHcy), folate (serum and RBC) and vitamin B12 in two groups. The study group was 293 consecutive patients at 12 (n=192) or 24 (n=101) months review after surgery. The controls were 244 consecutive patients presenting for this surgery. RESULTS: The group losing weight had higher geometric mean tHcy levels: 10.4 (95% CI, 9.8-10.8) micromol/l compared with 9.2 (95% CI, 8.9-9.7) in controls (P<0.001). This occurred with higher folate levels and unchanged vitamin B12 levels. Levels of folate and B12 together explained 35% (r (2)) of the homocysteine variance in the weight loss group compared with only 9% (r (2)) in controls (P<0.001). Those taking regular multivitamin supplements had lower tHcy levels: 9.6 (9.1-10.0) micromol/l vs 12.3 (11.4-13.3) in those not taking supplements (P<0.001). A low normal plateau of tHcy levels occurred at levels of folate >15 ng/l and B12)600 ng/ml. A curvilinear relationship exists between these cofactors and tHcy levels, with the dose-response relationship shifted to the right in the weight loss group. CONCLUSION: This study shows elevated tHcy levels with weight loss, without lower serum folate or vitamin B(12) levels. There is an altered dose-response relationship with higher serum B(12) and folate levels required to maintain recommended tHcy levels. Patients losing weight have significant health benefits; however, they may be at greater risk of vascular events or fetal abnormality in association with raised tHcy levels. Multivitamin supplementation is effective in lowering tHcy levels.

Modeling the impact of adjustable gastric banding on survival in patients with morbid obesity.

OBJECTIVE: Morbid obesity is associated with premature death. Adjustable gastric banding may lead to substantial weight loss in patients with morbid obesity. Little is known about the impact of weight loss on survival after adjustable gastric banding. We therefore developed a mathematical model to estimate life expectancy in patients with a body mass index (BMI) > or =40 kg/m(2) undergoing bariatric surgery. RESEARCH METHODS AND PROCEDURES: We developed a nonhomogeneous Markov chain consisting of five states: the absorbing state ("dead") and the four recurrent states BMI > or =40 kg/m(2), BMI 36 to 39 kg/m(2), BMI 32 to 35 kg/m(2), and BMI 25 to 31 kg/m(2). Scenarios of weight loss and age- and sex-dependent risk of death, as well as BMI-dependent excess mortality were extracted from life tables and published literature. All patients entered the model through the state of BMI > or =40 kg/m(2). RESULTS: In men aged either 18 or 65 years at the time of surgery, who moved from the state BMI > or =40 kg/m(2) to the next lower state of BMI 36 to 39 kg/m(2), life expectancy increased by 3 and 0.7 years, respectively. In women aged either 18 or 65 years at the time of surgery, who moved from the state BMI > or =40 kg/m(2) to the next lower state BMI 36 to 39 kg/m(2), life expectancy increased by 4.5 and 2.6 years, respectively. weight loss to lower BMI strata resulted in further gains of life expectancy in both men and women. DISCUSSION: Within the limitations of the modeling study, adjustable gastric banding in patients with morbid obesity may substantially increase life expectancy.

Relationship between different subcutaneous adipose tissue layers, fat mass, and leptin in response to short-term energy restriction in obese girls.

This study addresses whether the expected relationship of 15 specified subcutaneous adipose tissue layers (SAT layers) from 1-neck to 15-calf and body fat mass (FM) with leptin was influenced by a weight-loss program. In 30 obese girls (10 prepubertal, 15 pubertal, and 5 late/postpubertal) SAT layers were measured by means of the optical device Lipometer. Fat mass (FM) was estimated indirectly by means of bioelectrical impedance. Leptin and insulin were determined by means of radioimmunoassays. All measurements were performed before (pre) and after (post) 3 weeks of low-caloric diet and physical training. At the beginning of the study, there were significant correlations for all estimates of adiposity and leptin (0.67 to 0.79; P < 0.0001). Five SAT layers from the upper body and the trunk (0.48 to 0.67; P < 0.01) but none from the abdominal region and lower extremities were correlated with leptin. FM together with SAT layers 4-upper back and 8-lower abdomen (negative slope) explained 79% of the variation in pre leptin values (P < 0.0001). The weight-loss program significantly reduced leptin (P < 0.0001), insulin (P = 0.04), estimates of adiposity (P < 0.0001), and SAT layers 4-upper back (P = 0.0006), 11-front thigh, 13-rear thigh, and 14-inner thigh (P between <0.03 and <0.01). Although significant, the reductions in the four SAT layers were small. Estimated fat-free mass was significantly increased after three weeks (P < 0.05). Changes in SAT layers from the upper extremities and from the trunk were inversely correlated to the decrease in leptin (P between <0.05 and <0.001). Initial leptin was the best correlate of the decrease in leptin (adj. R(2) = 0.815; P < 0.0001). However, when only changes in adiposity and insulin were considered in the regression model, changes in insulin contributed to the fall in leptin (adj. R(2) = 0.23; P = 0.004). When changes in SAT layers were added to the model, changes in SAT layers 2-triceps and 10-hip (negative slopes) contributed to the decrease in leptin (adj. R(2) = 0.48; P < 0.0001). After weight loss, correlations between estimates of post adiposity and post leptin (0.40, P = 0.01 to 0.57, P = 0.0005) were lower compared with pre values. SAT layers 4-upper back and 3-biceps contributed independently to post leptin values (adj. R(2) = 0.50; P < 0.0001). It is suggested that fat mass and SAT layers from the upper body are the main determinants of leptin in obese girls before weight loss. The diet and sports intervention program reduced leptin independent of the reduction in adiposity. The distribution of subcutaneous fat might be a stable correlate of circulating leptin after a short-term reduction in energy intake. Am. J. Hum. Biol. 12:803-813, 2000. Copyright 2000 Wiley-Liss, Inc.

Inactivity and weight loss: effective criteria to identify frailty.

The effectiveness was examined of inactivity and weight loss as criteria to identify a frail subgroup within independently living elderly persons participating in the SENECA study (Survey in Europe on Nutrition and the Elderly, a Concerted Action). Eight-hundred-forty-nine participants (aged 75 to 80) from nine countries were classified in four subgroups: 1) inactive elderly (lowest tertile activity score: n = 204); 2) weight losing elderly (lowest quintile: * 6.3% weight loss over 4-5 years: n = 108); 3) both inactive and weight losing (n = 54); 4) neither inactive nor weight losing: reference (n = 483). Differences in health, physical functioning and nutritional characteristics between groups 1, 2 and 3 respectively, and the reference group were evaluated. Compared to the weight-stable, active reference group, both inactive, weight losing (group 3) and inactive subjects (group 1) reported significantly more chronic diseases (2.2 and 1.8 vs. 1.1), disabilities (81 and 80 vs. 43%), use of medications (both 2.3 vs. 1.1) and care services (26 and 21 vs. 6%), and a lower self-rated health (2.8 and 3.1 vs. 3.8), relative health (1.9 and 2.1 vs. 2.6), and physical performance score (17 and 18 vs. 22). In addition, inadequate micronutrient intake and biochemical deficiencies were more prevalent. Weight-losing elderly were not significantly different from the reference group with respect to these characteristics. Therefore, physical inactivity alone or in combination with weight loss seems to be a practical and inexpensive screening criterion for identifying a subgroup of elderly with less favourable health and nutritional characteristics and poorer physical functioning among non-institutionalised elderly.

Effect of weight reduction on liver histology and biochemistry in patients with chronic hepatitis C.

BACKGROUND: Steatosis occurs in more than 50% of patients with chronic hepatitis C and is associated with increased hepatic fibrosis. In many of these patients the pathogenesis of steatosis appears to be the same as for patients with non-alcoholic fatty liver disease-that is, related to visceral adiposity and obesity. METHODS: The effect of a three month weight reduction programme on liver biochemistry and metabolic parameters was examined in 19 subjects with steatosis and chronic hepatitis C. Paired liver biopsies were performed in 10 subjects, prior to and 3-6 months following the intervention, to determine the effect of weight loss on liver histology. RESULTS: There was a mean weight loss of 5.9 (3.2) kg and a mean reduction in waist circumference of 9.0 (5.0) cm. In 16 of the 19 patients, serum alanine aminotransferase levels fell progressively with weight loss. Mean fasting insulin fell from 16 (7) to 11 (4) mmol/l (p<0.002). Nine of 10 patients with paired liver biopsies had a reduction in steatosis irrespective of viral genotype. In these subjects the median modified Knodell fibrosis score decreased from 3 to 1 (p=0.04) and activated stellate cells significantly decreased (p<0.004). CONCLUSIONS: weight loss in patients with chronic hepatitis C may be associated with a reduction in steatosis and abnormal liver enzymes and an improvement in fibrosis, despite the persistence of the virus. Weight reduction may provide an important adjunct treatment strategy for patients with chronic hepatitis C.