Absence of cardiac arrhythmias during a very-low-calorie diet with high biological quality protein

Fourteen women who were at least 50 lb (22.7 kg) overweight entered the 15 week study which included 4 weeks of 1200 cal (5028 J) balanced diet followed by 7 weeks on a very-low-calorie diet (VLCD) and 4 weeks of refeeding. During the VLCD high biological quality protein (poultry, fish) and recommended supplements of vitamins, minerals and water were used. With the exception of week 5 and 14, 25-h Holter monitorings were done weekly. During the initial 4 weeks, 2 patients showed disturbances of cardiac rhythm and were discharged from the study. Twelve patients completed the trial without any clinically significant changes in cardiac rhythm. The 12 lead ECGs remained normal in all patients throughout the study. The average weight loss was 46 lb (20.9 kg) and the whole program was well tolerated. It is concluded that seven weeks of VLCD with high biological quality protein and recommended supplements appears to be a safe method for weight reduction for severely obese patients.     

Long-term (5-year) results after either horizontal gastroplasty or very-low-calorie diet for morbid obesity

Fifty-seven patients allocated at random to either diet supported by gastroplasty or very-low-calorie diet (VLCD) were followed for 5 years. One patient was lost to follow-up 1 year after surgery. Data were analyzed by survival statistics and success was liberally defined as a maintained weight loss of at least 10 kg. The cumulative success rate declined steadily in both groups, but it remained higher in the gastroplasty group (16 versus 3 percent, the 95 percent confidence limits being 11-21 percent and 1-5 percent, respectively; P less than 0.05). At 5 years, eight of 27 gastroplasty patients (30 percent, 95 percent confidence limits 14-50 percent) had not relapsed. Of 30 VLCD patients, relapse had not occurred in five (17 percent, 6-35 percent). The weight loss of patients without relapse did not differ significantly (medians of gastroplasty and VLCD patients 18 kg and 27 kg, respectively). Complications and side-effects were more numerous and serious among the gastroplasty patients. Although in this long-term study, the horizontal gastroplasty proved to be somewhat more effective than the diet alone, the surgical risks and the unsatisfactory maintenance of weight loss speak against the use of this operation.     

Effects of a very low calorie diet on weight, thyroid hormones and mood

Changes in weight, thyroid hormones and mood were examined in 15 obese (113 kg) women over an 18-week period. After 4 weeks of a 1200 kcal/day diet, patients were randomly assigned to one of two dietary conditions: very low calorie diet (VLCD) (n = 8) or balanced deficit diet (BDD) (n = 7). VLCD patients consumed 400 kcal/day for 8 weeks and then gradually returned to a 1200 kcal/day diet. BDD patients consumed 1200 kcal/day for the entire 18 weeks. Differences in weight losses between the conditions were statistically significant only during the consumption of the VLCD. Serum T3 decreased by as much as 66 percent in VLCD patients during consumption of the 400 kcal/day diet, whereas rT3 increased by as much as 27 percent. T3 increased when patients were realimented with a 1000 kcal/day balanced diet but remained a significant 22 percent below baseline at the end of the study. BDD patients also showed marked reductions in T3, as great as 40 percent, so that the differences between the two conditions were not statistically significant. Multiple regression analyses, collapsing across conditions (n = 15), indicated that weight loss at week 12 and baseline T3 accounted for 63 percent of the variance in the change in T3 at week 12. Patients in both conditions showed improvements in mood. Changes in depression were not associated with changes in serum T3.     

Metabolic and cardiovascular effects of very-low-calorie diet therapy in obese patients with Type 2 diabetes in secondary failure: outcomes after 1 year.

AIMS: To evaluate the short-term and 1-year outcomes of an intensive very-low-calorie diet (VLCD) on metabolic and cardiovascular variables in obese patients with Type 2 diabetes (T2DM) and symptomatic hyperglycaemia despite combination oral anti-diabetic therapy +/- insulin, and to assess patient acceptability and the feasibility of administering VLCD treatment to this subgroup of patients in a routine practice setting. METHODS: Forty obese patients with T2DM (22 M, mean age 52 years, body mass index (BMI) 40 kg/m2, duration of T2DM 6.1 years) and symptomatic hyperglycaemia despite combination oral therapy (n = 26) or insulin + metformin (n = 14) received 8 weeks of VLCD therapy (750 kcal/day) followed by standard diet and exercise advice at 2-3-month intervals up to 1 year. Insulin was discontinued at the start of the VLCD, and anti-diabetic therapy was adjusted individually throughout the study, including (re)commencement of insulin as required. RESULTS: Immediate improvements in symptoms and early weight loss reinforced good compliance and patient satisfaction. After 8 weeks of VLCD, body weight and BMI had fallen significantly: 119 +/- 19-107 +/- 18 kg and 40.6-36.6 kg/m2, respectively, with favourable reductions in serum total cholesterol (5.9-4.9 mm), blood pressure (10/6 mmHg) and fructosamine (386 +/- 73-346 +/- 49 microm) (equates to an HbA1c reduction of approximately 1%). Sustained improvements were evident after 1 year, with minimal weight regain, e.g. mean body weight 109 +/- 18 kg and BMI 37 +/- 4 kg/m2. Glycaemic control tended to deteriorate after 1 year. CONCLUSIONS: The absence of a control group is a major limitation, but the results indicate that 8 weeks of VLCD treatment may be effective and well tolerated in symptomatic obese patients with T2DM in secondary failure, producing sustained cardiovascular and metabolic improvements after 1 year. VLCD therapy is a treatment option that deserves greater consideration in this difficult-to-treat patient population.     

Loss of total body potassium during rapid weight loss does not depend on the decrease of potassium concentration in muscles. Different methods to evaluate body composition during a low energy diet

OBJECTIVE: The aim of the study was to elucidate whether combustion of skeletal muscle glycogen during a very low calorie diet (VLCD) was associated with decreased muscle potassium content. A comparison between different methods was also performed to evaluate body composition during a VLCD and a low calorie diet (LCD). DESIGN: Dietary treatment of obese women by VLCD and LCD. Measurements after 1 and 2 weeks of VLCD and 6 months of LCD. SUBJECTS: Fifteen perimenopausal obese women aged 46.5+/-1.3 y and 15 of 48.0+/-0.7 y of age. MEASUREMENTS: Skeletal muscle biopsies under local anaesthesia. Body composition measurements by means of deal-energy X-ray absorptiometry (DEXA), and measurements of total body potassium (40K) and total body nitrogen (TBN). Measurements of electrolytes and glycogen concentration in muscle samples. RESULTS: In the first study (1 week of VLCD) skeletal muscle glycogen decreased (P<0.01), but muscle potassium increased (P<0.01). Muscle sodium decreased (P<0.01), while muscle magnesium was unaltered. Body weight decreased by 2.9+/-0.5 kg and 40K decreased. Fat-free mass (FFM) calculated from 40K and DEXA decreased by 2.7 vs 1.9 kg (P<0.001). Body fat measured with DEXA decreased by 1.1 kg (P<0.01), but not body fat calculated from 40K. TBN decreased by 0.03+/-0.01 kg (P<0.05) and FFM calculated from TBN by 2.9+/-0.5 kg (P<0.002). In the second study, 6 months on the LCD resulted in 17.0+/-2.0 kg weight reduction and this was mainly due to reduced body fat, 14. 0+/-2.0 kg measured with DEXA and from 40K (P<0.001). The decrease in FFM was slight. CONCLUSION: One week of VLCD resulted in muscle glycogen depletion but increased muscle potassium content in spite of decreased total body potassium. FFM contributed to the main part of body weight loss during short periods of severe energy restriction, but remained unchanged during long-term dietary treatment. Body fat became mostly responsible for the body weight loss during long-term LCD. Calculations of changes of FFM from 40K and TBN seem to overestimate the FFM decrease associated with short-term VLCD. International Journal of Obesity (2000)24, 101-107     

Intermittent versus on-demand use of a very low calorie diet: a randomized 2-year clinical trial

OBJECTIVES: To compare two different very low calorie diet (VLCD)-based weight maintenance strategies. DESIGN AND SETTING: A randomized 2-year clinical trial performed at the Department of Body Composition and Metabolism, Sahlgrenska University Hospital, Sweden. SUBJECTS: A total of 334 patients, body mass index (BMI) >30 kg m-2, aged 18-60 years. INTERVENTIONS: All the patients started with 16 VLCD weeks. Subjects in the intermittent group were then scheduled to use VLCD for 2 weeks every third month, whilst patients in the on-demand group were instructed to use VLCD whenever their body weight passed an individualized cut-off level. Irrespective of the treatment group, all the subjects were recommended a hypocaloric diet during VLCD-free periods. MAIN OUTCOME MEASURES: Changes in body weight, body composition, anthropometric variables and cardiovascular risk factors. RESULTS: Completers in both groups maintained highly significant weight losses after 2 years: 7.0 +/- 11.0 kg (6.2 +/- 9.5%) in the intermittent group and 9.1 +/- 9.7 kg (7.7 +/- 8.1%) in the on-demand group (P < 0.001, ns between groups). Male completers in the on-demand group lost significantly more weight than men in the intermittent group, 14.5 +/- 11.0 kg vs. 4.0 +/- 10.5 kg, respectively (P < 0.01). Most cardiovascular risk factors improved during the first year, whilst anthropometric measures, insulin, HDL- and LDL-cholesterol were also significantly improved after 2 years of treatment. CONCLUSION: Clinically significant weight reductions were achieved after 2 years of VLCD-based treatment. The structure of VLCD treatment during the maintenance phase did not affect weight loss in the total study population, whilst male subjects might benefit from the VLCD on-demand strategy.     

A time-series analysis of longitudinal weight changes in two adult women.

This study was conducted to examine individual longitudinal serial trends in body weight of two moderately obese adult women. Self-measured daily weights (over 5000 data points for subject 1 and over 3500 for subject 2) were averaged for each month and analyzed using a time-series analysis approach. The best statistical model for both women indicated a significant upward trend (gain 30 and 22 lb, respectively) interrupted by linear decreases (P less than 0.05) during weight loss programs over the 16- and 10-year observation periods, respectively. The women participated in six and eight weight control programs, respectively, and consistently lost weight, averaging 9.17 +/- 1.85 lb and 8.00 +/- 3.57 lb. Both subjects regained weight after dieting, in a period approximately 2.25 times as long as the diet. Numerous weight fluctuations occurred and one subject lost and then regained 10 percent of her body weight during two 5-year periods. Results are examined in terms of a possible weight increase protection benefit, as well as the deleterious medical potential that may occur with numerous weight loss attempts. Suggestions for future research are provided regarding weight cycling, seasonal variations, set point theory, aging effects, and the use of self-directed weight loss initiatives in conjunction with formal weight reduction programs. This study may serve as a prototype for exploring weight fluctuation using time-series analyses and for further investigating the etiology and clinical management of obesity.     

Retention rates and weight loss in a commercial weight loss program

OBJECTIVE: To evaluate and describe retention rates and weight loss in clients participating in a commercial weight loss program. SUBJECTS: A total of 60 164 men and women ages 18-79 years who enrolled in the Jenny Craig Platinum program between May 2001 and May 2002. METHODS: Retention rates, mean weight loss and percent weight loss were calculated on a weekly basis for the 52-week period following initial enrollment in the weight loss program. Clients were categorized based on final week of participation in the program (weeks 1-4, weeks 5-13, weeks 14-26, weeks 27-39 and weeks 40-52) and weight loss was calculated at final week. A subgroup of clients was identified based on attendance through 13, 26 and 52 weeks. Mean and percent weight loss was calculated for these subgroups of clients. RESULTS: Of the 60 164 men and women who enrolled in the weight loss program, 73% were retained in the program after 4 weeks, 42% at 13 weeks, 22% at 26 weeks and 6.6% at 52 weeks. Clients who dropped out of the program during the first 4 weeks lost 1.1+/-1.6% (mean+/-s.d.) of their initial body weight, whereas clients who dropped out between 40 and 52 weeks lost 12.0+/-7.2%. Clients in the 13-week, 26-week and 52-week cohorts lost 8.3+/-3.3, 12.6+/-5.1 and 15.6+/-7.5% of their initial body weight, respectively. CONCLUSION: Weight loss was greater among clients who were retained in the program longer. The findings from this study suggest that a commercial weight loss program can be an effective weight loss tool for individuals who remain active in the program.     

Changes in abdominal subcutaneous fat water content with rapid weight loss and long-term weight maintenance in abdominally obese men and women

OBJECTIVE: Insulin resistance decreases blood flow and volume in fat tissue. We hypothesised that fat tissue nutritive blood flow and volume, and thereby water content, would increase during weight loss and weight maintenance in obese persons. DESIGN: Longitudinal clinical intervention with a 9-week very-low-calorie diet (VLCD) followed by one year of weight maintenance. SUBJECTS: Obese men (n=13) and women (n=14) with the metabolic syndrome. MEASUREMENTS: Water content of abdominal subcutaneous fat tissue as estimated by a sensor on the skin surface measuring the dielectric constant at 300 MHz. Anthropometric measures of fatness and fat distribution. Biochemical measures related to insulin resistance. RESULTS: Subjects lost 14.5+/-3.4% of body weight during the VLCD, and generally sustained this weight loss during weight maintenance. Insulin sensitivity as estimated by an index (qualitative insulin sensitivity check index) increased during the VLCD, and remained increased throughout weight maintenance. The dielectric constant increased from 23.3+/-2.3 to 25.0+/-2.1 (P<0.001) during the VLCD, and further to 27.8+/-1.9 (P<0.001) during weight maintenance, indicating an increase in the water content of subcutaneous fat. The increase in subcutaneous fat water content did not correlate with weight loss and other measures of adiposity during the VLCD, but there was an inverse correlation that strengthened in significance from baseline to 6, 9 and 12 mo (r=-0.32 to -0.64, P=0.079-0.002). Increases in subcutaneous fat water content also correlated with improvements in insulin sensitivity at 6, 9 and 12 months of weight maintenance (r=0.34-0.54, P=0.094-0.006). CONCLUSIONS: Water content of abdominal subcutaneous adipose tissue increases with weight loss in obese persons with the metabolic syndrome, and may reflect increased subcutaneous fat tissue nutritive blood flow. The increase in water content correlates with the increase in insulin sensitivity, suggesting that weight loss and consequent improved insulin sensitivity could mediate the increase in abdominal subcutaneous fat hydration.     

Influence of short-term dietary weight loss on cortisol secretion and metabolism in obese men

OBJECTIVES: Obesity is associated with increased inactivation of cortisol by hepatic A-ring 5alpha- and 5beta-reductases, impaired hepatic regeneration of cortisol from cortisone by 11beta-hydroxysteroid dehydrogenase type 1 (11HSD1), but increased subcutaneous adipose 11HSD1 activity enhancing local cortisol levels in fat. Cause and effect between obesity and abnormal cortisol metabolism is untested. DESIGN: Acute weight loss was induced by very low calorie diet (VLCD) or starvation in obese men. METHODS: Otherwise healthy males (aged 20-55 years; body mass index (BMI) 30-40 kg/m2) were studied after 6 days on a weight maintenance diet; then after either 6 days of starvation (n=6) or 3 weeks of VLCD (2.55 MJ; n=6); then after 1 week of weight maintenance; and finally after 2 weeks of being allowed to feed ad libitum. Plasma samples were obtained from indwelling cannulae at 0930 h and 1815 h and a 24 h urine collection was completed for analysis of cortisol metabolites by gas chromatography/mass spectrometry. RESULTS: Data are mean+/-S.E.M. BMI fell (kg/m3) from 34.8+/-0.8 at baseline to 31.8+/-1.4 on VLCD and 32.7+/-1.1 on starvation. Starvation caused a rise in plasma cortisol (at 0930 h from 143+/-17 to 216+/-11 nM, P<0.001) but no change in total urinary cortisol metabolites. VLCD did not alter plasma cortisol and markedly reduced cortisol metabolite excretion (from 15.8+/-1.1 mg/day at baseline to 7.0+/-1.1 mg/day, P<0.001). Relative excretion of 5alpha-reduced cortisol metabolites fell on both diets, but there were no changes in cortisol/cortisone metabolite ratios reflecting 11HSD activities. CONCLUSIONS: Weight loss with VLCD in obesity reverses up-regulation of hepatic A-ring reductases and normalises cortisol production rate; in contrast, starvation produces acute stress and further activation of cortisol secretion. We suggest that activation of cortisol secretion is not an irreversible intrinsic abnormality in obese patients, and speculate that dietary content has an important influence on the neuroendocrine response to weight loss.     

Effects on body weight of strict or liberal adherence to an initial period of VLCD treatment. A randomised, one-year clinical trial of obese subjects

OBJECTIVES: To examine the impact on early and late weight loss of three different, initial very low calorie diet (VLCD) approaches in a one-year obesity treatment program. DESIGN: Randomised clinical trial. SUBJECTS: 121 obese subjects, aged 21-60y, BMI > or = 30.0kg/m2. INTERVENTIONS: The VLCD-strict group was prescribed a strict outpatient VLCD for 16 weeks, followed by a 36-week hypocaloric diet. The VLCD-mw group received the same treatment, but were hospitalised in a metabolic ward for the initial week. The VLCD-plus group was allowed two small meals weekly, but received otherwise the same recommendations as the VLCD-strict group. RESULTS: After 16 weeks, there was no difference in weight loss between the treatment groups in the intent-to-treat population, while among completers, the weight loss was about 7 kg larger in the VLCD-strict group compared to the VLCD-plus group (P < 0.05). At one year, these groups differed by approximately 4 kg, both according to intention-to-treat and among completers (P < 0.05, both differences). These differences were more prominent among females. The weight reduction in the VLCD-mw group was generally not superior to the VLCD-strict group. CONCLUSIONS: In the short-term, strict VLCD only reduced weight better than a liberal VLCD approach among completers. However, after one year, a strict VLCD regimen seemed beneficial compared to a liberal VLCD for all patients. There was no extra weight loss if the VLCD period was initiated on a metabolic ward.     

Use of fluoxetine, a selective serotonin-uptake inhibitor, in the treatment of obesity: a dose-response study (with a commentary by Michael Weintraub)

Pharmacologic measures which increase serotonergic activity in the brain decrease food consumption and lead to decreased weight in animals. Fluoxetine, an inhibitor of serotonin reuptake, decreases food intake in animals and is associated with weight loss in depressed and otherwise healthy obese patients. To determine the most effective daily fixed dose which causes weight loss in nondepressed obese patients, fluoxetine (10, 20, 40 or 60 mg) or placebo was administered once daily for 8 weeks to 655 patients consisting primarily of women (mean age 40 years, mean weight 95 kg). Diet and activity were not controlled. The placebo-treated patients lost 0.6 +/- 2.3 kg. With the 60-mg fluoxetine dose, patients lost an average of 4.0 +/- 3.9 kg (P less than 0.001), with intermediate responses at the lower doses. Weight loss was proportional to the initial body mass index (weight/height squared). There were no statistically significant differences between any fluoxetine treatment group and placebo for discontinuations from the study. There were statistically significant dose-dependent increases in reports of asthenia, somnolence and sweating. Thus, fluoxetine 60 mg daily appears to be potentially effective for use in weight reduction.     

Changes in gallbladder motility and gallstone formation following laparoscopic gastric banding for morbid obestity.

Morbid obesity is associated with cholesterol gallstone formation, a risk compounded by rapid weight loss. Laparoscopic gastric banding allows for a measured rate of weight loss, but the subsequent risk for developing gallstones is unknown. METHOD: Twenty-six normal-weight volunteers (body mass index [BMI] less than 30) were compared with 14 morbidly obese patients (BMI greater than 40). Gallbladder volumes were measured ultrasonographically, after fasting and following stimulation with intravenous cholecystokinin-octapeptide (CCK-8) RESULTS: Preoperatively, fasting gallbladder volume and residual volume after CCK stimulation were both two times greater in the obese group (P<0.02 versus controls). Per cent gallbladder emptying was not different. Gallbladder refilling was four times higher in the obese patients (P<0.01). By six weeks postoperatively, the obese patients lost 1.4+/-0.1% body weight per week. Gallbladder emptying decreased 18.4% (80.3+/-3.9% to 65.5+/-6.9%; P<0.05); residual volume rose one-third (not significant), and refilling fell 60.5% (0.43+/-0.09 to 0.26+/-0.04 mL/min; P=0.07). Three patients with weight losses of greater than 1.7% per week developed gallstones; gallbladder emptying fell outside the 95 percentile. By six months, weight loss slowed to 0.5+/-0.1% per week; gallbladder motility improved modestly. No further stones developed. CONCLUSION: Rapid weight loss following laparoscopic gastric banding impairs gallbladder emptying and when pronounced, gallstones form by six weeks postoperatively. The accompanying reduction in gallbladder emptying, increased gallbladder residual volume and decreased refilling promote gallbladder stasis and hence stone formation.     

Effect of weight loss on QTc dispersion in obese subjects.

OBJECTIVE: Increased QTc dispersion is a predictor for ventricular arrhythmias. The aim of this study was to investigate whether QTc dispersion decreases after weight loss program with diet and medical treatment. METHODS: Total 30 (24 women and 6 men, mean age: 44+/-8 years) obese subjects who lost at least 10% of their original weight after 12 week weight loss program were included in present study. Obesity was defined as > or =30 kg/m(2) of body mass index (BMI). Normal weight was defined as < or = 25 kg/m(2) of BMI. RESULTS: After 12 week weight loss program, BMI decreased from 42+/-5 kg/m(2) to 36+/-4 kg/m(2) (p<0.001) and mean weight of obese subjects decreased from 110+/-17 kg to 95+/-15 kg (p<0.001). The mean amount of weight loss was 14.5+/-5.0 kg (range 9-32 kg). The average percent of weight loss was 13% (10.0%-20.3%). Maximum QTc interval (from 446+/-19 ms to 433+/-27 ms, p=0.024) and QTc dispersion (from 66+/-18 ms to 52+/-25 ms, p=0.024) significantly decreased after weight loss program. A statistically significant correlation was found between decrease in level of QTc dispersion and amount of weight loss (r=0.487, p=0.007). CONCLUSION: Substantial weight loss in obese subjects is accompanied by significantly decreased QTc dispersion. The degree of QTc dispersion reduction is associated with amount of weight loss.     

Weight loss and long-term follow-up of severely obese individuals treated with an intense behavioral program

OBJECTIVE: To review weight loss and maintenance for severely obese individuals enrolled in intensive behavioral weight loss program using very-low or low-energy diets. DESIGN: Chart review of consecutively treated patients between 1995 and 2002 seen at three weight loss centers. SUBJECTS: One thousand five hundred and thirty one patients with severe obesity (>or=40 kg/m(2)) treated in three cities ('Study Group'). Of these, 1100 completed the 12-week core curriculum ('Completer Group'). Weight loss >or=100 lbs (>45 kg) was seen in 268 patients ('100-Pound Group'). MEASUREMENTS: Charts were reviewed for baseline characteristics, weekly weights, follow-up weights and side effects. RESULTS: In the Study Group, average weight loss+/-s.e. for 998 women was 23.9+/-0.6 kg (18.5% of initial body weight (IBW)) and for 533 men was 36.0+/-1.0 kg (22.5%) over 30 weeks. For Completers, average weight loss for women was 30.8+/-0.6 kg (23.9%) and for men was 42.6+/-1.1 kg (26.7%) over 39 weeks. In the 100-Pound Group, average weight loss for women was 58.2+/-1.2 kg (41.5%) in 65 weeks and for men was 65.7+/-1.5 kg (37.5%) in 51 weeks. Side effects, assessed in 100 patients losing >45 kg, were mild to moderate in severity. Severe adverse events unrelated to the diet were noted in 5% of patients and during weight loss 1% had elective cholecystectomies. Follow-up weights were available for 86% of Completers at an average of 72 weeks with average maintenance of 23 kg or 59% of weight loss; follow-up weights were available for 94% of the 100-Pound Group at an average of 95 weeks with average maintenance of 41 kg or 65% of weight loss maintained. CONCLUSIONS: Intensive behavioral treatment with meal replacements is a safe and effective weight-loss strategy for selected severely obese individuals.     

Short- and long-term evolution of body composition in 1389 obese outpatients following a very low calorie diet (Pro'gram18 VLCD)

One thousand three-hundred and eighty-nine obese outpatients were followed by 28 practitioners. They were enrolled in a multidisciplinary weight control program for at least 1 year. The major components of the program include a commercial very low calorie diet (Pro'gram18 VLCD), behavior modification, and exercise. There was a significant decrease in body weight compared with baseline of approximately 12.3+/-5.3 kg at the end of the maintenance period; the weight loss was achieved essentially at the expense of fatty mass, -10.3+/-5.5 kg at 90 days while fat-free mass loss was -2.0+/-2.5 kg at 90 days. Mean serum total cholesterol and triglycerides were also lowered and systolic and diastolic blood pressure and fasting blood glucose values were normalized at the end of the weight-loss phase. Obese outpatients lost substantial amounts of weight using VLCD, reduced the risk factors associated with obesity, and had encouraging long-term results, with weight loss maintained at 2-year follow-up.     

Protein balance during very-low-calorie diets for the treatment of severe obesity

Very-low-calorie diets (less than 500 kcal/day; VLCD) are widely used for the treatment of severe obesity. We report the effects of such diets, consisting of proteins only or proteins and carbohydrates (CH), on nitrogen balance and protein nutritional status of morbidly obese patients. Cumulative nitrogen loss, serum albumin, transferrin, prealbumin (PA) and retinol-binding protein (RBP) concentrations, and plasma amino acid profile were determined in two groups of obese patients: 5 subjects (3 women, 2 men: BMI 55.3 +/- 2.2 kg/m2) subjected for 4 weeks to a protein VLCD (40 g protein + 2 g fat) and 7 others (4 women, 3 men: BMI 45.6 +/- 2.8 kg/m2) received for the same length of time a protein + CH VLCD (34 g protein + 26 g CH). Nitrogen balance was determined weekly whilst plasma and serum variables were measured on days 0, 3, 5, 10, 20 and 28 of treatment. Nitrogen balance did not significantly differ between the two groups of patients throughout the treatment. Serum PA and RBP concentrations decreased from day 5 and day 10, respectively, in both groups. Plasma amino acids showed a similar pattern in the protein and protein + CH groups. Alanine gradually decreased below baseline values; after a peak value on day 5, branched-chain amino acids (valine, leucine, isoleucine) returned to baseline values in both groups. In conclusion, in severely obese patients subjected to VLCD, nitrogen balance, labile protein concentrations and plasma amino acid profile are not significantly affected by adding CH to proteins.     

Changes in serum lipids after gastric bypass surgery. Lack of a relationship to weight loss

Serum lipid levels were measured in 65 obese patients before and a mean of 13.4 +/- 0.2 months after gastric bypass surgery performed to facilitate weight reduction. The 58 women studied lost an average of 39.8 +/- 1.2 kg thereby reducing their mean body mass index from 41.9 +/- 0.7 to 26.8 +/- 0.6. Postoperatively, total cholesterol, LDL cholesterol, and triglyceride levels were significantly lower and HDL cholesterol levels significantly higher than preoperative values (for each of the four comparisons P less than 0.0001). Whereas before surgery 83 percent of the women had levels of total, LDL, or HDL cholesterol indicative of an increased risk of coronary heart disease, after surgery only 24 percent did so. Preoperative cholesterol abnormalities in the seven men were not as severe as were those in the women, and the men's postoperative cholesterol changes were not as marked. Correlations of the difference between pre- and post-operative weight and the difference between pre- and post-operative lipid levels showed that weight loss accounted at most for just 8 percent of the simultaneous lipid change. The data indicate that gastric bypass surgery for morbid obesity produces a favorable change in serum lipid profiles and suggest that the change is due primarily to factors other than the associated weight reduction.     

Subcutaneous adipose tissue expression of plasminogen activator inhibitor-1 gene during very low calorie diet in obese subjects

OBJECTIVE: To determine whether changes in subcutaneous adipose tissue plasminogen activator inhibitor-1 (PAI-1) expression influence plasma PAI-1 level during weight loss in obese humans. DESIGN: Study of the variations of PAI-1 levels both in plasma and in subcutaneous abdominal adipose tissue in 15 volunteer non-diabetic obese subjects, body mass index (BMI) 40.4.+/-1.9 kg/m2, aged 48+/-3 y, before and after a 3 week very low calorie diet (VLCD) programme (3.9+/-0.1 MJ/day). MEASUREMENTS: Plasma and adipose tissue PAI-1 protein levels were measured by enzyme-linked immunosorbent assay and PAI-1 mRNA levels were quantified by quantitative RT-competitive PCR. RESULTS: VLCD induced weight loss (5.8+/-0.8 kg) and decreased plasma PAI-1 concentration (-26% (P<0. 01)). Surprisingly, PAI-1 mRNA and protein abundance in subcutaneous adipose tissue increased by 87% (P<0.05) and by 44% (P<0.01), respectively. CONCLUSION: These data indicate thus that changes in subcutaneous adipose tissue PAI-1 expression are not involved in the decrease of plasma PAI-1 levels during VLCD in obese subjects. International Journal of Obesity (2000)24, 70-74