Effect of low-calorie diets on plasma retinol-binding protein concentrations in overweight women.

The concentrations of total protein, albumin and retinol-binding protein, a major transport protein for vitamin A, are significantly decreased by protein-calorie malnutrition. weight-loss diets, sometimes involving severe energy deficits over prolonged periods of time, are common in the United States. The effect, if any, of prolonged low calorie weight-loss diets with normal intakes of protein on albumin, total protein and retinol-binding protein concentrations (and potentially on vitamin A metabolism) had not been extensively studied. We measured total protein, albumin, apo + holo retinol-binding protein and holo-free- and holo-transthyretin-bound retinol-binding protein concentrations during the course of a nutritionally adequate weight-loss diet (50% calorie restriction). We found that this type of dieting did not affect total protein, albumin or apo + holo, holo-free or holo-transthretin-bound retinol-binding protein concentrations significantly. This suggests that protein intake is more critical than caloric intake for retinol-binding protein status.

Current concepts in the management of obesity. An evidence based review.

The increasing prevalence of overweight and obesity is an important public health problem contributing to significant excess in morbidity and mortality. A cross-sectional national epidemiological household survey showed that the prevalence of obesity in female Saudi subjects was among the highest reported. obesity is a complex multifactorial chronic disease that develops from an interaction of genotype and the environment. Our understanding of how and why obesity develops is incomplete, but involves the integration of social behavioral, cultural physiological, metabolic and genetic factors. While there is agreement about health risks of over weight and obesity, there is less agreement about their management. Primary health care services should play the dominant role for obesity management. Family physicians need to assess the patient's readiness to enter weight loss therapy and take appropriate steps for motivation. weight loss and weight maintenance therapy should employ the combination of low caloric diet, increased physical activity, and behavioral therapy. weight loss drugs may be used as part of comprehensive weight loss program. weight loss surgery is an option for carefully selected patients with severe obesity Body Mass Index greater than 40. After successful weight loss, a program consisting of dietary therapy, physical activity, and behavioural therapy, which should be continued indefinitely, enhances the likelihood of weight loss maintenance.

Sibutramine ( Meridia ) treatment in obesity: initial eating behaviour in relation to weight loss results and changes in mood.

The aim of the study was to study the role of initial eating behaviour for subsequent weight loss in treatment with Sibutramine ( Meridia ) (Reductil, Meridia) an anti-obesity drug enhancing satiety, and also to assess changes in mood during the treatment. The participants were 36 obese patients with a mean BMI of 39 kg m(-2). Eating behaviour was assessed with the three factor eating questionnaire (TFEQ), and depressive features with the comprehensive psychopathological rating scale (CPRS). Sibutramine ( Meridia ) (15 mg) was administered daily. The TFEQ restraint scale was negatively related to 6 months weight loss. In particular, strategic dieting behaviour and a more controlled attitude towards self-regulation were negatively related to weight loss. A positive non-placebo controlled change in mood was found already after 2 months treatment. The changes in mood were not related to the weight loss. Patients with more unrestrained eating seem to have reduced their amount of food intake more radically with enhanced satiety, manifested by greater weight loss. Physiologically enhanced satiety could have the greatest weight loss effect for patients whose eating is more governed by hunger drives and appetite rather that by conscious efforts and cognitive control.

The effects of weight loss on renal function in patients with severe obesity.

Severe obesity is associated with increased renal plasma flow (RPF) and glomerular filtration rate (GFR). The aim of the present study was to examine whether weight loss may reverse glomerular dysfunction in obese subjects without overt renal disease. Renal glomerular function was studied in eight subjects with severe obesity (body mass index [BMI] 48.0 +/- 2.4) before and after weight loss. Nine healthy subjects served as controls. GFR and RPF were determined by measuring inulin and PAH clearance. In the obese group, GFR (145 +/- 14 ml/min) and RPF (803 +/- 39 ml/min) exceeded the control value by 61% (90 +/- 5 ml/min, P = 0.001) and 32% (610 +/- 41 ml/min, P < 0.005), respectively. Consequently, filtration fraction was increased. Mean arterial pressure, although normal, was higher than in the control group (101 +/- 4 versus 86 +/- 2 mmHg, P < 0.01). After weight loss, BMI decreased by 32 +/- 4%, to 32.1 +/- 1.5 (P = 0.001). GFR and RPF decreased to 110 +/- 7 ml/min (P = 0.01) and 698 +/- 42 ml/min (P < 0.02), respectively. Albumin excretion rate decreased from 16 microg/min (range, 4 to 152 microg/min) to 5 microg/min (range, 3 to 37 microg/min) (P < 0.01). Fractional clearance of albumin decreased from 3.2 x 10(-6) (range, 1.1 to 23 x 10(-6)) to 1.2 x 10(-6) (range, 0.5 to 6.8 x 10(-6)) (P < 0.02). This study shows that obesity-related glomerular hyperfiltration ameliorates after weight loss. The improvement in hyperfiltration may prevent the development of overt obesity-related glomerulopathy.

Weight-Loss attempts and reporting of foods and nutrients, and biomarkers in a national cohort.

OBJECTIVE: This study examined the reported intake of foods and nutrients, and biomarkers of dietary exposure and cardiovascular disease in relation to history of trying to lose weight. METHODS: Dietary, anthropometric and biochemical data were from the third National Health and Nutrition Examination Survey (1988-1994), n=13 092. The history of attempting weight loss variable was created as follows: trying to lose currently and tried in the past 12 months (Y/Y); trying to lose currently, but not tried in the past 12 months (Y/N), not trying currently, but tried in the past 12 months (N/Y); not trying now and not tried in the past 12 months (N/N). Multiple regression methods were used to examine the independent association of history of trying to lose weight with reported intakes of energy, nutrients, percentage energy from low-nutrient-dense foods (sweeteners, baked and dairy desserts, visible fats and salty snacks), and serum concentrations of vitamins, carotenoids and lipids. RESULTS: Men and women in the Y/Y group reported lower energy intake relative to the N/N group (P<0.0000). However, the reported percentage energy from fat and carbohydrate by the Y/Y group did not differ from the N/N group. Percentage of energy from low-nutrient-dense foods was lower in men in the Y/Y group but not women. The relative odds of reporting the estimated average requirement (EAR) of folate, and vitamins A, B(6), B(12), C, E and iron and adequate intake (AI) of calcium were not adversely affected by history of trying to lose weight in men. In women, the odds of meeting the folate and vitamin E EAR were lower in the Y/Y group. Some history of weight loss categories were significant positive predictors of serum vitamin and carotenoid concentrations, or unrelated to cardiovascular disease risk biomarkers. CONCLUSIONS: There was little evidence for increased nutritional risk in those reporting repeat attempts at weight loss.

Impact of weight loss on inflammatory proteins and their association with the insulin resistance syndrome in morbidly obese patients.

OBJECTIVE: obesity is closely linked to the insulin resistance syndrome (IRS), type 2 diabetes, and cardiovascular disease, the primary cause of morbidity and mortality in these patients. Elevated levels of C-reactive protein (CRP) and interleukin-6 (IL-6), indicating chronic subclinical inflammation, have been associated with features of the IRS and incident cardiovascular disease. METHODS AND RESULTS: We studied the cross-sectional and longitudinal relation of CRP, IL-6, and tumor necrosis factor-alpha (TNF-alpha) with features of the IRS in 37 morbidly obese patients with different stages of glucose tolerance before and 14 months after gastric surgery. weight loss after gastric surgery induced a significant shift from diabetes (37% vs 3%) to impaired glucose tolerance (40% vs 33%) and normal glucose tolerance (23% vs 64%). The baseline concentration of IL-6 was correlated with TNF-alpha (r=0.59, P<0.01) and CRP (r=0.44, P<0.05) levels. TNF-alpha, IL-6, and CRP were significantly correlated with insulin resistance estimated by the homeostatic model assessment (r=0.48, P<0.05; r=0.56, P<0.01; and r=0.35, P<0.05, respectively). Concentrations of CRP and IL-6 decreased after weight loss (median, 8.6 and interquartile range, 2.7/14.5 vs 2.5 and 1.2/4.1 mg/L; P<0.006, and 5.13 and 2.72/12.15 vs 3.95 and 1.97/5.64 pg/mL, P<0.02, respectively), whereas serum levels of TNF-alpha remained unchanged (8.6 and 6.3/18.8 vs 11.7 and 5.8/17.2 pg/mL; NS.). Multiple regression analysis revealed that the decrease in insulin resistance remained independently and significantly correlated with the decrease in IL-6 concentrations (P<0.01) and the decrease in body mass index with the decrease in CRP (P<0.05), respectively. CONCLUSIONS: weight loss in morbidly obese patients induces a significant decrease of CRP and IL-6 concentrations in association with an improvement of the IRS.

Gastric bypass surgery in adolescents with morbid obesity.

OBJECTIVE: The objective was to review retrospectively all patients undergoing bariatric surgery at a large university medical center. METHODS: Ten adolescents 17 years or younger underwent gastric bypass surgery; 7 of 10 adolescents had severe obesity-related morbidities. Follow-up >1 year was present in 9 of 10 adolescents. RESULTS: The average weight before surgery was 148 +/- 37 kg. Postoperative recovery was uneventful in all adolescents; 9 of 10 adolescents had weight loss in excess of 30 kg (mean weight loss was 53.6 +/- 25.6 kg). obesity related morbidities resolved in all adolescents. Five adolescents had mild iron deficiency anemia, and 3 adolescents had transient folate deficiency. Late complications requiring operative treatment occurred in 4 of the adolescents. CONCLUSION: Gastric bypass surgery was an effective method for weight reduction in morbidly obese adolescents. The procedure was well tolerated, with few unanticipated side effects. Gastric bypass remains a last resort option for severely obese adolescents for whom other dietary and behavioral approaches to weight loss have been unsuccessful.

Comparison of high-fat and high-protein diets with a high-carbohydrate diet in insulin-resistant obese women.

AIMS/HYPOTHESIS: A diet low in saturated fatty acids and rich in wholegrains, vegetables and fruit is recommended in order to reduce the risk of obesity, cardiovascular disease and type 2 diabetes mellitus. However there is widespread interest in high-fat ("Atkins Diet") and high-protein ("Zone Diet") alternatives to the conventional high-carbohydrate, high-fibre approach. We report on a randomised trial that compared these two alternative approaches with a conventional diet in overweight insulin-resistant women. METHODS: Ninety-six normoglycaemic, insulin-resistant women (BMI >27 kg/m(2)) were randomised to one of three dietary interventions: a high-carbohydrate, high-fibre (HC) diet, the high-fat (HF) Atkins Diet, or the high-protein (HP) Zone Diet. The experimental approach was designed to mimic what might be achieved in clinical practice: the recommendations involved advice concerning food choices and were not prescriptive in terms of total energy. There were supervised weight loss and weight maintenance phases (8 weeks each), but there was no contact between the research team and the participants during the final 8 weeks of the study. Outcome was assessed in terms of body composition and indicators of cardiovascular and diabetes risk. RESULTS: Body weight, waist circumference, triglycerides and insulin levels decreased with all three diets but, apart from insulin, the reductions were significantly greater in the HF and HP groups than in the HC group. These observations suggest that the popular diets reduced insulin resistance to a greater extent than the standard dietary advice did. When compared with the HC diet, the HF and HP diets were shown to produce significantly (p<0.01) greater reductions in several parameters, including weight loss (HF -2.8 kg, HF -2.7 kg), waist circumference (HF -3.5 cm, HF -2.7 cm) and triglycerides (HF -0.30 mmol/l, HF -0.22 mmol/l). LDL cholesterol decreased in individuals on the HC and HP diets, but tended to fluctuate in those on the HF diet to the extent that overall levels were significantly lower in the HP group than in the HF group (-0.28 mmol/l, 95% CI 0.04-0.52, p=0.02). Of those on the HF diet, 25% showed a >10% increase in LDL cholesterol, whereas this occurred in only 13% of subjects on the HC diet and 3% of those on the HP diet. CONCLUSIONS/INTERPRETATION: In routine practice a reduced-carbohydrate, higher protein diet may be the most appropriate overall approach to reducing the risk of cardiovascular disease and type 2 diabetes. To achieve similar benefits on a HC diet, it may be necessary to increase fibre-rich wholegrains, legumes, vegetables and fruits, and to reduce saturated fatty acids to a greater extent than appears to be achieved by implementing current guidelines. The HF approach appears successful for weight loss in the short term, but lipid levels should be monitored. The potential deleterious effects of the diet in the long term remain a concern.