Irregular patterns in the daily weight chart at night predict body weight regain

This study examined whether charting daily weight patterns can predict weight regain in obese patients. The subjects were 98 moderately obese Japanese women aged 23 to 66 years who were obliged to precisely record their daily weights during the initial 4-month education period, but not thereafter. The patients were followed up at 8, 12, and 16 months. Abdominal fat areas and blood samples were assessed in the outpatient clinic at 0, 4, and 16 months. The standard deviations (SDs) of the differences in body weight between "after waking up" and "after breakfast" (SDa), "after dinner" (SDb), and "before going to bed" (SDc) were calculated, which were parameters reflecting the fluctuations in the daily weight patterns during the first 4 months. SDc, but not SDa or SDb, was correlated positively with weight regain at 8, 12, and 16 months (P = 0.049, P = 0.002, and P = 0.001, respectively). There were significant differences in temporal change in body weight and abdominal visceral fat between the small SDc group (SDc 75th percentile), but not for subcutaneous abdominal fat or the serum concentrations of glucose, insulin, or lipids. The results indicate that fluctuation of body weight immediately before going to bed is useful for predicting the rebound in body weight.     

Greater weight loss and hormonal changes after 6 months diet with carbohydrates eaten mostly at dinner

This study was designed to investigate the effect of a low-calorie diet with carbohydrates eaten mostly at dinner on anthropometric, hunger/satiety, biochemical, and inflammatory parameters. Hormonal secretions were also evaluated. Seventy-eight police officers (BMI >30) were randomly assigned to experimental (carbohydrates eaten mostly at dinner) or control weight loss diets for 6 months. On day 0, 7, 90, and 180 blood samples and hunger scores were collected every 4 h from 0800 to 2000 hours. Anthropometric measurements were collected throughout the study. Greater weight loss, abdominal circumference, and body fat mass reductions were observed in the experimental diet in comparison to controls. Hunger scores were lower and greater improvements in fasting glucose, average daily insulin concentrations, and homeostasis model assessment for insulin resistance (HOMA(IR)), T-cholesterol, low-density lipoprotein (LDL) cholesterol, high-density lipoprotein (HDL) cholesterol, C-reactive protein (CRP), tumor necrosis factor-α (TNF-α), and interleukin-6 (IL-6) levels were observed in comparison to controls. The experimental diet modified daily leptin and adiponectin concentrations compared to those observed at baseline and to a control diet. A simple dietary manipulation of carbohydrate distribution appears to have additional benefits when compared to a conventional weight loss diet in individuals suffering from obesity. It might also be beneficial for individuals suffering from insulin resistance and the metabolic syndrome. Further research is required to confirm and clarify the mechanisms by which this relatively simple diet approach enhances satiety, leads to better anthropometric outcomes, and achieves improved metabolic response, compared to a more conventional dietary approach.     

Characterization of weight loss and weight regain mechanisms after Roux-en-Y gastric bypass in rats

Roux-en-Y gastric bypass (RYGB) is the most effective therapy for morbid obesity, but it has a approximately 20% failure rate. To test our hypothesis that outcome depends on differential modifications of several energy-related systems, we used our established RYGB model in Sprague-Dawley diet-induced obese (DIO) rats to determine mechanisms contributing to successful (RGYB-S) or failed (RYGB-F) RYGB. DIO rats were randomized to RYGB, sham-operated Obese, and sham-operated obese pair-fed linked to RYGB (PF) groups. Body weight (BW), caloric intake (CI), and fecal output (FO) were recorded daily for 90 days, food efficiency (FE) was calculated, and morphological changes were determined. d-Xylose and fat absorption were studied. Glucose-stimulated vagal efferent nerve firing rates of stomach were recorded. Gut, adipose, and thyroid hormones were measured in plasma. Mitochondrial respiratory complexes in skeletal muscle and expression of energy-related hypothalamic and fat peptides, receptors, and enzymes were quantified. A 25% failure rate occurred. RYGB-S, RYGB-F, and PF rats showed rapid BW decrease vs. Obese rats, followed by sustained BW loss in RYGB-S rats. RYGB-F and PF rats gradually increased BW. BW loss in RYGB-S rats is achieved not only by RYGB-induced decreased CI and increased FO, but also via sympathetic nervous system activation, driven by increased peptide YY, CRF, and orexin signaling, decreasing FE and energy storage, demonstrated by reduced fat mass associated with the upregulation of mitochondrial uncoupling protein-2 in fat. These events override the compensatory response to the drop in leptin levels aimed at conserving energy.     

Enhanced metabolic efficiency contributes to weight regain after weight loss in obesity-prone rats

Metabolic adjustments occur with weight loss that may contribute to a high rate of weight regain. We have previously observed in obesity-prone, obese rats that weight reduction is accompanied by a suppression in resting metabolic rate beyond what would be predicted for the change in metabolic mass. In the present study, we examine if this adjustment in metabolic efficiency is affected by the length of time in weight maintenance and if it contributes to the propensity to regain after weight loss. Twenty-four-hour, nonresting, and resting energy expenditure (REE) were obtained by indirect calorimetry and normalized to metabolic mass estimated by dual-energy X-ray absorptiometry. A 10% loss in body weight in weight-reduced rats was accompanied by a 15% suppression in adjusted REE. This enhancement in metabolic efficiency was not altered with either 8 or 16 wk of weight maintenance, but it did resolve when the forced control of intake was removed and the weight was regained. The rate of weight regain increased with the time in weight maintenance and was exceptionally high early during the relapse period. During this high rate of weight gain, the suppression in REE persists while consumption increases to a level that is higher than when they were obese. In summary, an enhanced metabolic efficiency and an elevated appetite both contribute (60% and 40%, respectively) to a large potential energy imbalance that, when the forcible control of energy intake is relieved, becomes actualized and results in an exceptionally high rate of weight regain.     

SHBG,plasma, and urinary androgens in weight lifters after a strength training

Previous studies with different results have suggested that total and bioavailable testosterone levels are modified by physical exercise. Such changes may be related to modifications in cortisol levels and could be reflected in some urine androgens. To determine how weight lifting training may affect serum and urinary androgens, we measured total serum testosterone (T), cortisol, sex hormone binding globulin (SHBG) and urinary testosterone, epitestosterone, androsterone, and etiocholanolone, in a group of 19 elite weight lifters after 20 weeks of training. SHBG increased (from 27.5 ± 9.5 to 34.7 ± 8.1 nM, p < 0.05) whereas T/SHBG decreased significantly (from 1.10 ± 0.4 to 0.85 ± 0.3, p < 0.05). Serum total testosterone and cortisol did not change significantly. In urine, androsterone and etiocholanolone decreased significantly, whereas testosterone and epitestosterone remained unchanged. Changes in T/SHBG were related positively with changes in urinary androgens (r = 0.680, p < 0.01), and changes in SHBG were negatively related with changes in urinary androgens (r = −0.578, p < 0.01). These results suggest that intense physical activity may have an influence on the elimination of androgenic hormones due mainly to changes in their transporting protein SHBG.     

Responses of adipose tissue lipoprotein lipase to weight loss affect lipid levels and weight regain in women

This study determines whether changes in abdominal (ABD) and gluteal (GLT) adipose tissue lipoprotein lipase (LPL) activity in response to a 6-mo weight loss intervention, comprised of a hypocaloric diet and low-intensity walking, affect changes in body composition, fat distribution, lipid metabolism, and the magnitude of weight regain in 36 obese postmenopausal women. Average adipose tissue LPL activity did not change with an average 5.6-kg weight loss, but changes in LPL activity were inversely related to baseline LPL activity (ABD: r = -0.60, GLT: r = -0.48; P < 0.01). The loss of abdominal body fat and decreases in total and low-density lipoprotein cholesterol were greater in women whose adipose tissue LPL activity decreased with weight loss despite a similar loss of total body weight and fat mass. Moreover, weight regain after a 6-mo follow-up was less in women whose adipose tissue LPL activity decreased than in women whose LPL increased (ABD: 0.9 +/- 0.5 vs. 2.8 +/- 0.6 kg, P < 0.05; GLT: 0.2 +/- 0.5 vs. 2.8 +/- 0.5 kg, P < 0.01). These results suggest that a reduction in adipose tissue LPL activity with weight loss is associated with improvements in lipid metabolic risk factors with weight loss and with diminished weight regain in postmenopausal women.     

Impaired skeletal muscle substrate oxidation in glucose-intolerant men improves after weight loss

Objective: An impaired fatty acid handling in skeletal muscle may be involved in the development of insulin resistance and diabetes mellitus type 2 (DM2). We investigated muscle fatty acid metabolism in glucose‐intolerant men (impaired glucose tolerance (IGT)), a prediabetic state, relative to BMI‐matched control men (normal glucose tolerance (NGT)) during fasting and after a meal, because most people in the western society are in the fed state most of the day. Methods and Procedures: Skeletal muscle free fatty acid (FFA) uptake and oxidation were studied using the stable isotope tracer [2,2‐²H]‐palmitate and muscle indirect calorimetry in the forearm model during fasting and after a mixed meal (33 energy % (E%) carbohydrates, 61 E% fat). Intramyocellular triglycerides (IMTGs) were monitored with ¹H‐magnetic resonance spectroscopy. IGT men were re‐examined after weight loss (?15% of body weight (BW)). Results: The postprandial increase in forearm muscle respiratory quotient (RQ) was blunted in IGT compared to NGT, but improved after weight loss. Weight loss also improved fasting‐fat oxidation and tended to decrease IMTGs (P = 0.08). No differences were found in fasting and postprandial forearm muscle fatty acid uptake between NGT and IGT, or in IGT before and after weight loss. Discussion: The ability to switch from fat oxidation to carbohydrate oxidation after a meal is already impaired in the prediabetic state, suggesting this may be an early factor in the development toward DM2. This impaired ability to regulate fat oxidation during fasting and after a meal (impaired metabolic flexibility) can be (partly) reversed by weight loss.     

Increased energy intake minimizes weight loss in men at high altitude.

The hypothesis that high-altitude weight loss can be prevented by increasing energy intake to meet energy requirement was tested in seven men, 23.7 +/- 4.3 (SD) yr, taken to 4,300 m for 21 days. Energy intake required to maintain body weight at sea level was found to be 3,118 +/- 300 kcal/day, as confirmed by nitrogen balance. Basal metabolic rate (BMR), determined by indirect calorimetry, increased 27% on day 2 at altitude and then decreased and reached a plateau at 17% above the sea level BMR by day 10. Energy expended during strenuous activities was 37% lower at altitude than at sea level. Fecal excretion of energy, nitrogen, total fiber, and total volatile fatty acids was not significantly affected by altitude. Energy intake at altitude was adjusted after 1 wk, on the basis of the increased BMR, to 3,452 +/- 452 kcal/day. Mean nitrogen balance at altitude was negative (-0.25 +/- 0.71 g/day) before energy intake was adjusted but rose significantly thereafter (0.20 +/- 0.71 and 0.44 +/- 0.66 g/day during weeks 2 and 3). Mean body weight decreased 2.1 +/- 1.0 kg over the 3 wk of the study, but the rate of weight loss was significantly diminished after the increase in energy intake (201 +/- 75 vs. 72 +/- 48 g/day). Individual regression lines drawn through 7-day segments of body weight showed that in four of seven subjects the slopes of body weight were not significantly different from zero after the 2nd wk. Thus weight loss ceased in four of seven men in whom increased BMR at altitude was compensated with increased energy intake.(ABSTRACT TRUNCATED AT 250 WORDS)     

Origin,loss, and regain of self-incompatibility in angiosperms

The self-incompatibility (SI) system with the broadest taxonomic distribution in angiosperms is based on multiple S-locus F-box genes (SLFs) tightly linked to an S-RNase termed type-1. Multiple SLFs collaborate to detoxify nonself S-RNases while being unable to detoxify self S-RNases. However, it is unclear how such a system evolved, because in an ancestral system with a single SLF, many nonself S-RNases would not be detoxified, giving low cross-fertilization rates. In addition, how the system has been maintained in the face of whole-genome duplications (WGDs) or lost in other lineages remains unclear. Here we show that SLFs from a broad range of species can detoxify S-RNases from Petunia with a high detoxification probability, suggestive of an ancestral feature enabling cross-fertilization and subsequently modified as additional SLFs evolved. We further show, based on its genomic signatures, that type-1 was likely maintained in many lineages, despite WGD, through deletion of duplicate S-loci. In other lineages, SI was lost either through S-locus deletions or by retaining duplications. Two deletion lineages regained SI through type-2 (Brassicaceae) or type-4 (Primulaceae), and one duplication lineage through type-3 (Papaveraceae) mechanisms. Thus, our results reveal a highly dynamic process behind the origin, maintenance, loss, and regain of SI.

Genetic, functional, phylogenomic, and ancestral state reconstruction studies reveal a highly dynamic process behind the origin, maintenance, loss, and regain of self-incompatibility in angiosperms.     

Effects of a supraphysiological dose of testosterone on physical function, muscle performance, mood, and fatigue in men with HIV-associated weight loss

Testosterone increases fat-free mass (FFM) in men infected with human immunodeficiency virus (HIV), but its effects on muscle performance, physical function, mood, and quality of life are poorly understood. Sixty-one HIV-infected men with weight loss were randomized to receive weekly intramuscular injections of 300 mg of testosterone enanthate or placebo for 16 wk. The primary outcome of interest was physical function (walking speed, stair-climbing power, and load-carrying ability). Secondary outcome measures included body weight and composition, muscle performance, sexual function, mood, and quality of life. Serum nadir free and total testosterone levels increased (+188.0 +/- 29.6 and +720 +/- 86 ng/dl) in the testosterone, but not placebo, group. Testosterone administration was associated with increased FFM (2.8 +/- 0.5 kg), which was significantly greater than in the placebo group (P < 0.0001). Leg press strength increased significantly in testosterone-treated (P = 0.027), but not placebo-treated, men; the difference between groups was not significant. Other measures of muscle performance and physical function did not change significantly in either group. Men receiving testosterone demonstrated significantly greater improvements in mental health and quality-of-life scores than those receiving placebo and improvements in fatigue/energy and mood scores that were not significantly different from those receiving placebo. Sexual function scores did not change in either group. In HIV-infected men with weight loss, a supraphysiological dose of testosterone significantly increased FFM but did not improve self-reported or performance-based measures of physical function. Improvements in mood, fatigue, and quality-of-life measures in the testosterone group, although clinically important, need further confirmation.     

Retinol-binding protein 4, visceral fat, and the metabolic syndrome: effects of weight loss

Retinol-binding protein 4 (RBP-4) has been reported to be associated with visceral-fat accumulation and parameters of the metabolic syndrome (MetS). In this study, we investigated the relationship between RBP-4, visceral fat, and the MetS during pronounced weight loss after bariatric surgery. Thirty-six subjects were examined before and 2 years after surgery. Abdominal-fat distribution was determined by ultrasound, metabolic parameters, and serum RBP-4 levels by standard methods. After surgery BMI decreased by 9.07 kg/m(2), visceral-fat diameter (VFD) decreased by 60.6%, and RBP-4 serum levels by 16.6%. Change of RBP-4 levels was associated with reductions of waist (r = 0.364, P = 0.037), waist-to-hip ratio (WHR) (r = 0.415, P = 0.016), and VFD (r = 0.425, P = 0.010). MetS, as defined by International Diabetes Federation (IDF), was present in 19 patients at baseline and in nine patients at follow-up. Change in RBP-4 levels was the best predictor for the diagnosis of MetS at follow-up. In the subgroup without MetS at baseline, the decrease in RBP-4 levels (-28.1% vs. -6.3%, P = 0.020) and reduction in VFD (-66.9% vs. -55.0%, P = 0.038) were significantly greater compared to the subgroup with MetS. We demonstrate a marked decrease of RBP-4 levels after bariatric surgery, which correlates with reduction in visceral-fat mass. Furthermore, the extent of changes in RBP-4 levels differs according to the severity of the MetS.