MCT1 T1470A polymorphism influences adherence to strength training in overweight and obese men following a weight loss program

The monocarboxylate transporter (MCT) family member MCT1 transports lactate into and out of myocytes. Oxidative cells import lactate through MCT1 as a substrate, being the role of MCT1 in glycolysis-derived lactate efflux less clear. MCT1 T1470A polymorphism (rs1049434), which has been related with lactate metabolism and sports specialty 1, 2, could be an influencing factor for exercise adherence. Therefore the aim of this study was to relate the adherence to different training modalities with the T1470A MCT1 polymorphism in overweight and obese men following a weight loss program (WLP).

An Evening with Richard Claxton “Dick” Gregory, Civil Rights Activist, Nutritionist, Comedian, and Author

Gregory, Richard Claxton “Dick” (Born, October 12, 1932, St. Louis, Mo.), African American comedian and civil rights activist whose social satire changed the way white Americans perceived African American comedians since he first performed in public. Gregory’s autobiography, Nigger, was published in 1963 prior to The assassination of President Kennedy, and became the number one best-selling book in America. Over the decades it has sold in excess of seven million copies. His choice for the title was explained in the forward, where Dick Gregory wrote a note to his mother. “Whenever you hear the word ‘Nigger’,” he said, “you’ll know their advertising my book.” In 1984 he founded Health Enterprises, Inc., a company that distributed weight loss products. In 1987 Gregory introduced the Slim-Safe Bahamian Diet, a powdered diet mix, which was immensely profitable. Economic losses caused in part by conflicts with his business partners led to his eviction from his home in 1992. Gregory remained active, however, and in 1996 returned to the stage in his critically acclaimed one-man show, Dick Gregory Live! The reviews of Gregory’s show compared him to the greatest stand-ups in the history of Broadway.

Proteolytic cleavage product of 30-kDa adipocyte complement-related protein increases fatty acid oxidation in muscle and causes weight loss in mice

Adipocyte complement-related protein (30 kDa) (Acrp30), a secreted protein of unknown function, is exclusively expressed in differentiated adipocytes; its mRNA is decreased in obese humans and mice. Here we describe novel pharmacological properties of the protease-generated globular head domain of Acrp30 (gAcrp30). Acute treatment of mice with gAcrp30 significantly decreased the elevated levels of plasma free fatty acids caused either by administration of a high fat test meal or by i.v. injection of Intralipid. This effect of gAcrp30 was caused, at least in part, by an acute increase in fatty acid oxidation by muscle. As a result, daily administration of a very low dose of gAcrp30 to mice consuming a high-fat/sucrose diet caused profound and sustainable weight reduction without affecting food intake. Thus, gAcrp30 is a novel pharmacological compound that controls energy homeostasis and exerts its effect primarily at the peripheral level.

Obesity, knee osteoarthritis, and polypathology: factors favoring weight loss in older people

Aim: We aimed to explore the meaning of obesity in elderly persons with knee osteoarthritis (KO) and to determine the factors that encourage or discourage weight loss. Background: Various studies have demonstrated that body mass index is related to KO and that weight loss improves symptoms and functional capacity. However, dietary habits are difficult to modify and most education programs are ineffective. Design: A phenomenological qualitative study was conducted. Intentional sampling was performed in ten older persons with KO who had lost weight and improved their health-related quality of life after participating in a health education program. A thematic content analysis was conducted following the stages proposed by Miles and Huberman. Findings: Participants understood obesity as a risk factor for health problems and stigma. They believed that the cause of obesity was multifactorial and criticized health professionals for labeling them as “obese” and for assigning a moral value to slimness and diet. The factors identified as contributing to the effectiveness of the program were a tolerant attitude among health professionals, group education that encouraged motivation, quantitative dietary recommendations, and a meaningful learning model based on social learning theories. Conclusion: Dietary self-management without prohibitions helped participants to make changes in the quantity and timing of some food intake and to lose weight without sacrificing some foods that were deeply rooted in their culture and preferences. Dietary education programs should focus on health-related quality of life and include scientific knowledge but should also consider affective factors and the problems perceived as priorities by patients.

Modest weight loss and physical activity in overweight patients with chronic liver disease results in sustained improvements in alanine aminotransferase, fasting insulin, and quality of life

Background and aim: Obesity is a risk factor for progression of fibrosis in chronic liver diseases such as non-alcoholic fatty liver disease and hepatitis C. The aim of this study was to investigate the longer term effect of weight loss on liver biochemistry, serum insulin levels, and quality of life in overweight patients with liver disease and the effect of subsequent weight maintenance or regain. Patients: Thirty one patients completed a 15 month diet and exercise intervention. Results: On completion of the intervention, 21 patients (68%) had achieved and maintained weight loss with a mean reduction of 9.4 (4.0)% body weight. Improvements in serum alanine aminotransferase (ALT) levels were correlated with the amount of weight loss (r=0.35, p=0.04). In patients who maintained weight loss, mean ALT levels at 15 months remained significantly lower than values at enrolment (p=0.004), while in regainers (n=10), mean ALT levels at 15 months were no different to values at enrolment (p=0.79). Improvements in fasting serum insulin levels were also correlated with weight loss (r=0.46, p=0.04), and subsequent weight maintenance sustained this improvement. Quality of life was significantly improved after weight loss. Weight maintainers sustained recommended levels of physical activity and had higher fasting insulin levels (p=0.03) at enrolment than weight regainers. Conclusion: In summary, these findings demonstrate that maintenance of weight loss and exercise in overweight patients with liver disease results in a sustained improvement in liver enzymes, serum insulin levels, and quality of life. Treatment of overweight patients should form an important component of the management of those with chronic liver disease.

Impact of acute weight loss and/or thermal stress on rowing ergometer performance

Purpose: The impact of acute weight loss on rowing performance was assessed when generous nutrient intake was provided in 2 h of recovery after making weight. Methods: Competitive rowers (N = 17) completed four ergometer trials, each separated by 48 h. Two trials were performed after a 4% body mass loss in the previous 24 h (WT) and two were performed after no weight restrictions, that is, unrestricted (UNR). In addition, two trials (I X WT, I X UNR) were in a thermoneutral environment (NEUTRAL, mean 21.1 +/- SD 0.7 degrees C, 29.0 +/- 4.5% RH) and two were in the heat (HOT 32.4, +/- 0.4 degrees C, 60.4 +/- 2.7% RH). Trials were performed in a counterbalanced fashion according to a Latin square design. Aggressive nutritional recovery strategies (WT 2.3 g(.)kg(-11) carbohydrate, 34 mg-kg(-1) Na, 28.4 mL(.)kg(-1) fluid; UNR ad libitum) were employed in the 2 h after weigh-in. Results: Both WT (mean 2.1, 95% CI 0.7-3.4 s; P = 0.003) and HOT (4.1, 2.7 - 5.4 s; P < 0.001) compromised 2000-m time-trial performance. Whereas WT resulted in hypohydration, the associated reduction in plasma volume explained only part of the performance compromise observed (0.2 s for every 1% decrement) Moreover, WT did not influence core temperature or indices of cardiovascular function. Conclusions: Acute weight loss compromised performance, despite generous nutrient intake in recovery, although the effect was small. Performance decrements were further exacerbated when exercise was performed in the heat.

Acute weight loss followed by an aggressive nutritional recovery strategy has little impact on on-water rowing performance

Objectives: To assess the influence of moderate, acute weight loss on on-water rowing performance when aggressive nutritional recovery strategies were used in the two hours between weigh in and racing. Methods: Competitive rowers (n=17) undertook three on-water 1800 m time trials under cool conditions ( mean (SD) temperature 8.4 (2.0)degrees C), each separated by 48 hours. No weight limit was imposed for the first time trial-that is, unrestricted body mass (UNR1). However, one of the remaining two trials followed a 4% loss in body mass in the previous 24 hours (WT-4%). No weight limit was imposed for the other trial (UNR2). Aggressive nutritional recovery strategies (WT-4%, 2.3 g/kg carbohydrate, 34 mg/kg Na+, and 28.4 ml/kg fluid; UNR, ad libitum) were used in the first 90 minutes of the two hours between weigh in and performance trials. Results: WT-4% had only a small and statistically non-significant effect on the on-water time trial performance ( mean 1.0 second, 95% confidence interval (CI) 20.9 to 2.8; p=0.29) compared with UNR. This was despite a significant decrease in plasma volume at the time of weigh in for WT-4% compared with UNR (-9.2%, 95% CI -12.8% to -5.6%; p

Does high intensity resistance training maintain bone mass during moderate weight loss in older overweight adults with type 2 diabetes

The aim was to investigate whether the addition of supervised high intensity progressive resistance training to a moderate weight loss program (RT+WLoss) could maintain bone mineral density (BMD) and lean mass compared to moderate weight loss (WLoss) alone in older overweight adults with type 2 diabetes. We also investigated whether any benefits derived from a supervised RT program could be sustained through an additional home-based program. This was a 12-month trial in which 36 sedentary, overweight adults aged 60 to 80 years with type 2 diabetes were randomized to either a supervised gymnasium-based RT+WLoss or WLoss program for 6 months (phase 1). Thereafter, all participants completed an additional 6-month home-based training without further dietary modification (phase 2). Total body and regional BMD and bone mineral content (BMC), fat mass (FM) and lean mass (LM) were assessed by DXA every 6 months. Diet, muscle strength (1-RM) and serum total testosterone, estradiol, SHBG, insulin and IGF-1 were measured every 3 months. No between group differences were detected for changes in any of the hormonal parameters at any measurement point. In phase 1, after 6 months of gymnasium-based training, weight and FM decreased similarly in both groups (P < 0.01), but LM tended to increase in the RT+WLoss (n=16) relative to the WLoss (n = 13) group [net difference (95% CI), 1.8% (0.2, 3.5), P < 0.05]. Total body BMD and BMC remained unchanged in the RT+WLoss group, but decreased by 0.9 and 1.5%, respectively, in the WLoss group (interaction, P < 0.05). Similar, though non-significant, changes were detected at the femoral neck and lumbar spine (L2-L4). In phase 2, after a further 6 months of home-based training, weight and FM increased significantly in both the RT+WLoss (n = 14) and WLoss (n = 12) group, but there were no significant changes in LM or total body or regional BMD or BMC in either group from 6 to 12 months. These results indicate that in older, overweight adults with type 2 diabetes, dietary modification should be combined with progressive resistance training to optimize the effects on body composition without having a negative effect on bone health.

Weight loss in tumour-bearing mice is not associated with changes in resistin gene expression in white adipose tissue

Resistin, a product of white adipose tissue, is postulated to induce insulin resistance in obesity and regulate adipocyte differentiation. The aim of this study was to examine resistin gene expression in adipose tissue from mice bearing the MAC16 adenocarcinoma, which induces cancer cachexia with marked wasting of adipose tissue and skeletal muscle mass. MAC16-bearing mice lost weight progressively over the period following tumour transplantation, while the weight of control mice remained stable. Leptin mRNA in gonadal fat was 50% lower in MAC16 mice than in controls (p<0.05). Plasma insulin concentrations were also significantly lower in the MAC16 group (p<0.05). However, resistin mRNA level in gonadal fat in MAC16 mice was similar to controls (94% of controls). Thus, despite severe weight loss and significant falls in leptin expression and insulin concentration, resistin gene expression appears unchanged in white adipose tissue of mice with MAC16 tumour. Maintenance of resistin production may help inhibit the formation of new adipocytes in cancer cachexia.

Editorial : which weight loss diet?

Full editorial: A recent study evaluating the long-term (2 yr) weight reducing efficacy of different types of diets – high or low in carbohydrates (CHOs), protein or fat - confirmed that it is calorie deficit not dietary composition that determines the loss and maintenance of body weight.1 Is there any advantage in following a specific weight loss diet? Short-term use of nutritionally complete commercially available (very) low calorie diets has benefited people with diabetes when  supported by education programmes.2 Initial weight loss has been encouraging with some fad diets eg the Atkins and the South Beach diets, but these diets are difficult to maintain and there are safety issues regarding their short- and long-term use – especially in people with diabetes.3 The types of macronutrients consumed can have a considerable impact on glycaemic control and energy metabolism. Although a low CHO diet additionally enhances initial weight loss by reducing cellular water content, if fat is not proportionally reduced the diet may not benefit the lipid profile for vascular disease risk. High fat and high protein diets – which are simultaneously low in CHOs – increase vulnerability to hypoglycaemia in people taking insulin secretagogues or on insulin therapy, and may promote excess fat metabolism and ketogenesis, particularly in people vulnerable to lack of insulin. Very low protein diets are not recommended as lean body mass tends to be reduced in diabetes. Altering the macronutrient balance has implications for the micronutrient mix: deficiencies are higher if more foods are excluded and conversely specific micronutrient excess can occur with some fad diets. The altered nutrient mix affects intestinal fauna and flora, and gut motility and glycaemic control are influenced by the quantity and type of fibre consumed. Support programmes help individuals achieve long term weight loss and there is mounting evidence that community schemes which educate and promote lifestyle changes may stem the rising tide of obesity and consequent type 2 diabetes.4 Consuming smaller portions of a balanced diet (and adjusting antidiabetic medications accordingly) will create an energy deficit to promote healthy weight loss. Increased movement/exercise will enhance this energy deficit. Knowledge (eg 1g fat has 2.25 times more energy than 1g CHO) allows sensible food choices and compensation for inclusion of small volumes of  ‘naughty but nice’ foods. Ultimately weight control requires self control. References 1. Sacks FM, Bray GA, Carey VJ et al. Comparison of weight-loss diets with different compositions of fat, protein, and carbohydrates. N Engl J Med 2009;360:859–73. 2. Bennett P. Obesity, diabetes and VLCD. Br J Diabetes Vasc Dis 2004;4:328–30. 3. Baldwin EJ. Fad diets in diabetes. Br J Diabetes Vasc DIs 2004;4:333–7. 4. Romon M, Lommoz A, Tafflet M et al. Downward trends in the prevalence of childhood overweight in the setting of 12-year school- and community-based programmes. Public Health Nutr 2008; Dec 28, 1–8 [Epub ahead of print].

Increased expression of proteasome subunits in skeletal muscle of cancer patients with weight loss

Atrophy of skeletal muscle is common in patients with cancer and results in increased morbidity and mortality. In order to design effective therapy the mechanism by which this occurs needs to be elucidated. Most studies suggest that the ubiquitin-proteasome proteolytic pathway is most important in intracellular proteolysis, although there have been no reports on the activity of this pathway in patients with different extents of weight loss. In this report the expression of the ubiquitin-proteasome pathway in rectus abdominis muscle has been determined in cancer patients with weight loss of 0-34% using a competitive reverse transcriptase polymerase chain reaction to measure expression of mRNA for proteasome subunits C2 and C5, while protein expression has been determined by western blotting. Overall, both C2 and C5 gene expression was increased by about three-fold in skeletal muscle of cachectic cancer patients (average weight loss 14.5 ± 2.5%), compared with that in patients without weight loss, with or without cancer. The level of gene expression was dependent on the amount of weight loss, increasing maximally for both proteasome subunits in patients with weight loss of 12-19%. Further increases in weight loss reduced expression of mRNA for both proteasome subunits, although it was still elevated in comparison with patients with no weight loss. There was no evidence for an increase in expression at weight losses less than 10%. There was a good correlation between expression of proteasome 20Sα subunits, detected by western blotting, and C2 and C5 mRNA, showing that increased gene expression resulted in increased protein synthesis. Expression of the ubiquitin conjugating enzyme, E214k, with weight loss followed a similar pattern to that of proteasome subunits. These results suggest variations in the expression of key components of the ubiquitin-proteasome pathway with weight loss of cancer patients, and suggest that another mechanism of protein degradation must be operative for patients with weight loss less than 10%. © 2004 Elsevier Ltd. All rights reserved.