Resting energy expenditure is lower than predicted in people taking atypical antipsychotic medication

Resting energy expenditure (REE) is lower than predicted in persons taking atypical antipsychotic medication, and weight management is a significant clinical challenge for some of them. However, to date there have been no published guidelines to assist clinicians in choosing appropriate prediction equations to estimate energy expenditure in persons taking atypical antipsychotic medications. The objectives of this study were to measure REE in a group of men taking the atypical antipsychotic clozapine and to determine whether REE can be accurately predicted for this population using previously published regression equations. REE was measured using indirect calorimetry via a ventilated hood on eight men who had completed at least 6 months of treatment with clozapine. Comparisons between measured REE and predicted REE using five different equations were undertaken. The commonly-used Harris-Benedict and Schofield equations systematically overestimated REE. Predictions of REE from other equations were too variable for clinical use. When estimating energy requirements as part of a weight-management program in men who have been taking clozapine for 6 months, predictions of REE from the equations of Harris-Benedict and Schofield should be reduced by 280 kcal/day.

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.

Compiling a caseload index for mental health case management

Objective: The purpose of this study was to explore methods of determining an appropriate caseload for mental health case managers. Method: Seven factors that may impinge on case manager performance and impact on caseload were identified, having reference to published literature and service practice in Victoria and Queensland. The advantages and disadvantages of including these factors in a caseload index were evaluated. Results: Three caseload index methodologies are presented. Each method makes use of different data and has advantages and disadvantages. There is a trade-off between simplicity and ease of application and the comprehensive use of relevant information. Methods vary in their implications for service efficiency and equity in workload distribution. Conclusions: Caseload is a key issue in service planning and staff management. Factors that have the potential to contribute to caseload can be readily identified. However, there is likely to be disagreement as to the weight assigned to any factor and the approach taken may depend on the purpose and context of the caseload calculation. A great deal more research is required to provide an empirical basis for algorithms used in caseload calculation.

Body-mass management of Australian lightweight rowers prior to and during competition

Purpose: Although the body-mass management strategies of athletes in high-participation weight-category sports such as wrestling have been thoroughly investigated, little is known about such practices among lightweight rowers. This study examined the body-mass management practices of lightweight rowers before competition and compared these with current guidelines of the International Federation of Rowing Association (FISA). Quantification of nutrient intake in the 1-2 h between weigh-in and racing was also sought. Methods: Lightweight rowers (N = 100) competing in a national regatta completed a questionnaire that assessed body-mass management practices during the 4 wk before and throughout a regatta plus recovery strategies after weigh-in. Biochemical data were collected immediately after weigh-in to validate questionnaire responses. Responses were categorized according to gender and age category (Senior B or younger than 23 yr old, i.e., U23, Senior A or OPEN, i.e., open age limit) for competition. Results: Most athletes (male U23 76.5%, OPEN 92.3%; female U23 84.0%, OPEN 94.1%) decreased their body mass in the weeks before the regatta at rates compliant with FISA guidelines. Gradual dieting, fluid restriction, and increased training load were the most popular methods of body-mass management. Although the importance of recovery after weigh-in was recognized by athletes, nutrient intake and especially sodium (male U23 5.3 ± 4.9, OPEN 7.7 ± 5.9; female U23 5.7 ± 6.8, OPEN 10.2 ± 5.4 mg-kg(-1)) and fluid intake (male U23 12.1 ± 7.1, OPEN 13.5 ± 8.1; female U23 9.4 ± 7.4, OPEN 14.8 ± 6.9 mL.kg(-1)) were below current sports nutrition recommendations. Conclusion: Few rowers were natural lightweights; the majority reduced their body mass in the weeks before a regatta. Nutritional recovery strategies implemented by lightweight rowers after weigh-in were not consistent with current guidelines.

Impact of two different body mass management strategies on repeat rowing performance

Purpose: The present study was conducted to examine the impact of acute weight loss on repeat 2000-m rowing ergometer performance during a simulated multiday regatta. and to compare two different body mass management strategies between races. Methods: Competitive rowers (N = 16) were assigned to either a control (CON), partial recovery (RECpartial), or complete recovery (RECcomplete) group. Volunteers completed four trials, each separated by 48 h. No weight restrictions were imposed for the first trial. Thereafter, athletes in RECpartial and RECcomplete were required to reduce their body mass by 4% in the 24 h before trial 2, again reaching this body mass before the final two trials. No weight restrictions were imposed on CON. Aggressive nutritional recovery strategies were used in the 2 h following weigh-in for all athletes. These strategies were maintained for the 12-16 h following racing for RECcomplete with the aim of restoring at least three quarters of the original 4% body mass loss. Postrace recovery strategies were less aggressive in RECpartial; volunteers were encouraged to restore no more than half of their initial 4% body mass loss. Results: Acute weight loss increased time to complete the first at-weight performance trial by a small margin (mean 3.0, 95% CI -0.3 to 6.3 s, P = 0.07) when compared with the CON response. This effect decreased when sustained for several day,. Aggressive postrace recovery strategies tended to eliminate the effect of acute Weight loss on subsequent performance. Conclusion: Acute weight loss resulted in a small performance compromise that was reduced or eliminated when repeated over several days. Athletes should be encouraged to maximize recovery in the 12-16 h following racing when attempting to optimize subsequent performance.

Feline obesity: causes, consequences and management

Regulation of food intake and body weight involves a complex balance between long-term control of fat mass involving insulin, adrenal steroids and leptin signals to the CNS and short-term, meal-related signals. Cats will normally limit their food intake to their energy requirements. However, in some instances cats appear unable to regulate energy balance. Our research has demonstrated that despite elevated circulating leptin levels in obese cats associated with increased fat mass, they continue to overeat and gain weight. This paradox of increased leptin concentrations in obesity has been observed in other species and is hypothesized to be a consequence of 'leptin resistance'.

Time weight collaborative filtering

Collaborative filtering is regarded as one of the most promising recommendation algorithms. The item-based approaches for collaborative filtering identify the similarity between two items by comparing users' ratings on them. In these approaches, ratings produced at different times are weighted equally. That is to say, changes in user purchase interest are not taken into consideration. For example, an item that was rated recently by a user should have a bigger impact on the prediction of future user behaviour than an item that was rated a long time ago. In this paper, we present a novel algorithm to compute the time weights for different items in a manner that will assign a decreasing weight to old data. More specifically, the users' purchase habits vary. Even the same user has quite different attitudes towards different items. Our proposed algorithm uses clustering to discriminate between different kinds of items. To each item cluster, we trace each user's purchase interest change and introduce a personalized decay factor according to the user own purchase behaviour. Empirical studies have shown that our new algorithm substantially improves the precision of item-based collaborative filtering without introducing higher order computational complexity.