The effects of dietary modification as denned by NACNE on the eating habits of 28 people

Twenty-eight members of the general public, with little nutritional knowledge and no previous commitment to dietary change, completed 7-day-weighed dietary diaries. They then attempted to change their diets, where appropriate, in line with current nutritional guidelines.
The panel achieved changes in diet that were consistent with the recent recommendations but several problems arose. In particular, although fat levels were reduced, energy levels fell and fibre goals were not reached; in addition, certain of the initial vitamin and mineral intakes gave cause for concern. These results emphasize the importance of giving advice not only about foods that might be reduced in the diet, but also about food that might be used as alternatives. They also illustrate the difficulty of persuading people to make radical changes to their eating habits even when given personal advice from a nutritionist.
The panel was small and not necessarily representative, but the results illustrate the need for more dietary analysis studies. It is not enough simply to formulate appropriate guidelines from a nutritional point of view; it is also important to ensure that the public understands them and that people make sensible decisions about their diet.     

Which constructs can predict emotional exhaustion in a working population? A study into its determinants

The main objective of this study was to examine the psychosocial stress model developed by Taylor and Aspinwall with emotional exhaustion as the outcome variable. Respondents, 409 men and 346 women, who had a paid job for at least 20 hours per week, completed questionnaires concerning demographic variables, personality, temperament, work pressure, workload, perceived social support, appraisal, coping, and emotional exhaustion. Structural equation analyses provided only partial support for the validity of the model. First, on theoretical and statistical grounds, one more path linking external resources to social support was added. Second, contrary to expectations, coping styles did not predict emotional exhaustion. To conclude, when coping is measured retrospectively, it does not add to our understanding of emotional exhaustion. It is suggested that future studies should be longitudinal and include objective measures of stressors and psychosocial health outcomes in addition to self‐reports. Copyright © 2007 John Wiley & Sons, Ltd.     

Working‐correlation‐structure identification in generalized estimating equations

Selecting an appropriate working correlation structure is pertinent to clustered data analysis using generalized estimating equations (GEE) because an inappropriate choice will lead to inefficient parameter estimation. We investigate the well‐known criterion of QIC for selecting a working correlation structure, and have found that performance of the QIC is deteriorated by a term that is theoretically independent of the correlation structures but has to be estimated with an error. This leads us to propose a correlation information criterion (CIC) that substantially improves the QIC performance. Extensive simulation studies indicate that the CIC has remarkable improvement in selecting the correct correlation structures. We also illustrate our findings using a data set from the Madras Longitudinal Schizophrenia Study. Copyright © 2008 John Wiley & Sons, Ltd.     

Analysis of the degree of precision of a computer-assisted dietary survey method

A computer-assisted method for the registration of food intakes in real time according to a concise and simple procedure was subjected to a series of controls in order to assess precision. The method employs the 'portion' of a composite dish as unit of measure. The constancy of the portion was tested. The results show that the recipes of the diet of a subject may be stored and utilized in deferred time without loss of precision: data to be recorded in real time are then very limited. The length of period of analysis was also studied. The time of investigation should not be shorter than two weeks to obtain precise information on the feeding habits of an individual subject, whereas for a group of subjects the diary of a single day provides information of sufficient precision.     

Low doses of the 5-HT1A agonist 8-hydroxy-2-(di-n-propylamino)-tetralin (8-OH DPAT) increase ethanol intake

Previous work has reported that the 5-hydroxytryptamine (5-HT)_1A agonist, 8-hydroxy 2-(di-n-propylamino)tetralin (8-OH DPAT), reduces ethanol intake by rats. However, as 8-OH DPAT reduces 5-HT neurotransmission, these findings are inconsistent with the proposed inhibitory role of central 5-HT neurons on ethanol intake. We examined the effect of 8-OH DPAT on ethanol, water and food intake in rats maintained on a limited access schedule using a lower dose range (6–250 µg/kg) and by assessing concomitant changes in behaviour. Low doses of 8-OH DPAT enhanced ethanol intake even when food and water were offered as alternatives. Suppression in ethanol intake was observed at higher doses where elements of the 5-HT syndrome were apparent. Similar observations were made in both fluid and non-fluid deprived water drinking rats, suggesting the latter effect is non-selective. Therefore 8-OH DPAT may both increase or decrease ethanol consumption in the rat depending on the dose used.     

Effect of Glycemic Carbohydrates on Short-term Satiety and Food Intake

We examine the relationships between glycemic carbohydrate and its effects on short-term satiety and food intake. Both high- and low-glycemic carbohydrates have an impact on satiety, but their effects have different time courses. High-glycemic carbohydrates are associated with a reduction in appetite and food intake in the short term (e.g., one hour), whereas the satiating effects of lower-glycemic carbohydrates appear to be delayed (e.g., 2 to 3 hours). There is no consistent evidence that an increase in blood glucose, either acute or sustained, is the primary determinant of their effects on food intake and satiety. Many other preabsorptive and postabsorptive signals for satiety exist and may be the determining factors. Further studies are needed to delineate the role of glycemic carbohydrates and their mechanisms of action in determining satiety.     

Daily nutrient intake represents a modifiable determinant of nutritional status in chronic haemodialysis patients.

BACKGROUND: In maintenance haemodialysis patients, daily food intake is changeable; however, its relationship with nutritional status is unexplored. This study aimed to evaluate the isolated, long-term effect of daily nutrient intake on nutritional status in haemodialysis patients. METHODS: We performed a prospective 1-year controlled study in 27 chronic haemodialysis patients, without recognized risk factors for malnutrition. Each day for 1 week, four times in the year, we measured protein nitrogen appearance, and assessed dietary protein (DPI) and energy (DEI) intake from dietary diaries. We compared the nutritional outcome of patients spontaneously reducing nutrient intake below the threshold of 0.8 g/kg body weight/day for DPI and 25 kcal/kg body weight/day for DEI during the week (LOW, n = 8), with controls at adequate nutrient intake (CON, n = 19). An interventional 6-month study was then carried out in LOW to verify the cause-effect relationship. RESULTS: All patients showed a day-by-day reduction of whole nutrient intake during interdialytic period, which was mostly relevant in the third interdialytic day (L3). During the 1-year study, even in the presence of adequate dialysis dose and normal inflammatory indexes, body weight (68.0 +/- 5.5 to 65.8 +/- 5.9 kg), serum albumin (3.96 +/- 0.07 to 3.66 +/- 0.06 g/dl) and creatinine (9.2 +/- 1.1 to 8.1 +/- 0.7 mg/dl) significantly decreased in LOW but not in CON. Diaries evidenced in LOW a reduced number of meals at L3 that was explained by the fear of excessive interdialytic weight gain. During the interventional study, daily DPI and DEI increased at L3; this was associated with a significant increment of body weight, and serum albumin and creatinine levels. CONCLUSIONS: In maintenance haemodialysis patients the persistent, marked reduction of daily nutrient intake, even if limited to a single day of the week, is an independent determinant of reversible impairment of nutritional status.     

全营养素混合液(TNA)在肠外营养的应用

脂肪乳剂、葡萄糖、氨基酸、电解质、维生素及微量元素按一定程序混合配成10种全营养素混合液。在4℃14天贮存期内,10种混合液的pH和渗透压变化不大,不同混合液在不同时期的脂粒平均直径变化为0.3135±0.1012μm～0.4813±0.1893μm,94.93％脂粒的直径<0.6μm,无直径>6μm的脂粒,细菌培养阴性。74例共输全营养素混合液1,796次,无不良临床反应和异常实验室检查结果;用1周以上者大都显示氮平衡改善,用2周以上者血清转铁蛋白和白蛋白浓度可有不同程度升高。