Margarida Martins

Evaluation of peritoneal transport and membrane status in peritoneal dialysis: focus on incident fast transporters.

Background/Aim: The determinants of baseline fast solute transport are still unclear. We prospectively investigated the relationship of peritoneal solute transport with markers of inflammation, angiogenesis, and membrane status, with a focus on fast transporters. Methods: Seventy-one incident peritoneal dialysis patients were assessed with baseline and annual peritoneal equilibration tests, using a 3.86% glucose dialysis solution. Residual renal function and markers of inflammation, including systemic and intraperitoneal interleukin-6 (IL-6), effluent cancer antigen 125 (CA-125), and vascular endothelial growth factor (VEGF) appearance rates (ARs), were investigated. The time course of the dialysate-to-plasma ratio of creatinine (D/P creatinine ratio) and its relationship with the biomarkers were investigated by a mixed linear model. Results: Incident fast/fast average transporters had a similar age, diabetes prevalence, and serum and effluent IL-6 levels, but significantly higher levels of CA-125 and VEGF ARs than the slow/slow average group; the D/P creatinine ratio was not correlated with systemic IL-6, but was correlated with effluent CA-125 AR (r = 0.45, p < 0.0001) and VEGF AR (r = 0.52, p < 0.0001). The D/P creatinine ratio decreased with a U-shaped profile (p = 0.02). Intraperitoneal IL-6 was the significant and positive determinant of the time course of the D/P creatinine ratio (p < 0.0001). Effluent CA-125 decreased with time on peritoneal dialysis (p = 0.013). Conclusions: Baseline peritoneal fast transport was not associated with systemic inflammation, but was related to peritoneal locally produced substances able to mediate transitory hyperpermeability. The D/P creatinine ratio changed during the follow-up period with a U-shaped profile. This was associated with effluent IL-6 and partly with VEGF. CA-125 decreased throughout the follow-up period.

Determination of plate waste in primary school lunches by weighing and visual estimation methods: A validation study

The aim of this study was to validate the visual estimation method for aggregated plate waste of main dish at Portuguese primary school canteens. For this purpose plate waste at school lunch was measured for 505 individual servings, using weighing individual servings and plate waste and visual estimation method by a 6-point scale, as developed by Comstock et al. (1981). A high variability of initial serving weights was found with serving sizes ranging from 88.9 to 283.3g and with a coefficient of variation ranging from 5.5% to 24.7%. Mean plate waste was 27.5% according to the weighing method. There was a significant bias in the conversion of the visual waste estimations to actual waste, being overestimated by an average of 8.0 g (ranging from -12.9 g to 41.4 g). According to Bland and Altman plot, the mean difference between methods was of 8.0 g and the amplitude interval was 102.6g. The study showed that the visual estimation method is not as accurate as the weighing method in assessing nonselective aggregated plate waste at primary school canteens. Our findings are thus very important on considering plate waste assessment, since the wide variation on initial servings introduces a relevant bias when considering standard portions or a random sample of initial servings. Although, greater convenience, time-saving and the possibility to monitor plate waste of large groups, make the visual estimation method an important method to assess plate waste at school canteens, these results highlighted the need of portions standardization and control of initial servings to allow for its use.

Food waste as an index of foodservice quality

Purpose – The purpose of this paper is to evaluate waste at a Portuguese university setting in order to suggest improvements on foodservice sustainability. Design/methodology/approach – The work was developed during four weeks in order to allow the evaluation of parameters of an entire menu cycle. The index of waste/consumption (%) was obtained by the ratio between plate waste and the quantity of foods distributed, subtracting the weight of leftovers. Findings – The average index of waste/consumption was approximately 24 percent, higher in the days with a fish menu, values considered unacceptable. Each canteen user is served with approximately 940 g of foods, from which only 660 g were effectively consumed, corresponding to 80 g of leftovers and 200 g of waste. Originality/value – It seems possible and desirable to reduce food waste in order to optimize food unit profitability and sustainability. Reducing food waste will contribute to improve foodservice quality as well as consumers satisfaction. Potenti...

Strategies to reduce plate waste in primary schools – experimental evaluation

OBJECTIVE To determine and compare the effect of two interventions in reducing the plate waste of school lunches. DESIGN A between-group analysis was conducted among children from three primary schools: (i) a group receiving intervention A, designed for children and focusing on nutrition education and food waste; (ii) a group receiving intervention B, intended for teachers and focusing on the causes and consequences of food waste; and (iii) a control group with no intervention. For each child, physical weighing of individual meals and leftovers was performed on three non-consecutive weeks at baseline (T0), 1 week (T1, short term) and 3 months (T2, medium term) following the intervention. Plate waste was recorded for a total of 1742 lunches during 14 d over eight different menus. SETTING Portuguese public primary schools in the city of Porto. SUBJECTS All fourth-grade children (n 212) attending the three preselected schools. RESULTS After intervention A focusing on nutrition education designed for children, a decrease in soup waste was observed compared with the control group. The effect was greater at T1 (-11·9 (se 2·8) %; P<0·001) than at T2 (-5·8 (se 4·4) %; P=0·103). The plate waste of identical main dishes decreased strongly at T1 (-33·9 (se 4·8) %; P<0·001). However, this effect was not found at T2 (-13·7 (se 3·2) %; P<0·001). After intervention B involving teachers, plate waste decreased at T2 (-5·5 (se 1·9) % for soup; -5·4 (se 2·4) % for identical main dishes). CONCLUSIONS Nutrition education designed for children was more effective in the short than the medium term. Thus, this kind of intervention was not effective in reducing food waste in the medium term. In contrast, an intervention focusing on teachers revealed better results in the medium term than in the short term.