Nutrient bioavailability from nasojejunally administered enteral formulas: comparison to solid food

Revising Dietary Phosphorus Advice in Chronic Kidney Disease G3-5D

We summarize how practicing dietitians combined available evidence with clinical experience, to define revised dietary recommendations for phosphorus in chronic kidney disease G3-5D. As well as a review of the evidence base, 4 priority topics were reviewed. These were translated into 3 nutrient level recommendations: the introduction of some plant protein where phosphorus is largely bound by phytate; consideration of protein intake in terms of phosphorus load and the phosphorus to protein ratio; and an increased focus on avoiding phosphate additives. This review summarizes and interprets the available evidence in order to support the development of practical food-based advice for patients with chronic kidney disease.

Methods of body composition analysis the status of the gold standard

The prevention, treatment, and comprehension of disease processes can be advanced with improved methods for assessing changes in body composition. Recently developed methodology has expanded our capacity to quantify body constituents and has stimulated a trend away from the two-compartment model (fat mass and fat-free mass) for describing body composition. As these advances take place, the "gold standard" for measuring living human subjects will likely shift from the frequently relied upon underwater weighing method to techniques that further divide the fat-free mass. New and widely used techniques for quantifying various body compartments are described.

Ethanol: relative fuel value and metabolic effects in vivo

A nasogastric formula infusion method was used to evaluate the steady-state fuel value of ethanol relative to that of glucose in eight chronically alcoholic men undergoing a 4- or 5-week balance experiment. Each subject received a maintenance infusion of the formula diet throughout the study. When control formula glucose (week 1) was isocalorically replaced with ethanol [week 2, 30% of kcal; week 3 or 4 (5-week experiment) 40% to 60% of kcal], the following was observed: weight loss; zero energy balance and reduced or negative balances of N, K, P, Mg, and Na; increased urinary urea N and 3-methylhistidine; lowered urinary C-peptide; no change in indirectly or directly measured thermal energy losses; and a blood level related rise in breath and urinary ethanol losses. All of these changes promptly reversed during the middle (week 3 in 5-week experiment) and final control weeks. Accounting for all diet-related energy losses (urine, breath, thermal), the fuel value of the ethanol-containing diet relative to the glucose control formula varied between 0.95 and 0.99, depending upon the blood alcohol level. Hence weight loss during short-term (seven-day) ethanol infusion is unrelated to overall negative energy balance, stems primarily from decrements in protein, minerals, and fluid, and may in part be mediated by the reduction in insulin secretion that accompanies switching from dietary glucose to ethanol.

The effects of acute clostridium difficile diarrhea on fecal nitrogen content in adult hospitalized patients

Clostridium difficile diarrhea (CDD) is a frequent cause of hospital-associated infectious diarrhea and a common reason for nutritional consultation. Limited data are available on fecal nitrogen losses during infectious diarrhea in adults. Eleven patients with acute CDD were studied for stool volume and fecal nitrogen. The mean stool output was 630 +/- 110 g/day and fecal nitrogen 2.5 +/- 0.3 g per 24 hour period (mean +/- SEM). Fecal nitrogen loss was increased from the predicted 12.0 mg/kg BW/day to 38.0 +/- 5.9 mg/kg BW/day. Fecal nitrogen loss in CDD can be an important source of nitrogen loss and should be measured in nitrogen balance studies in such patients.

A simple method for estimating nitrogen balance in hospitalized patients: a review and supporting data for a previously proposed technique

Total urinary nitrogen (TUN) and urinary urea nitrogen (UUN) in a 24-hour urine collection were measured under a variety of clinical and nutritional conditions in 81 patients for 564 study days. The difference between TUN and UUN averaged 1.8 +/- 0.9 g/day (range 0.0-5.8 g/day) and was independent of the absolute value for UUN. Since UUN was found to correlate linearly with TUN (R = 0.98) over a wide range of values, it is possible to estimate an approximate TUN excretion by adding a constant to the nitrogen excreted as urea. On the basis of the measured mean difference, we suggest using an estimate of 2 g of nitrogen per day. We feel this will not seriously under- or overestimate urinary nitrogen excretion in the calculation of nitrogen balance for the clinical management of nutritional support therapies. Since all hospitals can perform this routine test, it provides an effective, simple, and rapid method to follow accurately the protein catabolic response during disease and response to nutritional therapy. This method, without the supporting data presented here, has previously been recommended [Blackburn et al, 1977, JPEN 1:11-22] and has become a widely used technique for nutritional assessment.