March 23, 2010
High dietary phosphate intake may promote skin cancer formation
December 3, 2009
Weight control strategies for adolescents identified
August 20, 2009
Fat mass protects hospitalized elderly persons against morbidity and mortality [Nutritional status, dietary intake, and body composition]
Background: It is well established that the combination of protein-energy malnutrition and low body mass index (BMI) increases the risk of death in elderly patients, but recent studies indicate that the risk of death may decrease with higher body weight. However, these studies did not perform direct, separate, and reliable measurements of fat and lean mass by using a reference technique.
Objective: Our objective was to evaluate the relation between body composition, based on the 4-compartment model, and morbidity and mortality in hospitalized elderly patients.
Design: This prospective study enrolled 125 elderly patients evaluated at admission for body composition on the basis of BMI plus fat mass, lean mass, appendicular skeletal muscle mass, and body cell mass indexes (calculated as the ratio of the mass to the square of the height) measured by X-ray absorptiometry and bioelectrical impedance analysis. Outcomes were assessed 6 mo later by using a score system that takes into account complications (pressure ulcers and/or infections) and 6-mo mortality.
Results: The fat mass index correlated positively (r = 0.19 and P = 0.023 adjusted for sex; r = 0.18 and P = 0.043 adjusted for sex, albuminemia, and C-reactive protein) with outcome score (1: death, 2: complications, 3: no complications). There was no significant correlation between outcome score and BMI, lean mass, appendicular skeletal muscle mass, and body cell mass indexes.
Conclusions: This study clearly indicates that the generally accepted rule that overweight is associated with morbidity and mortality does not apply to hospitalized elderly patients, for whom fat mass is associated with a decreased risk of adverse events.
Prospective study of meat intake and dietary nitrates, nitrites, and nitrosamines and risk of adult glioma [Cancer]
Background: The hypothesis that nitrosamine exposure may increase the risk of glioma has been circulating for several decades, but testing it has been difficult because of the ubiquitous nature of nitrosamine exposure. Diet has been the focus of many studies because it can substantially influence nitrosamine exposure, mostly from the endogenous formation of nitrosamines based on intake of nitrite and nitrate.
Objective: The objective was to examine the relation between intakes of meats, nitrate, nitrite, and 2 nitrosamines [nitrosodimethylamine (NDMA) and nitrosopyrolidine (NPYR)] and glioma risk in a prospective analysis.
Methods: Data from 3 US prospective cohort studies were combined for this analysis; 335 glioma cases were diagnosed during ≤24 y of follow-up. Dietary intake was assessed with food-frequency questionnaires. Nitrate, nitrite, and nitrosamine values were calculated based on published values of these nutrients in various foods over different periods in time. Cox proportional hazards models were used to estimate incidence rate ratios (RRs) and 95% CIs. Estimates from each cohort were pooled by using a random-effects model.
Results: Risk of glioma was not elevated among individuals in the highest intake category of total processed meats (RR: 0.92; 95% CI: 0.48, 1.77), nitrate (RR: 1.02; 95% CI: 0.66, 1.58), nitrites (RR: 1.26; 95% CI: 0.89, 1.79), or NDMA (RR: 0.88; 95% CI: 0.57, 1.36) compared with the lowest category. No effect modification was observed by intake of vitamins C or E or other antioxidant measures.
Conclusion: We found no suggestion that intake of meat, nitrate, nitrite, or nitrosamines is related to the risk of glioma.
July 20, 2009
Differential effects of daily snack food intake on the reinforcing value of food in obese and nonobese women [Nutritional status, dietary intake, and body composition]
Background: Food reinforcement, ie, motivation to obtain food, is associated with energy intake and obesity. Finding ways to decrease the reinforcing value of unhealthy foods may help with adherence to diets and maintenance of weight loss. Our previous study in nonobese adults showed that daily consumption of the same snack food (food consumed apart from meals) for 14 d significantly decreased its reinforcing value.
Objectives: The aims of this study were to replicate and extend these findings to obese individuals and to examine the effects of different portion sizes of snack foods on food reinforcement.
Design: Food reinforcement and liking were tested in 31 obese and 27 nonobese women at baseline and after 2 wk of daily consumption of 0, 100, or 300 kcal/d of the same snack food.
Results: We found a significant interaction of phase, portion size, and body mass index on the pattern of operant responding for food. Obese women had a significant increase in food reinforcement after consuming the 300-kcal portion of food for 2 wk, whereas nonobese women had the opposite response. No significant differences were found on the reinforcing value with the 0- and 100-kcal portion-size conditions. Women in the 300-kcal group (obese and nonobese) reported a significant decrease in snack food liking from baseline to after daily intake.
Conclusions: These findings suggest that obese and nonobese women respond differently to the daily intake of a snack food and that this may not be a viable mechanism for reducing food reinforcement in obese women. This trial was registered at www.clinicaltrials.gov as NCT00837694.