Background:The validation of dietary assessment instruments is critical in the evaluation of diet as a chronic disease risk factor. Objective: The objective was to assess the validity of a selfadministered food-frequency questionnaire by comparison with dietary recall, urinary nitrogen excretion, and total energy expenditure data. Design: Over a 1-y period, data from twelve 24-h dietary recalls, a food-frequency questionnaire, and four 24-h urine samples were obtained from 134 study participants of the European Prospective Investigation into Cancer and Nutrition (EPIC) Study in Potsdam, Germany. In a substudy of 28 participants, total energy expenditure from doubly labeled water measurements was assessed. Results: Energy-adjusted, deattenuated correlation coefficients between the questionnaire and the recalls ranged from 0.54 for dietary fiber to 0.86 for alcohol. Cross-classification of quintiles of nutrient intakes from the questionnaire and recalls indicated severe misclassification to be < 4%. Reported protein intake correlated with estimated protein excretion (r = 0.46). Energy intake and total energy expenditure were also significantly correlated (r = 0.48); however, all but one subject underreported their energy intake. The magnitude of underreporting varied considerably, by 22% on average, and increased slightly with increasing energy intake. A similar pattern of underreporting was observed when energy intakes from the 24-h dietary recalls were compared with total energy expenditure. Conclusions: These data indicate an acceptable relative validity of the food-frequency questionnaire in this study population. Compared with measurements of total energy expenditure and protein excretion, however, only moderate agreement with both the food-frequency questionnaire and the 24-h dietary recalls was observed.

During the last decade, the traditional notion that green tea consumption benefits health has received significant scientific attention and, particularly, the areas of cardiovascular disease and cancer were subject to numerous studies. Due to the ever-growing obesity pandemic, the anti-obesity effects of green tea are being increasingly investigated in cell, animal, and human studies. Green tea, green tea catechins, and epigallocatechin gallate (EGCG) have been demonstrated in cell culture and animal models of obesity to reduce adipocyte differentiation and proliferation, lipogenesis, fat mass, body weight, fat absorption, plasma levels of triglycerides, free fatty acids, cholesterol, glucose, insulin and leptin, as well as to increase beta-oxidation and thermogenesis. Adipose tissue, liver, intestine, and skeletal muscle are target organs of green tea, mediating its anti-obesity effects. Studies conducted with human subjects report reduced body weight and body fat, as well as increased fat oxidation and thermogenesis and thereby confirm findings in cell culture systems and animal models of obesity. There is still a need for well-designed and controlled clinical studies to validate the existing and encouraging human studies. Since EGCG is regarded as the most active component of green tea, its specific effects on obesity should also be investigated in human trials.

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Background: Epidemiology associates whole-grain (WG) consumption with several health benefits. Mounting evidence suggests that WG wheat polyphenols play a role in mechanisms underlying health benefits. Objective: The objective was to assess circulating concentration, excretion, and the physiologic role of WG wheat polyphenols in subjects with suboptimal dietary and lifestyle behaviors. Design: A placebo-controlled, parallel-group randomized trial with 80 healthy overweight/obese subjects with low intake of fruit and vegetables and sedentary lifestyle was performed. Participants replaced precise portions of refined wheat (RW) with a fixed amount of selected WG wheat or RW products for 8 wk. At baseline and every 4 wk, blood, urine, feces, and anthropometric and body composition measures were collected. Profiles of phenolic acids in biological samples, plasma markers of metabolic disease and inflammation, and fecal microbiota composition were assessed. Results: WG consumption for 4-8 wk determined a 4-fold increase in serum dihydroferulic acid (DHFA) and a 2-fold increase in fecal ferulic acid (FA) compared with RW consumption (no changes). Similarly, urinary FA at 8 wk doubled the baseline concentration only in WG subjects. Concomitant reduction in plasma tumor necrosis factor-a (TNF-a) after 8 wk and increased interleukin (IL)-10 only after 4 wk with WG compared with RW (P = 0.04) were observed. No significant change in plasma metabolic disease markers over the study period was observed, but a trend toward lower plasma plasminogen activator inhibitor 1 with higher excretion of FA and DHFA in the WG group was found. Fecal FA was associated with baseline low Bifidobacteriales and Bacteroidetes abundances, whereas after WG consumption, it correlated with increased Bacteroidetes and Firmicutes but reduced Clostridium. TNF-a reduction correlated with increased Bacteroides and Lactobacillus. No effect of dietary interventions on anthropometric measurements and body composition was found. Conclusions: WG wheat consumption significantly increased excreted FA and circulating DHFA. Bacterial communities influenced fecal FA and were modified by WG wheat consumption. This trial was registered at clinicaltrials.gov as NCT01293175.Am J Clin Nutr 2015;101:251-61.

Irritable bowel syndrome (IBS) is one of the most common functional gastrointestinal disorders, with an estimated prevalence rate in the general population of 10-15% in industrialised countries. Although IBS is not a life-threatening disease, it contributes significantly to a large segment of healthcare resource consumption. This review provides an overview of studies addressing the direct and indirect costs of IBS in the US and the UK. A systematic literature search was conducted in MEDLINE and the Cochrane library; additionally, all reference lists covering the years from 1960 to May 2004 were scanned. Twenty-four publications for the US and the UK, published between 1991 and 2003, were identified: 6 were excluded, 18 were included. Data for the UK, US and UK + US were reported in 5, 11 and 2 publications, respectively. Total direct cost estimates per patient per year ranged from US 348 dollars to US 8750 dollars (calculated for year 2002). The average number of days off work per year because of IBS was between 8.5 and 21.6; indirect costs ranged from US 355 dollars to US 3344 dollars. The total costs and cost components of IBS are influenced by several factors: features of the investigated patient group (age, limitation to healthcare seekers or all IBS patients, comorbidity, severity of symptoms), database used, method of data collection (retrospective or prospective, varying cost components, time-point of data collection in relation to index-date of IBS diagnosis, method of cost calculation [incidence or prevalence based]) and different healthcare systems in the US and the UK. These factors led to the incomparability of published data, thus no comprehensive picture can be drawn of the total costs related to IBS in the UK and US. Data underline the magnitude of the economic impact of IBS in the UK and US, which is increased by a factor of 1.1-6.0, compared with matched non-IBS control groups. IBS contributes both direct and indirect costs to the total healthcare bill. Further studies should take influencial factors into account and report related data carefully in order to provide useful and comparable published cost data. Additionally, further research on the cost effectiveness of diagnostic procedures and therapies in IBS is required to define strategies to help IBS patients improve their quality of life and reduce related costs.