Effect Of Diet Composition Research Articles

Effect of diet composition and lysine supply on growth and body composition in juvenile turbot (Psetta maxima)

A 10-week feeding trial was conducted to study the effect of feeding level and dietary lysine concentration on growth, protein and lysine retention, and body composition in juvenile turbot. Maintenance requirement for lysine and the efficiency of lysine utilisation were determined as well. Two experimental diets were formulated based on fishmeal or wheat gluten as main protein sources, containing 6.4 g (Diet A, control) and 4.5 g lysine per 100 g CP (Diet B), respectively. Diets were fed once daily at six feeding levels (per day 0.3%, 0.6%, 0.9%, 1.2%, and 1.5% of body weight [BW] and ad libitum) to a total of 432 fish of 48 g initial BW. No differences in the growth parameters were observed between diets at the same feeding level, except a lower feed to gain ratio (p < 0.05) at the highest feeding level at Diet B. Whole-body composition was not affected by diet, whereas muscle protein concentration was significantly lower for fish fed Diet B. Amino acid concentration in whole-body protein was affected by dietary treatment and fish fed Diet B showed lower concentrations of all essential amino acids. In fish muscle protein, lysine, methionine, leucine, isoleucine, and valine concentrations were significantly lower in Diet B. Efficiency of lysine utilisation for growth (klys) was determined by linear regression analysis and amounted for 0.69 for Diet B. The maintenance lysine requirement defined at zero lysine retention was 6.5 mg · kg−0.8 · d−1. Lysine intakes at zero protein retention were 13.0 mg and 12.9 mg · kg−0.8 · d−1 for Diet A and B, respectively. Growth and nutrient retention were similar for both diets and, therefore, a lysine deficiency in Diet B did not occur. In conclusion, a proportion of 330 g wheat gluten per kg feed did not influence growth performance and maintenance requirement for lysine in juvenile turbot. However, the effect of diet composition on the amino acid profile of body protein might be relevant for the derivation of the amino acid requirement from protein retention.

Effects of dietary composition on life span of Drosophila buzzatii and its short-lived sibling species D. koepferae

Two sibling Drosophila species dramatically divergent in longevity, Drosophila buzzatii and D. koepferae, were examined for possible effects of both developmental culture medium and dietary composition (DC) on longevity. Longevity was greatly increased in the longer lived D. buzzatii when flies were reared and fed on a rich-in-nutrient and cactus-based culture (R-CBC) as compared to longevity in a poor nutrient culture (PNC). In D. buzzatii, life span was further increased by exposing flies to short periods of a poor-in-nutrient and cactus-based culture (P-CBC). In contrast, variation in the here used nutrient composition did not change life span in the shorter lived D. koepferae, as longevity in this species did not differ among R-CBC, P-CBC and PNC cultures. Hormesis is a plausible explanation for the beneficial biological effects against aging arising from brief exposure to a lowed calorie food source in D. buzzatii. This study shows that genetic variation between closely related species is substantial for dietary effects on longevity.

Sex-Age Related Rumination Behavior of Père David’s Deer under Constraints of Feeding Habitat and Rainfall

Extensive studies have been conducted on the rumination behavior of domestic herbivores. However, studies on wild animals are limited, particularly wild animals with specific ruminating parameters. In this study, Père David’s deer, a previously extirpated species, was observed to analyze the effects of sex-age, feeding habitat, and rainfall on rumination behavior in the Dafeng Nature Reserve, China. Rumination behavior was investigated based on four parameters: proportion of bedding time spent chewing, bolus processing time (s/bolus), chewing frequency (chews/bolus), and chewing rate (chews/s). Results showed that all three factors affect rumination behavior. The extent of their effects varied based on the four rumination parameters. Chewing rate and frequency decreased based on sex–age levels, i.e., from fawns to juvenile female, juvenile male, adult female, stag, and harem holder. Therefore, body size played a major role in shaping rumination behavior. Deer found in grasslands could chew faster compared with deer found in woodlands. This result might be caused by the effects of dietary composition and sunlight intensity. A deer spends a longer time ruminating while bedding during rainy days compared with rainless days to maximize energy and nutrition intake and compensate for the loss of feeding time during rainy days. Therefore, rumination behavior is plastic and is shaped by intrinsic and extrinsic factors.

A population‐based prospective study of energy‐providing nutrients in relation to all‐cause cancer mortality and cancers of digestive organs mortality

The effect of dietary composition on mortality in low-income countries is largely unknown. We evaluated whether percentages of dietary energy derived from protein, fat and carbohydrates were associated with all-cause and cancer mortalities in a Bangladeshi population. Data from a prospective population-based cohort study of 17,244 men and women were used. Percentages of dietary energy derived from protein, fat and carbohydrates, assessed using a validated food-frequency questionnaire at baseline, were analyzed in relation to mortality over an average of 9 years (155,126 person-years) of follow-up. Cox proportional hazards regression models were used to estimate hazard ratios for all cause, all cancer and cancers of the digestive organs mortalities. Percentage of dietary energy from protein appeared to be significantly associated with cancer mortality. Fully adjusted hazard ratios for cancer mortality in increasing tertiles of percentage of dietary energy from protein were 1.0 (reference), 1.21 (0.73, 2.00) and 1.84 (1.08, 3.15) (p for trend = 0.023). These associations were much stronger for deaths from cancers of the digestive organs with fully adjusted hazard ratios in increasing tertiles of percentage of dietary energy from protein being 1.0 (reference), 2.25 (0.91, 5.59) and 4.85 (1.88, 12.51) (p for trend = 0.001). No significant associations in relation to cancer-related mortality were observed for percentage of dietary energy from fat. Novel findings from this prospective study show protein is an important risk factor or proxy to an important risk factor for cancer mortality especially from digestive organ cancers in Bangladesh.

Effects of Diet Composition on Postprandial Energy Availability during Weight Loss Maintenance

BackgroundThe major circulating metabolic fuels regulate hunger, and each is affected by dietary composition. An integrated measure of postprandial energy availability from circulating metabolic fuels may help inform dietary recommendations for weight maintenance after weight loss.AimWe examined the effect of low-fat (LF, 60% of energy from carbohydrate, 20% fat, 20% protein), low-glycemic index (LGI, 40%–40%-20%), and very low-carbohydrate (VLC, 10%–60%-30%) diets on total postprandial metabolic fuel energy availability (EA) during weight loss maintenance.MethodsEight obese young adults were fed a standard hypocaloric diet to produce 10–15% weight loss. They were then provided isocaloric LF, LGI, and VLC diets in a randomized crossover design, each for a 4-week period of weight loss maintenance. At the end of each dietary period, a test meal representing the respective diet was provided, and blood samples were obtained every 30 minutes for 5 hours. The primary outcome was EA, defined as the combined energy density (circulating level×relative energy content) of glucose, free fatty acids, and β-hydroxybutyrate. Secondary outcomes were individual metabolic fuels, metabolic rate, insulin, glucagon, cortisol, epinephrine, and hunger ratings. Respiratory quotient was a process measure. Data were analyzed by repeated-measures analysis of variance, with outcomes compared in the early (30 to 150 min) and late (180 to 300 min) postprandial periods.ResultsEA did not differ between the test meals during the early postprandial period (p = 0.99). However, EA in the late postprandial period was significantly lower after the LF test meal than the LGI (p<0.0001) and VLC (p<0.0001) test meals. Metabolic rate also differed in the late postprandial period (p = 0.0074), with higher values on the VLC than LF (p = 0.0064) and LGI (p = 0.0066) diets.ConclusionThese findings suggest that an LF diet may adversely affect postprandial EA and risk for weight regain during weight loss maintenance.Trial RegistrationClinicalTrials.gov NCT00315354

Nutrition &amp; Metabolism: an impressive performance since inception

Nutrition &amp; Metabolism: an impressive performance since inception

The effects of diet composition and vitamin B supplementation on the urine isoprostane concentration in rats

The purpose of this research was to assess the amount of isoprostane 8-iPF2α-III, a marker of oxidation stress, in excreted urine. The study was conducted on 40 male rats aged 5 months. Group 1 received the basic diet, groups 2-4, the modified diet in which whole cereal grains were partly substituted with wheat flour and sucrose. Groups 1-2 received water to drink, groups 3 and 4 were given aqueous solutions of B group vitamins at different doses. On the fifth week of the experiment, a 24-h urine collection was conducted. The concentrations of creatinine and 8-iPGF2a-III were determined in urine samples. Modification of diet composition caused increased excretion of isoprostane, which may indicate enhancement of free-radical reactions in the examined animal. The provided supplementation decreased the value of this parameter expressed as a creatinine ratio, but not, however, to the values observed in the animals fed the basic diet. A stronger effect was observed with excess supplementation.

Effect of Diet Composition and Weight Loss on Resting Energy Expenditure in the POUNDS LOST Study

Weight loss reduces energy expenditure, but it is unclear whether dietary macronutrient composition affects this reduction. We hypothesized that energy expenditure might be modulated by macronutrient composition of the diet. The POUNDS LOST study, a prospective, randomized controlled trial in 811 overweight/obese people who were randomized in a 2×2 design to diets containing 20en% or 40en% fat and 15en% or 25en% (diets with 65%, 55%, 45% and 35% carbohydrate) provided the data to test this hypothesis. Resting energy expenditure (REE) was measured at baseline, 6 and 24 months using a ventilated hood. REE declined at 6 months by 99.5±8.0 kcal/d in men and 55.2±10.6 kcal/d in women during the first 6 months. This decline was related to the weight loss, and there was no difference between the diets. REE had returned to baseline by 24 months, but body weight was still 60% below baseline. Measured REE at 6 months was significantly lower than the predicted (−18.2±6.7 kcal/d) and was the result of significant reductions from baseline in the low fat diets (65% or 55% carbohydrate), but not in the high fat diet groups. By 24 months the difference had reversed with measured REE being slightly but significantly higher than predicted (21.8±10.1 kcal/d). In conclusion, we found that REE fell significantly after weight loss but was not related to diet composition. Adaptive thermogenesis was evident at 6 months, but not at 24 months.

Effects of Dietary Composition on Energy Expenditure During Weight-Loss Maintenance

Reduced energy expenditure following weight loss is thought to contribute to weight gain. However, the effect of dietary composition on energy expenditure during weight-loss maintenance has not been studied. To examine the effects of 3 diets differing widely in macronutrient composition and glycemic load on energy expenditure following weight loss. A controlled 3-way crossover design involving 21 overweight and obese young adults conducted at Children's Hospital Boston and Brigham and Women's Hospital, Boston, Massachusetts, between June 16, 2006, and June 21, 2010, with recruitment by newspaper advertisements and postings. After achieving 10% to 15% weight loss while consuming a run-in diet, participants consumed an isocaloric low-fat diet (60% of energy from carbohydrate, 20% from fat, 20% from protein; high glycemic load), low-glycemic index diet (40% from carbohydrate, 40% from fat, and 20% from protein; moderate glycemic load), and very low-carbohydrate diet (10% from carbohydrate, 60% from fat, and 30% from protein; low glycemic load) in random order, each for 4 weeks. Primary outcome was resting energy expenditure (REE), with secondary outcomes of total energy expenditure (TEE), hormone levels, and metabolic syndrome components. Compared with the pre-weight-loss baseline, the decrease in REE was greatest with the low-fat diet (mean [95% CI], -205 [-265 to -144] kcal/d), intermediate with the low-glycemic index diet (-166 [-227 to -106] kcal/d), and least with the very low-carbohydrate diet (-138 [-198 to -77] kcal/d; overall P = .03; P for trend by glycemic load = .009). The decrease in TEE showed a similar pattern (mean [95% CI], -423 [-606 to -239] kcal/d; -297 [-479 to -115] kcal/d; and -97 [-281 to 86] kcal/d, respectively; overall P = .003; P for trend by glycemic load < .001). Hormone levels and metabolic syndrome components also varied during weight maintenance by diet (leptin, P < .001; 24-hour urinary cortisol, P = .005; indexes of peripheral [P = .02] and hepatic [P = .03] insulin sensitivity; high-density lipoprotein [HDL] cholesterol, P < .001; non-HDL cholesterol, P < .001; triglycerides, P < .001; plasminogen activator inhibitor 1, P for trend = .04; and C-reactive protein, P for trend = .05), but no consistent favorable pattern emerged. Among overweight and obese young adults compared with pre-weight-loss energy expenditure, isocaloric feeding following 10% to 15% weight loss resulted in decreases in REE and TEE that were greatest with the low-fat diet, intermediate with the low-glycemic index diet, and least with the very low-carbohydrate diet. clinicaltrials.gov Identifier: NCT00315354.

Effect of diet composition on coenzyme A and its thioester pools in various rat tissues

Three coenzyme A (CoA) molecular species, i.e., acetyl-CoA, malonyl-CoA, and nonesterified CoA (CoASH), in 13 types of fasted rat tissue were analyzed. A relatively larger pool size of total CoA, consisting of acetyl-CoA, malonyl-CoA, and CoASH, was observed in the medulla oblongata, liver, heart, and brown adipose tissue. Focusing on changes in the CoA pool size in response to the nutrient composition of the diet given, total CoA pools in rats continuously fed a high-fat diet for 4weeks were significantly higher in the hypothalamus, cerebellum, and kidney, and significantly lower in the liver and skeletal muscle than those of rats fed a high-carbohydrate or high-protein diet. In particular, reductions in the liver were remarkable and were caused by decreased CoASH levels. Consequently, the total CoA pool size was reduced by approximately one-fifth of the hepatic contents of rats fed the other diets. In the hypothalamus, which monitors energy balance, all three CoA molecular species measured were at higher levels when rats were fed the high-fat diet. Thus, it was of interest that feeding rats a high-fat diet affected the behaviors of CoA pools in the hypothalamus, liver, and skeletal muscle, suggesting a significant relationship between CoA pools, especially malonyl-CoA and/or CoASH pools, and lipid metabolism in vivo.

The association of macro- and micronutrient intake with growth hormone secretion

ContextGrowth hormone (GH) is known to be nutritionally regulated, but the effect of dietary composition on detailed GH secretion parameters has not previously been comprehensively evaluated. ObjectiveThe objective of the study was to determine whether specific macro- and micronutrients are associated with discrete parameters of GH secretion among subjects with wide ranges of body mass index. DesignDetailed macro- and micronutrient intake was assessed by 4-day food records while GH secretion was assessed by standard stimulation testing in 108 men and women in one study (Study 1), and by overnight frequent blood sampling in 12 men in another study (Study 2). ResultsPeak stimulated GH was positively associated with vitamin C (r=+0.29; P=0.003), dietary fiber (r=+0.27; P=0.004), arachidic acid (r=+0.25; P=0.008), and behenic acid (r=+0.30; P=0.002) intake in univariate analysis. Controlling for age, gender, race/ethnicity, visceral fat, HOMA-IR, total caloric intake and these four dietary factors in step-wise multivariate modeling, peak GH remained significantly associated with vitamin C and visceral fat (both P<0.05). In addition, vitamin C intake was associated with various parameters of endogenous GH secretion including basal GH secretion (r=+0.95; P<0.0001), GH half-life (r=+.75; P=0.005), total GH production (r=+0.76; P=0.004), GH area-under-the-curve (r=+0.89; P=0.0001), mean log10 GH pulse area (r=+0.67; P=0.02), and overnight maximum (r=+0.62; P=0.03), nadir (r=+0.97; P<0.0001), and mean GH secretion (r=+0.89; P=0.0001). ConclusionsThese results suggest that certain micronutrients such as vitamin C intake are strongly and uniquely associated with stimulated and endogenous spontaneous GH secretion.

Response to Comment on: Lassenius et al. Bacterial Endotoxin Activity in Human Serum Is Associated With Dyslipidemia, Insulin Resistance, Obesity, and Chronic Inflammation. Diabetes Care 2011;34:1809–1815

We thank Koduru et al. (1) for highlighting their findings regarding the effects of diet composition on endotoxemia and inflammation. Based on their results, it is evident that dietary factors may modulate the state of endotoxemia in humans. We, however, believe that the issue is much more complex. Pathogen-associated microbial compounds may arise from various sources: diet, bacterial infections, and commensal microbiota. Different dietary food products contain various amounts of microbial compounds, the biological activity of which might be modulated by nutrient composition and …

Influence of diet and commingling on performance parameters in replacement broiler breeders following live oocyst coccidiosis vaccination

SUMMARY Two consecutive experiments were conducted to evaluate the effect of dietary composition, with respect to protein concentration and amino acid profile in the starter diet, on performance parameters after coccidiosis vaccination in 2 genetic lines of replacement broiler breeders (Line A and Line B) through 6 wk of age. Dietary formulation was based on either primary breeder-specific recommendations or formulations of a broiler integrator participating in the study. All replacement breeders were weighed weekly to determine average BW and pen uniformity. On d 28, males of each genetic line were added to female pens to evaluate the effect of commingling on male performance. During experiment 1, differences in BW were not observed in males or females of Line A; however, flock uniformity was improved (P ≤ 0.05) in Line A males fed the integrator diet. Increased BW and improved uniformity of Line B females was observed with the breeder-recommended diet. Commingling negatively affected (P ≤ 0.05) male BW in both genetic lines. In experiment 2, diet affected average BW in Line A males, Line B males, and Line B females; however, no effect on final flock uniformity was observed. Line A males fed the breeder-recommended diet had increased (P ≤ 0.05) BW at termination of the experiment. Line B males and females fed the breeder-recommended diet had increased (P ≤ 0.05) BW throughout the experiment. Similar to experiment 1, negative effects (P ≤ 0.05) on male BW resulting from commingling were observed. These data indicate that commingling negatively affects male BW and that flock performance can be influenced by dietary composition depending on genetic line and sex in replacement broiler breeders vaccinated with a live oocyst coccidiosis vaccine.

Effect of diet composition on energy expenditure during weight loss: the POUNDS LOST Study.

BackgroundWeight loss reduces energy expenditure, but the contribution of different macronutrients to this change is unclear.HypothesisWe tested the hypothesis that macronutrient composition of the diet might affect the partitioning of energy expenditure during weight loss.DesignA sub-study of 99 participants from the POUNDS LOST trial had total energy expenditure (TEE) measured by doubly labeled water and resting energy expenditure (REE) measured by indirect calorimetry at baseline and repeated at 6 months in 89 participants. Participants were randomly assigned to one of 4 diets with either 15% or 25% protein and 20% or 40% fat.ResultsTEE and REE were positively correlated with each other and with fat free mass and body fat, at baseline and 6 months. The average weight loss of 8.1±0.65 kg (LSmean±SE) reduced TEE by 120±56 kcal/d and REE by 136±18 kcal/d. A greater weight loss at 6 months was associated with a greater decrease in TEE and REE. Participants eating the high fat diet lost significantly more fat free mass (1.52±0.55 kg) than the low fat diet group (p<0.05). Participants eating the low fat diet had significantly higher measures of physical activity than the high fat group.ConclusionA greater weight loss was associated with a larger decrease in both TEE and REE. The low fat diet was associated with significant changes in fat free body mass and energy expenditure from physical activity compared to the high fat diet.

Effect of Diet Composition on the Determination of Ash and Moisture Content in Solid Cattle Manure Using Visible and Near-Infrared Spectroscopy

Visible and near-infrared (Vis-NIR, 350-2500 nm) diffuse reflection spectroscopy (DRS) models built from "as-collected" samples of solid cattle manure accurately predict concentrations of moisture and crude ash. Because different organic molecules emit different spectral signatures, variations in livestock diet composition may affect the predictive accuracy of these models. This study investigates how differences in livestock diet composition affect Vis-NIR DRS prediction of moisture and crude ash. Spectral signatures of solid manure samples (n = 216) from eighteen groups of cattle on six different diets were used to calibrate and validate partial least squares (PLS) regression models. Seven groups of PLS models were created and validated. In the first group, two-thirds of all samples were randomly selected as the calibration set and the remaining one-third were used for the validation set. In the remaining six groups, samples were grouped by livestock diet (ration). Each ration in turn was held out of calibrations and then used as a validation set. When predicting crude ash, the fully random calibration model produced a root mean square deviation (RMSD) of 2.5% on a dry basis (db), ratio of standard error of prediction to the root mean squared deviation (RPD) of 3.1, bias of 0.14% (db), and correlation coefficient r(2) of 0.90., When predicting moisture, an RMSD of 1.5% on a wet basis (wb), RPD of 4.3, bias of -0.09% (wb), and r(2) of 0.95 was achieved. Model accuracy and precision were not impaired by exclusion of any single ration from model calibration.

Effect of Dietary Composition with Different Feeding Regime on Compensatory Growth of Juvenile Olive Flounder Paralichthys olivaceus

Compensatory growth of juvenile olive flounder Paralichthys olivaceus fed different diets with different feeding regime was compared. Four hundred fifty fish (twenty five fish per tank) were randomly distributed into 18 of 180 L flow-through tanks. Six treatments were prepared: fish were hand-fed with the control (C) diet to satiation twice a day, six days a week, for 8 weeks (C-8W treatment); and other groups of fish were starved for 2 weeks and then fed with the C, high protein (HP), high carbohydrate (HC), high lipid (HL), and combined protein, carbohydrate and lipid (CPCL) diets to satiation twice a day, six days a week, for 6 weeks, referred to as C-6W, HP-6W, HC-6W, HL-6W, and CPCL-6W treatments, respectively. Final body weight of fish in HP-6W treatment was higher than that of fish in C-6W, but not different from that of fish in C-8W, HC-6W, HL-6W and CPCL-6W treatments. Specific growth rate of fish in HP-6W treatment was higher than that of fish in all other treatments except for fish in CPCL-6W treatment. Feeding rate of fish in C-8W treatment was higher than that of fish in HP-6W, HC-6W, HL-6W and CPCL-6W treatments, but not different from that of fish in C-6W treatment. In addition, feeding rate of fish in C-6W treatment was higher than that of fish in HP-6W, HL-6W and CPCL-6W treatments. Feed and protein efficiency ratios of fish in HP-6W, HC-6W, HL-6W and CPCL-6W treatments were higher than those of fish in C-6W treatment. None of moisture, crude protein and ash content of the whole body of fish excluding the liver was different among treatments. Dietary supplementation of protein, carbohydrate, lipid and their combination could improve compensatory growth of fish when fish were fed for 6 weeks after 2-week feed deprivation; especially, supplementation of dietary protein was the most effective to improve compensatory growth of fish.

Temperature and diet affect carbon and nitrogen isotopes of fish muscle: can amino acid nitrogen isotopes explain effects?

Stable isotope ratios of carbon ( δ 13C) and nitrogen ( δ 15N) are widely used in food-web studies to determine trophic positioning and diet sources. However in order to accurately interpret stable isotope data the effects of environmental variability and dietary composition on isotopic discrimination factors and tissue turnover rates must be validated. We tested the effects of temperature and diet on tissue turnover rates and discrimination of carbon and nitrogen isotopes in an omnivorous fish, black bream ( Acanthopagrus butcheri). Fish were raised at 16 °C or 23 °C and fed either a fish-meal or vegetable feed to determine turnover rates in fish muscle tissue up to 42 days after exposure to experimental treatments. Temperature and diet affected bulk tissue δ 15N turnover and discrimination factors, with increased turnover and smaller discrimination factors at warmer temperatures. Fish reared on the vegetable feed showed greater bulk tissue δ 15N changes and larger discrimination factors than those reared on a fish-meal feed. Temperature and diet affected bulk tissue δ 13C values, however the direction of effects among treatments changed. Analyses of δ 15N values of individual amino acids found few significant changes over time or treatment effects, as there was large variation at the individual fish level. However glutamic acid, aspartic acid and leucine changed most over the experiment and results mirrored those of treatment effects in bulk δ 15N tissue values. The results demonstrate that trophic discrimination for δ 15N and δ 13C can be significantly different than those typically used in food-web analyses, and effects of diet composition and temperature can be significant. Precision of compound-specific isotope analyses (0.9‰) was larger than our effect size for bulk δ 15N diet effects (0.7‰), therefore future experimental work in this area will need to establish a large effect size in order to detect significant differences. Our results also suggest that compound-specific amino acid δ 15N may be useful for determining essential and non-essential amino acids for different animals.

The effect of diet composition (plant vs fish oil-based diets) on the availability of oxytetracycline in gilthead sea bream (Sparus aurata) at two water temperatures

The effect of partial fish oil replacement (66%) by rapeseed, linseed and palm oil on the availability of oxytetracycline (OTC) was investigated in gilthead sea bream (Sparus aurata). Fish received a dosage of 75mg OTC/kg for 5days at 27 or 14°C water temperature. Tissues including blood and muscle plus skin were sampled on days 1, 3 and 5 during treatment and on days 6, 8, 12 and 16 post-treatment. At the high water temperature, OTC levels were undetectable in the tested tissues at all sampling points for both diets. At the winter temperature, plasma OTC concentrations were insignificantly higher in fish given plant oil-based diets compared to fish oil diets with maximum values of 1.03 and 0.73μg/ml respectively on day 6 for both groups. Similarly, OTC muscle plus skin levels were insignificantly lower in the fish oil compared to the plant oil group with respective values of 0.48μg/g on day 5 and 1.21μg/g on day 6. Overall, replacement of fish oil by plant oil sources showed no significant influence on OTC availability in gilthead sea bream at winter temperatures. The use of OTC should be discouraged at very high water temperatures in this species irrespective of the diet source probably due to inhibited absorption or very rapid elimination of OTC from circulation. Long withdrawal times were necessary in gilthead sea bream fed with both plant oil (312h) and fish oil (239h) to ensure consumer safety at winter temperatures.

The effect of modifying dietary protein and carbohydrate in weight loss on arterial compliance and postprandial lipidemia in overweight women with polycystic ovary syndrome

In overweight women with polycystic ovary syndrome, weight loss improves arterial compliance and postprandial lipidemia. Modifying dietary carbohydrate or protein in weight loss provided similar improvements in arterial compliance and postprandial lipidemia.

Effects of Diet Composition and Trophic Structure on Mercury Bioaccumulation in Temperate Flatfishes

The summer flounder Paralichthys dentatus and winter flounder Pseudopleuronectes americanus support valuable fisheries along the northeastern United States. The importance of these flatfish as a human dietary resource indicates they are potential sources of mercury (Hg) to fish-consuming citizens. In this study, summer flounder (SF) and winter flounder (WF) were collected from the Narragansett Bay (Rhode Island, USA) and were measured for total Hg burden in whole-body or dorsal muscle tissue. Interspecies differences in Hg contamination were analyzed relative to flounder body size, age, and Hg content of preferred prey. Stable isotope signatures were also used to elucidate the effect of trophic processes on Hg accumulation in the estuarine food web. The mean Hg content of SF exceeded concentrations measured in WF across multiple life-history stages (0.039-0.100 and 0.016-0.029 mg Hg/kg wet weight for SF and WF, respectively), and observed values for both species were lower than the US Environmental Protection Agency regulatory threshold of 0.3 mg Hg/kg wet weight. Total Hg concentrations were also positively correlated with flounder age and length, verifying that both flatfish bioaccumulate Hg. SF accumulate Hg at an accelerated rate, however, owing to this species consuming Hg-enriched prey (teleosts, squid, and macrocrustaceans; mean Hg content = 0.023 mg Hg/kg wet weight), whereas WF feed on prey with low Hg levels (amphipods and polychaetes; mean Hg content = 0.013 mg Hg/kg wet weight). The positive correlation observed between mean biota Hg content and stable nitrogen (delta(15)N) isotope signatures further indicates that Hg is trophically transferred through the food web, and higher trophic level organisms (i.e., enriched delta(15)N) have increased Hg concentrations. Therefore, results from this study suggest that dietary preference and trophic structure are the main factors affecting Hg bioaccumulation in the estuary. Total Hg concentrations of flatfish from the Narragansett Bay, however, do not necessarily reflect coastwide contamination patterns. This reinforces the importance of having research conducted at sufficiently small spatial scales, including the local assessment of Hg contamination for the purpose of issuing state consumption advisories.